Abhijit Duggal

Predicting neurologic outcome after targeted temperature management for cardiac arrest: systematic review and meta-analysis.

Objectives:Targeted temperature management improves survival and neurologic outcomes for adult out-of-hospital cardiac arrest survivors but may alter the accuracy of tests for predicting neurologic outcome after cardiac arrest. Data Sources:We systematically searched Medline, Embase, CINAHL, and CENTRAL from database inception to September 2012. Study Selection:Citations were screened for studies that examined diagnostic tests to predict poor neurologic outcome or death following targeted temperature management in adult cardiac arrest survivors. Data Extraction:Data on study outcomes and quality were abstracted in duplicate. We constructed contingency tables for each diagnostic test and calculated sensitivity, specificity, and positive and negative likelihood ratios. Data Synthesis:Of 2,737 citations, 20 studies (n = 1,845) met inclusion criteria. Meta-analysis showed that three tests accurately predicted poor neurologic outcome with low false-positive rates: bilateral absence of pupillary reflexes more than 24 hours after a return of spontaneous circulation (false-positive rate, 0.02; 95% CI, 0.01–0.06; summary positive likelihood ratio, 10.45; 95% CI, 3.37–32.43), bilateral absence of corneal reflexes more than 24 hours (false-positive rate, 0.04; 95% CI, 0.01–0.09; positive likelihood ratio, 6.8; 95% CI, 2.52–18.38), and bilateral absence of somatosensory-evoked potentials between days 1 and 7 (false-positive rate, 0.03; 95% CI, 0.01–0.07; positive likelihood ratio, 12.79; 95% CI, 5.35–30.62). False-positive rates were higher for a Glasgow Coma Scale motor score showing extensor posturing or worse (false-positive rate, 0.09; 95% CI, 0.06–0.13; positive likelihood ratio, 7.11; 95% CI, 5.01–10.08), unfavorable electroencephalogram patterns (false-positive rate, 0.07; 95% CI, 0.04–0.12; positive likelihood ratio, 8.85; 95% CI, 4.87–16.08), myoclonic status epilepticus (false-positive rate, 0.05; 95% CI, 0.02–0.11; positive likelihood ratio, 5.58; 95% CI, 2.56–12.16), and elevated neuron-specific enolase (false-positive rate, 0.12; 95% CI, 0.06–0.23; positive likelihood ratio, 4.14; 95% CI, 1.82–9.42). The specificity of available tests improved when these were performed beyond 72 hours. Data on neuroimaging, biomarkers, or combination testing were limited and inconclusive. Conclusion:Simple bedside tests and somatosensory-evoked potentials predict poor neurologic outcome for survivors of cardiac arrest treated with targeted temperature management, and specificity improves when performed beyond 72 hours. Clinicians should use caution with these predictors as they carry the inherent risk of becoming self-fulfilling.

Safety and efficacy of noninvasive ventilation in patients with blunt chest trauma: a systematic review

IntroductionThis systematic review looks at the use of noninvasive ventilation (NIV), inclusive of noninvasive positive pressure ventilation (NPPV) and continuous positive pressure ventilation (CPAP), in patients with chest trauma to determine its safety and clinical efficacy in patients with blunt chest trauma who are at high risk of acute lung injury (ALI) and respiratory failure.MethodsWe searched the MEDLINE, EMBASE and Cochrane Central Register of Controlled Trials (CENTRAL) databases. Pairs of reviewers abstracted relevant clinical data and assessed the methodological quality of randomized controlled trials (RCTs) using the Cochrane domain and observational studies using the Newcastle-Ottawa Scale.ResultsNine studies were included (three RCTs, two retrospective cohort studies and four observational studies without a comparison group). There was significant heterogeneity among the included studies regarding the severity of injuries, degree of hypoxemia and timing of enrollment. One RCT of moderate quality assessed the use of NPPV early in the disease process before the development of respiratory distress. All others evaluated the use of NPPV and CPAP in patients with blunt chest trauma after the development of respiratory distress. Overall, up to 18% of patients enrolled in the NIV group needed intubation. The duration of NIV use was highly variable, but NIV use itself was not associated with significant morbidity or mortality. Four low-quality observational studies compared NIV to invasive mechanical ventilation in patients with respiratory distress and showed decreased ICU stay (5.3 to 16 days vs 9.5 to 15 days), complications (0% to 18% vs 38% to 49%) and mortality (0% to 9% vs 6% to 50%) in the NIV group.ConclusionsEarly use of NIV in appropriately identified patients with chest trauma and without respiratory distress may prevent intubation and decrease complications and ICU length of stay. Use of NIV to prevent intubation in patients with chest trauma who have ALI associated with respiratory distress remains controversial because of the lack of good-quality data.

