Postoperative Low Output State Research Articles

Temporary mechanical circulatory support prevents the occurrence of a low-output state in high-risk coronary artery bypass grafting: A case series.

Coronary artery bypass grafting (CABG) is a durable treatment for coronary artery disease. Left ventricular dysfunction (LVD) (a division of cardiothoracic surgery) (ejection fraction < 35%) significantly elevates perioperative risk for patients pursuing surgical revascularization. Periprocedural support with temporary mechanical circulatory support (tMCS) has shown benefit in this patient population. Four patients with ischemic cardiomyopathy and LVD underwent CABG at our institution between 2017 and 2018. Each patient received perioperative ventricular support using a microaxial tMCS device (Impella 5.0®). The occurrence of a postoperative low-output state (LOS) was assessed for as well as postoperative morbidity and mortality, device-specific complications, and tMCS support duration. All patients survived to device explant without device-related complications. Two patients required reoperation for nondevice-related bleeding. All patients were without an LOS at 24 hpostoperatively with cardiac indices of 2.9-3.6 L/min/m2 , normalized serum lactate, and vasoactive-inotrope scores of 0-12.0. There was a notably high incidence of acute renal failure (50%), which was observed in patients with preoperative cardiogenic shock. One patient died 10 days after the device explant. Of the three patients that survived to discharge, two were alive at the most recent follow-up. Postoperative device support varied widely (0-500 h). Perioperative tMCS may be a viable strategy for preventing postoperative LOS in high-risk CABG patients with a low complication rate and acceptable morbidity. The application of microaxial tMCS devices in CABG is an area that warrants further investigation to delineate its impact on perioperative outcomes and potentially expand the indications for such devices.

The Role of Intraoperative Regional Oxygen Saturation Using Near Infrared Spectroscopy in the Prediction of Low Output Syndrome After Pediatric Heart Surgery

We report on the applicability of intraoperative regional oxygen saturation (rSO2) desaturation score by near-infrared spectroscopy in the early detection of postoperative low output state (LOS) in infants with congenital heart disease who underwent cardiac surgery. Between July and October 2011 the intra- and immediate postoperative courses of 22 patients undergoing elective cardiac surgery for congenital heart disease were analyzed. The intraoperative cerebral and somatic rSO2 were measured and a rSO2 desaturation score calculated (by multiplying the rSO2 below 50% of the threshold by seconds). The aim of the study was to evaluate the applicability of intraoperative rSO2 de-saturation score in the early detection of postoperative LOS. Thirteen of 22 patients (62%) had an intraoperative cerebral rSO2 desaturation score >3000% per second. Patients with a rSO2 de-saturation score >3000% per second had a significantly lower intraoperative central venous saturation (SvO2, p = 0.002), cardiac index (CI, p = 0.004), oxygen availability indexed (DO2I, p = 0.0004), and a significantly higher extraction of oxygen (ERO2, p = 0.0005) when compared to patients with a rSO2 desaturation score <3000% per second. Nine patients had postoperative LOS; all of them had an intraoperative rSO2 de-saturation score >3000% per second (9/13 patients, 69%; p = 0.001) requiring prompt treatment with major inotropic support, surface hypothermia, and extracorporeal membrane oxygenation (ECMO) support (n = 4). Twenty-one patients survived. One patient died from ventricular failure and inability to wean from ECMO support. The intraoperative use of NIRS provided an early warning sign of hemodynamic or metabolic compromise, enabling early and rapid intervention to prevent or reduce the severity of potentially life-threatening complications.

Abstract 3044: The Preoperative Utilization of Levosimendan (Preoperative Optimization) Reduced Mortality and Low Output Syndrome After Cardiac Surgery in Patients With Low Ejection Fraction (EF&lt;25%).

