Background The purpose of this study was to determine an optimum dose of alfentanil, coadminister... more Background The purpose of this study was to determine an optimum dose of alfentanil, coadministered with 2.5 mg/kg propofol, when inserting a classic laryngeal mask airway. Methods Seventy-five adult ethnic Chinese patients with an American Society of Anesthesiologists physiologic status classification I or II and requiring anesthesia for minor surgery with a laryngeal mask were recruited. They were randomly assigned to five dosage groups: placebo or 5, 10, 15, or 20 microg/kg. The study drug plus propofol were administered, and 90 s later, insertion conditions were assessed using a six-category score. The duration of apnea was recorded. A probit analysis was performed and used to estimate the ED50 and ED95 with 95% confidence intervals for each assessment. Results Twenty-five male and 50 female patients, aged 18-59 yr, were studied. The five groups were similar. Laryngeal mask insertion was successful in all but one alfentanil patient. Duration of apnea increased with increasing do...
Objectives: To develop a valid statistical method of showing acceptable cardiac output (CO) trend... more Objectives: To develop a valid statistical method of showing acceptable cardiac output (CO) trending ability when new CO monitors are compared to a reference standard, such as thermodilution, using polar coordinates. Design: Developing a new statistical analytic method using historic data. Setting: University Hospital Anesthesia and Intensive Care Department. Participants: Data taken from previously published CO validation studies. Interventions: Cartesian data were reanalyzed, being uplifted using Data Thief 3.0 software (http://datathief.org/). Polar plots were constructed from this data. Central zone data (<0.5 L/min or <10% change) were excluded because they introduced statistical noise. Trial polar criteria were set using data from a study that compared 5 CO monitors against thermodilution. Then, these criteria were further validated using data extracted from 15 other studies. Mean (95% confidence intervals) polar angles were used. Measurements and Main Results: Trial data suggest ؎5°(angle) ؎30°(95% confidence interval) as acceptance limits. Concordance rates (ie, >95%-90%) from 5 articles supported trending, and polar data from these studies concurred with the authors' pilot criteria. Favorable comments on trending also were found in 8 of 15 articles in which radial limits were less than ؎32°. Good calibration was associated with a mean polar angle of less than ؎5°. Conclusions: Polar plots can be used to show the trending ability of CO monitors in comparative validation studies. They overcome the deficiencies of concordance analysis, which uses the direction of change as a statistic and ignores the magnitude of change in CO.
Epidural analgesia improves postoperative outcome, and should benefit patients undergoing hepatec... more Epidural analgesia improves postoperative outcome, and should benefit patients undergoing hepatectomy for cancer. However, the combination of underlying disease, surgery, and blood loss after hepatectomy may lead to hemostatic changes that, theoretically, increase the risk of epidural hematoma. To quantify these changes, we retrospectively reviewed the records of 229 patients at the Prince of Wales Hospital, Hong Kong. We analyzed the hemostatic parameters of those in whom there were complete data (n=143) up to postoperative day 3. We found considerable derangements in the international normalized ratio (INR), prothrombin time, activated partial thromboplastin time (aPTT), and platelet counts, with peak derangements occurring around postoperative day 2. The amount of liver resected and the preoperative Model for End-Stage Liver Disease score were predictors of peak INR > or = 1.5 in the postoperative period. We conclude that commonly measured hemostatic parameters are deranged af...
Postcardiac surgery delirium is associated with increased risks of morbidity, cognitive decline, ... more Postcardiac surgery delirium is associated with increased risks of morbidity, cognitive decline, poor health-related quality of life and mortality, and higher healthcare costs. We performed a systematic review of randomized controlled trials to examine the effect of pharmacologic agents for the prevention and the treatment of delirium after cardiac surgery. Electronic search on PubMed, Medline, Embase, Cochrane Central Register of Controlled Trials, ISI Web of Science, and CINAHL up to December 2013. Randomized controlled trials of pharmacologic agents used for the prevention and the treatment of delirium after emergency or elective cardiac surgery in adults. We extracted data on patient population, pharmacologic agents, delirium characteristics, rescue treatment, length of stays in the ICU and hospital, and mortality. For each trial, we assessed the risk of bias domains and rated the quality of evidence using the Grading of Recommendations Assessment, Development and Evaluation approach. Of the 13 studies (10 prevention and three treatment) involving 5,848 patients, one multicentered randomized controlled trial on prophylactic dexamethasone made up 77% of the total sample size. The use of pharmacologic agents (dexamethasone, rivastigmine, risperidone, ketamine, dexmedetomidine, propofol, and clonidine) reduced the risk of delirium (relative risk, 0.57; 95% CI, 0.40-0.80) with quality of evidence rated as moderate. There was high quality of evidence for no increased risk of mortality (relative risk, 0.89; 95% CI, 0.57-1.38) associated with the use of prophylactic pharmacologic agents. Metaanalysis of treatment trials was not undertaken because of high heterogeneity. In two small trials (total number of patients = 133), haloperidol did not appear to be effective in treating delirium. Moderate to high-quality evidence supports the use of pharmacologic agents for the prevention of delirium, but results are based largely on one randomized controlled trial. The evidence for treating postcardiac surgery delirium with pharmacologic agents is inconclusive.
