Emergency Cardiopulmonary Bypass Research Articles

Perioperative Transfusion and Mortality for Cardiovascular Surgery: A Cohort Study Based on Population in Republic of Korea.

Objective:This study aimed to evaluate the rate of transfusion for cardiovascular surgeries between 2010 and 2019 in Republic of Korea and the association between blood transfusion and postoperative mortality. Methods: Data were extracted from the National Health Insurance Service database in Republic of Korea. This study includes adult patients who underwent cardiovascular surgery between 1 January 2010 and 31 December 2019. The endpoints were in-hospital mortality and the 1-year all-cause mortality. Results: The analysis included 62,794 cases, with transfusions used in 88.8% of cases. Multivariable logistic regression revealed that older age, comorbidities, hospital admission through the emergency room, aortic procedures (versus coronary artery bypass grafting), cardiopulmonary bypass, repeat procedures, and supportive therapies during the intensive care (extracorporeal membrane oxygenation and mechanical ventilation) were risk factors for blood transfusion. Female sex was associated with a lower risk of transfusion. Perioperative blood transfusion was associated with a 6.87-fold increased risk of in-hospital mortality (odds ratio [OR]: 6.87, 95% confidence interval [CI]: 3.95, 11.93; p < 0.001) and a 3.20-fold increased risk of 1-year all-cause mortality (OR: 3.35, 95% CI: 2.75, 3.93; p < 0.001). Conclusions: Blood transfusion is used at a high rate in cardiovascular surgeries, and it was associated with increases in the risk of in-hospital and 1-year all-cause mortality. However, these correlations should be viewed with caution as emergent phenomena rather than causative. Understanding factors associated with the need for blood transfusion can assist surgeons in predicting the outcomes of cardiovascular surgery and in tailoring procedures as needed to optimize outcomes.

Preoperative computed tomography in the planning of median resternotomy in children

The capabilities of computed tomography (CT) in the diagnosis of mediastinal adhesions and measuring the density of adhesions when planning midline resternotomy in children were assessed, and the effect of preoperative CT on the incidence of surgical complications was studied. According to several authors, the frequency of resternotomies in cardiac surgery is up to 20% of the total number of surgeries per year and is accompanied by significant difficulties in the isolation of the heart and vessels. In pediatric cardiac surgery, complex congenital heart disease (CHD) mostly requires a staged approach. The staging of complex CHD correction and the need for repeated surgeries in most cardiac defects make the problem of safe repeated surgical access urgent. Postoperative adhesions are one of the most acute problems in modern cardiac surgery. The formation of adhesions is an inevitable reaction of the body after primary cardiac surgery. Massive adhesions that develop after surgery most commonly lead to adhesion of the heart and major great vessels to the posterior surface of the sternum. These changes are especially pronounced in children due to the high reactivity of the body and the lack of technical possibility and expediency of pericardial suturing after surgery. Rough adhesions during resternotomy complicate the cardiac surgeons task and increase the risk of complications. The main dangers are damage to various structures in the thorax such as the right and left heart, aorta, coronary arteries, pulmonary artery, and brachiocephalic vein. The diagnosis of postoperative adhesions in the mediastinum before resternotomy is difficult. CT has the widest diagnostic capabilities for assessing mediastinal adhesions. When performing CT as a part of preoperative resternotomy planning, it is important to examine the mediastinal topography, assess the degree of adjacency of the pericardium and mediastinal structures, determine the presence and density of adhesions, and assess patency and diameter of great vessels to select cannulas and cannulation methods necessary for emergency start of cardiopulmonary bypass (CPB) in cardiac trauma. These criteria are important when planning midline resternotomy to reduce the risks of traumatization of cardiac structures and great vessels and allow correction of surgical tactics and timely preventive surgical measures. Depending on the density, extent, and localization of adhesions, the cardiolysis technique and cannulation of great vessels required for initiation of emergency CPB may be changed. The use of preoperative CT when planning midline resternotomy in children allows to predict the risks of damage of cardiac structures and great vessels and visualize adhesive bands and measure their density, which helps the surgeon to adjust surgical tactics regarding the method and volume of cardiolysis and assess patency and diameter of great arteries and veins, thus determining the cannulation method and cannula diameter in advance if urgent CPB is needed. Therefore, standardization of CT description protocols for midline resternotomy planning with assessment of key criteria is an urgent task and requires further development.