Background: Patients with low ejection fraction (EF&lt;25%) present high-risk of mortality and development of low output state (LOS) after cardiac surgery. The objective of this research was to evaluate the preoperative use of the calcium sensitizer Levosimendan (Levo) in patients with EF&lt;25%, underwent open heart surgery. Thirty-day mortality and development of postoperative LOS were the primary end-points of the study. Methods: Patients with EF&lt;25% and hemodynamic parameters of LOS (cardiac index&lt;2.2 L/min/m2 and pulmonary artery occlusion pressure&gt;15 mm Hg), underwent coronary bypass surgery between 12/01/2002 and 02/01/2007 were randomized to: preoperative infusion of Levo 0.1 mcg/Kg/min, 24 hours before surgery (Levo group-preoperative optimization), or placebo (Control group). LOS postoperative was defined for the same hemodynamic variables. A P value &lt; 0.05 was considered significant Results: Two-hundred and twenty one patients fulfilled the inclusion criteria, being randomized 111 of them to Levo, and 110 patients to placebo. Both groups were comparable in their general and surgical characteristics. No withdrawal of Levo was required during the preoperative administration, with 8 patients showing hypotension episodes which was resolved with fluid infusions. There were not ventricular arrhythmias, supraventricular arrhythmias (with heart rate over 125) or preoperative ischemic events. The 30-day mortality was 3 patients in the Levo group (2.7%) versus 12 patients in the Control group (10.9%, P value 0.001, OR 0.23, IC95 0.05– 0.90). Seven patients in the Levo group developed postoperative LOS (6.3%) against 20 patients in the Control group (18.2%, P value &lt;0.001, OR 0.30, IC95 0.11– 0.80) Conclusion: The preoperative optimization with Levosimendan reduced the operative mortality and the development of postoperative LOS in patients with EF&lt;25% underwent open heart surgery. The infusion was safety no needing to withdraw it in any case. These findings could represent a new strategy to reduce the operative risk in this group of patients.:

Determinants of Hospital Mortality after Repeat Mitral Valve Surgery for Rheumatic Mitral Valve Disease

The aim of this study is to detect the risk factors for hospital mortality in patients who underwent reoperative mitral valve replacement. Rheumatic mitral valve patients who underwent primary mitral valve replacement (386 cases) and repeat mitral valve replacement (94 cases) were analysed retrospectively. The incremental effects of the reoperative procedure on hospital mortality were studied by comparing primary and reoperative procedures and analyzing a series of possible predisposing factors. Operative mortality for repeat procedures was found significantly higher than the first operations (respectively 12.8% versus 4.3%, p=0.022). Risc factors affecting the hospital mortality in reoperation group were determined as advanced age, diameter of left atrium, prolonged bypass time and development of postoperative low output state. The indication for surgery also had a significant role in patients' outcome. Mortality found significantly higher in cases operated due to endocarditis or mitral mechanical valve thrombosis compared to other reoperation groups. Patients over age of 70 years, with a left atrial diameter over 60 mm, reoperated due to endocarditis and mechanical valve thrombosis, should be reevaluated for risk assessment while giving the decision of optimal operation timing. Especially patients with left ventricular hypertrophy and decreased myocardial reservoirs, efficient myocardial protection during the operation had an important role.

Aortic Atherosclerosis Predicts Postoperative Renal Dysfunction

Cardiac surgical procedures carry a relatively high risk of acute renal failure. Previously reported associated factors include advanced age, impaired left ventricular (LV) function, active bacterial endocarditis, pre-existing renal dysfunction, prolonged aortic cross-clamp time, and a postoperative low output state. This prospective U.S. study evaluated the importance of …

COENZYME Q10: Protects against cardiac postoperative low output state

COENZYME Q10: Protects against cardiac postoperative low output state

Evaluation of mechanical left ventricular assistance with left atrium to aorta bypass in dogs.

Effects of the left heart bypass (LHB) by the left atrium (LA) to the aorta (AO) shunt on the heart were evaluated by measuring such parameters as tension time index (TTI), diastolic pressure time index (DPTI), DPTI/TTI ratio, coronary blood flow and myocardial oxygen consumption (MVO2) in open-chest dogs. A pneumatically driven bypass pump made of polyurethane was utilized in this study. No significant change of MVO2 was observed with surgical maneuver to connect the LA-AO LHB pump to experimental animals. During synchronous pumping of LHB, TTI decreased by 35%, MVO2 decreased by 56% of the control and DPTI/TTI ratio increased by 79%. However, coronary flow decreased by 35%, presumably due to autoregulation mechanism of the coronary circulatory system. Both synchronous and asynchronous LHB demonstrated the same level of effect in volume unloading. However, significant diastolic augmentation was noted only in the former. LA-AO LHB, which has a sufficient supporting effect and does not damage the ventricular wall, was considered to be very useful for temporary support for the failing heart, especially for postoperative low output state.

Isoproterenol in Treatment of Heart Disease

Isoproterenol was effective in increasing cardiac output and in reducing left-ventricular end-diastolic pressure in virtually all forms of heart disease, with the exception of some cases of severe coronary-artery disease or aortic stenosis. Because of these physiological observations, isoproterenol was used in the acute treatment of certain expressions of circulatory failure. Isoproterenol was useful in potentiating mercurial diuresis, and occasionally was an effective potentiator when aminophylline was not. Isoproterenol was particularly helpful in treating either bradycardia or hypotension when these complicated congestive failure or the postoperative low output state.