Transthoracic echocardiographic evaluation of the heart and great vessels.

PURPOSE: Transthoracic examination of the heart and great vessels is an essential skill that allows the anesthesiologist to evaluate cardiac function. In this article, we describe a pragmatic technique to obtain the essential views to evaluate normal or abnormal cardiac function and to appreciate great vessel anatomy and physiology. PRINCIPAL FINDINGS: The cardiac anatomy and function can be described using standard parasternal, apical, and subcostal views. These windows can also be used to assess the aorta, pulmonary artery, and vena cavae; however, other transthoracic and abdominal windows can be used to complete the evaluation of the great vessels. CONCLUSIONS: The integration of the echocardiographic information particularly from the heart and great vessels with the case story, physical examination, laboratory data, and other relevant clinical information should become the way of the future, and this will benefit the patients under our care.

Automated weaning and spontaneous breathing trial systems versus non-automated weaning strategies for discontinuation time in invasively ventilated postoperative adults.

BACKGROUND: Automated systems use closed-loop control to enable ventilators to perform basic and advanced functions while supporting respiration. Selected automated systems can now not only measure selected respiratory variables and adapt ventilator output to individual patient needs by operationalizing predetermined algorithms but also automate the conduct of spontaneous breathing trials (SBTs). OBJECTIVES: To summarize the evidence comparing automated weaning and SBT systems to non-automated mechanical ventilation strategies on time to mechanical ventilation discontinuation in adult postoperative patients. In secondary objectives we ascertained differences between automated weaning and SBT systems and non-automated mechanical ventilation discontinuation strategies on clinical outcomes (time to successful extubation, time to first SBT and first successful SBT, mortality, total duration of ventilation, intensive care unit (ICU) and hospital lengths of stay, use of non-invasive ventilation (NIV) following extubation, and adverse events). SEARCH METHODS: We searched CENTRAL (The Cochrane Library 2013, Issue 5); MEDLINE (OvidSP) (1966 to May 2013); EMBASE (OvidSP) (1988 to May 2013); CINAHL (EBSCOhost) (1982 to May 2013), Evidence Based Medicine Reviews and Ovid Health Star (1999 to May 2013), conference proceedings, trial registration websites, and contacted authors and content experts to identify potentially eligible trials. SELECTION CRITERIA: Randomized and quasi-randomized trials comparing automated weaning and SBT systems to non-automated mechanical ventilation discontinuation strategies in intubated adults in the postoperative setting. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trial quality and abstracted data according to prespecified criteria. Sensitivity and subgroup analyses were planned to assess the impact of the type of (i) clinician primarily involved in implementing the automated weaning and SBT systems, (ii) intensive care unit (ICU), and (iii) non-automated discontinuation (control) strategy utilized on selected outcomes. MAIN RESULTS: We identified one randomized controlled trial of high quality, involving 300 patients , comparing SmartCare™ to a written protocol. In this trial, SmartCare™ had no effect on discontinuation time. While SmartCare™ significantly reduced the time to the first SBT (mean difference (MD) -0.34 days, 95% CI -0.60 to -0.08; P = 0.01) it did not reduce the time to the first successful SBT (MD -0.25 days, 95% CI -0.55 to 0.05; P = 0.10) and other clinically important outcomes. SmartCare™ did not demonstrate beneficial effects on most clinically important outcomes including time to successful extubation, total duration of mechanical ventilation, ICU and hospital lengths of stay, and the requirement for tracheostomy. Moreover, SmartCare™ did not favourably impact reintubation, mortality, self-extubation, and the proportion of patients undergoing protracted mechanical ventilation, with a small numbers of events in this single trial. AUTHORS' CONCLUSIONS: There is a paucity of evidence from randomized controlled trials to support or refute use of automated weaning and SBT systems in discontinuing invasive mechanical ventilation in adult postoperative patients. In a single large trial of high methodologic quality, while the use of SmartCare™ to adjust ventilator settings and conduct SBTs shortened the time to undergoing the first SBT, it did not reduce the time to the first successful SBT or the rate of tracheostomy compared to a written protocol implemented by physicians. SmartCare™ did not demonstrate beneficial effects on clinically important outcomes including time to mechanical ventilation discontinuation, time to successful discontinuation, total duration of mechanical ventilation, and ICU and hospital lengths of stay. Additional well-designed, adequately powered randomized controlled trials are needed to clarify the role for SmartCare™ on important outcomes in patients who predominantly require short term ventilation and in specific postoperative patient populations.