Risk factors of in-hospital mortality for isolated on-pump coronary artery bypass graft surgery in the northeast of Iran from 2007 to 2016.

Coronary artery bypass graft (CABG) surgery is the most common cardiac surgery worldwide. The reported mortality rates for this operation vary greatly. We aimed to determine the risk factors of in-hospital mortality for isolated on-pump CABG surgery. This was a large-scale retrospective cohort study of two heart centers in Golestan province. Patients over the age of 18 from both genders who underwent isolated on-pump CABG procedures from 2007 to 2016 were included. The study outcome was in-hospital mortality, which was determined according to the clinical records of study patients. A total of 3704 patients were included in the study, and 63% were men. In-hospital mortality occurred in 2.8% (n=103) of the patients. The median (IQR) age of survived and not-survived patients were 59 (53-65) and 62 (55-75) years, respectively. 44% of the mortalities occurred in patients older than 65, while28% of the survivors were older than 65. Multivariable logistic regression indicated that emergency CABG (OR 4.52, 95% CI, 1.45, 14.02; P = 0.009) and cardiopulmonary bypass time (CPB) (OR 1.004, 95% CI 1.001, 1.008; P = 0.034) were the risk factors of in-hospital mortality. The area under the receiver operating characteristic (ROC) curve (AUC) of the model consisting of operative and preoperative variables was 0.70 (acceptable performance). Our study revealed an acceptable mortalityproportion for CABG surgeries conducted in the region. Emergency CABG and CPB time were the main risk factors for in-hospital mortality after CABG.

A case of unexpected intraoperative airway obstruction in a patient with an aneurysm of the ascending aorta and aortic arch.

Upper airway compression is one of the clinical manifestations of thoracic aortic aneurysm, which is associated with poor prognosis and high mortality. A 44-year-old patient with ascending aortic and arch aneurysm who was scheduled for Bentall surgery and total arch replacement under cardiopulmonary bypass suffered difficult ventilation after endotracheal intubation. The patient did not exhibit any positional dyspnoea or orthopnoea, did not show any difficulties in the supine position, and had no noteworthy medical history. However, we encountered unexpected hypoventilation after intubation. Isoprenaline infusion was effective while emergency cardiopulmonary bypass was established to deal with this crisis. Fibreoptic bronchoscopy revealed complete obstruction of the carina and confirmed the supracarinal position of the tube. Complete airway obstruction may occur even if there are no symptoms before surgery in patients with thoracic aortic aneurysm. Comprehensive preoperative assessment, a well-developed airway management plan, and responses to possible emergencies are essential to reduce unnecessary events or complications.

Cuffed endotracheal tube as a cardiopulmonary bypass venous return cannula.

Cuffed endotracheal tube as a cardiopulmonary bypass venous return cannula.

Left ventricular ejection fraction is associated with intraoperative circulatory collapse during transcatheter aortic valve implantation.

BackgroundIntraoperative hemodynamic collapse during transcatheter aortic valve implantation (TAVI) is a devastating complication that requires mechanical support. In this study, we sought to analyze our early experience in using cardiopulmonary bypass (CPB) support to circumvent circulatory compromise during TAVI.MethodsBetween January 2018 and December 2020, 102 consecutive patients (54 males; mean age, 71.2±8.9 years) received TAVI at Tianjin Chest Hospital, and an emergency CPB device was used in 6 of these patients (5.9%). The clinical data of the CPB and no-CPB groups were analyzed to identify the factors associated with intraoperative hemodynamic collapse requiring CPB.ResultsAll 6 patients who needed emergency CPB support were successfully weaned from the device. This group had a higher Society of Thoracic Surgeons Score [4.09 (2.02, 6.85) vs. 7.47 (5.07, 23.46); P=0.030], more patients with a left ventricular ejection fraction (LVEF) ≤30% [4 (66.7%) vs. 2 (2.1%); P=0.000], a larger right ventricle anteroposterior diameter [20.50 (19.75, 21.25) vs.19.00 (17.00, 20.00); P=0.016], and a higher degree of aortic regurgitation [4.50 (2.75, 5.00) vs. 2.00 (1.00, 4.00); P=0.018] compared to the no-CPB group. The CPB group also had a higher in-hospital mortality rate than did the no-CPB group (16.7% vs. 4.7%; P=0.026). Multivariable analysis determined that the presence of lower pre-TAVI LVEF was associated with intraoperative hemodynamic collapse.ConclusionsOur results indicate that LVEF is an independent risk factor for requiring emergency CPB during the TAVI procedure. The need for emergency CPB support was associated with higher in-hospital mortality.