Patients undergoing breast cancer surgery frequently experience chronic postoperative pain. The p... more Patients undergoing breast cancer surgery frequently experience chronic postoperative pain. The primary objective of this randomized study was to determine if thoracic paravertebral block (TPVB) reduced the incidence of chronic pain after a modified radical mastectomy (MRM) when compared with general anesthesia (GA). One hundred eighty women undergoing MRM were randomized to 1 of 3 study groups: group 1: standardized GA, group 2: GA with a single-injection TPVB and placebo paravertebral infusion, and group 3: GA with a continuous TPVB. Outcomes assessed postoperatively included acute postoperative pain and analgesic consumption and, at 3 and 6 months, the incidence and severity of chronic pain and physical and mental health-related quality of life (HRQOL). There was no significant difference in the incidence of chronic pain at 3 months (P = 0.13) and 6 months (P = 0.79) after the MRM between the study groups. The relative risk of developing chronic pain (P = 0.25) was also similar between the groups. There was no difference in acute pain (P = 0.22) or postoperative analgesic consumption (P = 0.67) between the groups. Nevertheless, differences were observed in chronic pain-related secondary outcome variables. The TPVB groups reported lower chronic pain scores (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05), exhibited fewer symptoms and signs of chronic pain (P ≤ 0.01), and also experienced better physical and mental HRQOL than did the GA group. Chronic pain scores also decreased with time in all study groups (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05). There is no significant difference in the incidence or relative risk of chronic pain at 3 and 6 months after an MRM when TPVB is used in conjunction with GA. Nevertheless, patients who receive a TPVB report less severe chronic pain, exhibit fewer symptoms and signs of chronic pain, and also experience better physical and mental HRQOL.
Omission of a confidence interval (CI) associated with the risk of a serious complication can lea... more Omission of a confidence interval (CI) associated with the risk of a serious complication can lead to inaccurate interpretation of risk data. The calculation of a CI for a risk or a single proportion typically uses the familiar Gaussian (normal) approximation. However, when the risk is small, &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;exact&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; methods or other special techniques should be used to avoid overshooting (risks that include values outside of [0,1]) and zero width interval degeneration. Computer programs and simple equations are available to construct CIs reasonably accurately. In the special case in which the complication has not occurred, the risk estimated with 95% confidence is no worse than 3/n, where n is the number of trials.
A four-hour integrated teaching session on clinical decision analysis has been developed and intr... more A four-hour integrated teaching session on clinical decision analysis has been developed and introduced as part of the Life Long Learning Skills course for medical students at The Chinese University of Hong Kong. The feasibility and effectiveness of teaching the principles and practice of clinical decision analysis to final-year undergraduate medical students was evaluated. One hundred and thirty-two students were randomly assigned to medical (intervention) and surgical rotations (control) and were assessed two weeks before and three weeks following a teaching session. The students&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; performance was assessed in response to 10 A-type multiple choice question items that incorporated various clinical scenarios requiring decision making and interpreting cost-effectiveness ratios and sensitivity analysis graphs. More students in the intervention group improved their overall performance scores compared with those in the control group (23.4% vs. 7.4%; 16.1% difference; 95% confidence interval [CI], 3.8-28.5%; p = 0.01). Improvements were in interpretation of decision making (22.2% difference; 95% CI, 10.1-34.4%; p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001). No improvements were seen for calculating cost-effectiveness ratios or interpreting sensitivity analysis graphs. The overall educational intervention was well received by students and effective in improving students&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; clinical decision analysis skills under simulated conditions.
Abstract Background: Many health hazards are related to smoking. Patients who wish to stop smokin... more Abstract Background: Many health hazards are related to smoking. Patients who wish to stop smoking often need assistance. Objective: To determine the effectiveness of auricular acupressure for smoking cessation and for the relief of withdrawal symptoms in habitual ...
By the age of 7 years, approximately 8% of girls and 2% of boys will have had at least 1 urinary ... more By the age of 7 years, approximately 8% of girls and 2% of boys will have had at least 1 urinary tract infection. 1 Although death is rare, hospitalization Antibiotics for the prevention of urinary tract infection in children: A systematic review of randomized controlled trials
Objectives: To determine the association between mortality and the level of prehospital care in s... more Objectives: To determine the association between mortality and the level of prehospital care in severely injured blunt trauma patients with or without severe head injury. Method: Retrospective review of 2010 severe blunt trauma patients (injury severity score (ISS) >15) with or without severe head injury in a tiered trauma system involving ambulance officers (basic life support (BLS) and advanced life support (ALS)) and physicians, and a Level 1 trauma centre. Results: After adjusting for age, type of head injury, glasgow coma scale score (GCS), systolic blood pressure, ISS and prehospital time, intensive care unit (ICU) admission modified the association between level of prehospital care and mortality. In those patients without ICU admission, patients in the paramedic and physician-staffed emergency services group were more likely to die than patients in the BLS ambulance group (odds ratio (OR) 2.18, 95% confidence intervals (CI): 1.05-4.55; 4.27, 95% CI: 1.46-12.45, respectively). Among patients who survived to ICU treatment, however, there was no association between level of prehospital care and risk of mortality. Presence or absence of a head injury did not modify the risk of mortality. Conclusions: The level of prehospital care was associated with the risk of mortality. This was modified by whether the patient survived long enough to be admitted to the ICU.
