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

CASE PRESENTATION

“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”

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

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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.

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QUESTIONS?