End-tidal carbon dioxide and resuscitation

A Review of Carbon Dioxide Monitoring During Adult Cardiopulmonary Resuscitation

Although high quality cardiopulmonary resuscitation is one of the most significant factors related to favourable outcome, its quality depends on many components, such as airway management, compression depth and chest recoil, hands-off time, and early defibrillation. The most common way of controlling the resuscitation efforts is monitoring of end-tidal carbon dioxide. The International Liaison Committee on Resuscitation suggests this method both for in-hospital and out-of-hospital cardiac arrest. However, despite the abundant human and animal studies supporting the usefulness of end-tidal carbon dioxide, its optimal values during cardiopulmonary resuscitation remain controversial. In this review, the advantages and effectiveness of end-tidal carbon dioxide during cardiopulmonary resuscitation are discussed and specific target values are suggested based on the available literature.

Changes of end-tidal carbon dioxide during cardiopulmonary resuscitation from ventricular fibrillation versus asphyxial cardiac arrest

BACKGROUND

Partial pressure of end-tidal carbon dioxide (PETCO2) has been used to monitor the effectiveness of precordial compression (PC) and regarded as a prognostic value of outcomes in cardiopulmonary resuscitation (CPR). This study was to investigate changes of PETCO2 during CPR in rats with ventricular fibrillation (VF) versus asphyxial cardiac arrest.

METHODS

Sixty-two male Sprague-Dawley (SD) rats were randomly divided into an asphyxial group (n=32) and a VF group (n=30). PETCO2 was measured during CPR from a 6-minute period of VF or asphyxial cardiac arrest.

RESULTS

The initial values of PETCO2 immediately after PC in the VF group were significantly lower than those in the asphyxial group (12.8±4.87 mmHg vs. 49.2±8.13 mmHg, P=0.000). In the VF group, the values of PETCO2 after 6 minutes of PC were significantly higher in rats with return of spontaneous circulation (ROSC), compared with those in rats without ROSC (16.5±3.07 mmHg vs. 13.2±2.62 mmHg, P=0.004). In the asphyxial group, the values of PETCO2 after 2 minutes of PC in rats with ROSC were significantly higher than those in rats without ROSC (20.8±3.24 mmHg vs. 13.9±1.50 mmHg, P=0.000). Receiver operator characteristic (ROC) curves of PETCO2 showed significant sensitivity and specificity for predicting ROSC in VF versus asphyxial cardiac arrest.

CONCLUSIONS

The initial values of PETCO2 immediately after CPR may be helpful in differentiating the causes of cardiac arrest. Changes of PETCO2 during CPR can predict outcomes of CPR.

Passive leg raise (PLR) during cardiopulmonary (CPR) - a method article on a randomised study of survival in out-of-hospital cardiac arrest (OHCA)

BACKGROUND

It is estimated that about 275,000 inhabitants experience an out-of-hospital cardiac arrest (OHCA) every year in Europe. Survival in out-of-hospital cardiac arrest is relatively low, generally between five per cent and 10%. Being able to explore new methods to improve the relatively low survival rate is vital for people with these conditions. Passive leg raise (PLR) during cardiopulmonary resuscitation (CPR) has been found to improve cardiac preload and blood flow during chest compressions. The aim of our study is to evaluate whether early PLR during CPR also has an impact on one-month survival in sudden and unexpected out-of-hospital cardiac arrest (OHCA).

METHOD/DESIGN

A prospective, randomized, controlled trial in which all patients (≥18 years) receiving out-of hospital CPR are randomized by envelope to be treated with either PLR or in the flat position. The ambulance crew use a special folding stool which allows the legs to be elevated about 20 degrees. Primary end-point: survival to one month. Secondary end-point: survival to hospital admission to one month and to one year with acceptable cerebral performance classification (CPC) 1-2.

DISCUSSION

PLR is a simple and fast maneuver. We believe that the greatest benefit with PLR is when performed early in the process, during the first minutes of CPR and before the first defibrillation. To reach power this study need 3000 patients, we hope that this method article will encourage other sites to contact us and take part in our study.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01952197.

Predicting the lack of ROSC during pre-hospital CPR: should an end-tidal CO2 of 1.3 kPa be used as a cut-off value?

AIM

The aim of this study was to investigate if an initial ETCO2 value at or below 1.3 kPa can be used as a cut-off value for whether return of spontaneous circulation during pre-hospital cardio-pulmonary resuscitation is achievable or not.

MATERIALS AND METHODS

We prospectively registered data according to the Utstein-style template for reporting data from pre-hospital advanced airway management from February 1st 2011 to October 31st 2012. Included were consecutive patients at all ages with pre-hospital cardiac arrest treated by eight anaesthesiologist-staffed pre-hospital critical care teams in the Central Denmark Region.

