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.

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.

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.

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.

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.