Bedside echocardiography for diagnosis of intracardiac cement embolism after percutaneous vertebroplasty: A case report

This case report is to demonstrate that a female patient had suddenly become unconscious 14 hours after percutaneous vertebroplasty. Bedside echocardiogram showed that the patient had a strong echo in the right heart with a small amount of pericardial effusion. CT showed high density in the distal branches of both pulmonary arteries and a high density in the right heart. With the help of that, the doctor made the diagnosis of intracardiac cement embolism in a very short time. The bone cement in the heart was removed under emergency cardiopulmonary bypass, then the patient was discharged smoothly.

Does the exhaust air from oxygenator during open-heart surgeries in COVID-19 positive patients cause operating room air contamination? A case report

Introduction: New findings regarding Covid 19 are reviewed and reported daily, and safety protocols are changed regularly. In Covid positive patients, the exhaust air coming from oxygenator’s gas outlet may be a potential source of air contamination in operating room. This may also cause health issues for Operating room staff. As there has been no research regarding this issue, this study will reveal whether the exhaust air from the oxygenator in Covid positive patient may cause air contamination or not. Case presentation: The Covid positive patient underwent emergency cardiopulmonary bypass. After surgery, PCR swab was taken from the oxygenator exhaust, which evacuate the air inside the oxygenator into the operating room theatre. The positive PCR test for Covid may suggests the possibility of air contamination by oxygenator. Result: This may be the first study suggesting the possibility of room air contamination by oxygenator exhaust air during cardiopulmonary bypass. This study shows some current protocols may need to be reviewed in order to ensure increased safety within the operating room and amongst the personnel, therefore permanent changes may be applied to some procedures.

Right ventricular outflow tract stenting in symptomatic infants without the use of a long delivery sheath.

Right ventricular outflow tract (RVOT) stenting improves systemic oxygenation and facilitates pulmonary arterial growth in symptomatic infants prior to repair of tetralogy of Fallot. The aim of this study was to evaluate the safety and efficacy of RVOT stenting without the use of a long delivery sheath. Retrospective data analysis of patients under 1 year of age undergoing RVOT stenting from January 2010 to January 2020 at a single tertiary pediatric cardiology center. Sixty-three RVOT stents were deployed during 53 procedures into 44 patients. The median age and weight at insertion were 41 days (range 2-204) and 3.6kg (range 1.59-7) respectively. Thirty-one procedures were semi-elective and 22 were emergencies. Stent positioning was guided by transthoracic echocardiogram and/or RV angiography from a pigtail micro-catheter placed via the aorta. The median total procedure and fluoroscopy times were 67.5 (range 15-145) and 19 min (1-107), respectively. The median length of hospital stay was 7 days (range 1-258). Twenty-one patients were admitted to ICU post-procedure with a median ICU length of stay of 3 days (range 3-11). There were three major complications including two deaths within 30 days of the procedure. A patient with Cornelia de Lange Syndrome (1.8 kg) died following stent migration and inability to wean from emergency cardiopulmonary bypass and the second infant had an unexplained asystolic arrest post-procedure while awaiting transfer to ICU. RVOT stenting is technically possible with minimal complications without the need for a long delivery sheath. Additional imaging with transthoracic echocardiography can facilitate the safe deployment of the stent.

