Intensity of Vasopressor Therapy for Septic Shock and the Risk of In-Hospital Death.

CONTEXT: Given the high mortality of 30%-60% associated with septic shock, distinguishing which patients do or do not have a reasonable chance of surviving with aggressive treatment could help clinicians and families make informed decisions. OBJECTIVES: To determine if intensity of vasopressor therapy accurately predicts in-hospital death. METHODS: This observational cohort study analyzed in-hospital mortality as a function of intensity of vasopressor therapy in a consecutive series of adults with septic shock treated over a four-year period. Receiver operating characteristic curve analysis assessed the overall strength of the intensity-mortality relationship. RESULTS: A total of 808 patients with septic shock experienced an in-hospital death rate of 41.0% (331/808; 95% CI, 38.5%-44.5%). The greater the peak number of vasopressors required, the higher the death rate, which reached 92.3% (12/13; 95% CI, 79.4%-100.0%) when three different pressors were being infused at full dose. The receiver operating characteristic curve analysis revealed that number of simultaneous vasopressors and vasopressor dose load performed equally well in predicting death or survival. CONCLUSION: When a standard full dose of a vasopressor fails to normalize blood pressure in a patient with septic shock, escalation begins to yield diminishing returns as the dose and multiplicity of agents approach practical upper limits. Although it is not possible to specify a precise cutoff for limiting vs. intensifying therapy, a mortality of 80% or higher-characterized by two or more concurrent vasopressors at full dose-should prompt shared decision making with the patient's family.

Narrowed Aortoseptal Angle Is Related to Increased Central Blood Pressure and Aortic Pressure Wave Reflection.

The left ventricular (LV) aortoseptal angle (ASA) decreases with age, and is associated with basal septal hypertrophy (septal bulge). Enhanced arterial pressure wave reflection is known to impact LV hypertrophy. We assessed whether ASA is related to central blood pressure (BP) and augmentation index (AI), a measure of the reflected pressure wave. We studied 75 subjects (age 62 ± 16 years; 66% female) who were referred for transthoracic echocardiography and had radial artery applanation tonometry within 24 h. Peripheral systolic BP (P-SBP), peripheral diastolic BP (P-DBP), and peripheral pulse pressure (P-PP) were obtained by sphygmomanometry. Central BPs (C-SBP, C-DBP, C-PP) and AI were derived from applanation tonometry. AI was corrected for heart rate (AI75). The basal septal wall thickness (SWT), mid SWT and ASA were measured using the parasternal long axis echocardiographic view. Mean ASA and AI75 were 117 ± 11° and 22 ± 11%, respectively. ASA correlated with AI75 (r = -0.31, p ≤ 0.01), C-SBP (r = -0.24, p = 0.04), C-PP (r = -0.29, p = 0.01), but only showed a trend towards significance with P-SBP (r = -0.2, p = 0.09) and P-PP (r = -0.21, p = 0.08). Interestingly, C-PP was correlated with basal SWT (r = 0.27, p = 0.02) but not with mid SWT (r = 0.19, p = 0.11). On multivariate linear regression analysis, adjusted for age, gender, weight, and mean arterial pressure, AI75 was an independent predictor of ASA (p = 0.02). Our results suggest that a narrowed ASA is related to increased pressure wave reflection and higher central BP. Further studies are needed to determine whether narrowed LV ASA is a cause or consequence of enhanced wave reflection and whether other factors are involved.