Karen McAllen

Impact of dexmedetomidine on analgesic requirements in patients after cardiac surgery in a fast-track recovery room setting.

Study Objective. To compare postoperative opioid requirements in patients who received dexmedetomidine versus propofol after cardiac surgery.

Adverse drug reactions resulting in hyperthermia in the intensive care unit.

Hyperthermia is frequently seen in the intensive care setting and is associated with significant morbidity and mortality. It is often initially misdiagnosed as fever associated with infection. Atypical presentations of classic syndromes are common. Clinical suspicion is the key to diagnosis. Adverse drug reactions are a frequent culprit. Syndromes include adrenergic “fever,” anticholinergic “fever,” antidopaminergic “fever,” serotonin syndrome, malignant hyperthermia, uncoupling of oxidative phosphorylation, and withdrawal from baclofen. This review describes the pathophysiology of hyperthermia, as distinct from fever, and the physiology, diagnosis, and treatment of serotonin syndrome, neuroleptic malignant syndrome, malignant hyperthermia, and baclofen withdrawal. Much of the available evidence regarding the treatment of these disorders is based on single case reports, case series, or animal models. Therapeutic modalities consist of identification/withdrawal of possible offending agent(s), support directed at lowering temperature and preventing/treating complications, as well as targeted pharmacologic therapy directed at the specific cause. Early recognition and treatment using a multidisciplinary approach are essential to achieve the best possible outcome.

Limitations of a standardized weight-based nomogram for heparin dosing in patients with morbid obesity

BACKGROUND Confusion exists when dosing heparin using a weight-based nomogram in the obese population. At 2 affiliated community teaching hospitals, we compared the activated partial thromboplastin time (aPTT) values in morbidly obese and nonmorbidly obese patients using a standardized nomogram and determined factors associated with achieving a supratherapeutic aPTT value. METHODS This was a retrospective study that included patients who had received intravenous heparin according to a standardized weight-based nomogram for >or=12 hours. The exclusion criteria were age <18 years, pregnancy, and insufficient data. Patients were stratified into morbidly obese (body mass index [BMI] >or=40 kg/m(2)) and nonmorbidly obese (BMI <40 kg/m(2)) groups. The aPTT values were compared and predictors for a supratherapeutic aPTT values were identified. RESULTS A total of 101 patients were included in the study. Greater aPTT values were noted at 6 hours (155 +/- 37 versus 135 +/- 44, P = .020) and 12 hours (141 +/- 45 versus 117 +/- 45, P = .012) for patients with morbid obesity than for those without it, respectively. Increasing BMI (odds ratio = 1.06, 95% confidence interval 1.02-1.1; P = .003) and age (odds ratio 1.05, 95% confidence interval 1.02-.09; P = .001] were independent predictors of supratherapeutic aPTT values. CONCLUSION Heparin dosing with a weight-based nomogram will yield greater aPTT values in morbidly obese patients. Consideration of BMI and age can help identify those patients at risk of supratherapeutic aPTTs. Alternative strategies, such as a dose cap should be considered in patients with morbid obesity.

Cerebral perfusion pressure and intracranial pressure are not surrogates for brain tissue oxygenation in traumatic brain injury.

OBJECTIVE Utilization of brain tissue oxygenation (pBtO(2)) is an important but controversial variable in the treatment of traumatic brain injury (TBI). We evaluated the correlation between pBtO(2)/CPP and pBtO(2)/ICP and determined the parameter most closely related to survival. METHODS Consecutive, adult patients with severe TBI and pBtO(2) monitors were retrospectively identified. Time-indexed measurements of pBtO(2), CPP and ICP were collected and correlation coefficients were determined. Patients were then stratified according to survival and pBtO(2), CPP and ICP values were compared between groups. RESULTS There were 4169 time-indexed data points (i.e., pBtO(2) with respective CPP and ICP values) in 15 patients. The cohort consisted of a mean age of 37±17 years, ISS of 27±7 and GCS of 4.5±1.5. Survival was 53% (8/15). In a normal regression models, neither the ICP (p=0.58) nor the CPP (p=0.71) predict pBtO(2) significantly. There was a significant difference in pBtO(2) in survivors (31.5±3.1 vs. 25.2±4.8, p=0.010) but not in CPP or ICP. Survivors had a lower proportion of time with pBtO(2)<25 mmHg [20% (3.4-44.6) vs. 40% (16.2-89), p=0.049]. In contrast, survivors had a greater proportion of time with CPP<70 and no difference in the proportion of time with and ICP>20. CONCLUSIONS CPP and ICP should not be used as surrogates for pBtO(2) since cerebral oxygenation varies independently of cerebral hemodynamics and pressures. Brain tissue oxygen monitoring in patients with TBI provides unique information regarding cerebral oxygenation the utility of which remains to be fully described. SIGNIFICANCE CPP and ICP are not surrogates for pBtO(2). Brain tissue oxygenation monitoring provides unique information for the treatment of traumatically injured patients.