Therapeutic hypothermia after cardiac arrest: A systematic review/meta-analysis exploring the impact of expanded criteria and targeted temperature

AIMS OF THE STUDY We aimed to determine the benefit of an expanded use of TH. We also described the impact of a targeted temperature management on outcomes at discharge. DATA SOURCES We identified studies by searching MEDLINE, EMBASE and Cochrane Library databases. We included RCTs and observational studies restricted to those reporting achieved temperature during TH after OHCA. No other patient, cardiac arrest or hypothermia protocol restrictions were applied. Outcomes of interest were hospital mortality and neurological outcome at discharge. Appropriate risk of bias assessment for meta-analyzed studies was conducted. Studies contrasting hypothermia and normothermia outcomes were meta-analyzed using a random-effect model. Outcomes of cooling arms, obtained from enrolled studies, were pooled and compared across achieved temperatures. RESULTS Search strategy yielded 32,275 citations of which 24 articles met inclusion criteria. Eleven studies were meta-analyzed. The use of TH after OHCA, even within an expanded use, decreased the mortality (OR 0.51, 95%CI [0.41-0.64]) and improved the odds of good neurological outcome (OR 2.48, 95%CI [1.91-3.22]). No statistical heterogeneity was found for either mortality (I2=4.0%) or neurological outcome (I2=0.0%). No differences in hospital mortality (p=0.86) or neurological outcomes at discharge (p=0.32) were found when pooled outcomes of 34 hypothermia arms grouped by cooling temperature were compared. CONCLUSION The use of TH after OHCA is associated with a survival and neuroprotective benefit, even when including patients with non-shockable rhythms, more lenient downtimes, unwitnessed arrest and/or persistent shock. We found no evidence to support one specific temperature over another during hypothermia.

Cardiopulmonary Resuscitation in the Hospitalized Patient: Impact of System-Based Variables on Outcomes in Cardiac Arrest

Background:A better understanding of the factors affecting the outcome of inpatient cardiopulmonary resuscitation (CPR) is crucial in making key clinical decisions. We aim to study the impact of various patient-related and hospital-related variables in a community-based teaching setup that could affect the prognosis of in-hospital cardiac arrests. Methods:We analyzed the data on all patients who experienced cardiac arrest while hospitalized at a community teaching hospital in Youngstown, Ohio. A multivariable logistic regression was performed to identify patient- and system-based variables associated with mortality in inpatient cardiac arrest. Results:A total of 417 in-hospital cardiopulmonary arrests were recorded during the study period. We analyzed 299 events in our final sample. One hundred sixty-four patients (54.8%) achieved return of spontaneous circulation and 137 (48.5%) survived the cardiopulmonary arrest for at least 24 hours. The duration of CPR, age, initial rhythm, witnessed events and sex were strongly associated with mortality in our univariate analysis. After adjustment for age, location and whether the code was witnessed, the timing of the week, initial rhythm, the duration of CPR and the sex of the patient retained prognostic significance in predicting the mortality. Conclusions:In our study, we report a 17.4% survival to hospital discharge after an in-hospital cardiopulmonary arrest and subsequent CPR, similar to rates reported in larger multicenter studies. Prolonged duration of CPR (>10 minutes) and male sex were found to be associated with worse outcomes. We report the impact of system-based variables such as physician and nursing staffing during different days of the week, on survival in these patients.

