Dean D. Bell

Variable Ventilation Improves Perioperative Lung Function in Patients Undergoing Abdominal Aortic Aneurysmectomy

BackgroundOptimizing perioperative mechanical ventilation remains a significant clinical challenge. Experimental models indicate that “noisy” or variable ventilation (VV)—return of physiologic variability to respiratory rate and tidal volume—improves lung function compared with monotonous control mode ventilation (CV). VV was compared with CV in patients undergoing abdominal aortic aneurysmectomy, a patient group known to be at risk of deteriorating lung function perioperatively. MethodsAfter baseline measurements under general anesthesia (CV with a tidal volume of 10 ml/kg and a respiratory rate of 10 breaths/min), patients were randomized to continue CV or switch to VV (computer control of the ventilator at the same minute ventilation but with 376 combinations of respiratory rate and tidal volume). Lung function was measured hourly for the next 6 h during surgery and recovery. ResultsForty-one patients for aneurysmectomy were studied. The characteristics of the patients in the two groups were similar. Repeated-measures analysis of variance (group × time interaction) revealed greater arterial oxygen partial pressure (P = 0.011), lower arterial carbon dioxide partial pressure (P = 0.012), lower dead space ventilation (P = 0.011), increased compliance (P = 0.049), and lower mean peak inspiratory pressure (P = 0.013) with VV. ConclusionsThe VV mode of ventilation significantly improved lung function over CV in patients undergoing abdominal aortic aneurysmectomy.

Eliminating needless testing in intensive care--an information-based team management approach.

To determine if the application of an information-based management system in adult intensive care units (ICU) can produce sustained decreases in the use of laboratory resources and costs. Design:Interventional study with prospective data collection on consecutive patients admitted during three time periods. Setting:A 10-bed adult surgical ICU and an eight-bed adult medical ICU in a tertiary care hospital. Patients:All patients admitted to an ICU during a 7-month baseline period (n = 647), a 1-yr intervention period (n = 1236), and a 2-yr follow-up period (n = 2349). Interventions:Using a management database to track the use of 123 laboratory investigations during the baseline period, nine frequently ordered investigations (determination of blood gases, glucose, potassium, electrocardiogram, chest radiograph, sodium, chloride, complete blood count with differential, and serum osmolality) were targeted for reduction. Specific policies were developed by a multidisciplinary committee within the ICU to reduce the utilization of these laboratory, radiology, and cardiology tests. The policies were applied to all patients admitted during the 1-yr intervention period and during the 2-yr follow-up period. Measurements and Main Results:A 25% reduction was observed in the frequency of all 123 monitored tests during the intervention period.The most dramatic reductions occurred in the nine targeted tests (range 19% to 46%) (p < .001). There were significant reductions in only 13 of the untargeted 114 investigations during this period. Potential annual cost savings were >

Cardiothoracic Anesthesia, Respiration and Airway

150,000 Canadian. No increases in ICU mortality rate, length of stay, or cost of medication were observed, and the reductions in the frequency of targeted tests were maintained during the 2-yr follow-up period. Conclusions:Application of an information-based multidisciplinary management system in the ICU can produce marked and sustained reductions in unnecessary testing in a cost-effective manner. Although rationing of intensive care services may be necessary, reducing needless testing can be a safe and effective cost-containment strategy in the ICU.(Crit Care Med 1993; 21:1452–1458)

Management following resuscitation from cardiac arrest: recommendations from the 2003 Rocky Mountain Critical Care Conference.