Mechanical prophylaxis to prevent venous thromboembolism in surgical patients: A prospective trial evaluating compliance ☆

PURPOSE Sequential compression devices (SCDs) and venous foot pumps (VFPs) are used to prevent venous thromboembolism in surgical patients, but compliance is presumed to be poor. We evaluated compliance with these devices, compared compliance between intensive care unit (ICU) and non-ICU patients, and identified factors associated with better compliance. MATERIALS AND METHODS Compliance was prospectively evaluated twice daily from admission until discharge, ambulation, or device discontinuation. A compliance score was determined by dividing the number of compliant evaluations by the total number of assessments. Compliance was compared between ICU and non-ICU patients, and predictors for compliance were identified. RESULTS There were 150 patients evaluated. Overall compliance was 73 +/- 29. Compliance was higher in ICU patients compared to non-ICU patients (82 +/- 22 vs 62 +/- 32; P < .001). Admission to the ICU (odds ratio [OR], 2.21 [1.04-4.65]; P = .038) and SCD use (as opposed to VFP) (OR, 2.94 [1.36-6.37]; P = .006) were independent predictors for better compliance. CONCLUSIONS Compliance with mechanical prophylaxis is suboptimal particularly in non-ICU patients. Strategies to improve compliance or alternative prophylaxis should be considered in those patients.

Early Pharmacological Treatment of Delirium May Reduce Physical Restraint Use A Retrospective Study

Introduction: Evidence surrounding pharmacological treatment of delirium is limited. The negative impact of physical restraints on patient outcomes in the intensive care unit (ICU), however, is well published. The objective of this study was to evaluate whether initiating pharmacologic delirium treatment within 24 hours of a positive screen reduces the number of days in physical restraints and improves patient outcomes compared with delayed or no treatment. Methods: Patients from a mixed ICU with a documented positive delirium score using the Intensive Care Delirium Screening Checklist were retrospectively grouped based on having received pharmacologic treatment within 24 hours of the first positive screen or not. Primary end points were number of days spent in physical restraints and time to extubation after delirium onset. Secondary end points included hospital and ICU length of stay (LOS) and survival to discharge. Results: Two hundred intubated patients were either pharmacologically treated (n = 98) or not treated (n = 102) within 24 hours of the first positive delirium score. Patients receiving treatment spent a shorter median time in restraints compared with patients who were not treated (3 vs 6 days; P < .001), and had a shorter median time to extubation (3 vs 6.5 days; P < .001). The treatment group also experienced a shorter ICU LOS (9.5 vs 16 days; P < .001) and hospital LOS (14.5 vs 22 days; P < .001) compared with the no-treatment group. Conclusions: Delirious patients who received pharmacological treatment within 24 hours of the first positive screen spent fewer days in physical restraints and less time receiving mechanical ventilation compared with those who did not. Although delirium management is multifactorial, early pharmacological therapy may benefit patients diagnosed with delirium.

Medication Reconciliation Effect on Prolonged Inpatient Stress Ulcer Prophylaxis

Background: While medication reconciliation (MR) has been shown to reduce medication errors by limiting errors of transcription, omission, and duplicate therapy, its Impact on the provision of unnecessary prophylaxis is largely unknown. Objective: To determine the effect of MR on the incidence of prolonged stress ulcer prophylaxis (SUP) across the continuum of care from hospital admission to discharge as well as evaluate clinical conditions associated with prolonged SUR Methods: This retrospective study assessed patients who were admitted to the intensive care unit (ICU) and had SUP initiated. Patients were excluded if they were receiving gastroprotective therapy prior to ICU admission, were being treated for an acute gastrointestinal hemorrhage, or died. The need for SUP was determined using risk factors adapted from evidence-based guidelines developed by the American Society of Health-System Pharmacists. The use of SUP was assessed upon transfer from the ICU to a non-ICU setting and at hospital discharge. Results were compared between pre-MR and post-MR groups. Results: Data from 114 (pre-MR, n = 53; post-MR, n = 61) medical and surgical ICU patients were evaluated. There was no significant difference in the use of prolonged SUP upon transfer from the ICU to a non-ICU setting in the pre-MR and post-MR groups, respectively (85% [45/53] vs 79% [48/61), p = 0.393). Similarly, there was no significant difference in the use of prolonged SUP upon hospital discharge In the pre-MR and post-MR groups, respectively (14% [6/44] vs 23% [10743), p = 0.247), There were no clinical conditions for which prolonged SUP use was predominant. Conclusions: The strategy of MR alone will not decrease the incidence of prolonged SUP in hospitalized patients. Other techniques should be evaluated to encourage appropriate use of acid-suppressive agents.

