Prognostic value of venous blood analysis at the start of CPR in non-traumatic out-of-hospital cardiac arrest: association with ROSC and the neurological outcome

Abstract

Background: The knowledge of new prognostic factors in out-of-hospital cardiac arrest (OHCA) that can be evaluated since the beginning of cardiopulmonary resuscitation (CPR) manoeuvres could be helpful in the decisionmaking process of prehospital care. We aim to identify metabolic variables at the start of advanced CPR at the scene that may be associated with two main outcomes of CPR (recovery of spontaneous circulation (ROSC) and neurological outcome). Methods: Prospective observational study of all non-traumatic OHCA in patients older than 17 years assisted by emergency medical services (EMS), with doctor and nurse on board, between January 2012 and December 2017. Venous blood gases were sampled upon initially obtaining venous access to determine the initial values of pH, pCO 2 , HCO 3 − , base excess (BE), Na + , K + , Ca 2+ and lactate. ROSC upon arrival at the hospital and neurological status 30 days later (Cerebral Performance Categories (CPC) scale) were recorded. Results: We included 1552 patients with OHCA with blood test data in a 6-year period. ROSC was achieved in 906 cases (58.4%), and good neurological recovery at 30 days (CPC I-II) occurred in 383 cases (24.68%). In multivariate analysis, we found a significant relationship between non-recovery of spontaneous circulation (no-ROSC) and low pH levels (adjusted odds ratio (OR) 0.03 (0.002-0.59), p = 0.020), high pCO 2 levels (adjusted OR 1.03 [1.01-1.05], p = 0.008) and high potassium levels (adjusted OR 2.28 [1.43-3.61], p = 0.008). Poor neurological outcomes were associated with low pH levels (adjusted OR 0.06 [0.02-0.18], p < 0.001), high pCO 2 (adjusted OR 1.05 [1.03-1.08], p < 0.001), low HCO 3 − (adjusted OR 0.97 [0.94-0.999], p = 0.044), low BE (adjusted OR 0.96 [0.93-0.98], p < 0.001) and high potassium levels (adjusted OR 1.37 [1.16-1.60], p < 0.001). Conclusion: There is a significant relationship between severe alterations of venous blood-gas variables and potassium at the start of CPR of non-traumatic OHCA and low-ROSC rate and neurological prognosis.

Prognostic value of venous blood analysis at the start of CPR in non-traumatic out-of-hospital cardiac arrest: association with ROSC and the neurological outcome: do not forget the no-flow influence!

“…Corral Torres et al [1] observed a significant relationship between severe alterations of venous blood gas variables and potassium at the start of cardiopulmonary resuscitation (CPR) of non-traumatic out-of-hospital cardiac arrest (OHCA) and low return of spontaneous circulation (ROSC) rate and neurological prognosis. The authors should be congratulated for their noteworthy study on this relevant question; nevertheless, we believe that the results interpretation requires words of caution because of some issues.…”

“…We thank Drs. Jouffroy and Vivien from SAMU, with whom we shared so much, for their letter to our recent article regarding the prognostic value of blood analysis at the start of CPR in non-traumatic out-of-hospital cardiac arrest [1]. Firstly, whatever the difficulties in obtaining the first venous line, the truth is that it is the first sample available in every real situation.…”

Prediction of return of spontaneous circulation in out-of-hospital cardiac arrest with non-shockable initial rhythm using point-of-care testing: a retrospective observational study

“…[9] World J Emerg Med, Vol 14, No 2, 2023 Factors that predict ROSC and long-term survival in patients with OHCA have been studied, including prehospital information, such as age, sex, witnesses, bystander cardiopulmonary resuscitation (CPR), cause leading to cardiac arrest, and initial rhythm. [10] According to blood tests, various factors, such as levels of K + , [11,12] Na + , [13] blood glucose, [13] ammonia, [14] brain natriuretic peptide, [15] lactate, [16][17][18] and free thyroxine 4, [19] have been reported to affect the prognosis of OHCA. Moreover, significant activation of coagulation occurs as a part of the pathogenesis after cardiac arrest.…”

Dynamic changes in arterial blood gas during cardiopulmonary resuscitation in out-of-hospital cardiac arrest

“…In addition to the pre-arrest factors such as witnessed cardiac arrest, bystander CPR, and the presence of shockable rhythms, parameters obtained during CPR might add more accuracy to the prognostication. Some studies have reported that pH and base excess (BE) are associated with ROSC in OHCA 6 – 8 . Recently, two studies have shown that higher levels of paO 2 are significantly associated with increased rates of survival to hospital admission in OHCA 9 , 10 .…”