PurposeThis study was designed to examine the efficacy of low-dose intrathecal morphine (ITM) on extubation times and pain control after cardiac surgery.Methods43 patients undergoing elective cardiac surgery were enrolled in this prospective, randomized, double-blind placebo controlled trial. Patients were given a pre-induction dose of ITM (6 μg·kg-1 per ideal body weight in 5 mL normal saline, group ITM) or 5 mL of intrathecal normal saline (group ITS). Anesthesia was induced with thiopental (3 mgkg-1), sufentanil, midazolam and rocuronium. The total allowable doses of sufentanil and midazolam for the entire case were limited to 0.5 μg·kg-1 and 0.045 mg·kg-1 respectively. Anesthesia was maintained with isoflurane before and during cardiopulmonary bypass (CPB), and with propofol after CPB. In the postanesthesia care unit, patients received nurse-administered morphine followed by patient-controlled analgesia morphine. Serial visual analogue scale pain scores, morphine use, mini-mental state examinations and pulmonary function tests were measured for 48 hr. Patient satisfaction questionnaires were completed at the time of discharge.ResultsMean times to extubation from the application of dressings were short and did not differ between groups (ITM = 41.4 ± 33.0 min, ITS = 39.2 ± 37.1 min). During the first 24 hr postoperatively, the ITM group had improved pain control and a lower iv morphine requirement than the control group, both at rest and during deep breathing. Both forced expiratory volume in one second and forced vital capacity were improved in the ITM group. There were no differences in spinal-related side effects or in the overall complication rates. Patient satisfaction was high in both groups.ConclusionLow-dose ITM for cardiac surgery did not delay early extubation, but it improved postoperative analgesia and pulmonary function.RésuméObjectifVérifier ľefficacité ďune faible dose de morphine intrathécale (MIT) sur le temps ďextubation précoce et le contrôle de la douleur après une opération en cardiochirurgie.MéthodeĽétude prospective, randomisée et à double insu contre placebo a été menée auprès de 43 patients de cardiochirurgie élective. Les patients ont reÇu une dose de MIT avant ľinduction (6 μg·kg-1 par poids corporel idéal dans 5 mL de solution salée, groupe MIT) ou 5 mL de solution salée intrathécale (groupe SIT). Ľanesthésie a été induite avec du thiopental (3 mg·kg-1), du sufentanil, du midazolam et du rocuronium. Les doses totales permises de sufentanil et de midazolam pour toute ľopération ont été respectivement limitées à 0,5 μg·kg-1 et à 0,045 mg·kg-1. Ľanesthésie a été maintenue avec de ľisoflurane avant et pendant la circulation extracorporelle (CEC), et avec du propofol après la CEC. À la salle de réveil, les patients ont reÇu de la morphine administrée par une infirmière, puis par injection auto-contrôlée. Les séries de scores de douleur de ľéchelle visuelle analogique, la consommation de morphine, les mini-examens de ľétat mental et ľexploration respiratoire fonctionnelle ont été mesurés pendant 48 h. Des questionnaires sur la satisfaction des patients ont été remplis au moment du départ.RésultatsLe temps moyen écoulé entre ľapplication de pansement et ľextubation a été court et comparable ďun groupe à ľautre (MIT = 41,4 ± 33,0 min, SIT = 39,2 ± 37,1 min). Pendant les 24 premières heures après ľopération, les patients du groupe MIT ont été mieux soulagés de leurs douleurs et ont utilisé moins de morphine iv que ceux du groupe témoin, et ce, au repos et pendant la respiration profonde. Le volume expiratoire maximum par seconde et la capacité vitale forcée ont été améliorés dans le groupe MIT. Il n’y avait pas de différence intergroupe entre les complications liées à ľinjection rachidienne ou les autres complications en général. La satisfaction des patients a été élevée dans les deux groupes. Conclusion : Une faible dose de MIT ne retarde pas ľextubation précoce et améliore ľanalgésie postopératoire et la fonction pulmonaire après une opération en cardiochirurgie.PURPOSE This study was designed to examine the efficacy of low-dose intrathecal morphine (ITM) on extubation times and pain control after cardiac surgery. METHODS 43 patients undergoing elective cardiac surgery were enrolled in this prospective, randomized, double-blind placebo controlled trial. Patients were given a pre-induction dose of ITM (6 microg x kg(-1) per ideal body weight in 5 mL normal saline, group ITM) or 5 mL of intrathecal normal saline (group ITS). Anesthesia was induced with thiopental (3 mg x kg(-1)), sufentanil, midazolam and rocuronium. The total allowable doses of sufentanil and midazolam for the entire case were limited to 0.5 microg x kg(-1) and 0.045 mg x kg(-1) respectively. Anesthesia was maintained with isoflurane before and during cardiopulmonary bypass (CPB), and with propofol after CPB. In the postanesthesia care unit, patients received nurse-administered morphine followed by patient-controlled analgesia morphine. Serial visual analogue scale pain scores, morphine use, mini-mental state examinations and pulmonary function tests were measured for 48 hr. Patient satisfaction questionnaires were completed at the time of discharge. RESULTS Mean times to extubation from the application of dressings were short and did not differ between groups (ITM = 41.4 +/- 33.0 min, ITS = 39.2 +/- 37.1 min). During the first 24 hr postoperatively, the ITM group had improved pain control and a lower iv morphine requirement than the control group, both at rest and during deep breathing. Both forced expiratory volume in one second and forced vital capacity were improved in the ITM group. There were no differences in spinal-related side effects or in the overall complication rates. Patient satisfaction was high in both groups. CONCLUSION Low-dose ITM for cardiac surgery did not delay early extubation, but it improved postoperative analgesia and pulmonary function.