Automated weaning and SBT systems versus non-automated weaning strategies for weaning time in invasively ventilated critically ill adults.

BACKGROUND: Automated systems use closed-loop control to enable ventilators to perform basic and advanced functions while supporting respiration. SmartCare™ is a unique automated weaning system that measures selected respiratory variables, adapts ventilator output to individual patient needs by operationalizing predetermined algorithms and automatically conducts spontaneous breathing trials (SBTs) when predetermined thresholds are met. OBJECTIVES: The primary objective of this review was to compare weaning time (time from randomization to extubation as defined by study authors) between invasively ventilated critically ill adults weaned by automated weaning and SBT systems versus non-automated weaning strategies.As secondary objectives, we ascertained differences between effects of alternative weaning strategies on clinical outcomes (time to successful extubation, time to first SBT and first successful SBT, mortality, ventilator-associated pneumonia, total duration of ventilation, lengths of intensive care unit (ICU) and hospital stay, use of non-invasive ventilation (NIV), adverse events and clinician acceptance).The third objective of our review was to use subgroup analyses to explore variations in weaning time, length of ICU stay, mortality, ventilator-associated pneumonia, use of NIV and reintubation according to (1) the type of clinician primarily involved in implementing the automated weaning and SBT strategy, (2) the ICU (as a reflection of the population involved) and (3) the non-automated (control) weaning strategy utilized.We conducted a sensitivity analysis to evaluate variations in weaning time based on (4) the methodological quality (low or unclear versus high risk of bias) of the included studies. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) 2013, Issue 5; MEDLINE (1966 to 31 May 2013); EMBASE (1988 to 31 May 2013); the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (1982 to 31 May 2013), Evidence-Based Medicine Reviews and Ovid HealthSTAR (1999 to 31 May 2013), as well as conference proceedings and trial registration websites; we also contacted study authors and content experts to identify potentially eligible trials. SELECTION CRITERIA: Randomized and quasi-randomized trials comparing automated weaning and SBT systems versus non-automated weaning strategies in intubated adults. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trial quality and abstracted data according to prespecified criteria. Sensitivity and subgroup analyses were planned to assess the impact on selected outcomes of the following: (1) the type of clinician primarily involved in implementing automated weaning and SBT systems, (2) the ICU (as a reflection of the population involved) and (3) the non-automated (control) weaning strategy utilized. MAIN RESULTS: We pooled summary estimates from 10 trials evaluating SmartCare™ involving 654 participants. Overall, eight trials were judged to be at low or unclear risk of bias, and two trials were judged to be at high risk of bias. Compared with non-automated strategies, SmartCare™ decreased weaning time (mean difference (MD) -2.68 days, 95% confidence interval (CI) -3.99 to -1.37; P value < 0.0001, seven trials, 495 participants, moderate-quality evidence), time to successful extubation (MD -0.99 days, 95% CI -1.89 to -0.09; P value 0.03, seven trials, 516 participants, low-quality evidence), length of ICU stay (MD -5.70 days, 95% CI -10.54 to -0.85; P value 0.02, six trials, 499 participants, moderate-quality evidence) and proportions of participants receiving ventilation for longer than seven and 21 days (risk ratio (RR) 0.44, 95% CI 0.23 to 0.85; P value 0.01 and RR 0.39, 95% CI 0.18 to 0.86; P value 0.02). SmartCare™ reduced the total duration of ventilation (MD -1.68 days, 95% CI -3.33 to -0.03; P value 0.05, seven trials, 521 participants, low-quality evidence) and the number of participants receiving ventilation for longer than 14 days (RR 0.61, 95% CI 0.37 to 1.00; P value 0.05); however the estimated effects were imprecise. SmartCare™ had no effect on time to first successful SBT, mortality or adverse events, specifically reintubation. Subgroup analysis suggested that trials with protocolized (versus non-protocolized) control weaning strategies reported significantly shorter ICU stays. Sensitivity analysis excluded two trials with high risk of bias and supported a trend toward significant reductions in weaning time favouring SmartCare™. AUTHORS' CONCLUSIONS: Compared with non-automated weaning strategies, weaning with SmartCare™ significantly decreased weaning time, time to successful extubation, ICU stay and proportions of patients receiving ventilation for longer than seven days and 21 days. It also showed a favourable trend toward fewer patients receiving ventilation for longer than 14 days; however the estimated effect was imprecise. Summary estimates from our review suggest that these benefits may be achieved without increasing the risk of adverse events, especially reintubation; however, the quality of the evidence ranged from low to moderate, and evidence was derived from 10 small randomized controlled trials.

