Anesthesia management in the postpartum period requires important considerations of the physiological changes that occur during pregnancy and after childbirth. The postpartum period has 3 phases: acute, early, and late postpartum. Generally, there is physical fatigue after delivery, potentially an elevated pulse rate or blood pressure, and a slight elevation in temperature. The respiratory rate tends to fall. In terms of blood volume, hematocrit returns to normal in 3-5 days post-partum and plasma volume begins to increase. The hypercoagulable state of pregnancy also resolves after birth. During pregnancy cardiac output is increased, and in the immediate postpartum period there is a rise in cardiac output which drops to pre-pregnancy levels 2 weeks postpartum. These postpartum changes and many not mentioned have implications for anesthesia (Chauham & Tadi, 2022).
Following childbirth, patients often experience pain, including acute perineal, uterine, and incisional pain. Postpartum pain is extremely common, persistent, and can hurt an individual’s ability to care for themselves and their infant. NSAIDs are used as first line management for postpartum pain, including in individuals with hypertensive disorders of pregnancy. For vaginal births, escalating to an opioid may be necessary after delivery, ideally starting with a short-acting oral opioid. For pain following a cesarean birth, a similar stepwise approach should be used with acetaminophen, NSAIDs, and opioids. Some individuals who undergo cesarean sections may benefit from a transversus abdominis plane block, especially individuals who have a cesarean delivery under general anesthesia (“Pharmacologic Stepwise Multimodal Approach for Postpartum Pain Management”, 2021).
The choice of anesthesia for postpartum tubal ligation should be based on clinical opinion and must be individualized. The timing of this procedure also relies on anesthetic concerns. If there are no significant complications after a delivery, postpartum sterilization can occur within 8 hours of delivery. Performing general anesthesia within 8 hours of delivery must be carefully considered. Patients who have undergone cesarean sections have higher risks of failed intubation. This may be due to the urgency of many cesarean sections. Generally, physiologic changes resolve rapidly after delivery, but there are anecdotal reports that airway changes can persist longer after cesarean section. Delays in gastric emptying should also be considered, and patients with an elective ligation within 8 hours of delivery should avoid intake of solid foods during labor until after surgery. Intrapartum opioid administration can also contribute to delays in gastric emptying and must be considered in a case where general anesthesia may be necessary. Other options of anesthesia for postpartum tubal ligation include regional anesthesia or local anesthesia with sedation (Bucklin & Smith, 1999).
For breastfeeding, anesthetics and nonopioid analgesics are generally safe. First-line agents for pain management in patients who plan to breastfeed include acetaminophen and ibuprofen (“Pharmacologic Stepwise Multimodal Approach for Postpartum Pain Management”, 2021). These substances transfer to breast milk in minimal amounts. Opioid-sparing drugs and local/regional anesthesia are preferred options, while caution should be exercised with ketamine, opioids, and benzodiazepines, particularly in multiple doses and for infants < 6 weeks. Codeine should not be used at all (Mitchell, et al., 2020).
Ultimately, understanding the physiologic changes that occur during pregnancy and after childbirth is vital for optimal anesthesia management in postpartum patients. Pain management, surgical interventions, and breastfeeding considerations require cautious assessment and personalized approaches (Chauhan & Tadi, 2023).
References
Bucklin, B A, and C V Smith. “Postpartum tubal ligation: safety, timing, and other implications for anesthesia.” Anesthesia and analgesia vol. 89,5 (1999): 1269-74.
Chauhan, Gaurav, and Prasanna Tadi. “Physiology, Postpartum Changes – Statpearls – NCBI Bookshelf.” National Library of Medicine , 14 Nov. 2022, www.ncbi.nlm.nih.gov/books/NBK555904/.
Mitchell, J et al. “Guideline on anaesthesia and sedation in breastfeeding women 2020: Guideline from the Association of Anaesthetists.” Anaesthesia vol. 75,11 (2020): 1482-1493. doi:10.1111/anae.15179
“Pharmacologic Stepwise Multimodal Approach for Postpartum Pain Management.” ACOG, 19 Aug. 2021, www.acog.org/clinical/clinical-guidance/clinical-consensus/articles/2021/09/pharmacologic-stepwise-multimodal-approach-for-postpartum-pain-management.