Use of carotid artery cannulation during redo sternotomy in congenital cardiac surgery: a single-centre experience.

Management of resternotomy is often a difficult challenge in patients with congenital diseases who have undergone multiple sternotomies. Our goal was to report our single-centre experience with carotid cannulation using a graft interposed during redo sternotomy in complex cardiac reintervention procedures. We performed a retrospective review of all patients who had undergone complex redo sternotomies between January 2019 and May 2020 utilizing a cervical cannulation technique with a Gore-Tex graft interposed on the carotid artery. We classified our population study on the basis of the primary diagnosis and the type of surgery. The primary outcomes of our analysis were the evaluation of the safety of the procedure in terms of survival and freedom from neurological events. We analysed 22 patients who had undergone previous complex operations. The median age and weight at the time of reintervention were 130.35 (range 0.46-435) months and 31.5 (range 2.2-85) kg, respectively. Composite graft carotid cannulation provided adequate arterial flow in all patients with a median arterial flow of 3.5 l/min/m2 (range 0.6-6). One major cardiac injury occurred during sternotomy when emergency cardiopulmonary bypass (CPB) was initiated. Moreover, during their hospital stays, all patients had an uneventful recovery without neurological or vascular complications and no cervical wound infections. Carotid cannulation using interposition of a side graft on the common carotid artery for arterial inflow is a reliable and safe method for initiation of CPB in complex redo surgeries in patients with congenital disease. Complications directly associated with this type of cannulation are uncommon and allow surgical re-entry with overall low risks.

Risk factors of delayed awakening after aortic arch surgery under deep hypothermic circulatory arrest with selective antegrade cerebral perfusion.

To determine the risk factors of delayed awakening following aortic arch surgery under deep hypothermic circulatory arrest (DHCA) in combination with selective antegrade cerebral perfusion (SACP). We retrospectively analyzed the clinical data of all patients who underwent aortic arch surgery under DHCA + SACP between September 2015 and September 2017 in our hospital. Delayed awakening was defined as recovery of consciousness later than 24 hours after the surgery. Risk factors of delayed awakening were evaluated using multivariate logistic regression analysis. A total of 168 subjects were included. In-hospital mortality of the overall sample was 19.05% (n=32). Delayed awakening occurred in 76 (45.23%) subjects. Subjects with delayed awakening had older age, hypertension, higher rate of emergency surgery and blood transfusion, and longer cardiopulmonary bypass (CPB) time and myocardial blocking time. Multivariate regression analysis showed emergency surgery (P=0.005) and CPB time >240 min (P<0.001) as risk factors for delayed awakening, even after adjusting potential confounders, including age, hypertension, aortic cross-clamp time and blood transfusion. In patients undergoing aortic arch surgery under DHCA + SACP, emergency surgery and CPB time >240 min are risk factors for delayed awakening.

Perioperative Outcomes of Repeated Open Surgery on the Thoracic Aorta.

Repeated thoracic aorta repair is increasingly common. With the increase in hybrid procedures, determination of the best treatment strategy requires evaluation of the clinical outcomes of classic open surgery. We retrospectively reviewed 119 patients (84 men and 35 women, aged 51.0 ± 16.7 years) with a history of open repair involving the thoracic aorta above the diaphragm. The patients underwent an average of 1.3 ± 0.8 surgeries (range: 1-8) on the thoracic aorta before the final operation. Clinical outcomes were evaluated on the basis of the need for emergency surgery, indications for surgery, pathologic causes, and other operative variables. Hospital mortality was 6.7% (n = 8). Postoperative bleeding occurred in 16% (n = 19). On multivariable analysis, emergency surgery (odds ratio [OR], 19.005; P = .003; 95% confidence interval [CI], 2.710-133.305) and cardiopulmonary bypass (CPB) time (OR, 1.562 per 30 minutes; P = .007; 95% CI, 1.126-2.165) were predictors of hospital death. Emergency surgery (OR, 4.105; P = .029; 95% CI, 1.157-14.567) and CPB time (OR, 1.189 per 30 minutes; P = .035; 95% CI, 1.012-1.396) were also associated with postoperative bleeding, in addition to surgery for an infectious cause (OR, 10.824; P = .010; 95% CI, 1.755-66.770). Estimated survival at 1, 5, and 7 years was 86.6%, 80.5%, and 78.2%, respectively. Despite the variety of preoperative conditions and operations performed, repeated open surgery for thoracic aorta repair can be performed with acceptable early and late outcomes.

