[Predictive value of continuous monitoring end-tidal carbon dioxide partial pressure on in-hospital resuscitation outcome: secondary analysis of the data from a multicenter observational study].

Objective To approach the predictive value of continuous monitoring end-tidal carbon dioxide partial pressure (PETCO2) on the outcome of in-hospital cardiopulmonary resuscitation (CPR), and explored the indicators of termination of resuscitation. Methods A secondary analysis of a multicenter observational study data was conducted. The screening aim was adult non-traumatic in-hospital CPR patients whose PETCO2 were recorded within 30 minutes of CPR. Clinical information was reviewed. The mean PETCO2 in restoration of spontaneous circulation (ROSC) and non-ROSC patients was recorded. The outcome of CPR was continuously assessed by PETCO2 ≤ 10 mmHg (1 mmHg = 0.133 kPa) for 1, 3, 5, 8, 10 minutes. Receiver operating characteristic (ROC) curve was plotted, and the predictive value of PETCO2 ≤ 10 mmHg for different duration on the outcome of CPR was evaluated. Results A total of 467 recovery patients, including 419 patients with complete recovery were screened. Patients who were out-of-hospital resuscitation, non-adults, traumatic injury, had no PETCO2 value, PETCO2 value failed to explained the clinical conditions, or patients had not monitored PETCO2 within 30 minutes of resuscitation were excluded, and finally 120 adult patients with non-traumatic in-hospital resuscitation were enrolled in the analysis. The mean PETCO2 in 50 patients with ROSC was significantly higher than that of 70 non-ROSC patients [mmHg: 17 (11, 27) vs. 9 (6, 16), P < 0.01]. ROC curve analysis showed that the area under ROC curve (AUC) of PETCO2 during the resuscitation for predicting recovery outcome was 0.712 [95% confidence interval (95%CI) = 0.689-0.735]; when the cut-off was 10.5 mmHg, the sensitivity was 57.8%, and the specificity was 78.0%, the positive predictive value (PPV) was 84.6%, and negative predictive value (NPV) was 46.9%. The duration of PETCO2 ≤ 10 mmHg was used for further analysis, which showed that with PETCO2 ≤10 mmHg in duration, the prediction of the sensitivity of the patients failed to recover decreased from 58.2% to 28.2%, but specificity increased from 39.4% to 100%; PPV increased from 40% to 100%, and NPV decreased from 57.5% to 34.2%. Conclusion For adult non-traumatic in-hospital CPR patients, continuous 10 minutes PETCO2 ≤10 mmHg may be an indicate of termination of CPR. Key words: Cardiopulmonary resuscitation; End-tidal carbon dioxide partial pressure; Termination of resuscitation