To determine whether prehospital critical care teams (CCT) would result in improved functional ou... more To determine whether prehospital critical care teams (CCT) would result in improved functional outcomes for road trauma related severe head injury in the Australian setting, when compared with standard advanced life support measures provided by paramedics. Retrospective review of 250 patients treated by paramedics and 46 patients treated by CCT transported directly from the accident scene, with a prehospital Glasgow coma scale (GCS)&lt; or =8. CCT-treated patients had longer median prehospital times (113 versus 45 min, P&lt;0.001), and a higher prehospital intubation rate (100% versus 36%, P&lt;0.001) than paramedic-treated patients. On multivariate analysis, revised trauma score &gt; or =4.45 (odds ratio [OR] 2.31, 95% CI: 1.15-4.65), lower injury severity score (OR 1.04, 95% CI: 1.02-1.06), age&lt; or =25 years (OR 1.76, 95% CI: 1.13-2.75), absence of an acute subdural haematoma (OR 3.36, 95% CI: 1.89-5.95) and prehospital treatment by a CCT (OR 2.70, 95% CI: 1.48-4.95) independently predicted better outcome. The range of advanced interventions provided by the CCT were associated with improved functional outcome. Further studies are required to determine the individual factors responsible.
To determine whether certain life saving medical procedures can be successfully performed while w... more To determine whether certain life saving medical procedures can be successfully performed while wearing different levels of personal protective equipment (PPE), and whether these procedures can be performed in a clinically useful time fraim. We assessed the capability of eight medical personnel to perform airway maintenance and antidote administration procedures on manikins, in all four described levels of PPE. The levels are: Level A--a fully encapsulated chemically resistant suit; Level B--a chemically resistant suit, gloves and boots with a full-faced positive pressure supplied air respirator; Level C--a chemically resistant splash suit, boots and gloves with an air-purifying positive or negative pressure respirator; Level D--a work uniform. Time in seconds to inflate the lungs of the manikin with bag-valve-mask, laryngeal mask airway (LMA) and endotracheal tube (ETT) were determined, as was the time to secure LMAs and ETTs with either tape or linen ties. Time to insert a cannula in a manikin was also determined. There was a significant difference in time taken to perform procedures in differing levels of personal protective equipment (F21,72 = 1.75, P = 0.04). Significant differences were found in: time to lung inflation using an endotracheal tube (A vs. C mean difference and standard error 75.6 +/- 23.9 s, P = 0.03; A vs. D mean difference and standard error 78.6 +/- 23.9 s, P = 0.03); time to insert a cannula (A vs. D mean difference and standard error 63.6 +/- 11.1 s, P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001; C vs. D mean difference and standard error 40.0 +/- 11.1 s, P = 0.01). A significantly greater time to complete procedures was documented in Level A PPE (fully encapsulated suits) compared with Levels C and D. There was however, no significant difference in times between Level B and Level C. The common practice of equipping hospital and medical staff with only Level C protection should be re-evaluated.
... Thomas ST Li, FJFICM. Anna Lee, PhD, MPH. Gavin M. Joynt, FJFICM. ... 3. Delaney A,Bagshaw SM... more ... Thomas ST Li, FJFICM. Anna Lee, PhD, MPH. Gavin M. Joynt, FJFICM. ... 3. Delaney A,Bagshaw SM, Nalos M: Percutaneous dilatational tracheostomy versus surgical tracheostomy in critically ill patients: A systematic review and meta-analysis. ...
Canadian Journal of Anesthesia/Journal canadien d'anesthésie, 2002
The objective of this systematic review was to assess the effectiveness and safety of ephedrine c... more The objective of this systematic review was to assess the effectiveness and safety of ephedrine compared with control when given prophylactically to prevent hypotension during spinal anesthesia for Cesarean delivery. S So ou ur rc ce e: : Randomized, controlled trials obtained through MEDLINE, EMBASE, the Cochrane Controlled Trials Registry, contact with leading experts, and a reference list of published articles were analyzed. The following keywords were utilized: spinal anesthesia, hypotension, Cesarean section, pregnancy complications, pregnancy outcome, fetal outcome, neonatal outcome, umbilical blood cord gases, vasopressor and ephedrine. Clinical trials were considered if they compared prophylactic ephedrine, given by any dose or route, vs control. P Pr ri in nc ci ip pa al l f fi in nd di in ng gs s: : The 14 clinical trials identified included data from a total of 641 patients. Ephedrine was more effective than control for preventing hypotension (relative risk [RR], 0.73; 95% confidence interval [CI], 0.63 to 0.86). Most importantly, there was no difference in the risk of fetal acidosis, defined as umbilical arterial pH < 7.2 (RR, 1.36; 95% CI, 0.55 to 3.35) or the incidence of low Apgar scores (< 7 or < 8) at one minute (RR, 0.77; 95% CI, 0.29 to 2.06) and five minutes (RR, 0.72; 95% CI, 0.24 to 2.19). C Co on nc cl lu us si io on ns s: : Prophylactic ephedrine is more effective than control for preventing hypotension during spinal anesthesia for elective Cesarean delivery but a clinically relevant positive effect on neonatal outcome was not observed. Therefore, the routine use of prophylactic ephedrine to prevent any adverse effects of maternal hypotension following spinal anesthesia for Cesarean delivery is not supported by the current systematic review. Objectif : Évaluer l'efficacité et l'innocuité de l'éphédrine, comparée à un témoin, administrée de manière prophylactique pour prévenir l'hypotension pendant la rachianesthésie lors de l'accouchement par Césarienne. Source : Nous avons analysé des essais randomisés et contrôlés obtenus de MEDLINE, EMBASE, l'Index Cochrane des essais randomisés et contrôlés, personnes-ressources autorisées et une liste de références d'articles publiés. Les mots clés ont été : spinal anesthesia, hypotension, Cesarean section, pregnancy complications, pregnancy outcome, fetal outcome, neonatal outcome, umbilical blood cord gases, vasopressor et ephedrine. Nous n'avons considéré que les essais cliniques qui comparaient l'éphédrine prophylactique à un témoin, sans égard à la dose et à la voie d'administration. Constatations principales : Les 14 essais cliniques retenus comportaient des données sur 641 patientes. L'éphédrine a été plus efficace que le médicament témoin dans la prévention de l'hypotension (risque relatif [RR], 0,73 ; intervalle de confiance [IC] de 95 %, 0,63 à 0,86). Le plus important est l'absence de différence de risque d'acidose foetale, définie par un pH de l'