Cardiopulmonary Bypass in Non-Cardiac Surgery

Cardiopulmonary bypass (CPB) and extracorporeal membrane oxygenation (ECMO) are used to facilitate circulatory support in standard cardiac surgery and emergency intervention, but CPB and ECMO are not used routinely in non-cardiac surgery involving the thorax and major vessels. The primary aim of this study was to identify the type of non-cardiac procedures and bypass used in our institution and review the patient outcomes including perioperative and bypass complications. A retrospective study was performed within the Royal Adelaide Hospital Cardiothoracic Surgery Unit (CTSU) that examined all operations between 2006 and 2014. There were 1,816 non-cardiac cases, of these nine used CPB or ECMO. Cases excluded from the study were those that required cardiac surgical management with the use of CPB or ECMO. Twelve (12) non-cardiac surgery cases were reviewed, with three, and nine cases, respectively, using ECMO and CPB standby or support. The non-cardiac surgical procedures included eight thoracic cases, two renal cases and two tracheal cases. Of the thoracic cases, five were elective, two were bailout and one was an emergency. Both renal cases were bailout (with one as major vessel support and one as standby). Both tracheal cases were bailout (one as an emergency and one as standby). Intraoperative complications included severe haemorrhage in three cases. General postoperative complications included increased analgesia requirement, atelectasis, fever; and prolonged ECMO support and ICU stay which occurred in seven cases. No direct complications of CPB or ECMO are reported. Four of the 12 cases that encompassed thoracic, renal and tracheal surgery are discussed in detail. Our review of 12 cases managed under the CTSU has shown that extracorporeal circulatory support can be used in a range of thoracic, renal and tracheal surgery. These surgical procedures have involved the management of haemodynamically unstable patients. Patient outcomes have been encouraging with few complications. With further research including the use of a larger sample size and control groups, more definitive conclusions could be made on the benefit of CPB and ECMO to patients in non-cardiac surgery.

Successful pulmonary embolectomy for massive pulmonary embolism during pregnancy: a case report

BackgroundPulmonary embolism (PE) resulting from venous thromboembolism is a leading cause of maternal mortality in pregnancy. In patients with massive PE and hemodynamic instability, the treatment options often considered are thrombolytics, inferior vena caval filters, or embolectomy. We report here the case of a patient with massive PE at 28 weeks’ gestation, who underwent emergency pulmonary embolectomy via cardiopulmonary bypass.Case presentationA 35-year old primigravida with a history of massive PE at 25 weeks of gestation was referred to our hospital at 28 weeks of gestation, following treatment failure after insertion of an inferior vena cava filter and heparin administration. Emergency thrombectomy was performed, and intracardiac echography was used for intraoperative fetal heart rate monitoring. However, the patient developed hemodynamic collapse following anesthesia induction; hence, emergency cardiopulmonary bypass (CPB) was performed via median sternotomy. Thrombectomy and tricuspid valve plication were performed under cardiac arrest. After confirming postoperative hemostasis, heparin administration was resumed. At 40 weeks of gestation, labor was induced under epidural analgesia. Both mother and child were discharged with no complications.ConclusionIn conclusion, intracardiac echography is useful for fetal heart rate monitoring during emergency cardiac surgery in pregnancy. Careful CPB management is important to maintain uteroplacental blood flow. Although there is no consensus on the delivery methods in such cases, epidural analgesia during labor was useful in reducing cardiac load and wound traction.