Wean earlier and automatically with new technology (the WEAN study). A multicenter, pilot randomized controlled trial.

RATIONALE: Automated weaning has not been compared with a paper-based weaning protocol in North America. OBJECTIVES: We conducted a pilot randomized trial comparing automated weaning with protocolized weaning in critically ill adults to evaluate clinician compliance and acceptance of the weaning and sedation protocols, recruitment, and impact on outcomes. METHODS: From August 2007 to October 2009, we enrolled critically ill adults requiring more than 24 hours of mechanical ventilation and at least partial reversal of the condition precipitating respiratory failure at nine Canadian intensive care units. We randomized patients who tolerated at least 30 minutes of pressure support and either failed or were not yet ready to undergo a spontaneous breathing trial to automated or protocolized weaning. Both groups used pressure support, included spontaneous breathing trials, used a common positive end-expiratory pressure-FI(O(2)) chart, sedation protocol, and criteria for extubation, reintubation, and noninvasive ventilation. MEASUREMENTS AND MAIN RESULTS: We recruited 92 patients (49 automated, 43 protocolized) over 26 months. Adherence to assigned weaning protocols and extreme sedation scale scores fell within prespecified thresholds. Combined physician-respiratory therapist and nurse acceptance scores of the study weaning and sedation protocols, respectively, were not significantly different. Automated weaning patients had significantly shorter median times to first successful spontaneous breathing trial (1.0 vs. 4.0 d; P < 0.0001), extubation (3.0 vs. 4.0 d; P = 0.02), and successful extubation (4.0 vs. 5.0 d; P = 0.01), and underwent fewer tracheostomies and episodes of protracted ventilation. CONCLUSIONS: Compared with a standardized protocol, automated weaning was associated with promising outcomes that warrant further investigation. Minor protocol modifications may increase compliance, facilitate recruitment, and enhance feasibility. Clinical trial registered with www.controlled-trials.com (ISRCTN43760151).

Effect of manual in-line stabilization of the cervical spine in adults on the rate of difficult orotracheal intubation by direct laryngoscopy: a randomized controlled trial.

PURPOSE: Although manual in-line stabilization (MILS) is commonly used during endotracheal intubation in patients with either known or suspected cervical spine instability, the effect of MILS on orotracheal intubation is poorly documented. This study evaluated the rate of failed tracheal intubation in a fixed time interval with MILS. METHODS: Two hundred elective surgical patients were randomized into two groups. In the MILS group, the patient's head was stabilized in a neutral position by grasping the patient's mastoid processes to minimize any head movement during tracheal intubation. In the control group, the patient's head rested in an optimal position for tracheal intubation. A 30-sec period was allowed to complete tracheal intubation with a #3 Macintosh laryngoscope blade. The primary endpoint was the rate of failed tracheal intubation at 30 sec. Secondary endpoints included tracheal intubation time and the Cormack & Lehane grade of laryngoscopy. RESULTS: Patient characteristics were similar with respect to demographic data and risk factors for difficult tracheal intubation. The rate of failed tracheal intubation at 30 sec was 50% (47/94) in the MILS group compared to 5.7% (6/105) in the control group (P < 0.0001). Laryngoscopic grades 3 and 4 were more frequently observed in the MILS group. Mean times for successful tracheal intubation were 15.8 +/- 8.5 sec and 8.7 +/- 4.6 sec for the MILS and control groups, respectively (mean difference 7.1, CI(95%) 5.0-9.3, P < 0.0001). All patients who failed tracheal intubation in the MILS group were successfully intubated when MILS was removed. CONCLUSION: In patients with otherwise normal airways, MILS increases the tracheal intubation failure rate at 30 sec and worsens laryngeal visualization during direct laryngoscopy.

