Espen Rostrup Nakstad

Bradycardia during therapeutic hypothermia is associated with good neurologic outcome in comatose survivors of out-of-hospital cardiac arrest.

Objective: Comatose patients resuscitated after out-of-hospital cardiac arrest receive therapeutic hypothermia. Bradycardia is frequent during therapeutic hypothermia, but its impact on outcome remains unclear. We explore a possible association between bradycardia during therapeutic hypothermia and neurologic outcome in comatose survivors of out-of-hospital cardiac arrest. Design: Retrospective cohort study, from January 2009 to January 2011. Setting: University hospital medical and cardiac ICUs. Patients: One hundred eleven consecutive comatose out-of-hospital cardiac arrest patients treated with therapeutic hypothermia. Interventions: Patients treated with standardized treatment protocol after cardiac arrest. Measurements and Main Results: All out-of-hospital cardiac arrest patients’ records were reviewed. Hemodynamic data were obtained every fourth hour during the first days. The patients were in temperature target range (32–34°C) 8 hours after out-of-hospital cardiac arrest and dichotomized into bradycardia and nonbradycardia groups depending on their actual heart rate less than or equal to 60 beats/min or more than 60 beats/min at that time. Primary endpoint was Cerebral Performance Category score at hospital discharge. More nonbradycardia group patients received epinephrine during resuscitation and epinephrine and norepinephrine in the early in-hospital period. They also had lower base excess at admission. Survival rate with favorable outcome was significantly higher in the bradycardia than the nonbradycardia group (60% vs 37%, respectively, p = 0.03). For further heart rate quantification, patients were divided into quartiles: less than or equal to 49 beats/min, 50–63 beats/min, 64–77 beats/min, and more than or equal to 78 beats/min, with respective proportions of patients with good outcome at discharge of 18 of 27 (67%), 14 of 25 (56%), 12 of 28 (43%), and 7 of 27 (26%) (p = 0.002). Patients in the lowest quartile had significantly better outcome than the higher groups (p = 0.027), whereas patients in the highest quartile had significantly worse outcome than the lower three groups (p = 0.013). Conclusions: Bradycardia during therapeutic hypothermia was associated with good neurologic outcome at hospital discharge. Our data indicate that bradycardia should not be aggressively treated in this period if mean arterial pressure, lactate clearance, and diuresis are maintained at acceptable levels. Studies, both experimental and clinical, are warranted.

Post-Resuscitation ECG for Selection of Patients for Immediate Coronary Angiography in Out-of-Hospital Cardiac Arrest

Background—We aimed to investigate coronary angiographic findings in unselected out-of-hospital cardiac arrest patients referred to immediate coronary angiography (ICA) irrespective of their first postresuscitation ECG and to determine whether this ECG is useful to select patients with no need of ICA. Methods and Results—All resuscitated patients admitted after out-of-hospital cardiac arrest without a clear noncardiac cause underwent ICA. Patients were retrospectively grouped according to the postresuscitation ECG blinded for ICA results: (1) ST elevation or presumably new left bundle branch block, (2) other ECG signs indicating myocardial ischemia, and (3) no ECG signs indicating myocardial ischemia. All coronary angiograms were reevaluated blinded for postresuscitation ECGs. Two hundred and ten patients were included with mean age 62±12 years. Six-months survival with good neurological outcome was 54%. Reduced Thrombolysis in Myocardial Infarction flow (0–2) was found in 55%, 34%, and 18% and a ≥90% coronary stenosis was present in 25%, 27%, and 19% of patients in group 1, 2, and 3, respectively. An acute coronary occlusion was found in 11% of patients in group 3. ST elevation/left bundle branch block identified patients with reduced Thrombolysis in Myocardial Infarction (0–2) flow with 70% sensitivity and 62% specificity. Among patients with initial nonshockable rhythms (24%), 32% had significantly reduced Thrombolysis in Myocardial Infarction flow. Conclusions—Initial ECG findings are not reliable in detecting patients with an indication for ICA after experiencing a cardiac arrest. Even in the absence of ECG changes indicating myocardial ischemia, an acute culprit lesion may be present and patients may benefit from emergent revascularization. Clinical Trial Registration—URL:http://www.clinicaltrials.gov. Unique identifier: NCT01239420.

