Haemodynamic management strategies are not explicitly defined in the majority of therapeutic hypothermia implementation studies

Background: Therapeutic hypothermia (TH) has revolutionized the management of comatose post-cardiac arrest syndrome (PCAS) patients. The 2008 ILCOR/AHA Consensus Statement for the treatment of PCAS suggests that goal-directed therapy, targeting mean arterial pressure (MAP), central venous pressure (CVP), and central venous oxygen saturation (ScvO(2)), should be employed to normalize oxygen delivery. However, the optimal PCAS haemodynamic management strategy has not been defined and few objective data exist to guide clinicians.

Objective: To describe the haemodynamic strategies used in TH implementation studies.

Methods: A Medline search (time period, 3/2002 to 3/2010) was performed using the terms cardiac arrest and hypothermia, induced, then limited post-search to implementation studies of TH in comatose adults. The identified studies were examined for explicit definitions of the following terms: MAP; systolic blood pressure (SBP), CVP, ScvO(2), pulmonary artery catheter (PAC), echocardiogram (ECHO), lactate, and volume status.

Results: Forty-four implementation studies were identified and 43% (19/44) of them mentioned haemodynamics in any fashion. At least one haemodynamic goal was specifically defined in 16/44 (36%). The median number defined was 4 (range 1-6); individual goals as follows: MAP, 13/44 (30%); SBP, 3/44 (7%); CVP, 5/44 (11%); ScvO(2), 4/44 (9%); PAC, 7/44 (16%); ECHO, 7/44 (16%); lactate, 5/44 (11%); and volume status, 8/44 (18%).

Conclusions: Specific haemodynamic goals are defined in a minority of published TH implementation studies. Given the volatile haemodynamics of the PCAS and lack of consensus on an optimal resuscitation strategy, explicit description of haemodynamic goals should be provided in future studies.