Use of Lactulose to Treat Hyperammonemia in ICU Patients Without Chronic Liver Disease or Significant Hepatocellular Injury.

OBJECTIVES: To review ICU patients with elevated ammonia without a clear hepatic etiology, to compare outcomes between those who received lactulose and those who did not. DESIGN: Retrospective observational study. SETTING: Medical, surgical, and subspecialty intensive care units at Wake Forest Baptist Medical Center, Winston-Salem, North Carolina between December 2012 and August 2016. PATIENTS: Adults with ammonia levels above 50 µmol/L, excluding those with known chronic liver disease, inborn error of metabolism, active use of valproic acid, total bilirubin ≥ 2 µmol/L, or alanine aminotransferase ≥ 100 units/L. INTERVENTIONS: Comparison in ICU length of stay (LOS), hospital LOS, in-hospital mortality, and mortality at 30 and 90 days. MEASUREMENTS AND MAIN RESULTS: Criteria for inclusion were met in 103 cases. Mean ammonia level was 75 µmol/L, with undetermined etiology in the majority of subjects. Lactulose was given in 48 cases (46.6%), with a median of 9.5 doses given. There were no significant differences in outcomes between the lactulose and non-lactulose groups. Among subjects with multiple data points, lactulose did not have a dose-dependent effect on ammonia level, and was not associated with faster ammonia normalization compared to non-lactulose. When analyzed separately, patients with moderate hyperammonemia (60-99 µmol/L) who received lactulose had longer hospital and ICU length of stay compared to non-lactulose (417.8 hours vs. 208.4 hours, P = 0.003, and 229.2 hours vs. 104.7 hours, P = 0.025; respectively), though confounders were present. CONCLUSIONS: Routine use of lactulose to treat mild to moderate hyperammonemia in this patient population was not associated with improved outcomes.

Factor IX complex for the treatment of severe bleeding after cardiac surgery.

BACKGROUND: Previous reports have been published on the use of recombinant Factor VIIa for intractable bleeding after cardiac surgery; however, there is limited information on the use of Factor IX Complex in this population. METHODS: A retrospective cohort study of adult patients who underwent cardiac surgery and experienced severe postoperative bleeding, defined as a mean chest tube output ≥300 mL/h. Primary outcomes were changes in chest tube output and blood product usage pre- and post-Factor IX Complex administration. RESULTS: Eleven patients received Factor IX Complex for severe postoperative bleeding. The mean dose of Factor IX Complex was 35 (13-52) units/kg. Chest tube output was significantly reduced after Factor IX Complex administration (mean pre-Factor IX Complex 381 ± 49 mL/h, mean post-Factor IX Complex 151 ± 38 mL/h; P = 0.003). Blood product usage decreased after Factor IX Complex but was not statistically significant (mean pre-Factor IX Complex 373 ± 81 mL/h, mean post-Factor IX Complex 212 ± 48 mL/h; P = 0.669). Adverse events included 1 pulmonary embolism (postoperative day 43) and 2 episodes of acute renal failure requiring dialysis (postoperative days 2 and 5). CONCLUSIONS: In this small group of patients, Factor IX Complex effectively controlled severe bleeding after cardiac surgery preventing the need for re-exploration.

Variability in central venous pressure measurements and the potential impact on fluid management.

In the intensive care unit (ICU) of our tertiary care university medical center, central venous pressure (CVP) measurements derived from bedside monitors differ considerably from measurements by trained intensivists using paper tracings. To quantify these differences, printed CVP tracings and concurrent respiratory waveforms were collected from 100 consecutive critically ill patients along with the corresponding monitor-displayed CVP. Four blinded intensivists interpreted the tracings. The mean difference between the intensivists and the monitor was -0.26 mmHg (95% confidence interval, +7.19 to -7.71 mmHg). Seventy-six percent of the paired measurements were within 2 mmHg, whereas 7% differed by more than 5 mmHg. To determine the potential clinical impact of these differences, we used the original Surviving Sepsis Campaign Guidelines for fluid administration based upon the measurement of CVP. For individual physicians, protocol-driven fluid management strategy would have differed in 19.2% to 25.3% of cases, dependent upon which measured value was chosen. Although protocol-driven strategies to direct fluid infusion therapy may improve outcomes, these interventions in a specific patient are dependent upon the method by which the CVP is measured.

Nosocomial pneumonia risk and stress ulcer prophylaxis: a comparison of pantoprazole vs ranitidine in cardiothoracic surgery patients.

