Faculty Bibliography

WHAT IS KNOWN AND OBJECTIVE/OBJECTIVE:There is limited guidance on how to transition critically ill patients from intravenous (IV) to oral (PO) amiodarone. The objective of this study was to assess the impact of IV and PO amiodarone overlap on short-term tachyarrhythmia recurrence and adverse hemodynamic outcomes in the intensive care unit. METHODS:This is a retrospective, single-center analysis of critically ill adults who were treated with IV amiodarone for a supraventricular arrhythmia with rapid ventricular rate (RVR) and transitioned to PO amiodarone while inpatient. Patients were excluded if rate control was not achieved prior to the PO transition. Receipt of concomitant IV and PO therapy for ≤2 hours was considered no overlap (NOV) and >2 hours was considered overlap (OV). Tachyarrhythmia recurrence and adverse hemodynamic events were compared between groups. RESULTS:A total of 90 patients (45 NOV, 45 OV) were included in the analysis. The median overlap duration was 0.1 (-1.3 to 1.2) hours in the NOV arm and 4 (2.6-6.1) hours in the OV arm. Recurrence of RVR occurred in 9 (20%) patients in each arm (P = 1.0). The median time from IV discontinuation to return of tachyarrhythmia was 10.5 hours. There were no significant differences in amiodarone dosing, electrolyte abnormalities, volume status or concomitant cardiac medications at the time of IV to PO transition. Hypotension occurred in 13% and 20% (P = 0.369) and bradycardia in 9% and 13% (P = 0.502) of patients in the NOV and OV arms, respectively. WHAT IS NEW AND CONCLUSION/CONCLUSIONS:Providing IV and PO overlap of amiodarone for a median of 4 hours did not decrease the rate of early tachyarrhythmia recurrence. Future studies are warranted to evaluate the impact of alternative amiodarone dosing strategies on breakthrough tachyarrhythmia.

Inotropes are an integral component of the early stabilization of the patient presenting with cardiogenic shock. Despite years of clinical experience with the 2 most commonly used inotropes, dobutamine and milrinone, there remains limited data comparing outcomes between the two. We conducted a retrospective review to compare the effectiveness and safety of milrinone or dobutamine for the initial management of cardiogenic shock. Adult patients with cardiogenic shock regardless of etiology who received initial inotrope therapy with either milrinone (n = 50) or dobutamine (n = 50) and did not receive mechanical circulatory support were included. The primary end point was the time to resolution of cardiogenic shock. Changes in hemodynamic parameters from baseline and adverse events were also assessed. Resolution of shock was achieved in similar numbers in both the groups (milrinone 76% vs dobutamine 70%, P = .50). The median time to resolution of shock was 24 hours in both groups ( P = .75). There were no differences in hemodynamic changes during inotrope therapy, although dobutamine trended toward a greater increase in cardiac index. Arrhythmias were more common in patients treated with dobutamine than milrinone, respectively (62.9% vs 32.8%, P < .01), whereas hypotension occurred to a similar extent in both groups (milrinone 49.2% vs dobutamine 40.3%, P = .32). The use of concomitant vasoactive medications, dosage required, and duration of therapy did not differ between groups. There was no difference in the overall rate of discontinuation due to adverse event; however, milrinone was more commonly discontinued due to hypotension (13.1% vs 0%, P < .01) and dobutamine was more commonly discontinued due to arrhythmia (0% vs 11.3%, P < .01). Milrinone and dobutamine demonstrated similar effectiveness and safety profiles but with differences in adverse events. The choice of milrinone or dobutamine as initial inotrope therapy for cardiogenic shock may depend more on tolerability of adverse events.

