Prognostic factors associated with hospital survival in comatose survivors of cardiac arrest

Association of Hypercapnia and Hypercapnic Acidosis With Clinical Outcomes in Mechanically Ventilated Patients With Cerebral Injury

IMPORTANCE

Clinical studies investigating the effects of hypercapnia and hypercapnic acidosis in acute cerebral injury are limited. The studies performed so far have mainly focused on the outcomes in relation to the changes in partial pressure of carbon dioxide and pH in isolation and have not evaluated the effects of partial pressure of carbon dioxide and pH in conjunction.

OBJECTIVE

To review the association of compensated hypercapnia and hypercapnic acidosis during the first 24 hours of intensive care unit admission on hospital mortality in adult mechanically ventilated patients with cerebral injury.

DESIGN, SETTING, AND PARTICIPANTS

Multicenter, binational retrospective review of patients with cerebral injury (traumatic brain injury, cardiac arrest, and stroke) admitted to 167 intensive care units in Australia and New Zealand between January 2000 and December 2015. Patients were classified into 3 groups based on combination of arterial pH and arterial carbon dioxide (normocapnia and normal pH, compensated hypercapnia, and hypercapnic acidosis) during the first 24 hours of intensive care unit stay.

MAIN OUTCOMES AND MEASURES

Hospital mortality.

RESULTS

A total of 30 742 patients (mean age, 55 years; 21 827 men [71%]) were included. Unadjusted hospital mortality rates were highest in patients with hypercapnic acidosis. Multivariable logistic regression analysis and Cox proportional hazards analysis in 3 diagnostic categories showed increased odds of hospital mortality (cardiac arrest odds ratio [OR], 1.51; 95% CI, 1.34-1.71; stroke OR, 1.43; 95% CI, 1.27-1.6; and traumatic brain injury OR, 1.22; 95% CI, 1.06-1.42; P <.001) and hazard ratios (HR) (cardiac arrest HR, 1.23; 95% CI, 1.14-1.34; stroke HR, 1.3; 95% CI, 1.21-1.4; traumatic brain injury HR, 1.13; 95% CI, 1-1.27), in patients with hypercapnic acidosis compared with normocapnia and normal pH. There was no difference in mortality between patients who had compensated hypercapnia compared with patients who had normocapnia and normal pH. In patients with hypercapnic acidosis, the adjusted OR of hospital mortality increased with increasing partial pressure of carbon dioxide, while no such increase was noted in patients with compensated hypercapnia.

CONCLUSIONS AND RELEVANCE

Hypercapnic acidosis was associated with increased risk of hospital mortality in patients with cerebral injury. Hypercapnia, when compensated to normal pH during the first 24 hours of intensive care unit admission, may not be harmful in mechanically ventilated patients with cerebral injury.

Clinical outcomes of 3-year experience of targeted temperature management in patients with out-of-hospital cardiac arrest at Songklanagarind Hospital in Southern Thailand: an analysis of the MICU-TTM registry

Background

Out-of-hospital cardiac arrest (OHCA) is one of the leading causes of intensive care unit admission, which results in high hospital mortality. Targeted temperature management (TTM) was introduced several years ago and is considered to improve neurological and mortality outcomes. This management process was implemented in our hospital in 2012, which was expected to improve the standard of care in OHCA patients.

Purpose

We aimed to report the clinical and mortality outcomes after TTM was introduced to our hospital in 2012.

Patients and methods

An analysis of data from the Medical Intensive Care Unit-TTM registry between 2012 and 2015 was performed. After successful cardiopulmonary resuscitation, TTM was applied to all OHCA patients regardless of causes if there was no contraindication. The Cerebral Performance Category scale score and other clinical outcomes were recorded and analyzed.

Results

Out of 23 patients, 87% were male and the mean age was 54.5±18.1 years. The causes of OHCA from cardiac etiology comprised 52.2%. The most common initial cardiac rhythm was ventricular fibrillation (47.8%). The survival rate to hospital discharge was 47.8% (11/23), but neurological outcomes were in a persistent vegetative state (8/11, 72.7%). The group with poor neurological outcomes had a significantly higher Acute Physiologic Assessment and Chronic Health Evaluation II score than the group with good neurological outcomes (22.9±4.2 vs 16.0±3.6, P=0.01). In the multivariate analysis, initial shockable rhythm was associated with survival at hospital discharge (odds ratio 10.1, 95% confidence interval 1.1–94.3, P=0.04).

Conclusion

TTM in OHCA patients gave better mortality benefits compared to our previous records, despite poor neurological outcomes. Ventilator-associated pneumonia was the major complication of TTM. Therefore, TTM should be considered in OHCA patients, especially in shockable rhythms, after return of spontaneous circulation.