A Case Report of Hypotension and Methemoglobinemia Associated With Gunshot Residue Poisoning: Nitrite-Induced Methemoglobinemia.

A patient with gunshots within inches of the skin developed intraoperative vasodilatory hypotension and methemoglobinemia, both recognized consequences of nitrite poisoning. A 1- mg/kg dose of methylene blue transiently and partially reversed methemoglobinemia, but the color of the methylene blue faded rapidly, consistent with bleaching of methylene blue by nitrite in vivo. Methylene blue did not raise blood pressure, consistent with inhibition of nitric oxide (NO) synthase. Because NO production from nitrite uses an NO synthase (NOS)-independent pathway, methylene blue is expected to have little effect on reversing hypotension from nitrite poisoning. Consider nitrite toxicity in gunshot patients with refractory vasodilatory hypotension and elevated methemoglobin.

Predisposing and Precipitating Factors Associated With Postoperative Delirium in Patients Undergoing Cardiac Surgery at a Veterans Affairs Medical Center: A Pilot Retrospective Analysis.

OBJECTIVE: Patients treated at Veterans Affairs (VA) medical centers are in poorer health, experience more medical and psychiatric conditions, and make greater use of medical resources than do patients in the general population. In the present pilot study, the authors examined their recent experience at a VA medical center to determine the incidence and risk factors associated with the development of postoperative delirium in VA patients after cardiac surgery and hypothesized that the risk factors for postoperative delirium after cardiac surgery are different between VA and non-VA patients. DESIGN: Retrospective cohort study. SETTING: Clement J. Zablocki Veterans Affairs Medical Center. PARTICIPANTS: The study comprised 250 consecutive patients undergoing cardiac surgery from July 2014 to March 2016. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Demographics, coexisting diseases, and medications were obtained from the VA electronic medical record. The European System for Cardiac Operative Evaluation II mortality risk index was calculated for each patient. The type and duration of the procedure and the duration of bypass were recorded. Intraoperative crystalloid, colloid, cell saver, and blood product volumes were compiled. Progress notes and International Classification of Diseases, Tenth Revision, Clinical Modification codes were searched for documentation of postoperative delirium. Thirty-eight patients (15.2%) developed postoperative delirium. Stepwise logistic regression analysis demonstrated that the European System for Cardiac Operative Evaluation II mortality risk index (odds ratio [OR] 1.036, 95% confidence interval [CI] [1.003-1.070]; p = 0.0344), congestive heart failure (OR 2.223 [95% CI 1.046-4.722]; p = 0.0377), pre-existing cognitive impairment (OR 5.147 [95% CI 1.994-13.28]; p = 0.0007), and the presence of a neuropsychiatric disorder (OR 2.015 [95% CI 1.004-4.043]; p = 0.0487) were predisposing factors associated with higher odds of postoperative delirium. The duration of surgery; transfusion of blood products (including packed red blood cells, fresh frozen plasma, and platelets); the durations of mechanical ventilation and conscious sedation (using either propofol or dexmedetomidine); and the length of intensive care unit stay were precipitating factors associated with higher odds of postoperative delirium. CONCLUSIONS: The results demonstrate that congestive heart failure, pre-existing cognitive impairment, and the presence of a neuropsychiatric disorder are predisposing risk factors for postoperative delirium after cardiac surgery in VA patients, whereas the duration of surgery, transfusion of blood products, durations of mechanical ventilation and conscious sedation, and length of intensive care unit stay are precipitating factors for postoperative delirium. These findings in VA patients generally are similar to those observed in the civilian population despite the differences between these cohorts.

Palliative surgery for malignant bowel obstruction from carcinomatosis: a systematic review.

IMPORTANCE: Care of patients with malignant bowel obstruction caused by peritoneal metastases may present an ethical dilemma for surgeons when nonoperative management fails. OBJECTIVE: To characterize outcomes of palliative surgery for malignant bowel obstruction from peritoneal carcinomatosis to guide decision making about surgery and postoperative interventions for patients with terminal illness. EVIDENCE REVIEW: We searched PubMed, EMBASE, Cochrane Library, Web of Knowledge, Cumulative Index to Nursing and Allied Health Literature Plus, and Google Scholar and performed manual searches of selected journals from inception to August 30, 2012, with no filters, limits, or language restrictions. We used database-specific combinations of the terms intestinal obstruction, malignant, surgery or surgical, and palliat*. We included studies reporting outcomes after palliative surgery for malignant bowel obstruction from peritoneal carcinomatosis from any primary malignant neoplasm and excluded case studies, curative surgery, isolated percutaneous procedures, stenting for intraluminal lesions, and studies in which benign and malignant obstructions could not be distinguished. We assessed quality with the Newcastle-Ottawa Scale. FINDINGS: We screened 2347 unique articles, selected 108 articles for full-text review, and included 17 studies. Surgery was able to palliate obstructive symptoms for 32% to 100% of patients, enable resumption of a diet for 45% to 75% of patients, and facilitate discharge to home in 34% to 87% of patients. Mortality was high (6%-32%), and serious complications were common (7%-44%). Frequent reobstructions (6%-47%), readmissions (38%-74%), and reoperations (2%-15%) occurred. Survival was limited (median, 26-273 days), and hospitalization for surgery consumed a substantial portion of the patient's remaining life (11%-61%). CONCLUSIONS AND RELEVANCE: Although palliative surgery can benefit patients, it comes at the cost of high mortality and substantial hospitalization relative to the patient's remaining survival time. Preoperatively, surgeons should present realistic goals and limitations of surgery. For patients choosing surgery, clarifying preferences for aggressive postoperative interventions preoperatively is critical given the high complication rate and limited survival after surgery for malignant bowel obstruction.