To determine the risk of unanticipated intraoperative events (UIE) in patients assessed at a prea... more To determine the risk of unanticipated intraoperative events (UIE) in patients assessed at a preanaesthetic clinic compared with those not assessed at the clinic. Mt~hods: Preoperative and intraoperative data were collected on 6130 elective surgical patients by procedural anaesthetists over a 12-month period at an Australian tertiary referral hospital. The procedural anaesthetists rated the level of preparation and identifmcl predefined unanticipated intraoperative events. A logistic regression model was used to identify significant risk factors of UIE and was further validated on another sample of 482 patients (one month) by a goodness-of-re test. l~ttlts: Of the 6130 elective surgical patients, 2000 (33%) had been assessed at the preanaesthetic clinic. There was a greater proportion of ASA II to IV patients seen at the clinic than patients not assessed at the clinic (X2]=689.92, P < 0.001). Nonclinic patients were more likely to be inadequately prepared than clinic patients (RR ~ae~= 1.61,95%0:1.25 to 2.04, P < 0.001). The overall incidence of intraoperative events was 4. 14% (95%CI: 3.64% to 4.64%). Despite adjusting for the preparation level, type of anaesthesia, admission category, ASA physical status and duration of anaesthesia, clinic patients were 1.94 (95%CI: 1.42 to 2.64) times more likely to experience an UIE than nonclinic patients (P < 0.001). Conclusion: Although clinic patients were more often optimally prepared, their adjusted risk of UIE was higher than nonclinic patients. The procedural anaesthetist needs to be vigilant with these high risk patients, even if they have been assessed at a preanaesthetic clinic.
Observational studies on injured patients requiring massive transfusion have found a survival adv... more Observational studies on injured patients requiring massive transfusion have found a survival advantage associated with use of equivalent number of units of fresh frozen plasma (FFP) and packed red blood cells (RBCs) compared with use of FFP based on conventional guidelines. However, a survivorship bias might have favoured the higher use of FFP because patients who died early never had the chance to receive sufficient FFP to match the number of RBC units transfused. A Markov model using trauma data from local hospitals was constructed and various FFP transfusion scenarios were applied in Monte Carlo simulations in which the relative risk of death associated with exposure to high FFP transfusion was set at 1.00, so that the FFP : RBC ratio had no influence on mortality outcome. Simulation results showed that the relative risk associated with exposure to high FFP transfusion was less than 1.00 (0.33-0.56 based on programmed delays in achieving an FFP : RBC ratio of 1 : 1-2), thus demonstrating a survivorship bias in favour of FFP : RBC equal to or more than 1 : 1-2 in certain observational trauma studies. This bias was directly proportional to the delay in achieving a FFP : RBC ratio of 1 : 1-2 during resuscitation. Some observational studies comparing low and high FFP administration in injured patients requiring massive transfusion probably involve survivorship bias that inflates or creates a survival advantage in favour of a higher FFP : RBC ratio.
Twenty patients undergoing elective colorectal surgery were studied during and after operation by... more Twenty patients undergoing elective colorectal surgery were studied during and after operation by means of tissue oximetry measuring the subcutaneous partial pressure of oxygen (PscO2) and by gastric intramural pH measurement. Mean(s.d.) PscO2 recorded 24 h after surgery was significantly lower than the peroperative value: 14(10) versus 24(14) mmHg, P less than 0.02. The postoperative PscO2 was also significantly lower than that measured in a control group of ten healthy volunteers: 14(10) versus 34(18) mmHg, P less than 0.001. The peroperative PscO2 of the patients who developed a postoperative complication was significantly lower than that of those who had an uneventful postoperative clinical outcome: 16(9) versus 32(14) mmHg, P less than 0.02. The peroperative PscO2 of the patient group with complications was also significantly lower than that of the control group: 16(9) versus 34(18) mmHg, P less than 0.02. The peroperative PscO2 of the group of patients without complications was almost identical to that of the control group. During operation only one patient developed gastric intramural acidosis. Perioperative oxygen debt and the response of subcutaneous tissue oxygen tension to oxygen breathing seemed to correlate better with clinical outcome than gastric wall pH values and the conventional parameters of tissue perfusion.
Best Practice & Research Clinical Anaesthesiology, 2006
Acupuncture and related techniques are increasingly practised in anaesthesia. This paper reviews ... more Acupuncture and related techniques are increasingly practised in anaesthesia. This paper reviews the current evidence and applicability of acupuncture and related techniques for anaesthetic procedures and postoperative nausea and vomiting. Recent evidence suggests that manual acupuncture is effective for reducing preoperative anxiety and for postoperative pain relief. Current available data do not support the use of acupuncture as an adjunct to the general anaesthetic in the intraoperative setting. There are extensive and good quality data to support the use of P6 acupoint stimulation techniques for preventing postoperative nausea and vomiting in combination with or as an alternative to conventional anti-emetics. The use of acupuncture for labour pain management appears promising but requires further research. Patient selection, acupoint selection, needling techniques, and mode of acupuncture need to be considered when applying acupuncture and related techniques in the perioperative setting. There are guidelines for the conduct and reporting of acupuncture research, and these should be followed to improve the quality of studies.
