Case Presentation: Anesthetic Management For POEM Procedure in a Patient with Severe Pulmonary Hypertension CHUCK STRAUBHAAR BSN, SRNA
OBJECTIVES Comprehend basic pathophysiology of pulmonary hypertension Appreciate anesthetic considerations and intraoperative management of pulmonary hypertension Understand anesthetic management and basic surgical technique for peroral endoscopic myotomy
PULMONARY VASCULATURE PHYSIOLOGY Low pressure system, less than 10% resistance to flow compared to systemic vasculature Normal pulmonary artery pressure at rest at sea level: 20/10 mm Hg Resting PA pressure rises with higher altitudes Systolic PA pressures gradually rise with age
PULMONARY HYPERTENSION PATHOPHYSIOLOGY Pulmonary HTN: mean PA pressure greater 25 mm Hg Pulmonary arterial hypertension: left sided heart filling pressure must be 15 mm Hg or less 5 clinical classifications PA pressures and PVR increased at rest RV hypertrophy impaired LV filling impaired CO progressive RV failure and sudden death
PULMONARY ARTERIAL HYPERTENSION PATHOBIOLOGY Characterized by endothelial dysfunction, apoptosis:proliferation in pulmonary arterial smooth muscle, thickened adventitia Panvasculopathy affecting small pulmonary arterioles Intimal hyperplasia, medial hypertrophy, adventitial proliferation Imbalance of vasoactive mediators Not enough nitric oxide and prostacyclin Too much thromboxane and endothelin
PULMONARY HYPERTENSION ANESTHETIC CONSIDERATIONS Preanesthesia evaluation and preoperative testing Intraoperative goals Avoid increased pulmonary vascular resistance Maintain preload but avoid fluid overload Maximize RV O2 supply, minimize O2 demand MAC/peripheral nerve block vs Neuraxial vs General Laparoscopic vs open procedures Standard monitoring +/- arterial line, CVC, PAC, TEE
PULMONARY HYPERTENSION ANESTHETIC CONSIDERATIONS Induction slow and steady Short acting hypnotic (etomidate 0.15-0.3 mg/kg), moderate dose of opioid (fentanyl 1-2 mcg/kg), lidocaine 50-100 mg, muscle relaxant Critical to maintain oxygenation and avoid hypercarbia Maintenance avoid increased PVR and decreased SVR Minimal data on inhalational anesthetic effects on PVR Best to avoid nitrous oxide and ketamine TIVA? Ventilation avoid high peak pressures/high PEEP, acidosis, hypoxia, and atelectasis Fluid avoid abrupt changes Emergence smooth
PULMONARY HYPERTENSION ANESTHETIC CONSIDERATIONS
PULMONARY HYPERTENSION TREATMENT For groups 2-5, management of the underlying disease process Group 1 Pulmonary Arterial Hypertension Prostacyclin agonists (epoprostenol, treprostinil) Endothelin receptor antagonist (bosentan, ambrisentan) Nitric oxide-cgmp enhancers (sildenafil, tadalafil)
PERORAL ENDOSCOPIC MYOTOMY (POEM)
POEM PROCEDURE AND ANESTHESIA CONSIDERATIONS Indicated for achalasia esophageal dysmotility Clear liquids only 1-5 days preop, and NPO at least 6 hours preop May still retain contents in esophagus Performed in OR or high-intensity endoscopy suite Reverse trendelenburg and RSI recommended Supine throughout procedure, EBL minimal, 1 PIV Stimulating? Adverse events: insufflation-related, bleeding, mucosal perforation
No general anesthesia if possible. If no alternative to GA, she will need anesthesia with knowledge of how to manage PH and RV failure, as risk of decompensation following intubation is HIGH Perioperative cardiopulmonary risk is high CASE PRESENTATION
KC is a 29 year old female, 170 cm, 59 kg presenting for a POEM procedure due to gastroparesis, persistent N/V, and early satiety. Other history: severe idiopathic pulmonary arterial HTN, right HF, mild asthma, 2 L O2 at night, and recent URI. KC is also being considered for a lung transplant, but can walk >1000 ft so not yet a candidate. KC has some atelectasis and diminished basilar breath sounds. Medications PAH: IV treprostinil via Hickman catheter, ambrisentan, riociguat Right HF: Lasix Asthma: Flonase, albuterol ECG: NSR, RAD, incomplete RBBB, nonspecific ST & T wave changes, QTc 551 ms CXR: cardiac silhouette enlarged. Main & central PAs dilated with abrupt peripheral tapering Rt heart cath: RV pressure 116/22, PA 116/60 (79) Echo: RV & RA severely dilated, RV function severely decreased, 1+ TR, 2+ PR. Main PA dilated at 6.1 cm
SO. WHAT DID WE DO? Pre-operative: continued PO PAH meds along with IV treprostinil, thorough interview Intra-operative: GETA with modified rapid sequence induction Alfentanil, etomidate, rocuronium Increasing peak pressures asthma/spasm? Rhonchi? Postoperative: PONV but prolonged QT What if things went wrong? Acute right heart failure inhaled nitric oxide or epoprostenol, IV milrinone Hypotension norepinephrine
Overall, there are many different ways anesthesia could have been provided to this patient. This way is not better or worse than other ways, but it did provide a safe anesthetic.
SOURCES Hopkins, W., & Rubin, L. J. (2018). Treatment of pulmonary hypertension in adults (J. Mandel & G. Finlay, Eds.). Retrieved August 4, 2018, from https://www.uptodate.com/contents/treatment-of-pulmonary-hypertension-inadults?sectionname=prostacyclin pathway agonists&topicref=94362&anchor=h21&source=see_link#h3257161491 Mclaughlin, V. (2016). Chapter 68 Pulmonary Hypertension. In Goldman Cecil Medicine (25th ed., pp. 397-403). Philadelphia, PA: Elsevier Saunders. Pannala, R., Abu Dayyeh, B. K., Aslanian, H. R., Enestvedt, B. K., Komanduri, S., Manfredi, M.,... Banerjee, S. (2016). Per-oral endoscopic myotomy. In Gastrointestinal Endoscopy(Vol. 83, pp. 1051-1060). Elsevier. Sharp, C. D., T. E., & Ginsberg, G. G. (2017). Anesthesia for Routine and Advanced Upper Gastrointestinal Endoscopic Procedures. In Anesthesiology Clinics (Vol. 35, pp. 669-674). Zafirova, Z., & Rubin, L. J. (2018). Anesthesia for patients with pulmonary hypertension or right heart failure (B. A. Borlaug, R. Hines, N. A. Nussmeier, & S. B. Yeon, Eds.). Retrieved August 4, 2018, from https://www.uptodate.com/contents/anesthesia-for-patients-with-pulmonary-hypertension-or-right-heartfailure?search=pulmonary%20hypertension%20anesthesia&source=search_result&selectedtitle=1~150&usage_t ype=default&display_rank=1#h1900480851
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