RESULTS

We registered data from 595 cardiac arrest patients; in 60.2% (n=358) of these cases the pre-hospital critical care teams performed pre-hospital advanced airway management beyond bag-mask ventilation. An initial end-tidal CO2 measurement following pre-hospital advanced airway management were available in 75.7% (n=271) of these 358 cases. We identified 22 patients, who had an initial end-tidal CO2 at or below 1.3 kPa. Four of these patients achieved return of spontaneous circulation.

CONCLUSION

Our results indicates that an initial end-tidal CO2 at or below 1.3 kPa during pre-hospital CPR should not be used as a cut-off value for the achievability of return of spontaneous circulation.

Passive leg raising during cardiopulmonary resuscitation in out-of-hospital cardiac arrest--does it improve circulation and outcome?

BACKGROUND

Passive leg raising (PLR), to augment the artificial circulation, was deleted from cardiopulmonary resuscitation (CPR) guidelines in 1992. Increases in end-tidal carbon dioxide (P(ET)CO(2)) during CPR have been associated with increased pulmonary blood flow reflecting cardiac output. Measurements of P(ET)CO(2) after PLR might therefore increase our understanding of its potential value in CPR. We also observed the alteration in P(ET)CO(2) in relation to the return of spontaneous circulation (ROSC) and no ROSC.

METHODS AND RESULTS

The P(ET)CO(2) was measured, subsequent to intubation, in 126 patients suffering an out-of-hospital cardiac arrest (OHCA), during 15 min or until ROSC. Forty-four patients were selected by the study protocol to PLR 35 cm; 21 patients received manual chest compressions and 23 mechanical compressions. The PLR was initiated during uninterrupted CPR, 5 min from the start of P(ET)CO(2) measurements. During PLR, an increase in P(ET)CO(2) was found in all 44 patients within 15 s (p=0.003), 45 s (p=0.002) and 75 s (p=0.0001). Survival to hospital discharge was 7% among patients with PLR and 1% among those without PLR (p=0.12). Among patients experiencing ROSC (60 of 126), we found a marked increase in P(ET)CO(2) 1 min before the detection of a palpable pulse.

CONCLUSION

Since PLR during CPR appears to increase P(ET)CO(2) after OHCA, larger studies are needed to evaluate its potential effects on survival. Further, the measurement of P(ET)CO(2) could help to minimise the hands-off periods and pulse checks.

Extracorporeal membrane oxygenation rescue for cardiopulmonary resuscitation in pediatric patients

OBJECTIVE

To describe survival and neurologic outcome and identify the factors associated with survival among pediatric patients following extracorporeal cardiopulmonary resuscitation (ECPR) for in-hospital cardiac arrest.

DESIGN

Retrospective study.

SETTING

A university-affiliated tertiary care hospital.

PATIENTS

Eligible patients were < or = 18 yrs of age and received extracorporeal membrane oxygenation during active cardiopulmonary resuscitation for in-hospital cardiac arrest.

INTERVENTIONS

Extracorporeal membrane oxygenation (ECMO) during active cardiopulmonary resuscitation.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was survival to hospital discharge. The secondary outcome was neurologic status after ECPR at hospital discharge and late follow-up. Good neurologic outcome was defined as Pediatric Cerebral Performance Categories 1, 2, and 3. Continuous variables were expressed as medians (interquartile range). We prospectively defined the early cohort (January 1999 to December 2001) and late cohort (January 2002 to January 2006) and compared the survival rates. We identified 27 ECPR events. The survival rate to hospital discharge was 41% (11 of 27). The nonsurvivors had higher pre-cardiopulmonary resuscitation serum lactate levels (14 [10.2-19.6] mmol/L vs. 8.5 [4.4-12.6] mmol/L, p < .01), longer durations of cardiopulmonary resuscitation (60 [37-81] mins vs. 45 [25-50] mins, p < .05) with longer activating time for ECMO (12.5 [7.5-33.8] mins vs. 5 [0-10] mins, p < .01), and more renal failure after ECPR (68% [11 of 16] vs. 9% [1 of 11], p < .01). The survival rate of the late cohort was better than that of the early cohort (58% [11 of 19] vs. 0% [0 of 8], p < .05). By exact multiple logistic regression analysis, the early cohort and renal failure after ECPR were two independent risk factors for mortality. Among the 11 survivors, ten had good neurologic outcomes.

CONCLUSIONS

ECPR successfully rescued some pediatric patients who failed rescue with conventional in-hospital CPR. Good neurologic outcomes were achieved in the majority of the survivors. Early cohort and post-ECPR renal failure were associated with mortality.