Intensive care unit admission following successful cardiopulmonary resuscitation: resource utilization, functional status and long-term survival

PurposeTo propose a strategy for the management of patients admitted to critical care units after resuscitation from cardiac arrest.SourcePrior to the conference relevant studies were identified via literature searches and brief reviews circulated on the following topics: glucose and blood pressure management; therapeutic hypothermia; prearrest outcome prediction; post-arrest outcome prediction; and management of myocardial ischemia. Two days were devoted to assessing evidence and developing a management strategy at the conference. Consensus opinion of conference participants [intensive care unit (ICU) physicians] was used when high grade evidence was unavailable. Additional literature searches and data grading were performed post-conference.Principal findingsHigh grade evidence was lacking in most areas. Specific goals of treatment were proposed for: general care; neurologic care; respiratory care; cardiac care; and gastrointestinal care. There was adequate evidence to recommend therapeutic hypothermia for comatose patients who had witnessed ventricular fibrillation or ventricular tachycardia arrests. Conference participants supported extending therapeutic hypothermia to other presenting rhythms in selected circumstances. Additional goals included mean arterial pressure 80 to 100 mmHg, glucose 5 to 8 mmol·L-1 using insulin infusions, and PaO2 > 100 mmHg for the first 24 hr. Absent withdrawal to pain 72 hr after resuscitation should prompt consideration of palliative care. The level of evidence for other recommendations was low.ConclusionsThe proposed management strategy represents an approach to manage patients in the ICU following resuscitation from cardiac arrest. Most of the recommendations are based on low grade evidence. Additional research is needed to improve the evidence base. A standard post-arrest management strategy could help facilitate future research.RésuméObjectifProposer une stratégie de traitement à adopter avec les patients admis aux unités de soins intensifs (USI) après la réanimation post-arrêt cardiaque.SourceAvant la conférence, les études utiles ont été repérées dans les publications et de brèves revues ont circulé sur : le glucose et le traitement de la tension artérielle; l’hypothermie thérapeutique; la prédiction de l’évolution pré-arrêt; la prédiction des suites de l’arrêt cardiaque et le traitement de l’ischémie myocardique. Deux jours ont été alloués à l’évaluation de la preuve et au développement d’une approche thérapeutique à la conférence. L’opinion générale des par-ticipants, médecins intensivistes, a prévalu quand une preuve de haut niveau n’était pas assurée. Des recherches de documents et une clas-sification de données supplémentaires ont été faites après la con-férence.Constatations principalesUne preuve de haut niveau manquait dans la majorité des domaines. On a proposé des objectifs spécifiques de traitement pour : les soins généraux, neurologiques, respiratoires, cardiaques et gastro-intestinaux. Des preuves suffisantes ont permis de recommander l’hypothermie thérapeutique chez les patients comateux victimes d’arrêts cardiaques causés par une fibrillation ou une tachycardie ventriculaire. Les participants à la conférence ont appuyé l’extension de l’hypothermie thérapeutique aux rythmes présentés dans des circonstances choisies. D’autres objectifs incluent une tension artérielle moyenne de 80 à 100 mmHg, le glucose à 5 àObjectif Proposer une strategie de traitement a adopter avec les patients admis aux unites de soins intensifs (USI) apres la reanimation post-arret cardiaque.