The first 72 hours of brain tissue oxygenation predicts patient survival with traumatic brain injury.

BACKGROUND: Utilization of brain tissue oxygenation (pBtO2) is an important but controversial variable in the treatment of traumatic brain injury. We hypothesize that pBtO2 values over the first 72 hours of monitoring are predictive of mortality. METHODS: Consecutive, adult patients with severe traumatic brain injury and pBtO2 monitors were retrospectively identified. Time-indexed measurements of pBtO2, cerebral perfusion pressure (CPP), and intracranial pressure (ICP) were collected, and average values over 4-hour blocks were determined. Patients were stratified according to survival, and repeated measures analysis of variance was used to compare pBtO2, CPP, and ICP. The pBtO2 threshold most predictive for survival was determined. RESULTS: There were 8,759 time-indexed data points in 32 patients. The mean age was 39 years ± 16.5 years, injury severity score was 27.7 ± 10.7, and Glasgow Coma Scale score was 6.6 ± 3.4. Survival was 68%. Survivors consistently demonstrated higher pBtO2 values compared with nonsurvivors including age as a covariate (F = 12.898, p < 0.001). Individual pBtO2 was higher at the time points 8 hours, 12 hours, 20 hours to 44 hours, 52 hours to 60 hours, and 72 hours of monitoring (p < 0.05). There was no difference in ICP (F = 1.690, p = 0.204) and CPP (F = 0.764, p = 0.389) values between survivors and nonsurvivors including age as a covariate. Classification and regression tree analysis identified 29 mm Hg as the threshold at which pBtO2 was most predictive for mortality. CONCLUSION: The first 72 hours of pBtO2 neurologic monitoring predicts mortality. When the pBtO2 monitor remains below 29 mm Hg in the first 72 hours of monitoring, mortality is increased. This study challenges the brain oxygenation threshold of 20 mm Hg that has been used conventionally and delineates a time for monitoring pBtO2 that is predictive of outcome. LEVEL OF EVIDENCE: III, prognostic study.

High glucose variability increases cerebral infarction in patients with spontaneous subarachnoid hemorrhage

PURPOSE High glucose variability is a significant marker for poor outcome in critically ill patients. We evaluated the impact of high glucose variability on cerebral infarction following spontaneous subarachnoid hemorrhage (SAH). MATERIALS AND METHODS Consecutive adult patients with spontaneous SAH and Hunt Hess score of at least 3 were retrospectively identified. Patients were excluded if their intensive care unit length of stay was less than 24 hours or if there were less than 5 glucose assessments. Glucose values from the first 7 days of intensive care unit admission were assessed. Variability was calculated as the average change in glucose over time for each patient. Classification and regression tree analysis was used to determine high vs low glucose variability, and the incidence of cerebral infarction was compared. Multivariate analysis was used to control for confounding variables. RESULTS There were 42 patients. Classification and regression tree analysis revealed a change in glucose greater than 9.52 mg/dL/h as the determinant for high variability. The incidence of cerebral infarction was 64% when glucose variability was high vs 20% when it was low (P=.006). Multivariate analysis identified high glucose variability (odds ratio [95% confidence interval]=11.4 [1.9-70.2], P=.008) and female sex (odds ratio [95% confidence interval]=5.2 [1-26.8], P=.047) as independent predictors for cerebral infarction. CONCLUSION Glucose variability is a significant predictor of cerebral infarction in patients with severe spontaneous SAH.

Current and Future Treatment Considerations in the Management of Aneurysmal Subarachnoid Hemorrhage

Aneurysmal subarachnoid hemorrhage (aSAH) is a type of hemorrhagic stroke that can cause significant morbidity and mortality. Although guidelines have been published to help direct the care of these patients, there is insufficient quality literature regarding the medical and pharmacological management of patients with aSAH. Treatment is divided into 3 categories: supportive therapy, prevention of complications, and treatment of complications. There are numerous pharmacological therapies that are targeted at prevention and treatment of the neurological and medical complications that may arise. Rebleeding, hydrocephalus, cerebral vasospasm, and seizures are the most common neurological complications while the most common medical complications include hyponatremia, pulmonary edema, cardiac arrhythmias, neurogenic stunned myocardium, fever, anemia, infection, hyperglycemia, and venous thromboembolism. Risk factors, clinical presentation, diagnosis, pathophysiology, as well as initial management, prevention, and treatment of complications will be the focus of this discussion.