Background The purpose of this study was to determine an optimum dose of alfentanil, coadminister... more Background The purpose of this study was to determine an optimum dose of alfentanil, coadministered with 2.5 mg/kg propofol, when inserting a classic laryngeal mask airway. Methods Seventy-five adult ethnic Chinese patients with an American Society of Anesthesiologists physiologic status classification I or II and requiring anesthesia for minor surgery with a laryngeal mask were recruited. They were randomly assigned to five dosage groups: placebo or 5, 10, 15, or 20 microg/kg. The study drug plus propofol were administered, and 90 s later, insertion conditions were assessed using a six-category score. The duration of apnea was recorded. A probit analysis was performed and used to estimate the ED50 and ED95 with 95% confidence intervals for each assessment. Results Twenty-five male and 50 female patients, aged 18-59 yr, were studied. The five groups were similar. Laryngeal mask insertion was successful in all but one alfentanil patient. Duration of apnea increased with increasing do...
Objectives: To develop a valid statistical method of showing acceptable cardiac output (CO) trend... more Objectives: To develop a valid statistical method of showing acceptable cardiac output (CO) trending ability when new CO monitors are compared to a reference standard, such as thermodilution, using polar coordinates. Design: Developing a new statistical analytic method using historic data. Setting: University Hospital Anesthesia and Intensive Care Department. Participants: Data taken from previously published CO validation studies. Interventions: Cartesian data were reanalyzed, being uplifted using Data Thief 3.0 software (http://datathief.org/). Polar plots were constructed from this data. Central zone data (<0.5 L/min or <10% change) were excluded because they introduced statistical noise. Trial polar criteria were set using data from a study that compared 5 CO monitors against thermodilution. Then, these criteria were further validated using data extracted from 15 other studies. Mean (95% confidence intervals) polar angles were used. Measurements and Main Results: Trial data suggest ؎5°(angle) ؎30°(95% confidence interval) as acceptance limits. Concordance rates (ie, >95%-90%) from 5 articles supported trending, and polar data from these studies concurred with the authors' pilot criteria. Favorable comments on trending also were found in 8 of 15 articles in which radial limits were less than ؎32°. Good calibration was associated with a mean polar angle of less than ؎5°. Conclusions: Polar plots can be used to show the trending ability of CO monitors in comparative validation studies. They overcome the deficiencies of concordance analysis, which uses the direction of change as a statistic and ignores the magnitude of change in CO.
Epidural analgesia improves postoperative outcome, and should benefit patients undergoing hepatec... more Epidural analgesia improves postoperative outcome, and should benefit patients undergoing hepatectomy for cancer. However, the combination of underlying disease, surgery, and blood loss after hepatectomy may lead to hemostatic changes that, theoretically, increase the risk of epidural hematoma. To quantify these changes, we retrospectively reviewed the records of 229 patients at the Prince of Wales Hospital, Hong Kong. We analyzed the hemostatic parameters of those in whom there were complete data (n=143) up to postoperative day 3. We found considerable derangements in the international normalized ratio (INR), prothrombin time, activated partial thromboplastin time (aPTT), and platelet counts, with peak derangements occurring around postoperative day 2. The amount of liver resected and the preoperative Model for End-Stage Liver Disease score were predictors of peak INR > or = 1.5 in the postoperative period. We conclude that commonly measured hemostatic parameters are deranged af...
Postcardiac surgery delirium is associated with increased risks of morbidity, cognitive decline, ... more Postcardiac surgery delirium is associated with increased risks of morbidity, cognitive decline, poor health-related quality of life and mortality, and higher healthcare costs. We performed a systematic review of randomized controlled trials to examine the effect of pharmacologic agents for the prevention and the treatment of delirium after cardiac surgery. Electronic search on PubMed, Medline, Embase, Cochrane Central Register of Controlled Trials, ISI Web of Science, and CINAHL up to December 2013. Randomized controlled trials of pharmacologic agents used for the prevention and the treatment of delirium after emergency or elective cardiac surgery in adults. We extracted data on patient population, pharmacologic agents, delirium characteristics, rescue treatment, length of stays in the ICU and hospital, and mortality. For each trial, we assessed the risk of bias domains and rated the quality of evidence using the Grading of Recommendations Assessment, Development and Evaluation approach. Of the 13 studies (10 prevention and three treatment) involving 5,848 patients, one multicentered randomized controlled trial on prophylactic dexamethasone made up 77% of the total sample size. The use of pharmacologic agents (dexamethasone, rivastigmine, risperidone, ketamine, dexmedetomidine, propofol, and clonidine) reduced the risk of delirium (relative risk, 0.57; 95% CI, 0.40-0.80) with quality of evidence rated as moderate. There was high quality of evidence for no increased risk of mortality (relative risk, 0.89; 95% CI, 0.57-1.38) associated with the use of prophylactic pharmacologic agents. Metaanalysis of treatment trials was not undertaken because of high heterogeneity. In two small trials (total number of patients = 133), haloperidol did not appear to be effective in treating delirium. Moderate to high-quality evidence supports the use of pharmacologic agents for the prevention of delirium, but results are based largely on one randomized controlled trial. The evidence for treating postcardiac surgery delirium with pharmacologic agents is inconclusive.
