Temperature Outcomes without heater cooler units in adult patients supported with extracorporeal membrane oxygenation: A retrospective cohort study.

INTRODUCTION: Heater-cooler units (HCUs) are frequently incorporated into extracorporeal membrane oxygenation (ECMO) circuits to help maintain patient normothermia. However, these devices may be associated with increased cost and infection risk. This study describes our institution's experience managing adult ECMO patients without the routine use of in-circuit HCUs. METHODS: We performed a retrospective analysis of adult patients treated with veno-venous (VV) or veno-arterial (VA) ECMO at our institution. The primary outcomes were rates of HCU use and the relative duration of the ECMO treatment course in which patients maintained normothermia (36-37.5°C), with and without HCUs. Secondary outcomes of mortality and ECMO-related complications were planned across HCU and non-HCU groups; exploratory analyses were performed across a 75% "ECMO time in normothermia" threshold. RESULTS: Among a cohort of 71 patients, zero (0%) were managed with in-circuit HCUs. A majority of ECMO patient-hours were spent in the normothermic range. Median and mean percentages of ECMO normothermia time were 75% (IQR 49%-81%) and 62% (SD ± 27%). Twenty-nine patients (40%) met the threshold of 75% ECMO normothermia time, as used to evaluate secondary outcomes. At this threshold, mortality risk was significantly higher among the non-normothermic cohort; other ECMO-related complications did not vary significantly. CONCLUSIONS: In the absence of HCU use, the majority of ECMO patient-hours were spent in normothermia. However, only a minority of patients achieved normothermia for at least 75% of their ECMO course. In-circuit HCUs may be required to maintain high percentages of normothermic time in adult EMCO patients.

Distal Perfusion Cannulation and Limb Complications in Venoarterial Extracorporeal Membrane Oxygenation.

The utility of distal perfusion cannula (DPC) placement for the prevention of limb complications in patients undergoing femoral venoarterial (VA) extracorporeal membrane oxygenation (ECMO) is poorly characterized. Patients undergoing femoral VA ECMO cannulation at two institutions were retrospectively assessed. Patients were grouped into those who did and those who did not receive a DPC at the time of primary cannulation. The primary outcome was any limb complication. Secondary outcomes included successfully weaning ECMO and in-hospital mortality. A total of 75 patients underwent femoral cannulation between December 2010 and December 2017. Of those, 65 patients (86.7%) had a DPC placed during primary cannulation and 10 patients (13.3%) did not. Baseline demographics, indications for ECMO, and hemodynamic perturbations were well matched between groups. The rate of limb complications was 14.7% (11/75) for the overall cohort and did not differ between groups (p = .6). Three patients (4%) required a four-compartment fasciotomy for compartment syndrome in the DPC group; no patients without a DPC required fasciotomy. Of the three patients who required a thrombectomy for distal ischemia, two were in the DPC group and one was in the no-DPC group (p = .3). Two patients (2.7%) underwent delayed DPC placement for limb ischemia with resolution of symptoms. The in-hospital morality rate was 59.5% and did not differ between groups (p = .5). Patients in the present study, undergoing femoral VA ECMO without preemptive DPC placement did not experience a higher rate of limb complications. However, the two patients who underwent delayed DPC placement for post-cannulation ischemia experienced resolution of symptoms, suggesting that a DPC may be used as an effective limb salvage intervention.

Incidence, risk factors, and prognostic impact of re-exploration for bleeding after cardiac surgery: A retrospective cohort study.

