Michael L. Ault

Higher hemoglobin is associated with less cerebral infarction, poor outcome, and death after subarachnoid hemorrhage.

OBJECTIVE:Higher-goal hemoglobin (hgb) and more packed red blood cell transfusions lead to worse outcomes in general critical care patients. There are few data on hgb, transfusion, and outcomes after aneurysmal subarachnoid hemorrhage (SAH). METHODS:We reviewed the daily hgb levels of 103 patients with aneurysmal SAH. Cerebral infarction was diagnosed by computed tomographic scan. We corrected for Hunt and Hess grade, age, and angiographic vasospasm in multivariate models. RESULTS:Of 103 patients, the mean age was 55.3 ± 14.5 years, 63% were women, and 29% were Hunt and Hess Grades 4 and 5; hgb values steadily declined from 12.6 ± 1.7 g/dl the day of SAH to 10.4 ± 1.2 g/dl by Day 14. Patients who died had lower hgb than survivors on Days 0, 1, 2, 4, 6, 10, 11, and 12 (P ≤ 0.05). Higher mean hgb was associated with reduced odds of poor outcome (odds ratio, 0.57 per g/dl; 95% confidence interval [CI], 0.38–0.87; P = 0.008) after correcting for Hunt and Hess grade, age, and vasospasm; results for hgb on Days 0 and 1 were similar. Higher Day 0 (odds ratio, 0.7 per g/dl; 95% CI, 0.5–0.99; P = 0.05) and mean hgb (odds ratio, 0.57 per g/dl; 95% CI, 0.38–0.87; P = 0.009) predicted a lower risk of cerebral infarction independent of vasospasm. There were no associations between hgb and other prognostic variables. CONCLUSION:We found that SAH patients with higher initial and mean hgb values had improved outcomes. Higher hgb in SAH patients may be beneficial. The efficacy and safety of blood transfusions to increase hgb in patients with SAH may warrant further study.

The effect of a new NPO policy on operating room utilization

STUDY OBJECTIVES To prospectively assess the impact of a liberalized preoperative fasting policy on operating room (OR) utilization. STUDY DESIGN Prospective cohort study involving data collection before and after a change in nil per os (NPO) policy. SETTING Academic teaching hospital. PATIENTS 5,420 consecutive outpatients and AM admissions. INTERVENTIONS Data collection was done on all adult patients who presented to our OR suite over two 15-week periods. During the first 15-week period, patients were instructed to drink no liquids after midnight (control group, n = 2,646). In the second 15-week period, patients were allowed to consume unlimited clear fluids until 2 to 3 hours prior to surgery (study group, n = 2,774). MEASUREMENTS AND MAIN RESULTS We found no difference between the control and study groups in the number of cases cancelled (0 in each group) or delayed (8 vs. 9; relative risk [RR] = 1.07, 95% confidence interval [CI] = 1.000 to 1.148) due to noncompliance with fasting guidelines. There was no difference between the groups in the number of cases of aspiration (0 in each group). In the control group, significantly more episodes of regurgitation were noted (12 vs. 9; RR = 0.715, 95% CI = 0.535 to 0.955) and more rapid-sequence/awake intubations were performed (119 vs. 51; RR = 0.409, 95% CI = 0.306 to 0.546) than in the study group. CONCLUSIONS Liberalizing a preoperative fasting policy and allowing patients to consume unrestricted clear fluids up until 3 hours before their scheduled time of surgery did not affect their compliance with fasting requirements. No increase in cancellations or delays of surgical procedures due to inappropriate oral intake was observed.

United States Practice Patterns in the Use of Transesophageal Echocardiography During Adult Liver Transplantation

OBJECTIVE To characterize contemporary practice patterns in the use of transesophageal echocardiography during adult liver transplantation and to identify factors preventing more frequent use. DESIGN Online questionnaire. SETTING Liver transplantation centers in the United States performing 12 or more adult liver transplants in 2011. PARTICIPANTS One representative from each qualifying center: The transplant anesthesiology director, a transplant anesthesiologist personally known to the authors, or the department of anesthesiology chair. INTERVENTIONS Three e-mail attempts were made to solicit participation in the study between June and August 2012. MEASUREMENTS AND MAIN RESULTS Of the 97 institutions identified, an anesthesiologist from each of 79 (81.4%) centers completed the questionnaire; 38.0% of centers reported routine use and 57.0% for special circumstances or rescue situations, yielding an overall use rate of 94.9%. This distribution was consistent regardless of operative volume, practice size, or academic affiliation. The sole factor predictive of routine transesophageal echocardiography use was an overlap between an institutions cardiac and transplant anesthesiology teams. In practices not routinely employing the technology, the most compelling reason was a sense that it was not necessary. Although 69.9% of transplant anesthesiologists reportedly were proficient in echocardiography, inadequate anesthesiologist training was also a strongly cited hindrance. CONCLUSIONS Transesophageal echocardiography during adult liver transplantation in the United States has become widely prevalent, with notable growth in its use as a routine diagnostic and monitoring modality. Almost all institutions now use the technology at least occasionally, with the participation of cardiac anesthesiologists being predictive of a centers routine use.