Impact of acute kidney injury on patient outcome in out-of-hospital cardiac arrest: a prospective observational study.

Kidney disease after out‐of‐hospital cardiac arrest (OHCA) is incompletely described. We examined the occurrence of acute kidney injury (AKI) in OHCA patients and impact of AKI, with or without renal replacement therapy (RRT), on 6‐month mortality and neurological outcome.

Comparison of three haemodynamic monitoring methods in comatose post cardiac arrest patients

Abstract Objectives. Haemodynamic monitoring during post arrest care is important to optimise treatment. We compared stroke volume measured by minimally-invasive monitoring devices with or without thermodilution calibration, and transthoracic echocardiography (TTE), and hypothesised that thermodilution calibration would give stroke volume index (SVI) more in agreement with TTE during targeted temperature management (TTM). Design. Comatose out-of-hospital cardiac arrest survivors receiving TTM (33 °C for 24 hrs) underwent haemodynamic monitoring with arterial pulse contour analyses with (PiCCO2®) and without (FloTrac®/Vigileo® monitor®) transpulmonary thermodilution calibration. Haemodynamic parameters were collected simultaneously every fourth hour during TTM (hypothermia) and (normothermia). SVI was measured with TTE during hypothermia and normothermia. Bland-Altman analyses were used for determination of SVI bias (±1SD). Results. Twenty-six patients were included, of whom 77% had initial shockable rhythm and 52% discharged with good outcome. SVI (bias ±2SD) between PiCCO (after thermodilution calibration) vs FloTrac/Vigileo, TTE vs FloTrac/Vigileo and TTE vs PiCCO were 1.4 (±25.8), −1.9 (±19.8), 0.06 (±18.5) ml/m2 during hypothermia and 9.7 (±23.9), 1.0 (±17.4), −7.2 (±12.8) ml/m2 during normothermia. Continuous SVI measurements between PiCCO and FloTrac/Vigileo during hypothermia at reduced SVI (<35 ml/m2) revealed low bias and relatively narrow limits of agreement (0.5 ± 10.2 ml/m2). Conclusion. We found low bias, but relatively wide limits of agreement in SV with PiCCO, FloTrac/Vigileo and TTE during TTM treatment. The methods are not interchangeable. Precision was not improved by transpulmonary thermodilution calibration during hypothermia.

Manual ventilation and open suction procedures contribute to negative pressures in a mechanical lung model

Introduction Removal of pulmonary secretions in mechanically ventilated patients usually requires suction with closed catheter systems or flexible bronchoscopes. Manual ventilation is occasionally performed during such procedures if clinicians suspect inadequate ventilation. Suctioning can also be performed with the ventilator entirely disconnected from the endotracheal tube (ETT). The aim of this study was to investigate if these two procedures generate negative airway pressures, which may contribute to atelectasis. Methods The effects of device insertion and suctioning in ETTs were examined in a mechanical lung model with a pressure transducer inserted distal to ETTs of 9 mm, 8 mm and 7 mm internal diameter (ID). A 16 Fr bronchoscope and 12, 14 and 16 Fr suction catheters were used at two different vacuum levels during manual ventilation and with the ETTs disconnected. Results During manual ventilation with ETTs of 9 mm, 8 mm and 7 mm ID, and bronchoscopic suctioning at moderate suction level, peak pressure (PPEAK) dropped from 23, 22 and 24.5 cm H2O to 16, 16 and 15 cm H2O, respectively. Maximum suction reduced PPEAK to 20, 17 and 11 cm H2O, respectively, and the end-expiratory pressure fell from 5, 5.5 and 4.5 cm H2O to –2, –6 and –17 cm H2O. Suctioning through disconnected ETTs (open suction procedure) gave negative model airway pressures throughout the duration of the procedures. Conclusions Manual ventilation and open suction procedures induce negative end-expiratory pressure during endotracheal suctioning, which may have clinical implications in patients who need high PEEP (positive end-expiratory pressure).