BACKGROUND: Postoperative re-exploration for bleeding (RB) is a frequent complication following cardiac surgery. We aim to assess incidence, risk factors, and prognostic significance of RB in a large cohort of cardiac patients. MATERIALS AND METHODS: We reviewed prospectively collected data for all patients who underwent cardiac surgery at our institution from 2007 to 2015. Logistic regression analysis was used to identify independent predictors of RB and specific outcomes. Propensity matching using a 1:1-ratio compared outcomes of patients who had RB with patients who did not. RESULTS: During the study period, 7381 patients underwent cardiac operations. Of them, 189 (2.6%) underwent RB. RB was an independent predictor of in-hospital mortality (Odds Ratio (OR):2.62 Confidence Interval (CI):1.38-4.96; p = 0.003), major adverse events (OR:3.94, CI:2.79-5.62; p < 0.001), gastrointestinal events (OR:3.54 CI:1.73-7.24), renal failure (OR:2.44, CI:1.23-4.82), prolonged ventilation (OR:3.83, CI:2.60-5.62, p < 0.001), and sepsis (OR:2.50, CI:1.03-6.04, p = 0.043). Preoperative shock (OR:3.68, CI:1.66-8.13; p = 0.001), congestive heart failure (OR:1.70 CI:1.24-2.32; p = 0.001), and urgent and emergent status (OR:2.27, CI:1.65-3.12 and OR:3.57, CI:1.89-6.75; p < 0.001 for both) were predictors of RB operative mortality. Operative mortality, incidence of major adverse events, gastrointestinal events, and respiratory failure were all significantly higher in the propensity matched RB group (p = 0.050, p < 0.001, p = 0.046, and p < 0.001 respectively). CONCLUSIONS: RB significantly increases in-hospital mortality and morbidity after cardiac surgery.

Variability in End-Organ Perfusion with Femoral-Femoral Venoarterial Extracorporeal Membrane Oxygenation: Aortographic Evidence.

In femoral-femoral venoarterial extracorporeal membrane oxygenation (VA-ECMO), the outflow of oxygenated blood from the circuit enters the aorta in retrograde fashion. As a result, variability in end-organ oxygenation (e.g., cerebral vs. splanchnic) may arise-particularly, when the heart is unable to contribute forward flow. We present the case of a 74-year-old man supported by femoral-femoral VA-ECMO in whom aortography was used to visualize the retrograde distribution of arterial ECMO flow that can produce such differences in end-organ perfusion. We do this by describing a series of still images captured during the aortography; we then discuss the importance of monitoring end-organ oxygenation in this setting and outline several interventions that can ameliorate this flow phenomenon.

Extracorporeal Membrane Oxygenation as a Bridge through Chemotherapy in B-Cell Lymphoma.

A 41-year-old female presented with a large anterior mediastinal mass adjacent to the heart. Biopsy demonstrated lymphoma. Upon administration of chemotherapy, she developed cardiogenic shock requiring a 5-day course of extracorporeal membrane oxygenation (ECMO) as a bridge through her treatment. After one cycle of chemotherapy, ECMO was discontinued and the patient completed her course of chemotherapy and recovered to hospital discharge.

Nonischemic Postoperative Seizure Does Not Increase Mortality After Cardiac Surgery.

BACKGROUND: Postoperative seizure (PS) is an infrequent, yet distressing, complication after cardiac surgery. We wished to determine the prognostic significance of these complicated neurologic events. METHODS: The Weill Cornell Medical College Department of Cardiothoracic Surgery database and the New York State Department of Health Database were reviewed to identify all patients having PS after cardiac surgery between January 1, 2008, and December 31, 2011. RESULTS: During the study period 3,518 patients had cardiac surgery at the index hospital; 45 of them had PS (1.27%). Overall, patients having PS had a significant increase in 30-day mortality when compared with those not having PS (6.7% versus 1.5%; p < 0.006). The incidence of major postoperative complications in those having PS was also significantly higher (53.3% versus 10.5%; p < 0.001). However, logistic regression failed to demonstrate PS as an independent predictor of perioperative mortality. When the PS group was further stratified by the presence or absence of cerebrovascular accident, those having both PS and cerebrovascular accident had substantially increased morbidity and mortality (mortality, 0 of 33 versus 3 of 12; major morbidity, 12 of 12 versus 12 of 33; p < 0.01 for both), whereas PS patients without cerebrovascular accident did not have greater risk for either major adverse events or mortality. CONCLUSIONS: When PS is associated with acute cerebrovascular accident, a significant increase in postoperative morbidity and mortality can be expected. However, in those with isolated PS (without evidence of new neurologic injury), perioperative mortality and morbidity are comparable to those without any neurologic complications.

