Steven R. Insler

Association between postoperative hypothermia and adverse outcome after coronary artery bypass surgery

BACKGROUND We examined the effect on outcome of mild hypothermia (< 36 degrees C) upon intensive care unit (ICU) admission on patient outcome after coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB). METHODS We performed a retrospective database analysis of 5,701 isolated CABG patients requiring CPB, operated upon from January 1995 to June 1997. Patients were classified as either hypo- (< 36 degrees C) or normothermic (> or = 36 degrees C) upon ICU admission. ICU admission bladder core temperature (BCT) versus outcome was evaluated. Outcome measures included mortality, resource utilization (mechanical ventilation time, ICU and hospital length of stay, and postoperative packed red blood cell transfusion), and major morbidity (cardiac, renal, neurologic, or major infection). RESULTS Overall, patients admitted to the ICU with BCT < 36 degrees C had a significantly greater mortality (p = 0.02), prolonged mechanical ventilation (p = 0.007), packed red blood cell transfusion (p = 0.001), ICU (p = 0.01), and hospital (p = 0.005) length of stay. CONCLUSIONS BCT of less than 36 degrees C, upon ICU admission, has a significant association with adverse outcome after CABG with CPB. M An __ Tl QA_7_t-0

Dexamethasone Decreases the Incidence of Shivering After Cardiac Surgery: A Randomized, Double-Blind, Placebo-Controlled Study

Shivering after cardiac surgery is common, and may be a result of intraoperative hypothermia.Another possible etiology is fever and chills secondary to activation of the inflammatory response and release of cytokines by cardiopulmonary bypass. Dexamethasone decreases the gradient between core and skin temperature and modifies the inflammatory response. The goal of this study was to determine whether dexamethasone can reduce the incidence of shivering. Two hundred thirty-six patients scheduled for elective coronary and/or valvular surgery were randomly assigned to receive either dexamethasone 0.6 mg/kg or placebo after the induction of anesthesia. All patients received standard monitoring and anesthetic management. After arrival in the intensive care unit (ICU), nurses unaware of the treatment groups recorded visible shivering, as well as skin and pulmonary artery temperatures. Analysis of shivering rates was performed by using chi squared tests and logistic regression analysis. Compared with placebo, dexamethasone decreased the incidence of shivering (33.0% vs 13.1%; P = 0.001). It was an independent predictor of reduced incidence of shivering and was also associated with a higher skin temperature on ICU admission and a lower central temperature in the early postoperative period. Implications: Dexamethasone is effective in decreasing the incidence of shivering. The effectiveness of dexamethasone is independent of temperature and duration of cardiopulmonary bypass. Shivering after cardiac surgery may be part of the febrile response that occurs after release of cytokines during cardiopulmonary bypass. (Anesth Analg 1998;87:795-9)

Lidocaine and the inhibition of postoperative pain in coronary artery bypass patients.

OBJECTIVE This study was designed to evaluate whether a continuous low-dose lidocaine infusion reduces postoperative pain and anxiety in patients undergoing coronary artery bypass grafting (CABG) and to retrospectively examine time to extubation, intensive care unit stay (ICU), and hospital length of stay. DESIGN A double-blinded, randomized, and prospective approach. SETTING Hospital patients undergoing first-time CABG. PARTICIPANTS After informed consent, 100 patients were enrolled in this study. INTERVENTIONS Lidocaine infusion or placebo substitute was begun after induction of anesthesia. The fentanyl/midazolam infusion was discontinued on ICU admission; lidocaine or placebo continued until ICU discharge. Supplemental fentanyl, midazolam, or propranolol was administered for pain, anxiety, or hemodynamic stress. MEASUREMENTS AND MAIN RESULTS Drug dosages were compared between groups. Postoperative assessment included visual analog pain score, hemodynamics, sedation score, and nursing assessment. Mean total dosages of fentanyl, midazolam, and propranolol between the lidocaine and placebo groups were 620.40 +/- 815.74 microgram versus 689.16 +/- 692.99 microgram, p = 0.244; 0.54 +/- 1.13 mg versus 1.20 +/- 2.44 mg p = 0.465; 0.11 +/- 0.75 mg versus 3.56 +/- 17.2 mg, p = 0.564, respectively. Times to extubation, ICU length of stay, and hospital stay did not achieve statistical significance. CONCLUSIONS Continuous infusion of low-dose lidocaine did not significantly decrease supplemental fentanyl, midazolam, or propranolol requirement postoperatively. Similarly, a lidocaine infusion does not result in reduced time to extubation. ICU stay, or hospital length of stay.