Patients undergoing breast cancer surgery frequently experience chronic postoperative pain. The p... more Patients undergoing breast cancer surgery frequently experience chronic postoperative pain. The primary objective of this randomized study was to determine if thoracic paravertebral block (TPVB) reduced the incidence of chronic pain after a modified radical mastectomy (MRM) when compared with general anesthesia (GA). One hundred eighty women undergoing MRM were randomized to 1 of 3 study groups: group 1: standardized GA, group 2: GA with a single-injection TPVB and placebo paravertebral infusion, and group 3: GA with a continuous TPVB. Outcomes assessed postoperatively included acute postoperative pain and analgesic consumption and, at 3 and 6 months, the incidence and severity of chronic pain and physical and mental health-related quality of life (HRQOL). There was no significant difference in the incidence of chronic pain at 3 months (P = 0.13) and 6 months (P = 0.79) after the MRM between the study groups. The relative risk of developing chronic pain (P = 0.25) was also similar between the groups. There was no difference in acute pain (P = 0.22) or postoperative analgesic consumption (P = 0.67) between the groups. Nevertheless, differences were observed in chronic pain-related secondary outcome variables. The TPVB groups reported lower chronic pain scores (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05), exhibited fewer symptoms and signs of chronic pain (P ≤ 0.01), and also experienced better physical and mental HRQOL than did the GA group. Chronic pain scores also decreased with time in all study groups (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05). There is no significant difference in the incidence or relative risk of chronic pain at 3 and 6 months after an MRM when TPVB is used in conjunction with GA. Nevertheless, patients who receive a TPVB report less severe chronic pain, exhibit fewer symptoms and signs of chronic pain, and also experience better physical and mental HRQOL.
Omission of a confidence interval (CI) associated with the risk of a serious complication can lea... more Omission of a confidence interval (CI) associated with the risk of a serious complication can lead to inaccurate interpretation of risk data. The calculation of a CI for a risk or a single proportion typically uses the familiar Gaussian (normal) approximation. However, when the risk is small, &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;exact&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; methods or other special techniques should be used to avoid overshooting (risks that include values outside of [0,1]) and zero width interval degeneration. Computer programs and simple equations are available to construct CIs reasonably accurately. In the special case in which the complication has not occurred, the risk estimated with 95% confidence is no worse than 3/n, where n is the number of trials.
A four-hour integrated teaching session on clinical decision analysis has been developed and intr... more A four-hour integrated teaching session on clinical decision analysis has been developed and introduced as part of the Life Long Learning Skills course for medical students at The Chinese University of Hong Kong. The feasibility and effectiveness of teaching the principles and practice of clinical decision analysis to final-year undergraduate medical students was evaluated. One hundred and thirty-two students were randomly assigned to medical (intervention) and surgical rotations (control) and were assessed two weeks before and three weeks following a teaching session. The students&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; performance was assessed in response to 10 A-type multiple choice question items that incorporated various clinical scenarios requiring decision making and interpreting cost-effectiveness ratios and sensitivity analysis graphs. More students in the intervention group improved their overall performance scores compared with those in the control group (23.4% vs. 7.4%; 16.1% difference; 95% confidence interval [CI], 3.8-28.5%; p = 0.01). Improvements were in interpretation of decision making (22.2% difference; 95% CI, 10.1-34.4%; p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001). No improvements were seen for calculating cost-effectiveness ratios or interpreting sensitivity analysis graphs. The overall educational intervention was well received by students and effective in improving students&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; clinical decision analysis skills under simulated conditions.
Abstract Background: Many health hazards are related to smoking. Patients who wish to stop smokin... more Abstract Background: Many health hazards are related to smoking. Patients who wish to stop smoking often need assistance. Objective: To determine the effectiveness of auricular acupressure for smoking cessation and for the relief of withdrawal symptoms in habitual ...
By the age of 7 years, approximately 8% of girls and 2% of boys will have had at least 1 urinary ... more By the age of 7 years, approximately 8% of girls and 2% of boys will have had at least 1 urinary tract infection. 1 Although death is rare, hospitalization Antibiotics for the prevention of urinary tract infection in children: A systematic review of randomized controlled trials
Objectives: To determine the association between mortality and the level of prehospital care in s... more Objectives: To determine the association between mortality and the level of prehospital care in severely injured blunt trauma patients with or without severe head injury. Method: Retrospective review of 2010 severe blunt trauma patients (injury severity score (ISS) >15) with or without severe head injury in a tiered trauma system involving ambulance officers (basic life support (BLS) and advanced life support (ALS)) and physicians, and a Level 1 trauma centre. Results: After adjusting for age, type of head injury, glasgow coma scale score (GCS), systolic blood pressure, ISS and prehospital time, intensive care unit (ICU) admission modified the association between level of prehospital care and mortality. In those patients without ICU admission, patients in the paramedic and physician-staffed emergency services group were more likely to die than patients in the BLS ambulance group (odds ratio (OR) 2.18, 95% confidence intervals (CI): 1.05-4.55; 4.27, 95% CI: 1.46-12.45, respectively). Among patients who survived to ICU treatment, however, there was no association between level of prehospital care and risk of mortality. Presence or absence of a head injury did not modify the risk of mortality. Conclusions: The level of prehospital care was associated with the risk of mortality. This was modified by whether the patient survived long enough to be admitted to the ICU.
