What is the most common complication of general anesthesia in preeclampsia?

Hypertensive Response to Intubation is the Most Common Complication of General Anesthesia in Preeclampsia

The most common complication of general anesthesia in preeclampsia is a severe hypertensive response to laryngoscopy and tracheal intubation, which can lead to life-threatening consequences such as cerebral hemorrhage.1

Pathophysiology and Risks

In women with preeclampsia, general anesthesia induction and intubation can trigger:

• Significant increases in mean arterial pressure (MAP) after rapid induction and tracheal intubation 1
• Concurrent increases in middle cerebral artery flow velocity, creating risk for cerebral complications 1
• Direct relationship between blood pressure elevations and cerebral blood flow velocity, increasing risk of intracranial hemorrhage 1, 2

This hypertensive response is particularly dangerous because preeclamptic patients already have:

• Compromised cerebral autoregulation
• Endothelial dysfunction
• Increased risk of cerebral edema and hemorrhage 3

Prevention and Management Strategies

To mitigate this dangerous complication, the following approach is recommended:

1. Preoperative preparation:

   • Administer antihypertensive medications before induction to lower diastolic pressure to <100 mmHg 1
   • Consider hydralazine infusion to reduce mean arterial pressure and avoid risk of eclampsia or intracranial hemorrhage 2

2. Anesthetic technique:

   • Use medications to attenuate the hypertensive response to intubation:
     • Fentanyl (5 μg/kg IV) to blunt the hypertensive response 2
     • Consider sublingual nifedipine (10 mg) which effectively attenuates pressor response 4
     • Labetalol can be used in divided doses to control blood pressure 1

3. Intubation approach:

   • Rapid sequence induction with appropriate dosing of induction agents 2
   • Ensure adequate depth of anesthesia before intubation
   • Minimize duration of laryngoscopy
   • Consider videolaryngoscopy for difficult airways 2

Other Important Complications

While hypertensive response is the most common, other significant complications include:

• Difficult airway management: Airway edema is common in preeclampsia, potentially complicating intubation 3, 2
• Thrombocytopenia: May increase risk of bleeding, especially in HELLP syndrome 2
• Exaggerated hypotension: Can occur after induction if aggressive antihypertensive therapy was used 5
• Pulmonary edema: Due to decreased oncotic pressure and capillary leak 3

Special Considerations for HELLP Syndrome

In patients with HELLP syndrome (a severe form of preeclampsia):

• Platelet transfusion may be required before surgery if count is <50,000/mm³ 2
• Fresh frozen plasma may be needed to correct coagulopathy 2
• More intensive monitoring is required, including central venous pressure 2

Key Pitfalls to Avoid

1. Failing to anticipate difficult airway: Always prepare for difficult intubation in preeclamptic patients due to potential airway edema 2

2. Inadequate blood pressure control: Both pre-induction hypertension and post-intubation hypertensive surges must be prevented 1

3. Excessive fluid administration: Preeclamptic patients are at risk for pulmonary edema; fluid therapy should be limited 5

4. Neglecting thrombocytopenia: Always check platelet count before anesthesia in preeclamptic patients 2

5. Inadequate postoperative monitoring: These patients require close monitoring in a high-dependency setting after surgery 2

By understanding and addressing the risk of hypertensive response to intubation, anesthesiologists can significantly reduce morbidity and mortality in preeclamptic patients requiring general anesthesia.