Automating the weaning process with advanced closed-loop systems.

BACKGROUND: Limiting the duration of invasive ventilation is an important goal in caring for critically ill patients. Several clinical trials have shown that compared to traditional care, protocols can reduce the total duration of mechanical ventilation. Computerized or automated weaning has the potential to improve weaning, while decreasing associated workload, and to transfer best evidence into clinical practice by integrating closed-loop technology into protocols that can be operationalized continuously. DISCUSSION: In this article, we review the principles of automated systems, discuss automated systems that can be used during weaning, and examine the best-current evidence from randomized trials and observational studies supporting their use. We highlight three commercially available systems (Mandatory Minute Ventilation, Adaptive Support Ventilation and SmartCare) that can be used to automate the weaning process. We note advantages and disadvantages associated with individual weaning systems and differences among them. CONCLUSIONS: We discuss the potential role for automation in complimenting clinical acumen, reducing practice pattern variation and facilitating knowledge translation into clinical practice, and underscore the need for additional high quality investigations to evaluate automated weaning systems in different practice settings and diverse patient populations.

International Practice Variation in Weaning Critically Ill Adults from Invasive Mechanical Ventilation.

RATIONALE: Randomized trials and meta-analyses have informed several aspects of weaning. Results are rarely replicated in practice, as evidence is applied in intensive care units that differ from the settings in which it was generated. OBJECTIVES: We aimed to: 1) describe weaning practice variation (identifying weaning candidates, conducting spontaneous breathing trials, using ventilator modes, and other aspects of care during weaning); 2) characterize regional differences in weaning practices; and 3) identify factors associated with practice variation. METHODS: We conducted a cross-sectional, self-administered, international postal survey of adult intensivist members of regional critical care societies from six geographic regions, including Canada, India, the United Kingdom, Europe, Australia/New Zealand, and the United States. We worked with societies to randomly select potential respondents from membership lists and administer questionnaires with the goal of obtaining 200 responses per region. RESULTS: We analyzed 1,144 questionnaires (Canada, 156; India, 136; United Kingdom, 219; Europe, 260; Australia/New Zealand, 196; United States, 177). Across regions, most respondents screened patients once daily to identify spontaneous breathing trials candidates (regional range, 70.0%-95.6%) and less often screened twice daily (range, 12.2%-33.1%) or more than twice daily (range, 1.6%-18.2%). To wean patients, most respondents used pressure support alone (range, 31.0%-71.7%) or with spontaneous breathing trials (range, 35.7%-68.1%). To conduct spontaneous breathing trials, respondents predominantly used pressure support with positive end-expiratory pressure (range, 56.5%-72.3%) and T-piece (8.9%-59.5%). Across regions, we found important variation in screening frequency, spontaneous breathing trials techniques; ventilator modes, written directives to guide care, noninvasive ventilation; and the roles played by available personnel in various aspects of weaning. CONCLUSIONS: Our findings document the presence and extent of practice variation in ventilator weaning on an international scale, and highlight the multidisciplinary and collaborative nature of weaning.

Noninvasive ventilation in the ICU / La ventilation non invasive aux soins intensifs.

CONCLUSION: La ventilation non invasive est probablement un des progrès majeurs des dix dernières années dans le traitement de l'insuffisance respiratoire aiguë aux soins intensifs. Son efficacité a été démontrée dans plusieurs indications. Dans l'insuffisance respiratoire aiguë hypercapnique, la VNI devrait constituer le traitement de premier choix. En évitant l'intubation endotrachéale, la VNI permet de réduire de façon importante la morbidité infectieuse et non infectieuse associée à la ventilation mécanique, de même que la mortalité dans certains groupes de patients. Comme il demeure toujours possible d'intuber le patient en cas d'échec, la VNI peut être tentée dans plusieurs situations cliniques. Finalement, les succès de la VNI dépendent de l'intérêt et de l'expérience de l'équipe soignante.