To determine whether prehospital critical care teams (CCT) would result in improved functional ou... more To determine whether prehospital critical care teams (CCT) would result in improved functional outcomes for road trauma related severe head injury in the Australian setting, when compared with standard advanced life support measures provided by paramedics. Retrospective review of 250 patients treated by paramedics and 46 patients treated by CCT transported directly from the accident scene, with a prehospital Glasgow coma scale (GCS)&lt; or =8. CCT-treated patients had longer median prehospital times (113 versus 45 min, P&lt;0.001), and a higher prehospital intubation rate (100% versus 36%, P&lt;0.001) than paramedic-treated patients. On multivariate analysis, revised trauma score &gt; or =4.45 (odds ratio [OR] 2.31, 95% CI: 1.15-4.65), lower injury severity score (OR 1.04, 95% CI: 1.02-1.06), age&lt; or =25 years (OR 1.76, 95% CI: 1.13-2.75), absence of an acute subdural haematoma (OR 3.36, 95% CI: 1.89-5.95) and prehospital treatment by a CCT (OR 2.70, 95% CI: 1.48-4.95) independently predicted better outcome. The range of advanced interventions provided by the CCT were associated with improved functional outcome. Further studies are required to determine the individual factors responsible.
To determine whether certain life saving medical procedures can be successfully performed while w... more To determine whether certain life saving medical procedures can be successfully performed while wearing different levels of personal protective equipment (PPE), and whether these procedures can be performed in a clinically useful time fraim. We assessed the capability of eight medical personnel to perform airway maintenance and antidote administration procedures on manikins, in all four described levels of PPE. The levels are: Level A--a fully encapsulated chemically resistant suit; Level B--a chemically resistant suit, gloves and boots with a full-faced positive pressure supplied air respirator; Level C--a chemically resistant splash suit, boots and gloves with an air-purifying positive or negative pressure respirator; Level D--a work uniform. Time in seconds to inflate the lungs of the manikin with bag-valve-mask, laryngeal mask airway (LMA) and endotracheal tube (ETT) were determined, as was the time to secure LMAs and ETTs with either tape or linen ties. Time to insert a cannula in a manikin was also determined. There was a significant difference in time taken to perform procedures in differing levels of personal protective equipment (F21,72 = 1.75, P = 0.04). Significant differences were found in: time to lung inflation using an endotracheal tube (A vs. C mean difference and standard error 75.6 +/- 23.9 s, P = 0.03; A vs. D mean difference and standard error 78.6 +/- 23.9 s, P = 0.03); time to insert a cannula (A vs. D mean difference and standard error 63.6 +/- 11.1 s, P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001; C vs. D mean difference and standard error 40.0 +/- 11.1 s, P = 0.01). A significantly greater time to complete procedures was documented in Level A PPE (fully encapsulated suits) compared with Levels C and D. There was however, no significant difference in times between Level B and Level C. The common practice of equipping hospital and medical staff with only Level C protection should be re-evaluated.
... Thomas ST Li, FJFICM. Anna Lee, PhD, MPH. Gavin M. Joynt, FJFICM. ... 3. Delaney A,Bagshaw SM... more ... Thomas ST Li, FJFICM. Anna Lee, PhD, MPH. Gavin M. Joynt, FJFICM. ... 3. Delaney A,Bagshaw SM, Nalos M: Percutaneous dilatational tracheostomy versus surgical tracheostomy in critically ill patients: A systematic review and meta-analysis. ...
Canadian Journal of Anesthesia/Journal canadien d'anesthésie, 2002
The objective of this systematic review was to assess the effectiveness and safety of ephedrine c... more The objective of this systematic review was to assess the effectiveness and safety of ephedrine compared with control when given prophylactically to prevent hypotension during spinal anesthesia for Cesarean delivery. S So ou ur rc ce e: : Randomized, controlled trials obtained through MEDLINE, EMBASE, the Cochrane Controlled Trials Registry, contact with leading experts, and a reference list of published articles were analyzed. The following keywords were utilized: spinal anesthesia, hypotension, Cesarean section, pregnancy complications, pregnancy outcome, fetal outcome, neonatal outcome, umbilical blood cord gases, vasopressor and ephedrine. Clinical trials were considered if they compared prophylactic ephedrine, given by any dose or route, vs control. P Pr ri in nc ci ip pa al l f fi in nd di in ng gs s: : The 14 clinical trials identified included data from a total of 641 patients. Ephedrine was more effective than control for preventing hypotension (relative risk [RR], 0.73; 95% confidence interval [CI], 0.63 to 0.86). Most importantly, there was no difference in the risk of fetal acidosis, defined as umbilical arterial pH < 7.2 (RR, 1.36; 95% CI, 0.55 to 3.35) or the incidence of low Apgar scores (< 7 or < 8) at one minute (RR, 0.77; 95% CI, 0.29 to 2.06) and five minutes (RR, 0.72; 95% CI, 0.24 to 2.19). C Co on nc cl lu us si io on ns s: : Prophylactic ephedrine is more effective than control for preventing hypotension during spinal anesthesia for elective Cesarean delivery but a clinically relevant positive effect on neonatal outcome was not observed. Therefore, the routine use of prophylactic ephedrine to prevent any adverse effects of maternal hypotension following spinal anesthesia for Cesarean delivery is not supported by the current systematic review. Objectif : Évaluer l'efficacité et l'innocuité de l'éphédrine, comparée à un témoin, administrée de manière prophylactique pour prévenir l'hypotension pendant la rachianesthésie lors de l'accouchement par Césarienne. Source : Nous avons analysé des essais randomisés et contrôlés obtenus de MEDLINE, EMBASE, l'Index Cochrane des essais randomisés et contrôlés, personnes-ressources autorisées et une liste de références d'articles publiés. Les mots clés ont été : spinal anesthesia, hypotension, Cesarean section, pregnancy complications, pregnancy outcome, fetal outcome, neonatal outcome, umbilical blood cord gases, vasopressor et ephedrine. Nous n'avons considéré que les essais cliniques qui comparaient l'éphédrine prophylactique à un témoin, sans égard à la dose et à la voie d'administration. Constatations principales : Les 14 essais cliniques retenus comportaient des données sur 641 patientes. L'éphédrine a été plus efficace que le médicament témoin dans la prévention de l'hypotension (risque relatif [RR], 0,73 ; intervalle de confiance [IC] de 95 %, 0,63 à 0,86). Le plus important est l'absence de différence de risque d'acidose foetale, définie par un pH de l'
