Pulmonary hypertension and anesthesia

pulmonary hypertension and general anesthesia

1. Pulmonary Hypertension & Anesthesia Dr. wesam farid Mousa Dr. Salwa hassan khalil Anesthesia & Surgical ICU Department Faculty of Medicine Tanta University

2. Definition. Classification. Pathogenesis. D iagnosis and treatment of PH. Peri -operative management of PH crisis. PH in special s ituations. . objectives

3. P ulmonary circulation is a high flow , low resistance circuit capable of accommodating the entire right ventricular output at one-fifth the pressure of the systemic circulation .

4. DEFINITION PH is defined as a mean pulmonary artery pressure greater than 25 mmHg at rest based upon right heart catheterization measurements . A mean pulmonary artery pressure of 8 to 20 mmHg at rest is considered normal, .

5. RV enlargement secondary to any underlying cardiac or pulmonary disease. Pulmonary hypertension is the most common cause of cor pulmonale . Cor pulmonale

6. An estimated 15 to 52 people in 1 million have PAH world wide. Armin Sablotzki1, Hans- Juergen SeyfarthJochen Gille1, Stefan Gerlach1, Michael Malcharek1 and Elke Czeslick . Critical Care and Pain Medicine, Klinikum St. Georg gGmbH , Germany Department of Pneumology , Universitätsklinikum Leipzig AöR , Germany Clinic for Anesthesiology and Critical Care Medicine, Martin-Luther-University of Halle-Wittenberg, Germany2015 Epidemiology

7. Classification

8. A distinction between pre-capillary and post capillary PH is fundamental to understand the vascular and hemodynamic changes present in patients with PH .

9. VC RA RV PA PV PC LA LV Ao Post-Capillary PH ( PCWP>15 mmHg; PVR nl ) Systemic HTN AoV Disease Myocardial Disease DCM,HCM,ischemic CM RCM,Obesity , others Atrial Myxoma Cor Triatriatum PV compression PVOD PAH Respiratory Diseases PE Pulmonary Hypertension: Define Lesion MV Disease  LVEDP Pre-capillary PH PCWP < 15 mmHg PVR > 3 Wu

10. CLASIFICATION Mean PAP (mmHg) 25 - 40 41 - 55 >55 Degree of disease Mild Moderate Severe

11. NORMAL REVERSIBLE DISEASE IRREVERSIBLE DISEASE Pathogenesis of Pulmonary Arterial Hypertension

12. Diagnosis of PH Symptoms of PH Dyspnea 60 % Fatigue 19 % Near syncope/syncope 13 % Chest pain 7% Palpitations 5% Leg edema 3%

13. Physical Examination Loud pulmonary component of the 2 nd heart sound P2 (increases PAP) Left parasternal lift (RV heave=R sided overload) Systolic ejection murmur of TR S3 gallop (advanced RV failure) Signs of RV failure: Jugular venous distention Hepatomegaly Perepheral edema C L E A R L U N G S

14. Investigations: Right heart catheterization is the gold standard to confirm the diagnosis and establish the severity of PH. Transthoracic echocardiogram (TTE) remains the method of choice for screening and assessing the PH when clinically suspected. Once the diagnosis is confirmed, other diagnostic tools assist in establishing the underlying etiology and clinical group to which the patient belongs.

15. Diagnosis Associated condition Echocardiography Left ventricular systolic and diastolic dysfunction Left-sided valvular heart disease CHD with systemic to pulmonary shunt X-ray chest, PFT COPD , sarcoidosis Interstitial pulmonary fibrosis V̇/Q̇ scan, CTPA Chronic thromboembolic pulmonary disease Sleep study Obstructive sleep apnoea Serological test (ANA, HIV) Lupus, scleroderma, HIV Liver ultrasound Portopulmonary hypertension Right heart Catheterisation CHD with systemic to pulmonary shunt Postcapillary PH due to left heart disease Cardiac MRI CHD , cardiomyopathie s Over night Oxymetry PH with OSAH

16. Algorithm for investigation of suspected PH

17. Treatment of PH Goals of Therapy Alleviate symptoms, improve exercise capacity and quality of life Improve cardiopulmonary hemodynamics and prevent right heart failure Delay time to clinical worsening morbidity and mortality

18. Teraputic TARGETS FOR PH

19. Anesthetic Management of ph . PH is a serious condition. perioperative mortality of 7-24%. Peri -operative morbidity 14–42 % includes: Respiratory failure H eart failure, dysrhythmias S epsis , R enal insufficiency, Myocardial infarction.

20. pre-operative evaluation: Multidisciplinary team anesthetists , surgeons, pulmonologists , and cardiologists. Patients ‘suspected’ of having PH and ungraded severity are at higher risk of peri -operative complications. Elective surgery must be postponed till a proper pre-op evaluation & optimization.

21. pre-operative evaluation: Patient with established PH should be based on a risk assessment : functional state severity of the disease type of surgery .

22. WHO classification of functional status of patient with PH

23. Signs of Disease Severity Dyspnea at rest ( WHO- FC class 4) Low cardiac output with metabolic acidosis Hypoxemia Signs of right heart failure Syncope (poor prognosis) Chest pain ( secondary to RV ischemia ) Rapid progression of symptoms 6 minute walking test < 300m .

24. PREOPERATIVE MANEGMENT

25. pre-operative evaluation: A detailed history and physical examination should be complemented with relevant investigations : Laboratory tests , electrocardiography, chest radiography, arterial blood gas analysis , echocardiography, recent right heart catheterization which is the gold standard for diagnosis of PH.