Blood conservation strategies in cardiac surgery: more is better.

OBJECTIVES: Recent data show that up to 50% of heart procedures require blood transfusion, which can have adverse long- and short-term outcomes for the patient. This led to the updated 2011 Society of Thoracic Surgery (STS)/Society of Cardiovascular Anesthesiologists (SCA) guidelines in an attempt to adopt more effective blood conservation techniques. We present our results after the implementation of a more aggressive strategy for intraoperative blood conservation in cardiac surgery. METHODS: Our cardiac surgery database was reviewed retrospectively, comparing outcomes from two different time periods, after the implementation of a more effective two-way blood conservation strategy beginning in March 2012: more aggressive intraoperative autologous donation (IAD) based on a newly constructed nomogram, and the use of a shorter length circuit of the cardiopulmonary bypass (CPB) which allowed for lower fluid volume as a prime. The method of retrograde autologous priming (RAP) was the same for both time periods. RESULTS: A total of 1126 patients (Group 1) were studied in a 12-month period (March 2012-February 2013) after the implementation of the new strategy, and compared with 3758 patients (Group 2) of the previous 36-month period (March 2009-February 2012). There was a significant reduction in the percent change of the intraoperative haematocrit between Groups 1 and 2 (14 vs 28%, P = 0.01), with an increase in the mean IAD volume (655 vs 390 ml, P = 0.02) and a reduction in the CPB priming volume (1000 vs 1600 ml, P = 0.03). Group 1 required significantly less blood transfusions in the perioperative period (29 vs 49%, P = 0.02) and had significantly reduced postoperative rates of respiratory failure (3 vs 7%, P = 0.03), pneumonia (1 vs 3.1%, P = 0.01), chest tube output (350 vs 730 ml, P = 0.01), reoperation for bleeding (1.2 vs 2.5%, P = 0.04) and length of stay (6.1 vs 8.2 days, P = 0.05). CONCLUSIONS: Blood conservation is safe and effective in reducing transfusions in cardiac surgery, minimizing perioperative morbidity and mortality. Aggressive IAD and low CPB prime, along with effective RAP, is the three-way blood conservation strategy that leads to improved outcomes in cardiac surgery.

Regional variation in arterial saturation and oxygen delivery during venoarterial extracorporeal membrane oxygenation.

UNLABELLED: Venoarterial extracorporeal membrane oxygenation (VA-ECMO) can be lifesaving in patients with cardiopulmonary collapse. However, observation studies have implied that oxygenated blood does not pass in a retrograde fashion from the VA-ECMO circuit to the aortic root and arch when the femoral artery (FA) is used. This study aims at accurately measuring the oxygen saturation in various arteries during VA-ECMO through different cannula sites. A total of 20 patients with VA-ECMO were in the study. Fourteen patients had FA cannulation, two patients received axillary arterial (AA) cannulation, and four patients received cannulation of the ascending aorta. Oxygen saturation was measured simultaneously in the radial artery and oxygenator outlet. In the patient group with FA cannulation, the oxygen saturation was lower in the radial artery (97%) when compared with the oxygenator outlet (> 99%). In the subset group of patients with severe lung dysfunction, oxygen saturation was even lower in the radial artery (73% saturation). In the patient group with AA cannulation, the oxygen saturation and partial oxygen pressure (PO2) in the oxygenator outlet and radial artery were similar (99% or greater). In the patient group with direct ascending aorta cannulation, the oxygen saturation and PO2 in the oxygenator outlet and radial artery were similar as well. Regional variations occur in the blood oxygen saturation depending on the site of the arterial cannulation in patients with VA-ECMO. With FA cannulation, the oxygen saturation in the radial artery is significantly lower than the one in the oxygenator outlet. This may imply that the coronaries and the brain receive hypoxic blood from the left ventricle. These results suggest that antegrade cannulation for VA-ECMO improves oxygen delivery to the proximal aorta distribution. KEYWORDS: VA-ECMO, arterial oxygen saturation.