Cardiac surgery in a patient taking monoamine oxidase inhibitors: an adverse fentanyl reaction.

M onoamine oxidase inhibitors (MAOIs), are used to treat endogenous psychotic depression. The MAOIs do not inhibit catecholamine synthesis; rather they block the oxidative deamination of endogenous catecholamines into inactive vanillylmandilic acid. This block of MA0 produces an accumulation of endogenous catecholamines in adrenergically active tissues, such as the brain, which is thought to be responsible for alleviation of depression. Major concerns with the clinical use of MAOIs are related to 1) the risk of dietary intake of tyramine, an indirect sympathomimetic, which can trigger a release of accumulated catecholamines, 2) drug interactions, specifically with opioids, which have been reputed to cause a syndrome of hyperpyrexia, hypertension, tachycardia, and coma (1 1, and 3) hepatotoxicity, which does not seem to be related to dose or duration of treatment. When patients on MAOIs require urgent surgery or the relief of severe pain, there is concern about these potentially fatal drug interactions. Despite such potential interactions and risks, adverse outcomes are rarely reported in clinical practice. However, there are 12 case reports in the world literature implicating the combination of meperidine and MAOIs as potentially fatal, this being related to an inhibition of 5-hydroxytryptamine (5-HT) uptake by both the opioid and MA01 in the brain leading to increased levels of 5-HT at the synaptic cleft and consequent adverse reactions including hyperpyrexia, hypertension, hypotension, tachycardia, or convulsions (2-12). There has been only one case described of an adverse morphine/MAOI interaction (13). This involved a patient who became hypotensive and unconscious after receiving morphine (6 mg intravenously [IV]), but the etiology was uncertain. Five cases have been reported of fentanyl being administered to patients on chronic MA01 therapy (14-16); four of these cases did not have an adverse outcome

Thrombosis during the Use of the Heparinoid Organon 10172 in a Patient with Heparin-induced Thrombocytopenia

Heparin-induced thrombocytopenia (HIT) and thrombosis is characterized by a progressive thrombocytopenia that most often occurs after 5-10 days of heparin exposure. Patients with a history of HIT requiring anti-coagulation for cardiopulmonary bypass (CPB) may face devastating consequences unless alternative anticoagulants are used. Management options have included postponing surgery until a time at which the antibody has disappeared and the patients platelets no longer aggregate after exposured to heparin. Alternative pharmacologic means of anticoagulation include the use of low molecular weight heparin (LMWH), ancrod, warfarin, platelet inhibitors, hidudin or argatroban. 1-4 In addition, other drugs with antiplatelet activity, such as the prostacyclin analogue, iloprost, have been administered before heparin administration in an attempt to prevent platelet aggregation. The investigational heparinoid, ORG 10172 (Organon International, The Netherlands), derived from porcine intestinal mucosa, is composed of a heterogeneous mixture of dermatan sulfate, and chondroitin sulfate. This heparinoid has been an effective anticoagulant for CPB in dogs 6 and has also been used successfully as an antithrombotic agent in patients with HIT. 7 Patients with HIT have decreased antibody cross reactivity with ORG 10172. In humans, case reports have been presented by Doherty et al. 8 and Rowlings et al. 9 in which ORG 10172 was used as the anticoagulant for CPB. In this report, we describe thrombosis that occurred in a patient with HIT receiving ORG 10172 during CPB

An Evaluation of a Full-Access Underbody Forced-Air Warming System During Near-Normothermic, On-pump Cardiac Surgery