26. PREOPERATIVE MANEGMENT Ideally before surgery, mean PAP should be reduced to a normal of 25 mm Hg. If substantial RV dysfunction is present, the advisability of surgery should be reexamined . Any chronic pulmonary hypertensive therapies that patients are currently taking should be continued perioperatively to avoid rebound PH Short acting anticoagulant like heparin should replace indirect anticoagulant until the surgical procedure. Avoid anxiety, pain, and sympathetic stimulation. Avoid over sedation and hypoventilation. Antibiotic prophylaxis must be given.

27. Intraoperative management Anesthetic and Hemodynamic goals for PH :

28. anesthetic Considerations Intraoperative “basic treatment ” to avoid an increase of pulmonary arterial pressure: “Luxury”-oxygenation with inspiratory FiO2 0.6 – 1.0 Moderate hyperventilation (goal: PaCO2 30-35 mmHg) Avoidance of metabolic acidosis (pH > 7.4) Recruitment-manoeuver to avoid ventilation/perfusion-mismatch. Low-tidal-volume ventilation to avoid over-inflation of aveoli (goal: 6 ml/kg ideal body weight) Temperature management to maintain body temperature of 36-37 °C “Goal-directed” fluid- and volume-therapy with hemodynamic monitoring

29. Intraoperative management Optimize RV function and CO with adequate preload, SVR, and avoid contractility , avoid myocardial depressants Conside r pulmonary vasodilators to decrease RV afterload Maintain sinus rhythm . It is good practice to remove air from intravenous syringes and lines

30. MONITORING There is no strong evidence to suggest that any specific type of monitoring has an influence on patient morbidity and mortality. The standard monitoring is considered sufficient for minor & medium procedures in functional state 2. A ll major interventions and those in functional state III should be carried out under extended monitoring. Transesophageal echocardiography (TOE ). pulmonary artery catheter.

31. MONITORING Invasive arterial monitoring before anesthetic induction Early recognition of hemodynamic instability. Intermittent arterial blood gas sampling to check adequacy of ventilation. Right atrial pressure measurement (central venous pressure) reflects the relationship of blood volume to the capacity of the venous system and also reflects the functional capacity of the right ventricle.

32. anesthetic techniques All standard anesthetic techniques can, in principle applied to patients with PH

33. anesthetic techniques Regional anesthetic techniques: N ot impairing spontaneous breathing postoperative analgesic therapy N early all patients with pulmonary hypertension receive continuous anticoagulant therapy; this fact must be taken under. In severe PH or in diseases affecting the lung , patients cannot be subjected to remaining in a flat position for long period of time. Regional anesthesia combined with careful GA to ensure adequate oxygenation.

34. general anesthesia the main advantages are Safe oxygenation , uncomplicated airway management, and intraoperative selective pulmonary vasodilation can – if necessary – easily be administered through the breathing circuit.

35. general anesthesia All standard induction anesthetics can be used in combination with opioids , as they have no influence on pulmonary vascular resistance and oxygenation. Ketamine may PVR due to catecholamine effect. However patients with RV failure may be catecholamine depeleted . Histamine-releasing muscle relaxants ( atracurium , mivacurium ) should be avoided for patients with PH, PVR.

36. general anesthesia Volatile anesthetic agents of concentrations up to 1 MAC can be administered without any negative effects on pulmonary pressure and resistance. Nitrous oxide better avoided as it may raise PVR. So use balanced technique, mixing higher doses of opioids and low-dose volatile anesthetic agents ,careful with stress response during i ntubation.

37. During Extubation : Maintaining haemodynamic stability and adequate ventilation can be difficult. Deep extubation May decrease SVR, contractility Hypoxia and hypercarbia will increase PVR Awake extubation Can cause severe pulmonary vasoconstriction Need tube tolerance without increased sympathetic tone Patient may need post-op ventilation with ICU admission

38. postoperative monitoring until pulmonary pressures and right-sided heart functions have stabilized at the preoperative level. sufficient analgesic therapy in the form of continuous regional anesthesia to avoids higher doses of opioid-based analgesics . The specific therapy for PH should be resumed at the preoperative dosage as soon as possible . In the postoperative course, it is also advisable to treat pressure elevations . Postop erative manegment

39. Peri -operative management of PH Crisis

40. Pulmonary Hypertension With laparoscopy Pneumoperitoneum with CO2 causes an increase in end tidal carbon dioxide. Acidosis, arrhythmias ,decrease preload PH crisis . post operative benefits of laparoscopic surgery must be balanced with intraoperative risk involved . IAP to be maintained at 10-12 mm of Hg. CO2 insufflation slow rate to attenuate abdominal stretch response T emporarily deflate the abdomen if necessary. Combined general with epidural anaesthesia decreasing intraoperative anaesthetic requirement. post operative pain relief.

41. Pulmonary Hypertension With P regnancy M ortality rate of 30% in patients with idiopathic PAH and 56% in patients with PH associated with other conditions. GA associated with a four-fold increase in maternal mortality Physiological increase in blood volume causes volume overload in the right heart may cause: thromboembolic events. cerebrovascular accidents. General principals for high risk parturient. Left lat. Position .

42. Fetal monitoring as IUGR due to hypoxemia and increased Hct level. Anticoagulation is usually recommended. LMWH . Warfarin and Endothelin receptor antagonists are avoided due to potential teratogenicity. Elective CS before 32 W s allows for better planning, a multidisciplinary team. Oxytocine use low dose (10 units IV inf ) slowly over 4-8 hr. Methergine absolute CI

43. SUMMARY

44. summary