The esophageal cooling device: A new temperature control tool in the intensivist's arsenal.

BACKGROUND: Therapeutic hypothermia has been demonstrated to improve neurological outcome in comatose survivors of cardiac arrest. Current temperature control modalities however, have several limitations. Exploring innovative methods of temperature management has become a necessity. METHODS: We describe the first use of a novel esophageal cooling device as a sole modality for hypothermia induction, maintenance and rewarming in a series of four postcardiac arrest patients. The device was inserted in a manner similar to standard orogastric tubes and connected to an external heat exchange unit. RESULTS: A mean cooling rate of 0.42 °C/hr (SD ± 0.26) was observed. An average of 4 hr 24 min (SD ± 2 hr 6 min) was required to reach target temperature, and this was maintained 90.25% (SD ± 16.20%) of the hypothermia protocol duration. No adverse events related to device use were encountered. Questionnaires administered to ICU nursing staff regarding ease-of-use of the device and its performance were rated as favorable. CONCLUSIONS: When used as a sole modality, objective performance parameters of the esophageal-cooling device were found to be comparable to standard temperature control methods. More research is required to further quantify efficacy, safety, assess utility in other patient populations, and examine patient outcomes with device use in comparison to standard temperature control modalities.

Temperature control in critically ill patients with a novel esophageal cooling device: a case series.

BACKGROUND: Mild hypothermia and fever control have been shown to improve neurological outcomes post cardiac arrest. Common methods to induce hypothermia include body surface cooling and intravascular cooling; however, a new approach using an esophageal cooling catheter has recently become available. METHODS: We report the first three cases of temperature control using an esophageal cooling device (ECD). The ECD was placed in a similar fashion to orogastric tubes. Temperature reduction was achieved by connecting the ECD to a commercially available external heat exchange unit (Blanketrol Hyperthermia - Hypothermia System). RESULTS: The first patient, a 54 year-old woman (86 kg) was admitted after resuscitation from an out-of-hospital non-shockable cardiac arrest. Shortly after admission, she mounted a fever peaking at 38.3 °C despite administration of cold intravenous saline and application of cooling blankets. ECD utilization resulted in a temperature reduction to 35.7 °C over a period of 4 h. She subsequently recovered and was discharged home at day 23. The second patient, a 59 year-old man (73 kg), was admitted after successful resuscitation from a protracted out-of hospital cardiac arrest. His initial temperature was 35 °C, but slowly increased to 35.8 °C despite applying a cooling blanket and ice packs. The ECD was inserted and a temperature reduction to 34.8 °C was achieved within 3 h. The patient expired on day 3. The third patient, a 47 year-old man (95 kg) presented with a refractory fever secondary to necrotizing pneumonia in the postoperative period after coronary artery bypass grafting. His fever persisted despite empiric antibiotics, antipyretics, cooling blankets, and ice packs. ECD insertion resulted in a decrease in temperature from 39.5 to 36.5 °C in less than 5 h. He eventually made a favorable recovery and was discharged home after 59 days. In all 3 patients, device placement occurred in under 3 min and ease-of-use was reported as excellent by nursing staff and physicians. CONCLUSIONS: The esophageal cooling device was found to be an effective temperature control modality in this small case series of critically ill patients. Preliminary data presented in this report needs to be confirmed in large randomized controlled trials comparing its efficacy and safety to standard temperature control modalities.

Failure-to-rescue rate as a measure of quality of care in a cardiac surgery recovery unit: a five-year study.

BACKGROUND: Failure to rescue, which is defined as the probability of death after a complication that was not present on admission, was introduced as a quality measure in the 1990s, to complement mortality and morbidity outcomes. The objective of this study was to evaluate possible incremental benefits of measuring failure to rescue after cardiac surgery, to facilitate quality improvement efforts. METHODS: Data were collected prospectively on 4,978 consecutive patients who underwent cardiac operations during a 5-year period. Institutional logistic regression models were used to generate predicted rates of mortality and major complications. Frequency distributions of morbidities were determined, and failure to rescue was calculated. The annual failure-to-rescue rates were contrasted using χ(2) tests and compared with morbidity and mortality measures. RESULTS: The overall mortality rate was 3.6%, the total complication rate was 16.8%, and the failure-to-rescue rate was 19.8% (95% confidence interval, 17.1% to 22.7%). The predicted risk of mortality and of major complications increased during the last 2 years of the study, whereas the observed complication rate decreased. Failure to rescue for new renal failure was the highest of all complications (48.4%), followed by septicemia (42.6%). Despite the decreased complication rate toward the end of the study, the failure-to-rescue rate did not change significantly (p = 0.28). CONCLUSIONS: Failure to rescue should be monitored as a quality-of-care metric, in addition to mortality and complication rates. Postoperative renal failure and septicemia still have a high failure-to-rescue rate and should be targeted by quality improvement efforts.

Treatment of severe accidental hypothermia with intermittent hemodialysis.

The optimal management of moderate-to-severe hypothermia with hemodynamic instability remains unclear. Although cardiopulmonary bypass offers the most rapid rate of rewarming and has been suggested as the method of choice in the presence of circulatory arrest, there is no evidence to support the use of this highly invasive technique over other rewarming modalities in the absence of circulatory collapse. We report the successful treatment of hemodynamically unstable hypothermia with conventional hemodialysis in a patient with normal renal function, after initial efforts of rewarming using conventional strategies had failed. This case report and review of the literature highlights the advantages and the challenges of using hemodialysis in this setting, and suggests a potential role for hemodialysis in the routine management of moderate-to-severe hypothermia in the absence of circulatory arrest.

