Therapeutic hypothermia: is it effective for non-VF/VT cardiac arrest?

Since 2003, therapeutic hypothermia (TH) is recommended for all comatose survivors after cardiac arrest (CA) due to VF/VT. However, only 25\u201330 % of CA patients have VF/VT as the initial recorded cardiac rhythm, and this percentage has further decreased in recent years. The benefit of TH for non-VF/VT CA are controversial. Methods: Meta-analysis. All studies evaluating the benefit of TH in adult comatose survivors from CA were included. No limitations of study design, publication date and publication status were imposed. Resuts: Two randomised trials and 15 observational studies were identified. Neither of the randomised trials was specifically designed to assess the benefit of TH in this patient population.TH-treated patients had a higher 6-mo survival rate than controls (5/22 vs. 2/22; risk ratio [RR] for mortality 0.85 [0.65\u20131.11] p = 0.24). Results of the 15 observational studies (12 reporting survival to discharge on 1,581 patients, and 13 reporting neurological outcome on 1,998 patients) showed that TH was associated to a significant reduction in the RR for both hospital mortality (0.88 [0.82\u20130.95]) and poor neurological outcome (0.95 [0.90\u20130.99]). However, several studies suggested no effect or possible harm from TH. Conclusions: in patients resuscitated from non-VF/VT CA, use of TH is associated with a significant decrease in both hospital mortality and neurological outcome. Observed heterogeneity in study results may be explained by differences in case mix or cooling protocols and the presence of uncontrolled confounders, being most of the studies observational

Management and outcome of mechanically ventilated patients after cardiac arrest

Introduction: The aim of this study was to describe and compare the changes in ventilator management and complications over time, as well as variables associated with 28-day hospital mortality in patients receiving mechanical ventilation (MV) after cardiac arrest. Methods: We performed a secondary analysis of three prospective, observational multicenter studies conducted in 1998, 2004 and 2010 in 927 ICUs from 40 countries. We screened 18,302 patients receiving MV for more than 12 hours during a one-month-period. We included 812 patients receiving MV after cardiac arrest. We collected data on demographics, daily ventilator settings, complications during ventilation and outcomes. Multivariate logistic regression analysis was performed to calculate odds ratios, determining which variables within 24 hours of hospital admission were associated with 28-day hospital mortality and occurrence of acute respiratory distress syndrome (ARDS) and pneumonia acquired during ICU stay at 48 hours after admission. Results: Among 812 patients, 100 were included from 1998, 239 from 2004 and 473 from 2010. Ventilatory management changed over time, with decreased tidal volumes (V T ) (1998: mean 8.9 (standard deviation (SD) 2) ml/kg actual body weight (ABW), 2010: 6.7 (SD 2) ml/kg ABW; 2004: 9 (SD 2.3) ml/kg predicted body weight (PBW), 2010: 7.95 (SD 1.7) ml/kg PBW) and increased positive end-expiratory pressure (PEEP) (1998: mean 3.5 (SD 3), 2010: 6.5 (SD 3); P <0.001). Patients included from 2010 had more sepsis, cardiovascular dysfunction and neurological failure, but 28-day hospital mortality was similar over time (52% in 1998, 57% in 2004 and 52% in 2010). Variables independently associated with 28-day hospital mortality were: older age, PaO 2 <60 mmHg, cardiovascular dysfunction and less use of sedative agents. Higher V T , and plateau pressure with lower PEEP were associated with occurrence of ARDS and pneumonia acquired during ICU stay. Conclusions: Protective mechanical ventilation with lower V T and higher PEEP is more commonly used after cardiac arrest. The incidence of pulmonary complications decreased, while other non-respiratory organ failures increased with time. The application of protective mechanical ventilation and the prevention of single and multiple organ failure may be considered to improve outcome in patients after cardiac arrest