BACKGROUND: A new underbody forced-air warming system is available for use during cardiac surgery. We tested the hypothesis combining underbody forced-air warming with standard thermal management would maintain intraoperative core temperature and reduce core temperature after-drop (largest decrease in core temperature in the 60 min after bypass) in patients undergoing near-normothermic cardiopulmonary bypass (CPB). METHODS: Patients undergoing routine, nonemergent cardiac surgery were randomly assigned to routine thermal management (fluid warming and passive insulation, n = 30) or routine management supplemented by an active underbody forced-air system (n = 30; Arizant Healthcare Model 635, Eden Prairie, MN). Core body temperature was measured by bladder catheter at 15-min intervals during the perioperative period. Comparisons were made between groups for temperature before, during, and after CPB. RESULTS: Data from four patients were excluded for cause, leaving 29 patients in the routine management group and 27 patients in the forced-air group. Initial temperatures were similar, but temperatures in the forced-air group were higher than in the routine group at the start of CPB (36.3°C ± 0.6°C vs 35.7°C ± 0.7°C, P = 0.002). There were no differences between groups in the lowest temperatures during CPB (forced air, 35.5°C ± 1.5°C vs routine, 35.3°C ± 1.3°C, P = 0.67); the end of CPB (36.7°C ± 0.4°C vs 36.6°C ± 0.4°C, P > 0.99); or the temperature at departure from the operating room (36.5°C ± 0.4°C vs 36.2°C ± 0.5°C, P = 0.36). After-drop was 0.03°C ± 0.54°C in patients randomized to underbody forced-air warming and 0.21°C ± 0.51°C in those assigned to routine management (P = 0.20). CONCLUSIONS: Adding an underbody forced-air warming system to the near-normothermic thermal management protocol significantly increased pre-bypass temperature; however, it had no further clinically important effect on core temperature.

Bleeding From a Pulmonary Artery Catheter Temperature Connection Port

p ERIOPERATIVE MONITORING with a balloon-tipped flow-directed pulmonary artery catheter (PAC) has been used clinically since 1970.1 The use of a PAC for cardiac surgical patients has become common practice, with low morbidity and mortality. However, significant complications during the insertion and use of this monitor include hematoma, 2 carotid artery puncture, 2 arrhythmias, 3,4 Homers syndrome, 5 pulmonary artery embolism or rupture, sepsis, pneumothorax, catheter knotting, or entrapment by sutures. 1,6-8 This report describes two unusual presentations of PAC entrapment by sutures not reported in the earlier literature.

159: EVALUATION OF INHALED FLOLAN VERSUS INHALED VELETRI IN A CARDIOTHORACIC SURGERY PATIENT POPULATION

Learning Objectives: Flolan and Veletri are two brand products of epoprostenol which have been administered via the inhalation route in cardiac surgery patients to correct hypoxemia, decrease pulmonary arterial pressure, and improve right ventricular function. Flolan and Veletri vary in stability, diluent, and inactive ingredients and it is unknown if these variances lead to differences in effectiveness and safety via the inhalation route. The aim of this project was to evaluate a formulary conversion from inhaled Flolan (iFLO) to inhaled Veletri (iVEL) to determine the impact on effectiveness, safety, or cost in cardiothoracic surgery patients. Methods: This was a retrospective, non-inferiority study performed at a large academic medical center comparing iFLO and iVEL in cardiothoracic surgery patients. Included subjects were ≥18 years old, who were admitted to the cardiothoracic intensive care unit, and received iFLO or iVEL therapy for ≥ 1 hour while being mechanically ventilated between January 1, 2015 and December 1, 2016. Results: A total of 244 patients were included in the primary outcome analysis. There were no significant differences in baseline characteristics between the iFLO and iVEL groups. The primary outcome, change in the PaO2/FiO2 ratio one hour after administration of iFLO or iVEL, did not cross the lower limit of the noninferiority margin of -20 mm Hg (95% CI = -14.8 to 65.4 mm Hg). Significant differences in secondary outcomes included duration of mechanical ventilation (iFLO 4.4 vs iVEL 2.6 days; p < 0.01), number of patients requiring tracheostomy (iFLO 19.7% vs iVEL 7.4%; p = 0.01), number of patients initiated on dialysis (iFLO 20.5% vs iVEL 9.8%; p = 0.02), and cost per median duration of therapy (iFLO

Effectiveness, safety, and Economic Comparison of Two Inhaled Epoprostentol Products (Flolan and Veletri) in Cardiothoracic Surgery Patients

257.08 vs iVEL

Postoperative pain: Meeting new expectations

183.30; p = 0.02). Conclusions: Inhaled Veletri is non-inferior to inhaled Flolan when comparing change in PaO2/FiO2 ratio one hour after therapy initiation. The conversion from inhaled Flolan to inhaled Veletri was likely justified.