Pulmonary Hypertension: Diagnostics and Therapeutics

1. Pulmonary Hypertension: Diagnostics and Therapeutics Presented by R3 林至芃2001.8.7

2. Brief history 1. • 49y/o male, uncontrolled DM • Smoking(+) 1~2ppd for 20+ yrs, drinking(+), both are quitted after MS • quite healthy until 1~2 years ago. He had an episode of cough and fever then dyspnea. • 恩主公 hospital, echo: mitral stenosis • frequent palpitation, exertional dyspnea (climbing stairs to 3F, carrying weight) • Early in this year he had an URI episode again. Dyspnea developed even if he walked slowly.

3. Brief history 2. • Mild MS with mild to moderate MR Spontaneous echo contrast in LA, no thrombus noted in LA and LAA. • Cath: LV angiogram: normal LV size, grade II mitral regurgitation, LVEF: 61% Mitral stenosis (pressure gradient 23 mmHg) Mitral regurgitationPulmonary hypertension 100/35

4. Brief history 3. • Sinus rhythm at OR • After induction, PAP>100, wedge 40 • TEE: MSMR, TR,PR • MVP-> MVR , TVP • Post CPB PAP~systemic, wedge 20+ • Dobutamine, NTG, Nipride • No La P • Reopen -> iNO -> LAP->remove ETT-> reon ETT-> expire.

5. DIAGNOSTIC CRITERIA • NIH, mean PAP > 25 mm Hg at rest (>30 mm Hg with exercise) • Echo: RVsys >50 mm Hg 不太準 • Screen: PE, CxR, ECG, Echo (最優)

6. Cause of PH • Primary Cardiac Abnormalities:mitral stenosis, severe aortic valve stenosis, left-to-right intracardiac shunts, and severe diastolic dysfunction or congestive heart failure • Obstructive Sleep Apnea • Chronic Pulmonary Embolism • Pulmonary Parenchymal Problems • Connective Tissue Disorders • Cirrhosis With Portal Hypertension • Appetite Suppressants • Other Disorders: sickle cell anemia, HIV infection

7. Medical Treatment • mainstay of pharmacological therapy is a combination of vasodilatation and anticoagulation • Ca channel blocker • patients with right-sided heart failure- digoxin • Intravenous prostacyclin, via 24 hr infusion FDA! • Perioperative medication • iNO • Avoid: hypoxia, acidosis, light anesthesia, N2O decrease ventricular function- hyperinflation, depressant anesthetics, hypothermia

8. Surgical, Catheterization, and Transplantation Options • Pulmonary Thromboendarterectomy • Atrial Septostomy- by cath, bridge to Tx • Organ Transplantation.-Lung transplantation (single lung, bilateral lung, or heart-bilateral lung) has been the definitive surgical treatment of primary PH

9. PRIMARY PH • Mean age: 45 (age range, 15-66 )62% females. Survival: RAP, MPAP, C.I.median survival: 2.5 years after diagnosis • spectrum of pulmonary arterial pathology medial hypertrophy, intimal proliferation, in situ thrombosis, fibrosis, and "plexogenic" changes

10. Circulatory failure after anesthesia induction in a patient with severe primary pulmonary hypertension. Anesthesiology. 91(6):1943-5, 1999 Dec

11. Pathophysiology of circulatory failure • anesthetic-induced suppression of sympathetic tone was associated with decreased cardiac output and decrease in MAP • positive-pressure ventilation impeded systemic venous return and could increase right ventricular afterload by closing of small pulmonary arteries • right ventricular dilatation with tricuspid regurgitation and leftward septal shift resulted from right-sided pressure overload. Subsequently, incomplete filling of the left ventricle with decreased diastolic compliance further impaired left ventricular function

12. Pathophysiology of circulatory failure • positive feedback mechanism involving interventricular coupling could be triggered, whereby the decreased left ventricular function (via septal motion) tends to reduce right ventricular systolic function and vice versa. Taken together, ventricular interdependence–positive feedback mechanisms and the series connections between the pulmonary and systemic circulation are implicated in the development of circulatory failure during anesthesia induction and positive-pressure mechanical ventilation. • pulmonary artery catheter (with mixed venous oximetry) and transesophageal echocardiography are the best ways to track cardiac function and fluid management during lung transplantation

13. Thank You