Passive leg raising in out-of-hospital cardiac arrest

Abstract

Background: The chances of survival after an out-of-hospital cardiac arrest (OHCA) are one in ten. The majority of survivors have no or relatively mild neurological sequelae. Interventions are time critical and well-timed management is challenging. All aspects of resuscitation in an OHCA are based on knowledge of clinically important actions and their timing in OHCA management. Randomised trials face ethical and legal barriers. The victim is unable to give informed consent and obtaining consent from a legal surrogate delays resuscitation actions. This highlights the need for observational efforts in cardiac arrest research, together with the further exploration of clinically relevant factors and their importance to survival chances in OHCA. Methods: Study I describes the importance of the number of defibrillations in OHCA and their association with survival chances. It is based on data from the Swedish Registry of Cardiopulmonary Resuscitation (SRCR). Study II describes the implementation and feasibility of a direct pathway to immediate coronary angiography after OHCA and its outcome. Patients were screened in the field by ambulance crews and referred to the catheterisation laboratory after consultation with the interventionalist. Study III examines the effect of a basic manoeuvre (passive leg-raising, PLR) in cardiopulmonary resuscitation (CPR) in an observation comparing PLR with standard CPR. Study IV determines the association between ambulance response time and survival after an OHCA, based on data reported to the SRCR. Results: Study I: Between 1990 and 2015, 19,519 patients with a shockable rhythm were reported to the SRCR and included in the study. The chances of survival decreased as the number of defibrillations required increased. Among patients found in a shockable rhythm, 7.5% required more than 10 shocks. Among the witnessed cases, we identified 12 factors associated with survival to 30 days, one of which was the number of shocks that were delivered. Study II: Prehospital screening identified 86 OHCA patients, but only 58% fulfilled the given criteria for pathway activation. Among these, the angiography procedure was started within an hour after collapse in half the cases and the majority had a culprit lesion. Thirty per cent of the patients survived to 30 days and 92% of the survivors presented with a shockable rhythm. All survivors had a good cerebral performance or sufficient function to manage activities of daily life independently. Study III: The PLR manoeuvre was performed in 44% of the n=3,554 OHCA patients included in the study. Survival to 30 days was 7.9% among patients who received PLR and 13.5% among those who did not (OR 0.55; 95% CI 0.44-0.69; p < 0.0001). When matching 1:1 on a propensity score, the difference in 30-day survival between the two groups disappeared (OR 1.07; CI 0.80-1.44; p = 0.65). The matched comparison showed a 30-day survival rate of 8.6% in the PLR group versus 8.2% in the control group. Study IV: Survival chances after a witnessed OHCA decreased as ambulance respo...

Clinical outcomes and safety of passive leg raising in out-of-hospital cardiac arrest: a randomized controlled trial

“…The survival results in our study are in the same line as those obtained by an observational study that introduced PLR in the treatment of OHCA and compared its effectiveness with a matched group that received standard treatment. In this Swedish study, PLR was performed more often in cases with a worse clinical scenario and it was suggested that early leg elevation could improve its benefit on survival [15].…”

“…A study of OHCA showed that 20º of leg elevation helped to increase cardiac output during CPR [14]. Despite these promising hemodynamic results, a recent observational study introducing PLR into the standard treatment of patients with OHCA found no difference in survival compared to a control group [15].…”

Clinical Outcomes and Safety of Passive Leg Raising in Out-of-Hospital Cardiac Arrest. A Randomized Clinical Trial.

“…The survival results in our study are in the same line as those obtained by an observational study that introduced PLR in the treatment of OHCA and compared its effectiveness with a matched group that received standard treatment. In this Swedish study, PLR was performed more often in cases with a worse clinical scenario and it was suggested that early leg elevation could improve its bene t on survival (11).…”

“…A study of OHCA showed that 20º of leg elevation helped to increase End Tidal CO2 (ETCO2) during CPR (10). Despite these promising hemodynamic results, a recent observational study introducing PLR into the standard treatment of patients with OHCA found no difference in survival compared to a control group (11).…”

Passive Leg Raising Effect at Resuscitation Among Patients With Vasoplegic State

“…A Swedish research group reported that PLR was performed more often in cases involving a worsened clinical scenario and early PLR could improve its benefit on survival. (9) The idea of a transient effect of PLR over time has been described among patients with septic shock and is attributed to capillary leak. (10) During acute circulatory failure, maintained tissue perfusion which could favor the shortened effect of PLR on CO. (11) Optimizing venous return is the key to improve survival outcomes.…”