What are the recent developments in anesthetic management for patients with pregnancy-induced hypertension (PIH) undergoing cesarean section?

Recent Developments in Anesthetic Management for PIH Patients Undergoing Cesarean Section

For patients with pregnancy-induced hypertension (PIH) undergoing cesarean section, a multidisciplinary team approach with specialized anesthetic management is strongly recommended to reduce maternal and fetal morbidity and mortality. 1

Preoperative Assessment and Planning

• Comprehensive multidisciplinary planning involving pulmonary hypertension specialists, high-risk obstetrical teams, and cardiovascular anesthesiologists is essential for PIH patients requiring cesarean section 1
• Early hospitalization for close monitoring once the fetus is viable is recommended for patients with severe pulmonary hypertension 1
• Antenatal airway assessment is critical, as physiological changes of pregnancy can complicate airway management if general anesthesia becomes necessary 1
• Elective cesarean delivery should be considered for patients with severe pulmonary hypertension to avoid emergency situations 1, 2

Hemodynamic Monitoring

• Invasive hemodynamic monitoring, including pulmonary artery catheterization, is recommended for patients with severe PIH to guide management 1, 2
• Central venous pressure monitoring is valuable for assessing intravascular volume status and guiding fluid management 1
• Continuous monitoring of arterial pressure, ECG, and oxygen saturation is essential during and after cesarean section 1

Choice of Anesthetic Technique

Regional Anesthesia

• Low-dose combined spinal-epidural anesthesia has emerged as a preferred approach for cesarean section in PIH patients, allowing for careful titration of anesthetic agents while minimizing hemodynamic instability 2, 3
• Epidural anesthesia with slow, incremental administration of local anesthetics can be safe for both mother and fetus in patients with pulmonary hypertension 4
• Continuous epidural anesthesia has shown relatively good outcomes for cesarean deliveries in patients with severe idiopathic pulmonary arterial hypertension 3

General Anesthesia

• When general anesthesia is required, careful attention must be paid to attenuating the hypertensive response to intubation 1
• Fentanyl (5 μg/kg IV) has been effectively used to blunt the hypertensive response during rapid sequence induction 1
• Thiopentone, suxamethonium, and atracurium with nitrous oxide and isoflurane have been successfully used for general anesthesia in PIH patients 1

Perioperative Management

• Cautious fluid management is critical, as both hypovolemia and fluid overload can be detrimental 1
• Fresh frozen plasma may be required to correct coagulopathy in patients with HELLP syndrome (hemolysis, elevated liver enzymes, low platelets) 1
• Platelet transfusion should be considered when platelet counts are below 50,000/mm³ to reduce bleeding risk 1
• Hydralazine infusion can be used to control blood pressure and reduce the risk of eclampsia or intracranial hemorrhage 1

Postoperative Care

• High-dependency monitoring for at least 24 hours postoperatively is recommended for PIH patients 1
• Continued invasive monitoring of central venous pressure, arterial pressure, and urine output is essential in the immediate postoperative period 1
• Multimodal analgesia including paracetamol, NSAIDs, and dexamethasone is recommended for post-cesarean pain management 1
• Intrathecal morphine (50-100 μg) or diamorphine (300 μg) provides effective postoperative analgesia when used as part of neuraxial anesthesia 1

Special Considerations

• Despite modern treatment approaches, maternal mortality remains high (12-36%) in patients with severe pulmonary hypertension 1, 2
• Pregnancy should be discouraged in women with severe pulmonary hypertension due to the high risk of maternal mortality 1, 3
• Immediate postpartum period is particularly dangerous due to marked volume shifts from decompression of the vena cava and return of uterine blood to systemic circulation 1
• Hemodynamic changes associated with pregnancy may persist for up to 6 weeks after delivery 1

Common Pitfalls and Caveats

• Avoiding hypovolemia is crucial, as it can worsen right ventricular function in patients with pulmonary hypertension 4, 2
• Rapid hemodynamic changes during induction of anesthesia can lead to cardiovascular collapse in PIH patients 2
• Failure to recognize HELLP syndrome can lead to inadequate preparation for potential coagulation abnormalities 1
• Underestimating the need for invasive monitoring can result in suboptimal management of hemodynamic instability 1