Nonlinear imputation of pa o 2/F io 2 from Sp o 2/F io 2 among mechanically ventilated patients in the ICU: A prospective, observational study

Objectives: In the contemporary ICU, mechanically ventilated patients may not have arterial blood gas measurements available at relevant timepoints. Severity criteria often depend on arterial blood gas results. Retrospective studies suggest that nonlinear imputation of PaO2/FIO2 from SpO2/FIO2 is accurate, but this has not been established prospectively among mechanically ventilated ICU patients. The objective was to validate the superiority of nonlinear imputation of PaO2/FIO2 among mechanically ventilated patients and understand what factors influence the accuracy of imputation. Design: Simultaneous SpO2, oximeter characteristics, receipt of vasopressors, and skin pigmentation were recorded at the time of a clinical arterial blood gas. Acute respiratory distress syndrome criteria were recorded. For each imputation method, we calculated both imputation error and the area under the curve for patients meeting criteria for acute respiratory distress syndrome (PaO2/FIO2 ⩽ 300) and moderate-severe acute respiratory distress syndrome (PaO2/FIO2 ⩽ 150). Setting: Nine hospitals within the Prevention and Early Treatment of Acute Lung Injury network. Patients: We prospectively enrolled 703 mechanically ventilated patients admitted to the emergency departments or ICUs of participating study hospitals. Interventions: None. Measurements and Main Results: We studied 1,034 arterial blood gases from 703 patients; 650 arterial blood gases were associated with SpO2 less than or equal to 96%. Nonlinear imputation had consistently lower error than other techniques. Among all patients, nonlinear had a lower error (p < 0.001) and higher (p < 0.001) area under the curve (0.87; 95% CI, 0.85–0.90) for PaO2/FIO2 less than or equal to 300 than linear/log-linear (0.80; 95% CI, 0.76–0.83) imputation. All imputation methods better identified moderate-severe acute respiratory distress syndrome (PaO2/FIO2 ⩽ 150); nonlinear imputation remained superior (p < 0.001). For PaO2/FIO2 less than or equal to 150, the sensitivity and specificity for nonlinear imputation were 0.87 (95% CI, 0.83–0.90) and 0.91 (95% CI, 0.88–0.93), respectively. Skin pigmentation and receipt of vasopressors were not associated with imputation accuracy. Conclusions: In mechanically ventilated patients, nonlinear imputation of PaO2/FIO2 from SpO2/FIO2 seems accurate, especially for moderate-severe hypoxemia. Linear and log-linear imputations cannot be recommended.

Procalcitonin-based algorithms to initiate or stop antibiotic therapy in critically ill patients: Is it time to rethink our strategy?

Procalcitonin (PCT)-based antibiotic management algorithms for critically ill patients have been described in the literature. An evaluation of the available evidence demonstrates that studies have utilised PCT in various clinical scenarios: for the initiation of antimicrobials; for cessation or de-escalation of antimicrobials; or for the combination of both strategies. Current PCT reviews and meta-analyses have combined studies from all different clinical scenarios. However, there may be significant variations in algorithm compliance and clinical outcomes associated with the use of PCT in these different strategies. As such, the current review focused on separating out the studies utilising PCT in the critically ill population for different treatment strategies. Based on this review, we would recommend that PCT should not be used as the sole deciding factor for the initiation of antimicrobials. As such, PCT should not be obtained in patients who do not exhibit evidence of infection. In patients who do have signs of infection and antimicrobials have been initiated, a strategy that utilises PCT for the discontinuation or de-escalation of antimicrobials is likely to decrease the duration of treatment without adversely affecting outcome.