Intraoperative anaphylactic shock from bacitracin nasal packing after septorhinoplasty.

A retrospective review of consecutive admissions (n = 285) to a university hospital intensive care unit (ICU) following cardiopulmonary resuscitation was conducted to determine long-term outcome, length of stay (LOS), and ICU resource consumption. Ninety-four patients (33%) survived to hospital discharge. Hospital survivors had longer ICU LOS than non-survivors (5.1 +/- 0.8 vs. 2.8 +/- 0.4 days, P < 0.001) and longer hospital stays (22.5 +/- 3.7 vs. 2.9 +/- 1.2 days, P < 0.001). Average laboratory and pharmacy costs per admission were greater in hospital survivors than non-survivors. Most patients returned to their pre-arrest homes functionally independent and 58% of hospital survivors were alive 2 years after discharge. It is possible that attempts to appropriately limit therapy in patients with poor prognosis may help direct resources towards patients who will benefit.

Resuscitating patients with early severe sepsis: A Canadian multicentre observational study

ANAPHYLAXIS is a life-threatening immunologically mediated reaction related to the administration of a substance that causes mast cell degranulation. We report a case of life-threatening anaphylaxis after topical application of bacitracin to the nasal mucosa at the conclusion of an anesthetic.

Conduite à tenir après la réanimation post-arrêt cardiaque: Recommandations de la conférence du Rocky mountain critical care 2003

BackgroundFluid resuscitation is a key factor in restoring hemodynamic stability and tissue perfusion in patients with severe sepsis. We sought to examine associations of the quantity and type of fluid administered in the first six hours after identification of severe sepsis and hospital mortality, intensive care unit (ICU) mortality, and organ failure.MethodsA retrospective, multicentre cohort study was undertaken at five Canadian tertiary care ICUs. We identified patients with severe sepsis admitted to the ICU between July 1, 2000, and June 30, 2002, using both administrative and clinical databases. Patients were included if they were hypotensive, had an infectious source, and at least two systemic inflammatory response syndrome criteria. We recorded total quantity and type of fluid administered for the first six hours after severe sepsis was identified. The first episode of hypotension defined the starting point for collection of fluid data. Multivariable regression analyses were performed to examine associations between quantity and type of fluid administered and hospital/ICU mortality, and organ failure.ResultsOf 2,026 potentially eligible patient charts identified, 496 patients met eligibility criteria. The mean age and Acute Physiology and Chronic Health Evaluation score (APACHE II) were 61.8 ± 16.5 yr and 29.0 ± 8.0, respectively. No associations between quantity or type of fluid administered and hospital mortality or ICU mortality were identified, and there were no statistically significant associations between quantity or type of fluid administered and organ failure. However, more fluid resuscitation was associated with an increased risk of cardiovascular failure [odds ratio (OR) and 95% confidence interval (CI)] for 2-4 L 1.67 (1.03-2.70) and > 4 L 2.34 (1.23-4.44) and a reduced risk of renal failure [OR, 95% CI for 2-4 L 0.48 (0.28-0.83) and > 4 L 0.45 (0.22-0.92)] in the first 24 hr of severe sepsis. Administration of colloid and crystalloid fluid as compared to crystalloid fluid alone was associated with a lower risk of renal failure [OR, 95% CI 0.45 (0.26 to 0.76)].ConclusionAn association between hospital mortality and quantity or type of fluid administered in the first six hours after the diagnosis of severe sepsis was not identifiable. These findings should be considered as hypothesis-generating and warrant confirmation or refutation by randomized controlled trials.ContexteLa réanimation liquidienne est un facteur crucial pour restaurer la stabilité hémodynamique et la perfusion tissulaire chez les patients en septicémie sévère. Nous avons cherché à examiner les liens entre la quantité et le type de liquide administré durant les six premières heures suivant le diagnostic d’une septicémie sévère et la mortalité hospitalière, la mortalité aux soins intensifs et la défaillance systémique.MéthodeUne étude de cohorte rétrospective et multi-centrique a été entreprise dans cinq unités de soins intensifs de soins tertiaires au Canada. Nous avons identifié les patients atteints de septicémie sévère admis aux soins intensifs entre le 1er juillet 2000 et le 30 juin 2002, en se fondant sur des bases de données administratives et cliniques. Les critères d’inclusion comprenaient: l’hypotension, la présence d’une source infectieuse, et au minimum deux critères du syndrome de réponse inflammatoire systémique. Nous avons enregistré la quantité totale et le type de liquide administré durant les six premières heures suivant le diagnostic d’une septicémie sévère. Le premier épisode d’hypotension a défini le point de départ pour la récolte des données concernant les liquides administrés. Des analyses de régression multivariées ont été menées afin d’examiner les liens entre la quantité et le type de liquide administré et la mortalité à l’hôpital/aux soins intensifs, ainsi que la défaillance systémique.RésultatsParmi les 2 026 dossiers de patients potentiellement éligibles, 496 patients ont présenté les critères d’admissibilité. L’âge moyen et le score APACHE II (Acute Physiology and Chronic Health Evaluation) étaient de 61,8 ± 16,5 ans et 29,0 ± 8,0, respective-ment. Aucun lien entre la quantité ou le type de liquide administré et la mortalité à l’hôpital ou aux soins intensifs n’a été identifié, et nous n’avons pas trouvé de liens statistiquement significatifs entre la quantité ou le type de liquide administré et la défaillance systémi-que. Toutefois, davantage de réanimation liquidienne a été associée a un risque accru de défaillance cardiovasculaire [rapport de cote (OR) et intervalle de confiance (CI) de 95 %] pour 2-4 L 1,67 (1,03-2,70) et> 4L 2,34 (1,23-4,44) ainsi qu’un risque réduit de défaillance rénale [OR, CI 95 % pour 2-4 L 0,48 (0,28-0,83) et> 4L 0,45 (0,22-0,92)] durant les premières 24 h de septicé-mie sévère. L’administration simultanée de colloïde et cristalloïde, comparativement à du cristalloïde seul, a été associée à un risque moindre de défaillance rénale [OR, CI 95 % 0,45 (0,26 à 0,76)].ConclusionAucune association entre la mortalité à l’hôpital et la quantité ou le type de liquide administré durant les six premières heures suivant le diagnostic d’une septicémie sévère n’a pu être identifiée. Ces données devraient être considérées comme génératrices d’hypothèses et exigent leur confirmation ou, au contraire, leur réfutation, par des études randomisées contrôlées.