A novel method for percutaneous insertion of a right ventricular assist device.

Right heart failure is a rare but often fatal complication both in the pre- and postoperative setting. Right heart support with a ventricular assist device inserted in the operating room through median sternotomy can be a time-consuming procedure that requires a reoperation for removal. In cases of urgent need of right heart support, a percutaneous technique option may be of benefit. We present our initial experience with a percutaneously inserted right ventricular assist device (RVAD) in an elderly patient with severe right heart failure. An 81-year-old female patient underwent combined aortic and mitral valve replacement at our institution. During the first postoperative evening, the patient sustained sudden cardiovascular collapse and a bedside transesophageal echocardiogram revealed severe right heart failure. A coronary angiogram showed thrombosis of the right coronary artery, which was cleared with a suction device. As a result of the patient's critical condition, it was decided that an RVAD was needed as a bridge to recovery. The patient's condition improved significantly almost immediately. Her right heart function recovered over the next few days and the RVAD was removed at the bedside. She made a complete recovery and was discharged home. This patient is a prime example that a totally RVAD can be inserted in urgent situations easily and safely under fluoroscopic and echocardiographic guidance. More clinical experience with percutaneous RVADs is required to establish this technique as an alternative equivalent to the traditional open method. Right heart failure complicates many heart diseases both in the pre- and the postoperative setting. In cases of urgent need of right heart support, a percutaneous technique of a RVAD is needed for a successful outcome. We present our initial experience with a percutaneously inserted RVAD in an elderly patient with severe postoperative right heart failure.

Improved environmental impact with diversion of perfusion bypass circuit to municipal solid waste.

The project goal was to reduce waste disposal volume, costs and minimize the negative impact that regulated waste treatment and disposal has on the environment. This was accomplished by diverting bypass circuits from the traditional regulated medical waste (RMW) to clear bag waste, or municipal solid waste (MSW). To qualify circuits to be disposed of through MSW stream, the circuits needed to be void of any free-flowing blood and be "responsibly clear." Traditionally the perfusion bypass circuit was emptied through the cardioplegia pump starting shortly after decannulation and heparin reversal. Up to 2000 mL of additional prime solution was added until the bypass circuit was rinsed clear. Three hundred sixty of 400 procedures (90%) had a complete circuit rinse and successful diversion to MSW. An additional 240 mL of processed cell salvage blood was available for transfusion. No additional time was spent in the operating room as a result of this procedure. Based on our procedure case volume and circuit weight of 15 pounds, almost 15,000 pounds (7.5 tons) of trash will be diverted from RMW. This technique represents another way for perfusionists to participate in sustainability efforts. Diverting the bypass circuit to clear bag waste results in a reduced environmental impact and annual cost savings. The treatment of RMW is associated with various environmental implications. MSW, or clear bag waste, on the other hand can now be disposed of in waste-to-energy facilities. This process not only releases a significantly less amount of carbon dioxide into the environment, but also helps generate renewable energy. Therefore, the bypass circuit diversion pilot project effectively demonstrates decreases in the carbon footprint of our organization and overall operating costs.

