The intraoperative management of patients with PH focuses on maintaining hemodynamic stability and preventing right heart failure:
Anesthetic Technique: Opt for regional anesthesia when appropriate to minimize the cardiovascular impact of general anesthesia. If general anesthesia is necessary, use agents with minimal effects on myocardial function and vascular resistance (e.g., etomidate, ketamine).
Ventilation Strategies: Employ lung-protective ventilation with low tidal volumes (6-8 ml/kg) and adequate PEEP to prevent hypoxia and hypercapnia, which can increase PVR. Avoid high PEEP levels that might decrease venous return and compromise right heart function. PVR is lowest at functional residual capacity: atelectasis compresses extra-alveolar vessels and overdistension compresses alveolar capillaries, so both underinflation and overinflation raise it.
Advanced Hemodynamic Monitoring: For high-risk patients, use pulmonary artery catheters, transesophageal echocardiography, or advanced cardiac output monitoring to guide fluid management and vasopressor use.
Example:
During a laparoscopic procedure on a patient with severe PAH, the anesthesia provider chooses etomidate for induction to maintain hemodynamic stability and uses inhaled nitric oxide to lower PVR, with norepinephrine ready to hold systemic pressure above pulmonary pressure, while closely monitoring right ventricular function with a pulmonary artery catheter.
Why laparoscopy deserves extra care: Pneumoperitoneum raises intrathoracic pressure and PVR, absorbed carbon dioxide drives hypercapnia, and steep head-down positioning shifts volume onto a right ventricle that cannot accept it. Keep insufflation pressure low (10 to 12 mm Hg or less), raise minute ventilation to hold end-tidal CO2 normal, limit the degree and duration of Trendelenburg, and agree in advance that the surgeon will desufflate at once if right ventricular failure appears. A pulmonary artery catheter or TEE lets the team see a rising pulmonary artery pressure or a dilating right ventricle before systemic pressure falls.