Incorporating Dynamic Assessment of Fluid Responsiveness Into Goal-directed Therapy: A Systematic Review and Meta-analysis

PurposeTo propose a strategy for the management of patients admitted to critical care units after resuscitation from cardiac arrest.SourcePrior to the conference relevant studies were identified via literature searches and brief reviews circulated on the following topics: glucose and blood pressure management; therapeutic hypothermia; prearrest outcome prediction; post-arrest outcome prediction; and management of myocardial ischemia. Two days were devoted to assessing evidence and developing a management strategy at the conference. Consensus opinion of conference participants [intensive care unit (ICU) physicians] was used when high grade evidence was unavailable. Additional literature searches and data grading were performed post-conference.Principal findingsHigh grade evidence was lacking in most areas. Specific goals of treatment were proposed for: general care; neurologic care; respiratory care; cardiac care; and gastrointestinal care. There was adequate evidence to recommend therapeutic hypothermia for comatose patients who had witnessed ventricular fibrillation or ventricular tachycardia arrests. Conference participants supported extending therapeutic hypothermia to other presenting rhythms in selected circumstances. Additional goals included mean arterial pressure 80 to 100 mmHg, glucose 5 to 8 mmol·L-1 using insulin infusions, and PaO2 > 100 mmHg for the first 24 hr. Absent withdrawal to pain 72 hr after resuscitation should prompt consideration of palliative care. The level of evidence for other recommendations was low.ConclusionsThe proposed management strategy represents an approach to manage patients in the ICU following resuscitation from cardiac arrest. Most of the recommendations are based on low grade evidence. Additional research is needed to improve the evidence base. A standard post-arrest management strategy could help facilitate future research.RésuméObjectifProposer une stratégie de traitement à adopter avec les patients admis aux unités de soins intensifs (USI) après la réanimation post-arrêt cardiaque.SourceAvant la conférence, les études utiles ont été repérées dans les publications et de brèves revues ont circulé sur : le glucose et le traitement de la tension artérielle; l’hypothermie thérapeutique; la prédiction de l’évolution pré-arrêt; la prédiction des suites de l’arrêt cardiaque et le traitement de l’ischémie myocardique. Deux jours ont été alloués à l’évaluation de la preuve et au développement d’une approche thérapeutique à la conférence. L’opinion générale des par-ticipants, médecins intensivistes, a prévalu quand une preuve de haut niveau n’était pas assurée. Des recherches de documents et une clas-sification de données supplémentaires ont été faites après la con-férence.Constatations principalesUne preuve de haut niveau manquait dans la majorité des domaines. On a proposé des objectifs spécifiques de traitement pour : les soins généraux, neurologiques, respiratoires, cardiaques et gastro-intestinaux. Des preuves suffisantes ont permis de recommander l’hypothermie thérapeutique chez les patients comateux victimes d’arrêts cardiaques causés par une fibrillation ou une tachycardie ventriculaire. Les participants à la conférence ont appuyé l’extension de l’hypothermie thérapeutique aux rythmes présentés dans des circonstances choisies. D’autres objectifs incluent une tension artérielle moyenne de 80 à 100 mmHg, le glucose à 5 àObjectif Proposer une strategie de traitement a adopter avec les patients admis aux unites de soins intensifs (USI) apres la reanimation post-arret cardiaque.

