Minoo N. Kavarana

Right ventricular dysfunction and organ failure in left ventricular assist device recipients: a continuing problem

BACKGROUNDnAlthough right ventricular assist device (RVAD) use has declined with the introduction of inhaled nitric oxide and phosphodiesterase inhibitors (type III), right ventricular dysfunction (RVD) is still a serious problem in patients receiving left ventricular assist devices (LVAD).nnnMETHODSnWe retrospectively analyzed Thoratec Vented Electrical LVAD recipients between June 1996 and September 1999. RVD was defined as inotropic requirement 14 days or more or need for RVAD postoperatively, or both.nnnRESULTSnSixty-nine LVAD recipients were analyzed. Twenty-one patients (30.4%) had RVD, with 1 patient requiring RVAD insertion, and there were 48 non-RVD patients. There were no significant differences between both groups for age, sex, etiology of congestive heart failure, days of support, and preoperative hemodynamics. Preoperative right ventricle stroke work index (mm Hg x m(-2) x L(-1)) had a trend toward being lower in the RVD group (4.1+/-3.2 versus 6.1+/-3.7, p = 0.06). A higher preoperative total bilirubin (mg/dL) was noticed in the RVD group (4.0+/-5.2 versus 2.1+/-1.7). The RVD group had a higher postoperative creatinine (2.2+/-1.4 mg/dL versus 1.5+/-0.8 mg/dL), incidence of continuous venovenous hemofiltration dialysis (73% versus 26%), transfusion of packed red blood cells (43.2+/-28.6 units versus 24.7+/-18.9 units), platelets (58.6+/-46.1 units versus 30.2+/-20.4 units), with longer intensive care unit length of stay (33.6+/-34.7 days versus 9.1+/-6.9) and higher mortality (42.8% versus 14.5%). When deaths were excluded, both intensive care unit and postoperative length of stay were significantly longer in the RVD group.nnnCONCLUSIONSnRVD in LVAD recipients remains poorly identified and is associated with a high transfusion rate and end organ failure that results in increased intensive care unit and hospital length of stay, and a high mortality rate. Preoperative identification of risk factors for RVD may select patients who would benefit from a biventricular assist device and prevent the subsequent end organ failure.

Mechanical support for the failing cardiac allograft: a single-center experience.

BACKGROUNDnMechanical support for pre-transplant stabilization is established, but its use in peri-operative graft failure (PGF) has not been well documented. With liberal acceptance criteria being used to enlarge the donor pool, an increased incidence of graft failure might be expected. We evaluated the incidence and outcome of PGF at our institution.nnnMETHODSnA retrospective review of 462 consecutive adult heart transplants performed between January 1993 and December 1999 revealed 20 cases of PGF. Donor-, surgery- and device-related variables were evaluated for association with operative mortality, survival and successful device weaning.nnnRESULTSnTransplant recipients included 17 men and 3 women, median age 56.5 years (20 to 66 years). PGF etiology included primary graft failure (n = 9); right heart failure (RHF) secondary to pulmonary hypertension, coagulopathy/intra-operative hemorrhage or sepsis (n = 9); and hyperacute rejection (n = 2). Device types included RVAD (n = 11), LVAD (n = 4), BIVAD (n = 3) and IABP (n = 2). The wean rate was 45%. Duration of device support ranged from 2 to 965 hours. Early ventricular recovery (within 96 hours) was associated with significantly better 30-day and 2-year survival. Weaned patients had an 88% 30-day and 67% 2-year survival, whereas the overall survival rate was 79% at 2 years (p = not significant).nnnCONCLUSIONSnEarly ventricular recovery is an important predictor of successful weaning and survival. In view of the prohibitive mortality associated with PGF and the dismal prognosis with re-transplantation, we advocate aggressive use of mechanical assistance for PGF, with an acceptable survival benefit.

Long-Term Survival and Quality of Life in Cardiac Surgical Patients With Prolonged Intensive Care Unit Length of Stay

BACKGROUNDnPatients with prolonged intensive care unit (ICU) stays after cardiac operations are labor intensive and expensive. We sought to determine whether exhaustive ICU efforts result in survival or quality-of-life benefits and whether outcome could be predicted.nnnMETHODSnWe retrospectively analyzed all adult cardiac surgical patients in 1998 for ICU stays more than 14 days. Data were analyzed to create multiple organ dysfunction scores (MODS, range 0 to 24) and hospital charges. Follow-up was conducted 1 and 2 years apart for survival and quality-of-life evaluation.nnnRESULTSnForty-nine patients remained in the ICU more than 14 days, comprising 3.8% of our patients but 28% of total ICU bed time. This population had a 28.5% hospital mortality, which was greater than those in the ICU less than 14 days (5.3%, p < 0.05). By 2 years, 22 of the 35 discharged patients were alive, 16 of whom had a normal quality of life. Patients alive at 2 years had lower MODS at day 14 than those who died (2.6 +/- 1.4 versus 5.5 +/- 3.8; p < 0.005) as well as lower hospital costs (