Impact of the opening of a specialized cardiac surgery recovery unit on postoperative outcomes in an academic health sciences centre.

PURPOSE: It is controversial as to whether cardiac surgery patients are optimally managed in a mixed medical-surgical intensive care unit (ICU) or in a specialized postoperative unit. We conducted a prospective cohort study in an academic health sciences centre to compare outcomes before and following the opening of a specialized cardiac surgery recovery unit (CSRU) in April 2005. METHODS: The study cohort included 2,599 consecutive patients undergoing coronary artery bypass grafting (CABG), valve and combined CABG-valve procedures from April 2004 to March 2006. From April 2004 to March 2005 (year 1) all patients received postoperative care in mixed medical-surgical ICUs at two different sites staffed by critical care consultants, fellows and residents. From April 2005 until March 2006 (year 2) patients were cared for in a newly-established CSRU on one site staffed by cardiac anesthesiology fellows, a nurse practitioner and consultants in critical care, cardiac anesthesiology and cardiac surgery. The effect of this change on in-hospital mortality, the incidence of ten major postoperative complications, postoperative ventilation hours, readmission rates and case cancellations due to a lack of capacity was assessed using Chi-square or Wilcoxon tests, where appropriate. RESULTS: Coronary artery bypass grafting, valve and combined CABG-valve mortality rates were similar in years 1 and 2. There was a significant reduction in the composite major complication rate (16.3% to 13.0%, P=0.02) and in median postoperative ventilation hours (8.8 vs 8.0 hr, P=0.005) from year 1 to 2. On multivariable logistic regression analysis, the pre-merger interval (year 1) was a significant independent predictor of the occurrence of death or major complications. CONCLUSION: A specialized CSRU with a multi-disciplinary consultant model was associated with stable or improved outcomes postoperatively, when compared to a mixed medical- surgical ICU model of cardiac surgical care.

Influence of injection rate of hyperbaric bupivacaine on spinal block in parturients: a randomized trial.

PURPOSE: A prospective, randomized, double-blind clinical trial was undertaken to determine whether a tenfold difference in the rate of intrathecal injection of bupivacaine would affect sensory block level in parturients. Secondary outcomes included onset of block and the incidence of hypotension and nausea. METHODS: Following Research Ethics Board approval, 90 ASA I and II term parturients scheduled for Cesarean delivery were randomized to receive either fast injection (over four seconds, Group F) or slow injection (over 40 sec, Group S) of 0.75% hyperbaric bupivacaine 12 mg plus morphine 200 microg. Sensory block, motor block, and blood pressure were assessed every minute for the first 15 min, then every five minutes for the next 20 min. All occurrences of nausea, hypotension (decrease in systolic blood pressure > 30%) and ephedrine requirements were recorded. RESULTS: Forty-three patients in Group F and 42 patients in Group S completed the study. No differences in maximum sensory block height (Group F = median T2, interquartile range [T2-T4], Group S = T3 [T2-T4], P = 0.077) or time to achieve block height (F = 9.3 +/- 4.3 min, S = 9.7 +/- 4.7, P = 0.64) were observed. The frequencies of hypotension (Group F = 35/43, Group S = 32/42, P = 0.56), ephedrine utilization (Group F = 32/43, Group S = 26/42, P = 0.21) and nausea (Group F = 15/43, Group S = 16/42, P = 0.76) were similar. CONCLUSION: Rapid intrathecal injection of hyperbaric bupivacaine does not affect spread of spinal anesthesia or the incidence of hypotension and nausea in parturients.

The effects of perioperative beta-blockade: results of the Metoprolol after Vascular Surgery (MaVS) study, a randomized controlled trial.

BACKGROUND: Patients undergoing vascular surgery comprise the highest risk group for perioperative cardiac mortality and morbidity after noncardiac procedures. Many current guidelines recommend the use of beta-blockers in all patients undergoing vascular surgery. We report a trial of the perioperative administration of metoprolol and its effects on the incidence of cardiac complications at 30 days and 6 months after vascular surgery. METHODS: Patients undergoing abdominal aortic surgery and infrainguinal or axillofemoral revascularizations were recruited to a double-blind randomized controlled trial of perioperative metoprolol versus placebo. Patients were randomized to receive study medication, starting 2 hours preoperatively until hospital discharge or maximum of 5 days postoperatively. Primary outcome were postoperative 30-day composite incidence of nonfatal myocardial infarction, unstable angina, new congestive heart failure, new atrial or ventricular dysrhythmia requiring treatment, or cardiac death. RESULTS: Patients were randomized to receive either metoprolol (n = 246) or placebo (n = 250). Primary outcome events at 30 days postoperative occurred in 25 (10.2%) versus 30 (12.0%) (P = .57) in metoprolol and placebo groups, respectively (relative risk reduction 15.3%, 95% CI -38.3% to 48.2%). Observed effects at 6 months were not significantly different (P = .81) (relative risk reduction 6.2%, 95% CI% -58.4% to 43.8%). Intraoperative bradycardia requiring treatment was more frequent in the metoprolol group (53/246 vs 19/250, P = .00001), as was intraoperative hypotension requiring treatment (114/246 vs 84/250, P = .0045). CONCLUSION: Our results showed metoprolol was not effective in reducing the 30-day and 6-month postoperative cardiac event rates. Prophylactic use of perioperative beta-blockers in all vascular patients is not indicated.