Packed red blood cell age does not impact adverse events or outcomes after subarachnoid haemorrhage

Objectives: To determine if the age of packed red blood cells (PRBCs) is associated with adverse events or outcomes in patients with subarachnoid haemorrhage (SAH).

A comparison of hemoglobin measured by co-oximetry and central laboratory during major spine fusion surgery.

BACKGROUND:Many factors affect the accuracy of hemoglobin concentration values. In this study, we evaluated whether the hemoglobin concentration obtained by means of arterial blood gas (ABG) co-oximetry and complete blood count (CBC) central laboratory techniques clinically correlate when using simultaneous measurements of hemoglobin concentration obtained during complex spine fusion surgery. METHODS:Three hundred forty-eight patients who underwent spinal fusion of >3 bony levels between September 2006 and September 2010, with concurrent ABG and CBC samples, were identified. The mean difference between pairs of measured hemoglobin values was determined using limits of agreement analysis. Error grid analysis was used to delineate correlation of samples in relation to hemoglobin values within the range considered for transfusion. RESULTS:The median difference (ABG-CBC) between the measured hemoglobin values was 0.4 g/dL (95% confidence interval [CI], 0.35–0.40 g/dL; P < 0.0001). Limits of agreement analysis correcting for repeated observations in multiple patients demonstrated that the mean difference between measured hemoglobin values (i.e., bias) was 0.4 g/dL (95% CI, 0.36–0.41 g/dL), and the 95% limits of agreement of the difference between paired measurements were −0.70 to 1.47 g/dL. The magnitude of the difference between the measured hemoglobin values was >0.5 g/dL in 44.5% of patients (95% CI, 42.2%–46.8%); however, 6.8% (95% CI, 5.8%–8.1%) of paired measurements had a difference of >1.0 g/dL. There was only fair-to-moderate agreement between the CBC and ABG values within the clinically significant range of hemoglobin values of 7 to 10 g/dL (Cohen &kgr; = 0.39; 95% CI, 0.33–0.45). CONCLUSIONS:The hemoglobin values obtained from ABG and CBC cannot be used interchangeably when verifying accuracy of novel point-of-care hemoglobin measurement modalities or when managing a patient with critical blood loss.

THE PREOPERATIVE ASSESSMENT CLINIC: Its Value and Function

The value of preoperative assessment is often assumed to be related to a reduction in morbidity and mortality during the perioperative period; but the paucity of evidence supporting this concept makes the benefit theoretical, at best. The documented value 5,6,13 of an organized approach to preoperative assessment includes cost-effective patient evaluation improved operating room efficiency improved patient safety through preoperative anticipation of intraoperative needs improved patient satisfaction because of clear communication and allayed anxiety regarding the risks and procedures associated with the administration of anesthesia If properly performed, therefore, the comprehensive preoperative assessment becomes a value-added service provided by the anesthesiologist. This serves to expand our role well beyond that of the physician-anesthetist to that of the perioperative physician. Such a role is vital to our function and survival in the future medicoeconomic environment. 17

Con: The Challenges of Utilizing Expanded-Criteria Donors for Orthotopic Heart Transplantation

PRIMUM NON NOCERE, or “First, do no harm.” For physicians, this guides practice and reminds us to weigh the risks of harm with each medical intervention from which the benefit may be uncertain. Physicians have been attempting to treat organ failure with transplantation for centuries. In the early days of organ transplantation, only patients facing imminent death from irreversible organ failure were considered for this uncertain and desperate surgery, with most patients dying quickly after surgery. Transplantation medicine has since overcome major technical limitations with improvements in procurement, preservation, surgical techniques, and the development of immunosuppression medications, which greatly have improved survival after organ transplantation. Thus, what was once considered a formidable surgery is now an established option for patients and physicians despite the risk of serious complications. With organ transplantation becoming more commonplace and limited only by suitable donors, surgeons are entertaining riskier procedures (eg, multiple-organ transplants, repeat transplants), expanded donor criteria (eg, living donors, donation after cardiac death, marginal donors), and less-vigorous recipients (eg, older, multiple comorbidities).