BACKGROUND:There is little data guiding clinicians on how to discontinue vasopressors among septic shock patients on concomitant norepinephrine (NE) and vasopressin (VP). OBJECTIVE:To determine the incidence of hypotension within 24 hours of discontinuing NE (NE DC first) versus VP (VP DC first) first in septic shock patients. METHODS:This retrospective study evaluated septic shock patients admitted to the medical intensive care unit (MICU) and surgical ICU (SICU) receiving concomitant NE and VP. Receipt of additional vasopressors, mixed shock states, expired or care withdrawn, and NE and VP discontinued simultaneously were exclusion criteria. The primary outcome was incidence of hypotension within 24 hours of first vasopressor discontinuation. Secondary outcomes included time to hypotension, hospital length of stay (LOS), ICU LOS, and ICU mortality. RESULTS:A total of 80 patients were included (NE DC first [n = 35]; VP DC first [n = 45]), with a median age of 73 years and median modified Acute Physiology and Chronic Health Evaluation II and Sequential Organ Failure Assessment scores of 21 and 7, respectively. More patients in the NE DC first group were in the SICU (42.9% vs 20.0%; P = 0.048) with more intra-abdominal infections (40.0% vs 15.6%; P = 0.021) and fewer appropriate empirical antibiotics (62.9% vs 86.7%; P = 0.018). Hypotension within 24 hours of first agent discontinuation was higher in the VP DC first group (28.6% vs 62.2%; P = 0.004), with similar hospital LOS and ICU mortality. Multivariate analysis identified VP DC first as an independent predictor of hypotension (odds ratio = 7.2; CI = 2.3-22.7). CONCLUSION/CONCLUSIONS:Among septic shock patients on concomitant NE and VP, discontinuation of VP first was associated with an increased incidence of hypotension; future prospective control trials are warranted.

PURPOSE: Enteral nutrition (EN) is often held in patients receiving vasopressor support for septic shock. The rationale for this practice is to avoid mesenteric ischemia. The objective of this study is to evaluate the tolerability of EN in patients with septic shock who require vasopressor support and determine factors associated with tolerance of EN. MATERIALS AND METHODS: This was a single-center retrospective review of adult patients admitted to the intensive care unit with a diagnosis of septic shock and an order for EN. The primary outcome was EN tolerance. Secondary outcomes included time to initiation of EN from the start of vasopressor(s), length of stay, and mortality. RESULTS: A total of 120 patients were included. Sixty-two percent of patients tolerated EN. The most common reason for intolerance of EN was gastric residuals > 250 mL (74%). No reports of mesenteric ischemia were observed. A multivariate analysis demonstrated that patients with septic shock initiating EN within 48 hours and receiving norepinephrine-equivalent doses of 0.14 mug/kg/min or less were more likely to tolerate EN. CONCLUSION: Based on our observation, early EN may be tolerated and safely administered in patients with septic shock who are adequately fluid resuscitated and receive doses of < 0.14 mug/kg/min of norepinephrine equivalents.

BACKGROUND: Several nomograms include recommendations to give intravenous (IV) vancomycin at 8-hour dosing intervals (Q8H). However, there is a lack of detailed data regarding this dosing recommendation. METHODS: A retrospective chart review of 100 patients who received 107 treatment courses of vancomycin Q8H for at least 5 days was performed. Distribution of vancomycin trough levels and rate of nephrotoxicity were evaluated. RESULTS: Median patient age was 38 years (interquartile range [IQR] 27-50 years), median weight was 67 kg (IQR 55-79 kg), and median creatinine clearance was 124 mL/min (IQR 101-147 mL/min). Median duration of Q8H dosing was 9 days (IQR 7-12 days). Within the initial 96 hours, only 7% (7 of 104) of maximum trough concentrations were >20 mg/L (median dose 15 mg/kg [IQR 15-18 mg/kg]). After 96 hours of Q8H dosing, 34% (30 of 89) of maximum troughs were >20 mg/L (median dose 17 mg/kg [IQR 15-20 mg/kg]), P = .0005. The rate of nephrotoxicity was 4%. CONCLUSION: We observed an increase in the percentage of trough levels >20 mg/L later during treatment courses of vancomycin IV Q8H with a relatively small corresponding increase in vancomycin dose. Close monitoring of trough levels (eg, every 3 days) with prolonged courses of vancomycin IV Q8H is warranted.

Critically ill patients are at high risk of adverse drug events during their intensive care unit stay. Of the potential adverse drug events, those related to the cardiovascular system are particularly concerning. Common cardiovascular adverse drug events include drug-induced arrhythmias, drug-induced blood pressure abnormalities, and drug-induced heart failure. The specific drug-induced events to be reviewed include bradycardia, tachycardia, corrected QT interval prolongation, hypertension, hypotension, and heart failure exacerbation.