Relative Bradycardia in Patients With Septic Shock Requiring Vasopressor Therapy. (Betters)

Beesley SJ, Wilson EL, Lanspa MJ, et al. Relative Bradycardia in Patients With Septic Shock Requiring Vasopressor Therapy. Crit Care Med. 2017 Feb; 45(2) :225-233.

OBJECTIVES: Tachycardia is common in septic shock, but many patients with septic shock are relatively bradycardic. The prevalence, determinants, and implications of relative bradycardia (heart rate, < 80 beats/min) in septic shock are unknown. To determine mortality associated with patients who are relatively bradycardic while in septic shock.

DESIGN: Retrospective study of patients admitted for septic shock to study ICUs during 2005-2013.

SETTING: One large academic referral hospital and two community hospitals.

PATIENTS: Adult patients with septic shock requiring vasopressors.

INTERVENTION: None.

MEASUREMENTS: Primary outcome was 28-day mortality. We used multivariate logistic regression to evaluate the association between relative bradycardia and mortality, controlling for confounding with inverse probability treatment weighting using a propensity score.

RESULTS: We identified 1,554 patients with septic shock, of whom 686 (44%) met criteria for relative bradycardia at some time. Twenty-eight-day mortality in this group was 21% compared to 34% in the never-bradycardic group (p < 0.001). Relatively bradycardic patients were older (65 vs 60 yr; p < 0.001) and had slightly lower illness severity (Sequential Organ Failure Assessment, 10 vs 11; p = 0.004; and Acute Physiology and Chronic Health Evaluation II, 27 vs 28; p = 0.008). After inverse probability treatment weighting, covariates were balanced, and the association between relative bradycardia and survival persisted (p < 0.001).

CONCLUSIONS: Relative bradycardia in patients with septic shock is associated with lower mortality, even after adjustment for confounding. Our data support expanded investigation into whether inducing relative bradycardia will benefit patients with septic shock.

The effect of atropine on rhythm and conduction disturbances during 322 critical care intubations. (Krohn)

Pediatr Crit Care Med. 2013 Jul;14(6):e289-e297.  PMID: 23689705 

OBJECTIVES: Our objectives were to describe the prevalence of arrhythmia and conduction abnormalities before critical care intubation and to test the hypothesis that atropine had no effect on their prevalence during intubation. DESIGN:: Prospective, observational study.

SETTING: PICU and pediatric/neonatal intensive care transport.

SUBJECTS: All children of age less than 8 years intubated September 2007-2009. Subgroups of intubations with and without atropine were analyzed.

INTERVENTION: None.

MEASUREMENT AND MAIN RESULTS: A total of 414 intubations were performed in the study period of which 327 were available for analysis (79%). Five children (1.5%) had arrhythmias prior to intubation and were excluded from the atropine analysis. Atropine was used in 47% (152/322) of intubations and resulted in significant acceleration of heart rate without provoking ventricular arrhythmias. New arrhythmias during intubation were related to bradycardia and were less common with atropine use (odds ratio, 0.14 [95% CI, 0.06-0.35], p < 0.001). The most common new arrhythmia was junctional rhythm. Acute bundle branch block was observed during three intubations; one Mobitz type 2 rhythm and five ventricular escape rhythms occurred in the no-atropine group (n = 170). Only one ventricular escape rhythm occurred in the atropine group (n = 152) in a child with an abnormal heart. One child died during intubation who had not received atropine.

CONCLUSIONS: Atropine significantly reduced the prevalence of new arrhythmias during intubation particularly for children over 1 month of age, did not convert sinus tachycardia to ventricular tachycardia or fibrillation, and may contribute to the safety of intubation.

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