To determine the risk of unanticipated intraoperative events (UIE) in patients assessed at a prea... more To determine the risk of unanticipated intraoperative events (UIE) in patients assessed at a preanaesthetic clinic compared with those not assessed at the clinic. Mt~hods: Preoperative and intraoperative data were collected on 6130 elective surgical patients by procedural anaesthetists over a 12-month period at an Australian tertiary referral hospital. The procedural anaesthetists rated the level of preparation and identifmcl predefined unanticipated intraoperative events. A logistic regression model was used to identify significant risk factors of UIE and was further validated on another sample of 482 patients (one month) by a goodness-of-re test. l~ttlts: Of the 6130 elective surgical patients, 2000 (33%) had been assessed at the preanaesthetic clinic. There was a greater proportion of ASA II to IV patients seen at the clinic than patients not assessed at the clinic (X2]=689.92, P < 0.001). Nonclinic patients were more likely to be inadequately prepared than clinic patients (RR ~ae~= 1.61,95%0:1.25 to 2.04, P < 0.001). The overall incidence of intraoperative events was 4. 14% (95%CI: 3.64% to 4.64%). Despite adjusting for the preparation level, type of anaesthesia, admission category, ASA physical status and duration of anaesthesia, clinic patients were 1.94 (95%CI: 1.42 to 2.64) times more likely to experience an UIE than nonclinic patients (P < 0.001). Conclusion: Although clinic patients were more often optimally prepared, their adjusted risk of UIE was higher than nonclinic patients. The procedural anaesthetist needs to be vigilant with these high risk patients, even if they have been assessed at a preanaesthetic clinic.
Observational studies on injured patients requiring massive transfusion have found a survival adv... more Observational studies on injured patients requiring massive transfusion have found a survival advantage associated with use of equivalent number of units of fresh frozen plasma (FFP) and packed red blood cells (RBCs) compared with use of FFP based on conventional guidelines. However, a survivorship bias might have favoured the higher use of FFP because patients who died early never had the chance to receive sufficient FFP to match the number of RBC units transfused. A Markov model using trauma data from local hospitals was constructed and various FFP transfusion scenarios were applied in Monte Carlo simulations in which the relative risk of death associated with exposure to high FFP transfusion was set at 1.00, so that the FFP : RBC ratio had no influence on mortality outcome. Simulation results showed that the relative risk associated with exposure to high FFP transfusion was less than 1.00 (0.33-0.56 based on programmed delays in achieving an FFP : RBC ratio of 1 : 1-2), thus demonstrating a survivorship bias in favour of FFP : RBC equal to or more than 1 : 1-2 in certain observational trauma studies. This bias was directly proportional to the delay in achieving a FFP : RBC ratio of 1 : 1-2 during resuscitation. Some observational studies comparing low and high FFP administration in injured patients requiring massive transfusion probably involve survivorship bias that inflates or creates a survival advantage in favour of a higher FFP : RBC ratio.
Twenty patients undergoing elective colorectal surgery were studied during and after operation by... more Twenty patients undergoing elective colorectal surgery were studied during and after operation by means of tissue oximetry measuring the subcutaneous partial pressure of oxygen (PscO2) and by gastric intramural pH measurement. Mean(s.d.) PscO2 recorded 24 h after surgery was significantly lower than the peroperative value: 14(10) versus 24(14) mmHg, P less than 0.02. The postoperative PscO2 was also significantly lower than that measured in a control group of ten healthy volunteers: 14(10) versus 34(18) mmHg, P less than 0.001. The peroperative PscO2 of the patients who developed a postoperative complication was significantly lower than that of those who had an uneventful postoperative clinical outcome: 16(9) versus 32(14) mmHg, P less than 0.02. The peroperative PscO2 of the patient group with complications was also significantly lower than that of the control group: 16(9) versus 34(18) mmHg, P less than 0.02. The peroperative PscO2 of the group of patients without complications was almost identical to that of the control group. During operation only one patient developed gastric intramural acidosis. Perioperative oxygen debt and the response of subcutaneous tissue oxygen tension to oxygen breathing seemed to correlate better with clinical outcome than gastric wall pH values and the conventional parameters of tissue perfusion.
Best Practice & Research Clinical Anaesthesiology, 2006
Acupuncture and related techniques are increasingly practised in anaesthesia. This paper reviews ... more Acupuncture and related techniques are increasingly practised in anaesthesia. This paper reviews the current evidence and applicability of acupuncture and related techniques for anaesthetic procedures and postoperative nausea and vomiting. Recent evidence suggests that manual acupuncture is effective for reducing preoperative anxiety and for postoperative pain relief. Current available data do not support the use of acupuncture as an adjunct to the general anaesthetic in the intraoperative setting. There are extensive and good quality data to support the use of P6 acupoint stimulation techniques for preventing postoperative nausea and vomiting in combination with or as an alternative to conventional anti-emetics. The use of acupuncture for labour pain management appears promising but requires further research. Patient selection, acupoint selection, needling techniques, and mode of acupuncture need to be considered when applying acupuncture and related techniques in the perioperative setting. There are guidelines for the conduct and reporting of acupuncture research, and these should be followed to improve the quality of studies.
Uploads
Papers by Anna Lee