Wean Earlier and Automatically with New technology (the WEAN study): a protocol of a multicentre, pilot randomized controlled trial.

BACKGROUND: Weaning is the process during which mechanical ventilation is withdrawn and the work of breathing is transferred from the ventilator back to the patient. Prolonged weaning is associated with development of ventilator-related complications and longer stays in the Intensive Care Unit (ICU). Computerized or Automated Weaning is a novel weaning strategy that continuously measures and adapts ventilator support (by frequently measuring and averaging three breathing parameters) and automatically conducts Spontaneous Breathing Trials to ascertain whether patients can resume autonomous breathing. Automated Weaning holds promise as a strategy to reduce the time spent on the ventilator, decrease ICU length of stay, and improve clinically important outcomes. METHODS/DESIGN: A pilot weaning randomized controlled trial (RCT) is underway in the ICUs of 8 Canadian hospitals. We will randomize 90 critically ill adults requiring invasive ventilation for at least 24 hours and identified at an early stage of the weaning process to either Automated Weaning (SmartCare) or Protocolized Weaning. The results of a National Weaning Survey informed the design of the Protocolized Weaning arm. Both weaning protocols are operationalized in Pressure Support mode, include opportunities for Spontaneous Breathing Trials, and share a common sedation protocol, oxygen titration parameters, and extubation and reintubation criteria. The primary outcome of the WEAN study is to evaluate compliance with the proposed weaning and sedation protocols. A key secondary outcome of the pilot RCT is to evaluate clinician acceptance of the weaning and sedation protocols. Prior to initiating the WEAN Study, we conducted a run-in phase, involving two patients per centre (randomizing the first participant to either weaning strategy and assigning the second patient to the alternate strategy) to ensure that participating centres could implement the weaning and sedation protocols and complete the detailed case report forms. DISCUSSION: Mechanical ventilation studies are difficult to implement; requiring protocols to be operationalized continuously and entailing detailed daily data collection. As the first multicentre weaning RCT in Canada, the WEAN Study seeks to determine the feasibility of conducting a large scale future weaning trial and to establish a collaborative network of ICU clinicians dedicated to advancing the science of weaning. TRIAL REGISTRATION NUMBER: ISRCTN43760151.

Effect of epidural analgesia in patients with traumatic rib fractures: a systematic review and meta-analysis of randomized controlled trials.

PURPOSE: A consensus group recently proposed epidural analgesia as the optimal analgesic modality for patients with multiple traumatic rib fractures. However, its beneficial effects are not consistently recognized in the literature. We performed a systematic review and a meta-analysis of randomized controlled trials (RCT) of epidural analgesia in adult patients with traumatic rib fractures. METHODS: A systematic search strategy was applied to MEDLINE, EMBASE, the Cochrane Library and to the annual meeting of relevant societies (up to July 2008). All randomized controlled trials comparing epidural analgesia with other analgesic modalities in adult patients with traumatic rib fractures were included. Primary outcomes were mortality, ICU length of stay (LOS), hospital LOS and duration of mechanical ventilation. RESULTS: Eight studies (232 patients) met eligibility criteria. Epidural analgesia did not significantly affect mortality (odds ratio [OR] 1.6, 95% CI, 0.3, 9.3, 3 studies, n = 89), ICU LOS (weighted mean difference [WMD] -3.7 days, 95% CI, -11.4, 4.0, 4 studies, n = 135), hospital LOS (WMD -6.7, 95% CI, -19.8, 6.4, 4 studies, n = 140) or duration of mechanical ventilation (WMD -7.5, 95% CI, -16.3, 1.2, 3 studies, n = 101). Duration of mechanical ventilation was decreased when only studies using thoracic epidural analgesia with local anesthetics were evaluated (WMD -4.2, 95% CI, -5.5, -2.9, 2 studies, n = 73). However, hypotension was significantly associated with the use of thoracic epidural analgesia with local anesthetics (OR 13.76, 95% CI, 2.89, 65.51, 3 studies, n = 99). CONCLUSIONS: No significant benefit of epidural analgesia on mortality, ICU and hospital LOS was observed compared to other analgesic modalities in adult patients with traumatic rib fractures. However, there may be a benefit on the duration of mechanical ventilation with the use of thoracic epidural analgesia with local anesthetics. Further research is required to evaluate the benefits and harms of epidural analgesia in this population before being considered as a standard of care therapy.

