Evaluation and Comparison of Early Hemodynamic Changes After Elective Mitral Valve Replacement in Patients With Severe and Mild Pulmonary Arterial Hypertension

• Published in: Journal of cardiothoracic and vascular anesthesia 2009-06, Vol.23 (3), p.298-305
• Main Authors: Tempe, Deepak K., MD, Hasija, Suruchi, MD, DNB, Datt, Vishnu, DA, DNB, Tomar, A.S., MD, Virmani, Sanjula, DA, DNB, Banerjee, Amit, MS, MCh, Pande, Bhuvan, MD
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Anesthesia & Perioperative Care; Critical Care; Female; Heart Valve Prosthesis Implantation - methods; Heart Valve Prosthesis Implantation - standards; Hemodynamics - physiology; Humans; Hypertension, Pulmonary - physiopathology; Hypertension, Pulmonary - surgery; Male; Mitral Valve - physiopathology; Mitral Valve - surgery; mitral valve disease, pulmonary hypertension, hemodynamic, mitral valve replacement; Mitral Valve Insufficiency - physiopathology; Mitral Valve Insufficiency - surgery; Postoperative Period; Prospective Studies; Young Adult
• ISSN: 1053-0770; 1532-8422
• DOI: 10.1053/j.jvca.2009.01.011

Objective To evaluate and compare early hemodynamic changes after elective mitral valve replacement (MVR) in patients with severe and mild pulmonary arterial hypertension (PAH). Design A prospective observational study. Setting University-affiliated hospital. Participants Sixty patients undergoing elective MVR. Interventions The patients were divided into 2 equal groups based on the presence (group A) or absence (group B) of severe PAH defined as systolic pulmonary artery pressure (PAP) ≥50 mmHg on preinduction pulmonary artery catheterization. Thiopental, fentanyl, midazolam, isoflurane, and rocuronium (or vecuronium if the heart rate >100 beats/min) were used for the induction and maintenance of anesthesia. MVR was performed using standard cardiopulmonary bypass (CPB) techniques. The therapy for PAH was electively instituted in all patients with a nitroglycerin infusion (0.5-1 μg/kg/min), deliberate hypocarbia (arterial carbon dioxide tension ≤35 mmHg), fractional inspired oxygen concentration = 1.0, and elective ventilation for at least 12 hours in the postoperative period. Hemodynamic and arterial blood gas parameters were serially measured before induction; after intubation; after termination of CPB; after extubation; and at 6, 24, and 48 hours after surgery. Differences in these parameters were analyzed within and among the groups using appropriate statistical tests. Measurements and Main Results The mean CPB and aortic cross-clamp times were similar in the 2 groups (78 ± 33 and 50 ± 21 minutes in group A and 63 ± 32 and 41 ± 23 minutes in group B). The mean PAP, pulmonary capillary wedge pressure, and pulmonary vascular resistance decreased significantly soon after CPB in both groups ( p < 0.001), but the decrease was significantly lower in group A ( p < 0.001). The mean PAP approached near-normal values in group A (23 ± 8 mmHg) and normal values in group B (16 ± 6 mmHg) immediately postoperatively. There was an increase in cardiac index ( p < 0.01) after CPB in group A. A relative improvement in oxygenation occurred after MVR in group A compared with group B ( p < 0.001). Patients in group A were ventilated for a longer duration (25.9 ± 18.8 v 17.3 ± 7.9 hours, p < 0.05). There was no significant difference in the inotropic requirement between the 2 groups. There was no mortality in either group. Conclusions PAP returns to near-normal values in patients with severe preoperative PAH and to normal values in patients with mild preoperative PAH immedia