Anaesthesia for non-obstetric surgery in obstetric patients

Abstract

Anaesthesia for pregnant patients presenting for non-obstetric surgery needs a thorough understanding of the physiological changes and altered pharmacokinetics of pregnancy. Considering the effects of surgery and anaesthesia on the foetus, only essential and emergency surgeries are performed during pregnancy. Surgical procedures in second trimester have the advantage of better foetal outcome. The primary concerns of maternal and foetal safety are achieved by a focused multidisciplinary team-based approach with respect to the surgical condition. Meticulous attention to preoperative patient counselling, airway management, haemodynamic stability, and thromboprophylaxis are the key factors in anaesthetic management. Choice of anaesthesia or anaesthetic drugs has minimal impact on the foetus provided utero-placental perfusion and uterine relaxation are maintained. Foetal monitoring when feasible and when done by a trained person enables to diagnose and treat the factors responsible for foetal heart rate variability. Anaesthetic technique needs to be modified according to the type of surgery.

Perioperative management of pregnant women undergoing nonobstetric surgery

“…9 These changes lead to an increased hypotensive response to both general and spinal anesthesia. 2 Cardiovascular examination reveals multiple signs of increased blood fl ow (Table 1). 10 Note.…”

“…A persistent third heart sound (gallop) or any diastolic murmur is abnormal and warrants immediate assessment. 2…”

“…17 Thus, one would expect faster induction with inhalation anesthesia. 2 Despite the expected pulmonary changes associated with pregnancy, tachypnea should be regarded as unusual and warrants formal assessment. If the patient suddenly begins breathing rapidly, evaluate for pulmonary embolism.…”

“…18,19 Anesthesiologists should consider reduced functional residual capacity, possible increased airway edema, and reduced oxygen delivery secondary to the physiologic anemia of pregnancy as risk factors for hypoxemic respiratory failure. 2 No formal guidelines have been published for preoperative pulmonary assessment in pregnancy. The most important purpose of assessment is to identify risks of a diffi cult airway and aspiration.…”

“…1,2 In order of frequency, the most common procedures are appendectomy, cholecystectomy, adnexal surgery (for torsion or masses), trauma repair, small-bowel obstruction surgery, and breast surgery. [2][3][4] The American College of Surgeons National Surgical Quality Improvement Program reported a postoperative complication rate of 5.8% in pregnancy. Complications included reoperation within 30 days (3.6%), infections (2%), wound problems (1.4%), respiratory complications (2%), thromboembolic complications (0.5%), transfusion requirements (0.2%), and death (0.25%).…”