Stability of norepinephrine infusions prepared in dextrose and normal saline solutions.

PURPOSE: Norepinephrine (NE) infusions are commonly used in the intensive care unit and in the operating room. Data on long term stability of NE solutions are lacking. This prospective study was designed to evaluate the stability of NE, in dextrose (5%) in water (D5W) and in normal saline (NS) solutions, for a period up to seven days. METHODS: We prepared norepinephrine solutions in quadruplicate, by aseptically diluting 1 mg NE in 250 mL of D5W or NS and 4 mg NE in 250 mL of D5W or NS (final concentrations, 4 microg x mL(-1) and 16 micro x mL(-1), respectively) and stored the solutions at room temperature under ambient light. We sampled the solutions, in duplicate, at times 0, 24, 48, 72, 120, and 168 hr and stored them at -80 degrees C for later assay. Norepinephrine concentrations were measured by high-performance liquid chromatography with electrochemical detection (coefficient of variation 4.6%). Statistical analysis was done by nonparametric, repeated measures ANOVA (Friedman test). RESULTS: There was no significant decrease in NE concentration for either, NE 4 microg x mL(-1) in D5W or NS (P = 0.09 and 0.11, respectively) or for NE 16 microg x mL(-1) in D5W or NS (P = 0.18 and 0.40, respectively). The ratios of NE concentration at 168 hr, compared to baseline, were 95.7% and 96.4%, for NE 4 microg x mL(-1) in D5W and NS, respectively, and 104.5% and 96.4%, for NE 16 microg x mL(-1) in D5W and NS, respectively. CONCLUSION: Norepinephrine solutions, in concentrations commonly used in the clinical setting, are chemically stable for seven days, at room temperature and under ambient light, when diluted either in D5W or NS.

Complications associated with the Esophageal-Tracheal Combitube in the pre-hospital setting.

PURPOSE: The Esophageal-Tracheal Combitube (Combitube) is widely used for the management of the airway during cardiopulmonary resuscitation in the pre-hospital setting. Although serious complications have been reported with the Combitube, there is a paucity of data relative to the frequency and nature of such complications. The objective of this retrospective study was to determine the incidence and the nature of complications associated to the Combitube in the pre-hospital setting. METHODS: Since 1993, in the Quebec City Health Region, the basic life support treatment algorithm for emergency medical technicians has included the use of a Combitube as the primary airway device for management of all patients presenting with cardiac or respiratory arrest. The database of the emergency coordination services was searched for the period between 1993 and 2003 (2,981 patients). Only those patients who survived at least 12 hr were included. Medical records of these patients were reviewed to identify complications related to the use of the Combitube. RESULTS: Two-hundred-eighty (280) patients were identified. Fifty-eight (58) patients (20.7%, confidence interval (CI)95%=16.0%-25.4%) presented 69 complications: aspiration pneumonitis (n=31), pulmonary aspiration (n=16), pneumothorax (n=6), upper airway bleeding (n=4), esophageal laceration (n=3), sc emphysema (n=2), esophageal perforation and mediastinitis (n=2), tongue edema (n=2), vocal cord injury (n=1), tracheal injury (n=1), and pneumomediastinum (n=1). Thirteen of these complications (12 patients, 4.3%, CI95%=2.0%-6.3%) were judged as most likely resulting from trauma associated with insertion of the Combitube. CONCLUSION: The use of the Combitube in the pre-hospital setting is associated with a notable incidence of serious complications.

Postoperative complications in patients with oculopharyngeal muscular dystrophy: a retrospective study.