Gastric hypercarbia and adverse outcome after cardiac surgery

223,000 +/-

Restoration of renal function in shock by perfusion of the renal artery with venous blood: A counterintuitive approach

128,000 versus

Continuous-flow, implantable biventricular assist device as bridge to cardiac transplantation in a small child with restrictive cardiomyopathy

306,000 +/-

Pediatric Mechanical Support with an External Cardiac Compression Device

128,000; p < 0.05). No patient with an MODS of at least 6 at day 14 survived.nnnCONCLUSIONSnPatients remaining in the ICU for more than 14 days suffer a higher mortality at greater expense. A MODS at day 14 may help predict those who will not enjoy long-term survival and thus aid in the decision to terminate care.

EARLY DIRECT PERFUSION WITH VENOUS BLOOD ENHANCES RENAL FUNCTION IN IMPENDING ACUTE RENAL FAILURE

Objective: It has been postulated that splanchnic ischemia, as manifested by gastric hypercarbia, helps to trigger excessive systemic inflammation, which has been linked to the development of adverse postoperative outcome. This study examined whether gastric PCO2 values are associated with adverse outcome in cardiac surgical patients.Design and settingProspective cohort study in a tertiary-care hospital.Patients43 patients undergoing elective cardiac surgery.InterventionsSimultaneous measurements of gastric PCO2 (using automated air tonometry) and arterial PCO2 were obtained at the beginning and end of surgery. The difference (gap) between regional PCO2 and arterial PCO2 (corrected for temperature) was calculated. Adverse outcome was defined as in-hospital death or prolonged (>10xa0days) postoperative hospitalization.Measurements and resultsFourteen patients fulfilled the predefined definition for adverse outcome. Postoperative ICU stay and postoperative hospital length of stay were significantly longer in these patients. At the end of surgery gastric minus arterial PCO2 gap was significantly larger in patients with adverse outcome. Global hemodynamic and perfusion related variables were not associated with adverse outcome (cardiac index, mean arterial pressure, mixed venous oxygen saturation, arterial lactate, arterial base excess).ConclusionsGastric minus arterial PCO2 gap after surgery is larger in patients with adverse postoperative outcome, which supports the theory that gastrointestinal reduced perfusion is relevant to the pathogenesis of postoperative morbidity

Circulatory support with a direct cardiac compression device: A less invasive approach with the AbioBooster device

ObjectiveAcute renal failure (ARF) in low-flow states may be reversed by increasing renal perfusion. When hemodynamics are maximized, renal perfusion can only be improved by shunting a higher proportion of cardiac output to the kidney; however, in low-flow states, this reduces already compromised systemic pressure and perfusion to other organs. Increasing perfusion using venous blood (VB) would be an attractive option because decreased systemic pressure and perfusion to other organs could be avoided. However, it is not known whether VB can provide adequate oxygen delivery to restore or maintain renal function. We studied whether antegrade VB perfusion of the kidney via the renal artery would restore urine output (UO) and glomerular filtration rate (GFR) in hypoperfused ARF. DesignShock was induced in six dogs via a hemorrhagic protocol resulting in a systolic blood pressure of 50–70 mm Hg, a mixed venous oxygen saturation of 25% to 40%, and a UO <10% of baseline. After 60 mins of shock, the left renal artery was cannulated under fluoroscopy and perfused at pressures of 100–150 mm Hg for 30 mins with VB drawn from the vena cava and delivered by an extracorporeal pump system. The right kidneys were controls and remained hypoperfused. ResultsAll VB-perfused kidneys recovered renal function after a sustained period of shock and marked oliguria: UO from 0.7 ± 1.6 mL/hr to 101 ± 58 mL/hr (p < .01); GFR from approximately 0 to 70.3 ± 55 mL/min (p = .04). The control kidneys’ UO (0.7 ± 1.6 mL/hr) and GFR (0 mL/min) remained unchanged throughout the study. The experimental kidneys were able to extract oxygen from VB (O2 saturation, 31 ± 7% to 16 ± 4%;p = .01). ConclusionWhen flow is controlled, kidneys in hypoperfused ARF can extract sufficient oxygen from antegrade VB perfusion to restore renal function (UO and GFR).

Improved Technique to Diagnose a Patent Foramen Ovale During Left Ventricular Assist Device Insertion

Continuous-flow, implantable biventricular assist device as bridge to cardiac transplantation in a small child with restrictive cardiomyopathy Lauren Glass, MD, Andrew Savage, MD, Osama Haddad, MD, and Minoo N. Kavarana, MD From the Department of Pediatrics, Division of Pediatric Cardiology, Medical University of South Carolina, Charleston, South Carolina, USA; and the Department of Surgery, Division of Cardiothoracic Surgery, Medical University of South Carolina, Charleston, South Carolina, USA