BACKGROUND: Stress ulcer prophylaxis (SUP) using ranitidine, a histamine H2 receptor antagonist, has been associated with an increased risk of ventilator-associated pneumonia. The proton pump inhibitor (PPI) pantoprazole is also commonly used for SUP. PPI use has been linked to an increased risk of community-acquired pneumonia. The objective of this study was to determine whether SUP with pantoprazole increases pneumonia risk compared with ranitidine in critically ill patients. METHODS: The cardiothoracic surgery database at our institution was used to identify retrospectively all patients who had received SUP with pantoprazole or ranitidine, without crossover between agents. From January 1, 2004, to March 31, 2007, 887 patients were identified, with 53 patients excluded (pantoprazole, 30 patients; ranitidine, 23 patients). Our analysis compared the incidence of nosocomial pneumonia in 377 patients who received pantoprazole with 457 patients who received ranitidine. RESULTS: Nosocomial pneumonia developed in 35 of the 377 patients (9.3%) who received pantoprazole, compared with 7 of the 457 patients (1.5%) who received ranitidine (odds ratio [OR], 6.6; 95% confidence interval [CI], 2.9 to 14.9). Twenty-three covariates were used to estimate the probability of receiving pantoprazole as measured by propensity score (C-index, 0.77). Using this score, pantoprazole and ranitidine patients were stratified according to their probability of receiving pantoprazole. After propensity adjusted, multivariable logistic regression, pantoprazole treatment was found to be an independent risk factor for nosocomial pneumonia (OR, 2.7; 95% CI, 1.1 to 6.7; p = 0.034). CONCLUSION: The use of pantoprazole for SUP was associated with a higher risk of nosocomial pneumonia compared with ranitidine. This relationship warrants further study in a randomized controlled trial.

Excessive argatroban anticoagulation for heparin-induced thrombocytopenia.

OBJECTIVE: To report 4 patients who became excessively anticoagulated with the recommended or lower starting doses of argatroban during treatment for heparin-induced thrombocytopenia type II (HIT-II) in a cardiothoracic intensive care unit. CASE SUMMARY: Four patients were treated with argatroban after confirmation of HIT-II after cardiac surgery. In 3 patients, argatroban was initiated at the recommended starting dose of 2 micro g/kg/min; in 1 patient, therapy was initiated at 1 micro g/kg/min. All patients had relatively normal hepatic function. In all cases, the resulting activated partial thromboplastin time was supertherapeutic and exceeded 100 seconds in 3 patients. Additionally, argatroban clearance appeared to be prolonged upon discontinuation. DISCUSSION: Argatroban pharmacokinetics in critically ill patients have not been investigated. Our case series demonstrates the potential over-anticoagulation that can occur in this patient population despite relatively normal hepatic function. An objective causality assessment revealed that the adverse drug event in these patients was probably caused by administration of argatroban. CONCLUSIONS: Formal pharmacokinetic studies of argatroban are needed in critically ill patients in order to optimize therapy.

Pulmonary artery catheter placement for elective coronary artery bypass grafting: before or after anesthetic induction?

UNLABELLED: Pulmonary arterial catheters (PACs) are often used during and after coronary artery bypass grafting. We hypothesized that placement of a PAC would be faster in anesthetized patients. We further hypothesized that the presence or absence of a PAC during the induction of anesthesia would make no difference in hemodynamics, vasoactive drug use, or IV fluid administration during the induction. Patients (n = 200) undergoing elective coronary artery bypass grafting were assigned to PAC insertion either before or after the induction of anesthesia. Total time for PAC insertion, number of finder needle and venous catheter insertion attempts, incidence of carotid artery puncture, arrhythmias or ST segment changes, arterial blood gas analysis, hemodynamic variables, IV fluids, and vasoactive drugs required during and after the anesthetic induction were recorded. Thirty-two different physicians placed the PACs. PAC placement was faster (10 versus 12 min, P = 0.0003) and required fewer punctures with a finder needle (P = 0.0107) in anesthetized patients. There were no significant differences between groups in hemodynamic values or use of vasoactive or anesthetic drugs or IV fluids during the induction. There were also no significant differences between groups in the incidence of myocardial ischemia, arterial hypoxemia, or hypercarbia. Placement of a PAC before the induction of anesthesia consumes more time and fails to improve hemodynamic stability or lessen vasoactive drug use during the induction of anesthesia. IMPLICATIONS: Insertion of pulmonary artery catheters (PACs) before the induction of anesthesia requires more needle sticks and takes longer than insertion after the induction of anesthesia; moreover, previous PAC insertion has no significant effect on hemodynamics or use of vasoactive drugs or IV fluid associated with the induction of anesthesia.

Late presentation of esophageal injury after transesophageal echocardiography.

Esophageal injury is a rare complication of intraoperative transesophageal echocardiography (TEE) associated with cardiac surgery. We report two cases of delayed presentation (2 and 6 days after surgery) of esophageal injury that were likely due to TEE. The differential diagnosis of postoperative pleural effusion or anemia must include esophageal injury from TEE, even 6 days after the procedure.