2010 John H. Gibbon Lecture. Just say yes!

Advancing anything requires change and a new method. It can be a challenge to bring about the change that you believe in. This change however requires you to plan and say no to the old way of doing things. Fortunately there is a positive way to say no whereby important needs are met. As Ury suggests, we need to focus on how the two opposing forces need to be addressed. There is your internal focus of what's important to you and the opposing external focus of others--what's important to them. We can't lose sight of this because when we do, we risk disrespecting others. As technicians we are in a unique position as perfusionists whereby we work closely with physicians and on occasion will direct them to perform tasks. Additionally, many other non-physicians are not familiar with our responsibilities. We need to make others knowledgeable of the education, skill, and passion we possess. I really enjoy what I do as a perfusionist and I am proud to be recognized for my team's contribution and of having received the Gibbon award. Bob Parsons, the CEO and founder of The Go Daddy Group, Inc., said "We're not here for a long time, we're here for a good time!" This all has been a real good time. Thank you. My Perfusion Team is currently: Barbara Elmer, Marie Kilcullen, Jim McVey, Marie Zanichelli, Junli Liu, Anthony Lamonica, Karen Hussey, Lilia Voevidko, Haleh Ebrahimi, Sergey Savy, Akilah Richards, Diana Froehlich.

Heparin sensitivity test for patients requiring cardiopulmonary bypass.

Anticoagulation for the open heart surgery patient undergoing cardiopulmonary bypass (CPB) is achieved with the use of heparin. The industry standard of activated clotting time (ACT) was used to measure the effect of heparin. The commonly acceptable target time of anticoagulation adequacy is 480 seconds or greater. Some patients, however, exhibit resistance to standard dosing of heparin and do not reach target anticoagulation time (480 seconds). Antithrombin III deficiency has been previously cited as the cause of heparin resistance. Early detection of heparin resistance (HR) may avoid both the delayed start of CPB and inadequate anticoagulation, if emergency bypass is required. An anticoagulation sensitivity test (AST) was developed by adding 12 units of porcine mucosa heparin to the ACT tube (International Technidyne, celite type). Before anticoagulation, 4 mL of blood was drawn from the patient arterial line. Following the manufacturer's instructions, 2 mL of blood was added to each tube (ACT-baseline and ACT-AST). Three minutes after anticoagulation with 4 mg heparin/kg body weight, a second sample (ACT-CPB) was taken to determine anticoagulation adequacy. The ACT times of each sample were recorded for 300 procedures occurring during 2004 and were retrospectively reviewed. Heparin resistance occurred in approximately 20% of the patients (n = 61). In 54 patients, heparin resistance was predicted by the ACT-AST. This was determined by the presence of an ACT-AST time and an ACT-CPB that were both < 480 seconds. The positive predictive value was 90%, with a false positive rate of 3%. Heparin resistance occurs in patients undergoing CPB. We describe a simple and reliable test to avoid the delays of assessing anticoagulation for CPB (90% positive predictive value). Depending on program guidelines, patients can be given additional heparin or antithrombin III derivatives to aid in anticoagulation. An additional ACT must be performed and reach target times before CPB initiation. Testing of patient blood before the time of incision for sensitivity to heparin is a way to avoid a delay that can be critical in the care of the patient. Commercial tests are available, but efficacy data are limited, and they lead to added inventory expense. This method of titrating a diluted heparin additive, mixed with patient blood in a familiar ACT test, has proven to be an inexpensive and reliable test to predict patient's sensitivity to heparin.

Cardiopulmonary bypass in patients with pre-existing coagulopathy.

Patients with pre-existing coagulopathies who undergo surgical interventions are at increased risk for bleeding complications. This risk is especially true in cardiac surgical procedures with cardiopulmonary bypass (CPB) because of the necessity for heparinization and the use of the extracorporeal circuits, which have destructive effects on most of the blood components. In this review, cases of cardiac surgeries in patients with certain pre-existing coagulopathies are summarized, which could shed a light on future managements of such patients undergoing cardiac procedures with CPB. Pre-existing coagulopathies include antithrombin III deficiency, heparin-induced thrombocytopenia, cancer, factor XII deficiency, hemophilia, idiopathic thrombocytopenic purpura, protein S deficiency, and drug-induced platelet inhibition. In summary, pre-existing coagulopathy in patients undergoing open-heart surgeries, if not recognized and appropriately managed, can cause serious complications. Management of patients undergoing cardiac procedures should include a routine coagulation work-up and a thorough past medical history examination. If any of the foregoing is abnormal, further evaluation is warranted. Proper diagnosis and management of the pre-existing coagulopathy disorders is of crucial importance to the surgical outcome and long-term morbidity.