Oral neutrophils are an independent marker of the systemic inflammatory response after cardiac bypass

BackgroundCardiopulmonary bypass (CPB) is an immuno-reactive state where neutrophils are activated and accumulate in different tissues. Edema and tissue necrosis are the most common sequelae observed, predominantly in the lungs, kidneys, and heart, heralding significant risk for postoperative complications. No method exists to noninvasively assess in vivo neutrophil activity. The objective of this study was to determine if neutrophil recruitment to the oral cavity would correlate with specific biomarkers after coronary bypass surgery (CPB).MethodsWe conducted a single site prospective observational study including non-consecutive adult patients undergoing elective, on-pump CPB. Blood and either oral cavity rinses or swabs were collected pre- and post-CPB. Absolute neutrophil counts from oral samples and serum biomarkers were measured. The association between neutrophil recruitment to the oral cavity, biomarkers and outcomes after CPB were analyzed.ResultsCPB was associated with statistically significant increases in oral and blood neutrophil counts, as well as an increase in certain biomarkers over preoperative baseline. Peripheral blood neutrophil count were increased at all time points however statistically significant differences in median oral neutrophil counts were observed only at the time point immediately postoperative, and in what seems to be two unique patient populations (p < 0.001; group 1, median: 1.6×105, Interquartile range [IQR], 1.1×105 - 4.8×105, and group 2, median: 1.9×106, IQR, 8.7×105 - 4.0×106).ConclusionsCPB is associated with a transient increase in oral neutrophils that may correlate with the systemic inflammatory response; oral neutrophils may have the ability to discriminate and identify unique patient populations based on their tissue migration.

Global Variability in Reported Mortality for Critical Illness during the 2009-10 Influenza A(H1N1) Pandemic: A Systematic Review and Meta-Regression to Guide Reporting of Outcomes during Disease Outbreaks

Purpose To determine how patient, healthcare system and study-specific factors influence reported mortality associated with critical illness during the 2009–2010 Influenza A (H1N1) pandemic. Methods Systematic review with meta-regression of studies reporting on mortality associated with critical illness during the 2009–2010 Influenza A (H1N1) pandemic. Data Sources Medline, Embase, LiLACs and African Index Medicus to June 2009-March 2016. Results 226 studies from 50 countries met our inclusion criteria. Mortality associated with H1N1-related critical illness was 31% (95% CI 28–34). Reported mortality was highest in South Asia (61% [95% CI 50–71]) and Sub-Saharan Africa (53% [95% CI 29–75]), in comparison to Western Europe (25% [95% CI 22–30]), North America (25% [95% CI 22–27]) and Australia (15% [95% CI 13–18]) (P<0.0001). High income economies had significantly lower reported mortality compared to upper middle income economies and lower middle income economies respectively (P<0.0001). Mortality for the first wave was non-significantly higher than wave two (P = 0.66). There was substantial variability in reported mortality among the specific subgroups of patients: unselected critically ill adults (27% [95% CI 24–30]), acute respiratory distress syndrome (37% [95% CI 32–44]), acute kidney injury (44% [95% CI 26–64]), and critically ill pregnant patients (10% [95% CI 5–19]). Conclusion Reported mortality for outbreaks and pandemics may vary substantially depending upon selected patient characteristics, the number of patients described, and the region and economic status of the outbreak location. Outcomes from a relatively small number of patients from specific regions may lead to biased estimates of outcomes on a global scale.

Hypotension Risk Based on Vasoactive Agent Discontinuation Order in Patients in the Recovery Phase of Septic Shock

Patients with septic shock often require vasoactive agents for hemodynamic support; however, the optimal approach to discontinuing these agents once patients reach the recovery phase is currently unknown. The objective of this evaluation was to compare the incidence of hypotension within 24 hours based on the discontinuation order of norepinephrine (NE) and vasopressin (AVP) in patients in the recovery phase of septic shock.

Compliance with Procalcitonin Algorithm Antibiotic Recommendations for Patients in Medical Intensive Care Unit.

To describe compliance with antibiotic recommendations based on a previously published procalcitonin (PCT)‐guided algorithm in clinical practice, to compare PCT algorithm compliance rates between PCT assays ordered in the antibiotic initiation setting (PCT concentration measured less than 24 hours after antibiotic initiation or before antibiotic initiation) with those in the antibiotic continuation setting (PCT concentration measured 24 hours or more after antibiotic initiation), and to evaluate patient‐ and PCT‐related factors independently associated with algorithm compliance in patients in the medical intensive care unit (MICU).