Postoperative opioid misuse in patients with opioid use disorders maintained on opioid agonist treatment.

BACKGROUND: Patients recovering from opioid use disorders (OUD) may be prone to relapse and opioid misuse in the postoperative period due to re-exposure to prescription opioids for pain control. This retrospective study analyzed the incidence of confirmed opioid misuse in the postoperative period in patients with OUDs enrolled in an opioid agonist treatment (OAT) program. METHODS: The study population was US veterans with a diagnosis of OUD who enrolled in the OAT program at VA Maryland Health Care System (Baltimore, Maryland, USA) between 1/1/2000 and 12/31/2016. The patients were excluded if they were enrolled in OAT for less than a year, or if they had surgery within the first 180 days after OAT admission. The surgical group consisted of veterans who had surgery or an invasive procedure during their enrollment in the OAT program. The control (reference) group consisted of enrolled veterans who did not have any invasive procedure. The primary outcome was the first opioid misuse within 365 days after surgery date in the surgical group or a randomly assigned sham surgery date in controls. Opioid misuse was defined as either inappropriate use of opioids detected via urinalysis or admission with a diagnosis of an opioid overdose. RESULTS: From a total of 1352 patients enrolled in the OAT program, 413 were excluded because they were enrolled for less than a year, and 26 were excluded because they had surgery within the first 180 days after admission to the OAT program. Of the 923 eligible patients, 87 had surgery while enrolled and 836 did not. Using propensity scores, all 87 of the surgical cases were matched to 249 of the control cases. In the matched groups, surgery was positively associated with postoperative opioid misuse (odds ratio (OR) of 1.91, 95% CI 1.05-3.48, p = 0.034) in logistic regression. CONCLUSION: Among patients with a history of opioid use disorders, the postoperative period was associated with an increased risk of opioid misuse. Moreover, opioid misuse among patients in an opioid agonist treatment program may well be considered a surgical hazard.

Interference in clinical chemistry assays by the hemoglobin-based oxygen carrier, Hemospan.

OBJECTIVE: To evaluate interference by the hemoglobin-based oxygen carrier Hemospan on clinical laboratory assays. DESIGN AND METHODS: Interfering Hemospan concentrations were determined for general chemistry and cardiac marker analytes in pooled serum and the corresponding hemolysis index was calculated. RESULTS: Hemospan did not interfere with 20 of 35 analytes. Hemospan produced a negative interference in serum creatinine, amylase, alkaline phosphatase, uric acid, and GGT assays and a positive interference in serum phosphate, LDH, iron, triglycerides, total protein, AST, cholesterol, magnesium, and albumin assays, and appeared to positively bias the serum cardiac troponin I (cTnI) assay only when cTnI is present in the sample. CONCLUSIONS: We present a report of assays affected by Hemospan and the threshold concentrations for interference. This study highlights the importance of interference studies in understanding the effects of hemoglobin-based oxygen carriers on results reported by the clinical laboratory.

Preoperative acute normovolemic hemodilution: a meta-analysis.

BACKGROUND: Acute normovolemic hemodilution (ANH) involves withdrawal of whole blood with concurrent infusion of fluids to maintain normovolemia. The aim of this study was to quantify the efficacy and safety of preoperative ANH with a systematic review and meta-analysis. STUDY DESIGN AND METHODS: Randomized controlled trials were identified through MEDLINE (1966-2002) and the Cochrane Controlled Trials Database and with hand searching of journals. All trials of preoperative ANH reporting on allogeneic transfusion, bleeding, or adverse outcomes were included. Paired reviewers independently abstracted data. Outcomes were pooled using random-effects models. RESULTS: A total of 42 trials compared hemodilution to usual care or to another blood conservation method. The risk of allogeneic transfusion was similar among patients receiving ANH and those receiving usual care (relative risk [RR], 0.96; 95% CI, 0.90-1.01), or another blood conservation method (RR, 1.11; 95% CI, 0.96-1.28). Hemodiluted patients, however, were transfused from 1 to 2 fewer units of allogeneic blood. They had less total bleeding than patients receiving usual care (91 mL; 95% CI, 25-158 mL), although more intraoperative bleeding. Only one-third of studies reported on adverse events. CONCLUSIONS: The literature supports only modest benefits from preoperative ANH. The safety of the procedure is unproven. Widespread adoption of ANH cannot be encouraged.

Use of a human polymerized hemoglobin solution as an adjunct to acute normovolemic hemodilution during complex abdominal aortic reconstruction.

Oxygen-carrying hemoglobin (Hb) solutions are under intense investigation as an alternative to allogeneic red cell transfusion during surgery, with or without acute normovolemic hemodilution. We present a case in which an investigational Hb solution was used as an adjunct to acute normovolemic hemodilution, and as a replacement for surgical blood loss in a patient undergoing complex aortic reconstruction with a large blood loss.

Polymerized human Hb use in acute chest syndrome: a case report.

BACKGROUND: Acute chest syndrome (ACS) is a complication of sickle cell disease that can cause significant morbidity. Transfusion therapy has been shown to significantly increase oxygenation in patients with ACS and RBC exchange is considered the standard of care in patients at high risk of respiratory failure. CASE REPORT: A patient with ACS and several high-risk features, including thrombocytopenia, profound anemia, bilateral pulmonary infiltrates, staphylococcal sepsis, and pulmonary embolism is presented. The patient refused transfusion on religious grounds and received 12 units of human polymerized Hb solution (poly SFH-P injection, PolyHeme, Northfield Laboratories) over the course of 13 days. The patient's respiratory status improved and she was discharged home without receiving RBC transfusions. CONCLUSION: This is the first reported case that describes the use of PolyHeme in a patient with sickle cell disease, ACS, and sepsis. This therapy is thought to have been lifesaving for this patient.

The life-sustaining capacity of human polymerized hemoglobin when red cells might be unavailable.

BACKGROUND: Human polymerized hemoglobin (PolyHeme, Northfield Laboratories, Evanston, IL) is a universally compatible, immediately available, disease-free, oxygen-carrying resuscitative fluid being developed as a red cell substitute for use in urgent blood loss. PolyHeme should be particularly useful when red cells may be temporarily unavailable. This article assesses survival at life-threatening RBC hemoglobin concentration ([Hb]) in massively bleeding patients who do not receive red cells. STUDY DESIGN: There were 171 patients who received rapid infusion of 1 to 20 units (1,000 g, 10 L) of PolyHeme in lieu of red cells as initial oxygen-carrying replacement in trauma and urgent surgery. The protocol simulated the unavailability of red cells, and the progressive fall in RBC [Hb] in bleeding patients was quantified. Thirty-day mortality was compared with a historical control group of 300 surgical patients who refused red cells on religious grounds. RESULTS: A total of 171 patients received rapid infusion of 1 to 2 units (n = 45), 3 to 4 units (n = 45), 5 to 9 units (n = 47), or 10 to 20 units (n = 34) of PolyHeme. Forty patients had a nadir RBC [Hb] < or = 3 g/dL (mean, 1.5 +/- 0.7 g/dL). But total [Hb] was adequately maintained (mean, 6.8 +/- 1.2 g/dL) because of plasma [Hb] added by PolyHeme. The 30-day mortality was 25.0% (10/40 patients) compared with 64.5% (20/31 patients) in historical control patients at these RBC [Hb] levels. CONCLUSIONS: PolyHeme increases survival at life-threatening RBC [Hb] by maintaining total [Hb] in the absence of red cell transfusion. PolyHeme should be useful in the early treatment of urgent blood loss and resolve the dilemma of unavailability of red cells.