Historical Perspectives in Critical Care Medicine : Blood Transfusion, Intravenous Fluids, Inotropes/Vasopressors, and Antibiotics

Objective: Dynamic tests of fluid responsiveness have been developed and investigated in clinical trials of goal-directed therapy. The impact of this approach on clinically relevant outcomes is unknown. We performed a systematic review and meta-analysis to evaluate whether fluid therapy guided by dynamic assessment of fluid responsiveness compared with standard care improves clinically relevant outcomes in adults admitted to the ICU. Data Sources: Randomized controlled trials from MEDLINE, EMBASE, CENTRAL, clinicaltrials.gov, and the International Clinical Trials Registry Platform from inception to December 2016, conference proceedings, and reference lists of relevant articles. Study Selection: Two reviewers independently identified randomized controlled trials comparing dynamic assessment of fluid responsiveness with standard care for acute volume resuscitation in adults admitted to the ICU. Data Extraction: Two reviewers independently abstracted trial-level data including population characteristics, interventions, clinical outcomes, and source of funding. Our primary outcome was mortality at longest duration of follow-up. Our secondary outcomes were ICU and hospital length of stay, duration of mechanical ventilation, and frequency of renal complications. The internal validity of trials was assessed in duplicate using the Cochrane Collaboration’s Risk of Bias tool. Data Synthesis: We included 13 trials enrolling 1,652 patients. Methods used to assess fluid responsiveness included stroke volume variation (nine trials), pulse pressure variation (one trial), and stroke volume change with passive leg raise/fluid challenge (three trials). In 12 trials reporting mortality, the risk ratio for death associated with dynamic assessment of fluid responsiveness was 0.59 (95% CI, 0.42–0.83; I 2 = 0%; n = 1,586). The absolute risk reduction in mortality associated with dynamic assessment of fluid responsiveness was –2.9% (95% CI, –5.6% to –0.2%). Dynamic assessment of fluid responsiveness was associated with reduced duration of ICU length of stay (weighted mean difference, –1.16 d [95% CI, –1.97 to –0.36]; I 2 = 74%; n = 394, six trials) and mechanical ventilation (weighted mean difference, –2.98 hr [95% CI, –5.08 to –0.89]; I 2 = 34%; n = 334, five trials). Three trials were adjudicated at unclear risk of bias; the remaining trials were at high risk of bias. Conclusions: In adult patients admitted to intensive care who required acute volume resuscitation, goal-directed therapy guided by assessment of fluid responsiveness appears to be associated with reduced mortality, ICU length of stay, and duration of mechanical ventilation. High-quality clinical trials in both medical and surgical ICU populations are warranted to inform routine care.