Emergent Cardiopulmonary Bypass during Cardiac Surgery

During orientation to the cardiac surgery operating room, new staff may not be exposed to emergent situations. Allowing team members the opportunity to practice their roles during less common, high-stakes emergency cardiac surgical scenarios may better prepare them when crises do arise in the OR. The Emergency Cardiopulmonary Bypass Course was developed to meet the needs of new staff starting in cardiac surgery. Recently, the course has expanded to include experienced staff. This communication describes a high fidelity simulation based course that includes four emergent cardiac surgery scenarios.

Laryngeal clefts

Laryngeal clefts

Pneumonectomy in the Indian scenario—a review of current indications and results

Pneumonectomy is an important procedure in the armamentarium of the thoracic surgeon dealing with both neoplastic and non-neoplastic diseases of the lung especially in a developing country like India where the sequelae of tuberculosis are still rampant and the incidence of lung cancer is on the rise. The indications for pneumonectomy are varied. The operative techniques are standardized. Assessment of risk-benefit ratio is important as pneumonectomy carries considerable morbidity. We present our experience with 74 cases of pneumonectomy performed for varied etiologies, the outcomes of which are retrospectively analyzed in this study. We retrospectively reviewed our institutional database for patients who underwent a pneumonectomy from January 2009 to April 2015. Demography, patient profile, indications for surgery, details of operative technique, development of perioperative complications, and mortality were analyzed. Seventy-four patients underwent pneumonectomy, with a male to female ratio of 2:1. The age range was 6 to 72 years out of which six were children (8.1 %). Post-tuberculosis-destroyed lung was the predominant indication (43.24 %). Nineteen (25.67 %) underwent pneumonectomy for various tumors. Completion pneumonectomy was done in four (5.40 %). Left pneumonectomy was performed in 48 patients (64.86 %). The operative time ranged between 110 and 385 min. The mean post-operative stay was 4 days. Two patients (2.70 %) required emergency cardiopulmonary bypass for torrential hemorrhage during hilar dissection. Post-operative complications encountered were reactionary hemorrhage (1), empyema (2), bronchopleural fistula (1), and chylothorax (1). There was one early post-operative death due to fulminant respiratory failure. Early mortality rate was 1.35 %. The outcomes following pneumonectomy are favorable when careful attention to patient selection, preoperative patient optimization, meticulous surgical technique, and post-operative principles are followed. Pneumonectomy in post-pulmonary tuberculosis-destroyed lungs did not carry extra morbidity or mortality. Pneumonectomy in malignant lung/bronchial diseases is safe. Pneumonectomy in children was remarkably uncomplicated. Completion pneumonectomy can be done with an acceptable morbidity in selected patients. Use of cardiopulmonary bypass when encountered with torrential intraoperative hemorrhage is an acceptable strategy. Outcomes of hand-sewn bronchial closure technique are comparable to stapling devices and cost effective.

Cardiac arrest: resuscitation and reperfusion.

The modern treatment of cardiac arrest is an increasingly complex medical procedure with a rapidly changing array of therapeutic approaches designed to restore life to victims of sudden death. The 2 primary goals of providing artificial circulation and defibrillation to halt ventricular fibrillation remain of paramount importance for saving lives. They have undergone significant improvements in technology and dissemination into the community subsequent to their establishment 60 years ago. The evolution of artificial circulation includes efforts to optimize manual cardiopulmonary resuscitation, external mechanical cardiopulmonary resuscitation devices designed to augment circulation, and may soon advance further into the rapid deployment of specially designed internal emergency cardiopulmonary bypass devices. The development of defibrillation technologies has progressed from bulky internal defibrillators paddles applied directly to the heart, to manually controlled external defibrillators, to automatic external defibrillators that can now be obtained over-the-counter for widespread use in the community or home. But the modern treatment of cardiac arrest now involves more than merely providing circulation and defibrillation. As suggested by a 3-phase model of treatment, newer approaches targeting patients who have had a more prolonged cardiac arrest include treatment of the metabolic phase of cardiac arrest with therapeutic hypothermia, agents to treat or prevent reperfusion injury, new strategies specifically focused on pulseless electric activity, which is the presenting rhythm in at least one third of cardiac arrests, and aggressive post resuscitation care. There are discoveries at the cellular and molecular level about ischemia and reperfusion pathobiology that may be translated into future new therapies. On the near horizon is the combination of advanced cardiopulmonary bypass plus a cocktail of multiple agents targeted at restoration of normal metabolism and prevention of reperfusion injury, as this holds the promise of restoring life to many patients for whom our current therapies fail.