Opioids, febrile responsiveness, and thinking outside the box.

Anesthesiologists have long been advocates for the use of meperidine to treat shivering secondary to postanesthetic effects. The mechanism of this action is not thoroughly understood, but it appears that this is most likely secondary to the effect of meperidine at the κ -opioid receptor (1). The ability of other opioids such as fentanyl and alfentanil to ameliorate shivering has also been investigated to some extent (2, 3). Nonetheless, for the intensivist, the effect of opioids on the febrile response clearly remains an area in need of further clinical research.

270: VA ECMO FOR VT STORM

Critical Care Medicine • Volume 46 • Number 1 (Supplement) www.ccmjournal.org Learning Objectives: Refractory ventricular tachycardia (VT) presents a challenge in the ICU. Extra corporeal membrane oxygenation (ECMO) may be utilized if anti-arrhythmic medications and cardioversion are unable to successfully terminate VT. While maintaining perfusion, venoarterial (VA) ECMO introduces other potential complications. Methods: Here we describe a case of shivering with VA ECMO causing rhabdomyolysis. A 57year-old male with arrhythmogenic cardiomyopathy and four previous ablations presented to our ICU in refractory VT. Despite amiodarone, lidocaine, metoprolol, diltiazem, multiple cardioversions, intubation and sedation, his VT persisted. VA ECMO support was used as a bridge to heart transplant. He continued to have episodes of VT while on ECMO. After ECMO cannulation, he began shivering severely for unknown reasons, which was treated unsuccessfully with propofol, fentanyl and meperidine. Approximately 12 hours post cannulation, his urine output decreased and became brown in color. Creatinine kinase (CK) was elevated to > 7,000 U/L and SVO2 was 44%. Renal perfusion was optimized with intravenous fluids, and a cisatracurium infusion was started. His shivering stopped and CK began to downtrend, but attempts at stopping cisatracurium yielded further shivering. Subsequently, he became febrile, and a bronchoscopy revealed purulent secretions. He was started on antibiotics for hospital acquired pneumonia. At this point, we thought the shivering may be a response to sepsis, and increased the temperature of his ECMO circuit from 37.1 to 38 degrees Celsius. Cisatracurium infusion was then discontinued without shivering. The patient was extubated the following day and was able to participate in physical therapy while awaiting transplant. In the interim, he received another ablation that was only possible given the ECMO support. This decreased the frequency of VT episodes and allowed for decannulation of VA ECMO. Results: VA ECMO can be vital in perfusing end organs in hemodynamically unstable VT storm. This can also allow for more extensive ablations. Here we successfully treated a rare complication of ECMO: shivering causing rhabdomyolysis. Although increasing the temperature of the ECMO circuit above 37 degrees Celsius is not commonly done, this should be considered in patients with shivering on ECMO.

The Clinical Significance of Patient Specimen Transport Modality: Pneumatic Tube System Impact on Blood Gas Analytes

INTRODUCTION: A pneumatic tube system (PTS) is a cost-effective, rapid transport modality that utilizes induced pressure changes. We evaluated the clinical importance of 2 transport modalities, human courier and PTS, for blood gas specimens. METHODS: Following open heart surgery, 35 simultaneous pairs of arterial and venous blood gas specimens were analyzed from 20 subjects. Of each pair, one specimen was transported to the blood gas laboratory via a human courier and the other via a SwissLog PTS. Transport modalities were compared using the Bland-Altman limits of agreement method. RESULTS: Compared with the walked specimen, the bias for PaCO2 was −8.0 mm Hg (95% CI, −40.0 to 24.5 mm Hg); PaCO2, −0.94 mm Hg (95% CI, −3.76 to 1.86 mm Hg); PvO2, −0.60 mm Hg (95% CI, −6.90 to 5.70 mm Hg); PvCO2, −0.58 mm Hg (95% CI, −3.12 to 1.92 mm Hg) for the PTS specimen. CONCLUSION: The difference in the PO2 and PCO2 of paired (walked vs tubed) arterial and venous blood gas specimens demonstrated a slight bias. PaCO2 values demonstrated the greatest bias, however not clinically important. Thus, PTS transport does not impact clinical interpretations of blood gas values.