Christian Ayoub

Innovative Approaches in the Perioperative Care of the Cardiac Surgical Patient in the Operating Room and Intensive Care Unit

Perioperative care for cardiac surgery is undergoing rapid evolution. Many of the changes involve the application of novel technologies to tackle common challenges in optimizing perioperative management. Herein, we illustrate recent advances in perioperative management by focusing on a number of novel components that we judge to be particularly important. These include: the introduction of brain and somatic oximetry; transesophageal echocardiographic hemodynamic monitoring and bedside focused ultrasound; ultrasound-guided vascular access; point-of-care coagulation surveillance; right ventricular pressure monitoring; novel inhaled treatment for right ventricular failure; new approaches for postoperative pain management; novel approaches in specialized care procedures to ensure quality control; and specific approaches to optimize the management for postoperative cardiac arrest. Herein, we discuss the reasons that each of these components are particularly important in improving perioperative care, describe how they can be addressed, and their impact in the care of patients who undergo cardiac surgery.

Reversal of decreases in cerebral saturation in high-risk cardiac surgery.

OBJECTIVES To measure the incidence of cerebral desaturation during high-risk cardiac surgery and to evaluate strategies to reverse cerebral desaturation. DESIGN Prospective observational study followed by a randomized controlled study with 1 intervention group and 1 control group. SETTING Tertiary care center specialized in cardiac surgery. PARTICIPANTS All patients were scheduled for high-risk cardiac surgery, 279 consecutive patients in the prospective study and 48 patients in the randomized study. INTERVENTIONS An algorithmic approach of strategies to reverse cerebral desaturation. In the control group, no attempts were made to reverse cerebral desaturation. MEASUREMENTS AND MAIN RESULTS Cerebral saturation was measured using near-infrared reflectance spectroscopy. A decrease of 20% from baseline for 15 seconds defined cerebral desaturation. The success or failure of the interventions was noted. Demographic data were collected. Models for predicting the probability and the reversal of cerebral desaturation were based on multiple logistic regressions. In the randomized study, 12 hours of measurements were continued in the intensive care unit without interventions. Differences in desaturation load (% desaturation × time) were compared between groups. Half of the high-risk patients had cerebral desaturation that could be reversed 88% of the time. Interventions resulted in smaller desaturation loads in the operating room and in the intensive care unit. CONCLUSIONS Cerebral desaturation in high-risk cardiac surgery is frequent but can be reversed most of the time resulting in a smaller desaturation load. A large randomized study will be needed to measure the impact of reversing cerebral desaturation on patients outcome.

Myocardial Protection in Mitral Valve Surgery: Comparison Between Minimally Invasive Approach and Standard Sternotomy

OBJECTIVE To compare antegrade and retrograde cardioplegia administration in minimally invasive mitral valve surgery (MIMS) and open mitral valve surgery (OMS) for myocardial protection. DESIGN Retrospective study. SETTING Tertiary care university hospital. PARTICIPANTS The study comprised 118 patients undergoing MIMS and 118 patients undergoing OMS. INTERVENTIONS The data of patients admitted for MIMS from 2006 to 2010 were reviewed. Patients undergoing isolated elective OMS from 2004 to 2006 were used as a control group. Cardioplegia in the MIMS group was delivered via the distal port of the endoaortic clamp and an endovascular coronary sinus catheter positioned using echographic and fluoroscopic guidance. Antegrade and retrograde cardioplegia were used in OMS. Data regarding myocardial infarction (MI) (creatine kinase [CK]-MB, troponin T, electrocardiography); myocardial function; and hemodynamic stability were collected. MEASUREMENTS AND MAIN RESULTS There was no difference in the perioperative MI incidence between both groups (1 in each group, p = 0.96). No statistically significant difference was found for maximal CK-MB (35.9 µg/L [25.1-50.1] v 37.9 µg/L [28.6-50.9]; p = 0.31) or the number of patients with CK-MB levels >50 µg/L (29 v 33; p = 0.55) or CK-MB >100 µg/L (3 v 4; p = 0.70) between the OMS and MIMS groups. However, maximum troponin T levels in the MIMS group were significantly lower (0.47 µg/L [0.32-0.79] v 0.65 µg/L [0.45-0.94]; p = 0.0007). No difference in the incidence of difficult weaning from bypass and intra-aortic balloon pump use between the MIMS and OMS groups was found. CONCLUSIONS Antegrade and retrograde cardioplegia administration during MIMS and OMS provided comparable myocardial protection.

Perioperative Right Ventricular Pressure Monitoring in Cardiac Surgery

Right ventricular (RV) dysfunction is a cause of increased morbidity and mortality in both cardiac surgery and noncardiac surgery and in the intensive care unit. Early diagnosis of this condition still poses a challenge. The diagnosis of RV dysfunction traditionally is based on a combination of echocardiography, hemodynamic measurements, and clinical symptoms. This review describes the method of using RV pressure waveform analysis to diagnose and grade the severity of RV dysfunction. The authors describe the technique, optimal use, and pitfalls of this method, which has been used at the Montreal Heart Institute since 2002, and review the current literature on this method. The RV pressure waveform is obtained using a pulmonary artery catheter with the capability of measuring RV pressure by connecting a pressure transducer to the pacemaker port. The authors describe how RV pressure waveform analysis can facilitate the diagnosis of systolic and diastolic RV dysfunction, the evaluation of RV-arterial coupling, and help diagnose RV outflow tract obstruction. RV pressure waveform analysis also can be used to guide pharmacologic treatment and fluid resuscitation strategies for RV dysfunction.

Pulmonary production of osteopontin in humans: effects of left ventricular systolic dysfunction and cardiopulmonary bypass.

BACKGROUND We evaluated pulmonary production of osteopontin (OPN) in left ventricular systolic dysfunction (LVSD) and after cardiopulmonary bypass surgery (CPB). OPN is a phosphoglycoprotein involved in inflammation and remodeling. In subjects with LVSD, plasma OPN correlates with prognosis but its origin is unknown. We hypothesized that the lungs produce OPN and that this could be affected by LVSD and CPB. METHODS AND RESULTS Subjects with (n = 57; left ventricular ejection fraction [LVEF] 32 ± 8%) and without (n = 63; LVEF 59 ± 7%) LVSD were studied during CPB. Arterial and venous OPN plasma levels were determined. Arterial and venous OPN levels were higher in LVSD (P = .0290). For both groups, levels dropped 1 hour after surgery and nearly doubled 24 hours after (P < .0001 vs basal). Notably, there was a significant positive arteriovenous gradient with arterial levels higher than venous levels. Arteriovenous differences were statistically significant at baseline (P = .0120) and 1 hour (P < .0001) but not at 24 hours (P = .0649). Arterial levels in heart failure correlated inversely with renal function (P = .016) and positively with mean pulmonary pressure (P = .028), heart rate (P = .036), and C-reactive protein (P = .047). CONCLUSIONS There is production of circulating OPN by the lungs, unaffected by LVSD or CPB. This likely represents an overflow from local lung production and does not contribute to increased levels in LVSD or after CPB.