Diagnosis and treatment of heparin-induced thrombocytopenia.

Heparin-induced thrombocytopenia (HIT) is a major side effect secondary to the administration of heparin. This syndrome is serious and potentially life threatening. This response is the result of antibodies formed against the platelet factor 4 (PF4)/heparin complex. The incidence of this immune-mediated syndrome has been estimated to be 1-3% of all patients receiving heparin therapy. The occurrence of HIT in patients requiring full anticoagulation for cardiopulmonary bypass (CPB), therefore, presents a serious challenge to the cardiac surgery team. The diagnosis of HIT should be based on both clinical and laboratory evidence. While functional assays, platelet aggregation tests, and the serotonin release assay can be used to support the diagnosis, the negative predictive value of these tests is generally less than 50%. In contrast, although non-functional antibody detection assays are more sensitive, they have a low specificity. HIT can be treated in several ways, including cessation of all heparin and giving an alternative thrombin inhibitor, platelet inhibition followed by heparin infusion, and the use of low molecular weight heparins. In this presentation, the pathology and current diagnostic tests, as well as the successful management of patients with HIT undergoing CPB at New York Presbyterian Hospital, are reviewed.

Negative fluid displacement: an alternative method to assess patency of arterial line cannulation.

Optimal flow rate with minimal pressure gradient is the goal of arterial cannulation for cardiopulmonary bypass (CPB). Misplacement of the arterial cannula or vascular pathology can lead to hemolysis or intimal damage with subsequent aortic dissection. The risk of dissection with aortic cannulation is low, 0.04-0.2% for ascending aortic cannulation and 0.2-3% for femoral cannulation. However, dissection-related mortality is significant. Common methods for assessing adequacy of arterial cannulation include minimal pressure when injecting 100-mL boluses and the presence of pulsation in the cannula. Using these techniques, misplacement of the cannula can be masked due to the small amount of volume that is transfused during the assessment. Displacement of fluid into a cannula that is in a false lumen or close to the intimal surface may not indicate a misplaced arterial cannula. Negative fluid displacement is an alternative method of evaluating the integrity of arterial cannulation. During retrograde arterial priming (RAP), fluid is drained from the arterial cannula into a collection bag. Absence of fluid return or a flow < 500 mL/minute is indicative of either arterial line occlusion or cannula misplacement. At this point, the arterial cannula can be repositioned prior to instituting CPB. Since using this technique in over 13000 bypass procedures, we have had only one dissection. This one event occurred during partial occlusion clamping of the ascending aorta. With increased use of femoral cannulation for minimally invasive cardiac surgical procedures, this RAP technique can enhance the perfusionist's and the surgeon's ability to safely perform bypass in the presence of higher dissection risk.

The effects of platelet inhibitors on blood use in cardiac surgery.

Platelet inhibition via glycoprotein (GP) IIb/IIIa receptor antagonists has greatly reduced the need for emergent cardiac surgery. However, this change has come at a cost to both the patient and the cardiac surgical team in terms of increased bleeding risk. Current guidelines for patients requiring coronary artery bypass surgery include: 1) cessation of GP IIb/IIIa inhibitor; 2) delay of surgery for up to 12 h if abciximab, tirofiban, or eptafibitide is used; 3) utilization of ultrafiltration via zero balance technique; 4) maintenance of standard heparin dosing despite elevated bleeding times; and 5) transfusion of platelets as needed, rather than prophylactically. These agents present cardiac surgery teams with increased risk during CABG, although overall risk may be diminished by the substantial benefits to patients with acute coronary syndromes and percutaneous interventions, i.e., reduced infarction rates and improved vessel patency. With judicious planning, urgent coronary artery bypass can be safely performed on patients who have been treated with GP IIb/IIIa receptor inhibitors.