PURPOSE: Oculopharyngeal muscular dystrophy (OPMD) is a genetic disease with autosomal dominant transmission particularly common in Quebec where its prevalence is about 1:1000. The main features are bilateral ptosis of the eyelids and dysphagia. These symptoms are frequently treated surgically by levator palpebrae resection (LPR) and cricopharyngeal myotomy (CPM). The objectives of this retrospective chart review were to describe the postoperative complications in OPMD patients undergoing LPR or CPM and to determine their incidence. METHODS: Medical records of all OPMD patients who had either LPR or CPM between 1997 and 2002 were reviewed. The following complications were collected: death, pneumonia, aspiration pneumonitis, airway obstruction, reintubation, and severe coughing and choking caused by profuse secretions. RESULTS: One hundred and fourteen surgeries on 92 OPMD patients were studied. Fifty-nine were LPR under general anesthesia (LPR-GA) and 22 were LPR under local anesthesia (LPR-LA). Thirty-three surgeries were CPM, all under general anesthesia. There was no death or reintubation. Patients who had LPR-LA had shorter postanesthesia care unit (P<0.001) and ambulatory surgery unit (P<0.001) stays than those who had LPR-GA. Complications were more frequent after CPM than LPR-GA (P<0.001). CONCLUSION: The complication rate after LPR was low. Both local and general anesthesia are safe alternatives in OPMD patients operated for LPR. Patients having CPM presented more respiratory complications than those having LPR.

Efficacy of a T-piece system and a continuous positive airway pressure system for apnea testing in the diagnosis of brain death.

OBJECTIVE: To prospectively compare three methods of apnea testing for the confirmation of brain death. DESIGN: Prospective, randomized, crossover study. SETTING: Intensive care unit of a tertiary care university hospital. PATIENTS: Twenty adult patients requiring apnea testing for confirmation of brain death. INTERVENTIONS: Ten minute apnea testing was repeated in random order for every patient with the three oxygenation systems: oxygen catheter inserted through the endotracheal tube (oxygen 6 L/min), T-piece system (oxygen 12 L/min), and continuous positive airway pressure (CPAP) system 10 cm H2O (oxygen 12 L/min). MEASUREMENTS AND MAIN RESULTS: Arterial blood was drawn at 0, 2, 5, and 10 mins of each test. Compared with baseline, Paco2 increased by 30.6 +/- 7.4, 30.0 +/- 7.3 and 30.2 +/- 7.5 mm Hg during the apnea period (p = .96), reaching 73.3 +/- 8.3, 71.6 +/- 11.1, and 72.7 +/- 9.0 mm Hg at the end of the apnea test (p = .73) for the oxygen catheter, the T-piece, and the CPAP, respectively. Pao2 decreased less with the CPAP compared with the oxygen catheter or the T-piece (-22.4 +/- 76, -99.1 +/- 158, and -91.6 +/- 133 mm Hg, respectively, p < .01). In two patients, apnea testing could not be completed with the oxygen catheter and the T-piece because of desaturation, although it could be completed with the CPAP. CONCLUSIONS: The T-piece and the CPAP systems are effective alternatives to the standard oxygen catheter technique for apnea testing. Oxygenation was best maintained with the CPAP system, which can be useful in some patients.

Cricoid pressure does not increase the rate of failed intubation by direct laryngoscopy in adults.

BACKGROUND: Cricoid pressure (CP) is applied during induction of anesthesia to prevent regurgitation of gastric content and pulmonary aspiration. However, it has been suggested that CP makes tracheal intubation more difficult. This double-blind randomized study evaluated the effect of CP on orotracheal intubation by direct laryngoscopy in adults. METHODS: Seven hundred adult patients undergoing general anesthesia for elective surgery were randomly assigned to have a standardized CP (n = 344) or a sham CP (n = 356) during laryngoscopy and intubation. After anesthesia induction and complete muscle relaxation, a 30-s period was allowed to complete intubation with a Macintosh No. 3 laryngoscope blade. The primary endpoint was the rate of failed intubation at 30 s. The secondary endpoints included the intubation time, the Cormack and Lehane grade of laryngoscopic view, and the Intubation Difficulty Scale score. RESULTS: Groups were similar for demographic data and risk factors for difficult intubation. The rates of failed intubation at 30 s were comparable for the two groups: 15 of 344 (4.4%) and 13 of 356 (3.7%) in the CP and sham CP groups, respectively (P = 0.70). The grades of laryngoscopic view and the Intubation Difficulty Scale score were also comparable. Median intubation time was slightly longer in the CP group than in the sham CP group (11.3 and 10.4 s, respectively, P = 0.001). CONCLUSIONS: CP applied by trained personnel does not increase the rate of failed intubation. Hence CP should not be avoided for fear of increasing the difficulty of intubation when its use is indicated.

