Background: In-hospital cardiac arrest (IHCA) is a devastating medical event that affects 200,000 patients every year and carries a high mortality rate, with only 54% surviving their arrest and 22% surviving to discharge. Current research aims to identify risk factors associated with morbidity and mortality in these patients, but there is little research on the environmental or human factors that may play a role in determining outcomes. This pilot study aims to determine the relationship between noise and crowd control during resuscitation and the likelihood of return of spontaneous circulation (ROSC), survival to hospital discharge, and good neurologic outcome.
Methods: This is a single-center, retrospective observational study conducted at a 650-bed academic medical center. Adult inpatients who experienced cardiac arrest between January 2010 and April 2013 were considered for analysis. The primary outcome was ROSC, and secondary outcomes were survival to hospital discharge and good neurologic outcome (defined as Cerebral Performance Category Score of 1-2). Data was abstracted from the patients’ medical records and the resuscitation flow sheets, which included subjective noise and crowd control scores (1-5, higher is worse) obtained immediately following the event. Noise control and crowd control scores were analyzed separately as both continuous variables and as dichotomized variables of “good” (score 1-2) and “bad” (3-5) scores. Patient demographics, comorbidities, and other potential explanatory variables were included in the analysis. We first applied univariate logistic and then multivariable logistic regression models to determine the independent association between noise and crowd control during cardiac arrest resuscitation and the primary and secondary outcomes. The results of the logistic regression models are presented as odds ratios (OR) with 95% confidence intervals (CI).
Results: 182 IHCA events were included in the analysis. Sixty percent of the included patients were male, and the median age was 71 (62-82) years (Table 1). Overall, 67% of patients achieved ROSC, 27% survived to hospital discharge, and 20% had a good neurological outcome. The median values for noise and crowd control scores were 2 (2 – 3) and 2 (2 – 3), respectively. Multivariable analysis using the dichotomized variables showed that “bad” scores for noise control were not associated with ROSC (OR: 1.14 [CI: 0.57, 2.30]), survival to hospital discharge (OR: 1.44 [CI:0.66, 2.88]) or good neurological outcome (OR: 1.38 [CI: 0.66, 2.88) (Table 2). Likewise, “bad” scores for crowd control were not associated with ROSC (OR: 1.43 [CI: 0.69,0.69, 2.95]), survival to hospital discharge (OR: 1.34 [CI: 0.59, 3.06]) or good neurological outcome (OR: 1.29 [CI: 0.61, 2.76]) in multivariable analyses (Table 2). Analysis of the scores as continuous variables yielded similar results. Subgroup analysis of the non-ICU patients likewise did not show any statistically significant associations.
Conclusions: In this pilot study, we found no association between subjective assessments of noise and crowd control and outcomes after in-hospital cardiac arrest. Future studies should aim to assess noise and crowd control in a more objective fashion.