Developing dual hemofiltration plus cardiopulmonary bypass in rodents

BackgroundEmerging therapies for prolonged cardiac arrest (CA) include advanced circulatory interventions like emergency cardiopulmonary bypass (ECPB) and continuous venovenous hemofiltration (CVVHF). However, preclinical studies are limited because of the absence of a practical method of using CVVHF along with ECPB in rodents. MethodsWe modified a CA model with ECPB resuscitation to include the CVVHF circuit. Adult rats were cannulated via the femoral artery or vein and the jugular vein for the ECPB circuit. A new circuit for CVVHF was added to allow ECPB and CVVHF to be started simultaneously. CVVHF blood flow at 3 mL/min could be controlled with a screw clamp during ECPB. After cessation of ECPB, the CVVHF flow was maintained using a roller pump. The filtration rate was controlled at 40 mL/h/kg in the standard volume of CVVHF and 120 mL/h/kg in the high volume (HV) of CVVHF. The driving force of hemofiltration was evaluated by monitoring transmembrane pressure and filter clearance (FCL). ResultsTransmembrane pressure in both groups was stable for 6 h throughout CVVHF. FCL of blood urea nitrogen and potassium in the standard volume group was significantly less than the HV group (P < 0.01). FCL of blood urea nitrogen and potassium was stable throughout the CVVHF operation in both groups. ConclusionsWe developed a method of CVVHF along with ECPB in rodents after CA. We further demonstrated the ability to regulate both standard and HV filtration rates.

Abstract 20074: Hemodynamic Profile of Prolonged Normothermic, Mild Hypothermic, and Deep Hypothermic Emergency Cardiopulmonary Bypass Reperfusion in Rats

Background: The hemodynamic profile of rats randomized into prolonged normothermic (NT, 37±0.5°C), mild hypothermic (MH, 33±0.5°C) or deep hypothermic (DH, 27±0.5°C) reperfusion with emergency cardiopulmonary bypass (ECPB), following refractory ventricular fibrillation cardiac arrest (VF CA) was explored. Methods: Fifty adult male Sprague-Dawley rats were put on bypass for 15 min, following 10 min of VF CA. The ECPB setup included a circulating water bath which temperature controlled all animals at target. After 15 min, rats were defibrillated, weaned from bypass, and controlled at 33°C (MH, DH) or 37°C (NT) externally. All rats received a single dose of epinephrine (30 μg/kg), heparin and sodium bicarbonate with the crystalloid priming of the ECPB circuit. ECPB flow rate was kept at 100 mL/kg in all groups. Mean arterial pressure (MAP) was continuously monitored in the femoral artery and is presented as median with 25th/75th quartile mmHg. Results: See figure. There was no difference in MAP before or during CA. For the first 5 min of resuscitation, MAP at a given ECPB flow rate was highest in the DH group (DH 84(69;89), MH 51(49;61), NT 48(37;55) , p = &lt;.001). This was reversed during the last 5 min on bypass (DH 35(30;42), MH 44(37;64), NT 42(33;67), p = .034). For 10 min off bypass, the DH group was relatively hypotensive (DH 46(40;62, MH 64(60;77), NT 61(54;77), p = .005), which was again reversed for the remaining post resuscitation period (DH 68(60;78), MH 59(54;66), NT 53(49;62), p = .008). Conclusions: While the temperature profiles of NT and MH reperfusion were similar, DH caused initially higher pressures followed by a period of hypotension as compared to NT and MH groups at identical epinephrine doses and ECPB flow rates. Off bypass, DH animals were again relatively hypotensive, coinciding with their rewarming to mild hypothermia. Further experiments are needed to determine the cause of this, like hypothermic vasoconstriction, or altered pharmacokinetics.