Nausea and vomiting after laparoscopic surgery are not associated with an increased peripheral release of serotonin.

PURPOSE: To determine whether patients suffering postoperative nausea and vomiting (PONV) present a different serotonin release pattern from those who do not present this complication. METHODS: Forty-eight consecutive women undergoing outpatient laparoscopic tubal ligation were enrolled in this prospective, cumulative case-control study. The study compared serotonin activity in 15 patients totally free of emetic symptoms (asymptomatic group) and, among patients with PONV (n = 33), those 15 who presented the most severe symptoms (PONV group). Patients were anesthetized with a regimen including sufentanil (0.1-0.3 microg x kg(-1)) plus thiopental (3-5 mg x kg(-1)) for induction and isoflurane (0.6-1%) in nitrous oxide (60%) for maintenance. Peripheral serotonin activity was assessed by measurement with high-performance liquid chromatography of serotonin's principal urinary metabolite: 5-hydroxyindoacetic acid (5-HIAA) corrected for urinary creatinine. RESULTS: The preoperative and postoperative urinary 5-HIAA:creatinine ratios were 6.9 ng x microg(-1) (confidence interval; CI 95%, 2.7-11.0) and 5.9 ng x microg(-1) (CI 95%, 2.4-9.4) respectively in the asymptomatic group (P = 0.69), and were 5.1 ng x microg(-1) (CI 95%, 2.5-7.7) and 5.6 ng x micro(-1) (CI 95%, 3.4-7.7) respectively in the PONV group (P = 0.75). There was also no difference between groups in the variation of 5-HIAA:creatinine ratios from the preoperative to the postoperative period (P = 0.21). CONCLUSION: PONV after laparoscopic tubal ligation are not associated with an increased urinary excretion of serotonin metabolites. Patients with severe PONV present a peripheral serotonin release comparable to asymptomatic patients.

An in vivo evaluation of the mycobacterial filtration efficacy of three breathing filters used in anesthesia.

BACKGROUND: The use of breathing filters (BFs) has been recommended to protect the anesthesia apparatus in proven or suspected cases of tuberculosis. Some investigators have also suggested the use of BF to alleviate the need to change anesthesia breathing circuits after each case. This study evaluated the filtration efficacy of three different BFs to prevent mycobacterial contamination of breathing circuits in a model that uses a test animal. METHODS: Ten Pall BB25A (pleated hydrophobic) (Pall Canada Ltd., Mississauga, Ontario, Canada), six DAR Barrierbac S (felted electrostatic; Mallinckrodt DAR, Mirandola, Italy), and six Baxter Airlife (felted electrostatic; Baxter Canada, Mississauga, Ontario, Canada) BFs were studied. For each BF tested, 20 ml of a high concentration suspension of Mycobacterium chelonae (range, 2.0 x 10 to 9.0 x 10 colony-forming units/ml) was nebulized during 2 h at the proximal end of the endotracheal tube of anesthetized pigs. At the end of the nebulization period, the BFs were sampled for culture. The titer reduction value (number of microorganisms challenging the BF divided by the number of microorganisms recovered downstream of the BF) and the removal efficiency (difference between the number of microorganisms challenging the BF and the number of microorganisms recovered downstream of the BF, divided by the number of microorganisms challenging the BF) were calculated. RESULTS: The median titer reduction values were 5.6 x 10, 6.0 x 10, and 8.0 x 10 (P < 0.0005), and the median removal efficiencies were greater than 99.999%, greater than 99.999%, and 100% (P = not significant) for the DAR Barrierbac S, the Baxter Airlife, and the Pall BB25A, respectively. CONCLUSIONS: Among the three BFs studied, only the Pall BB25A completely prevented the passage of M. chelonae, thus protecting the anesthesia breathing circuit from mycobacterial contamination.