Cesarean section

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Revision as of 18:36, 2 May 2021 by Nirav Kamdar (talk | contribs) (Additional evidence regarding azithromycin and tranexamic acid use in C-Section.)
Cesarean section
Anesthesia type General vs. Regional
Airway ETT if GA
Lines and access 2 large bore PIV
Monitors Standard ASA
FHR monitor
Primary anesthetic considerations
Preoperative Full stomach precautions

Aspiration prophylaxis

Left lateral tilt
Intraoperative
Postoperative


A Cesarean section, also known as C-section, is a surgical procedure where the baby is delivered through an incision in the uterus. C-sections are typically performed when a vaginal delivery would put the mother or baby at risk. As of 2017, about 32% of deliveries in the United States were performed via C-section[1].

Preoperative management

Patient evaluation

System Considerations
Neurologic
Cardiovascular
  • Pregnant patients typically have decreased systemic vascular resistance, decreased diastolic pressure, decreased MAP, increased HR, and increased CO.
  • Left uterine tilt to minimize aortocaval compression
  • Evaluate for pregnancy induced hypertension (PIH)
Respiratory
  • Pregnant patients typically have compensated respiratory alkalosis, increased minute ventilation, decreased FRC, and increased oxygen consumption.
  • Decreased FRC results in rapid desaturation if ventilation is compromised.
  • Atelectasis can occur secondary to an elevated diaphragm, thereby causing V/Q mismatch and decreased PaO2.
  • Increased MV and decreased FRC increase uptake of inhalational agents.
  • Mucosal capillary engorgement in upper airway may necessitate smaller endotracheal tube.
Gastrointestinal / Hepatic
  • Increased gastric pressure
  • Decreased esophageal sphincter tone
  • Decreased gastric motility
  • Full stomach precautions
  • Risk for aspiration
  • Liver enzymes may be mildly elevated
    • Check for HELLP
Hematologic
  • Increased RBC mass, plasma volume, and blood volume
  • Leukocytosis
  • Iron deficiency anemia + dilutional anemia of pregnancy
  • Excessive blood loss possible with uterine atony, multiple gestation, previous C-section, placental pregnancy, placental abruption, pregnancy induced hypertension, or prolonged labor.
Renal
  • Increased renal blood flow, GFR, and creatinine clearance
  • Decreased serum creatinine and BUN
  • Dependent edema secondary to increased water and sodium retention
Other

Labs and studies

  • T&S
  • T&C only if significant blood loss anticipated
  • Coagulation panel
  • Chemistry panel
  • Complete Blood Count (CBC)
  • Other tests as indicated by H&P

Operating room setup

Patient preparation and premedication

  • Full stomach precautions
  • Nonparticulate oral antacid (e.g. sodium citrate) immediately prior to general or regional anesthesia
  • Intravenous promotility agent (eg. metoclopramide)
  • Intravenous antacids (e.g. ranitidine, famotidine)
  • Anxiolysis not typically used unless patient is extremely anxious
  • Elevate the right hip to provide left uterine displacement
  • Adjunctive azithromycin 500mg IV to standard beta-lactam antibiotics shown to reduce the incidence in endometriosis and wound infection occurring in the first 6 weeks after Cesarean Section[2].

Regional and neuraxial techniques

  • Epidural, spinal, and combined spinal-epidural (CSE) techniques are all commonly employed
    • Check coagulation and platelets panel prior to neuraxial anesthesia

Intraoperative management

Monitoring and access

Induction and airway management

  • Avoid nasal airways due to potential for mucosal capillary engorgement in upper airway

Positioning

  • Left lateral tilt (15o) to avoid aortocaval compression and supine hypotension.

Maintenance and surgical considerations

  • Anticipate EBL of 700-1000 mL
    • Be prepared for excessive blood loss if underlying risk factors
  • Immediately post-partum, ~600-800 mL of blood will enter the central circulation (placental autotransfusion), which will increase cardiac output
  • Tranexamic acid 1g administered over 30-60 seconds during the first 3 minutes after birth, and after the uterotonic agent has been administered (e.g. oxytocin) is shown to reduce the incidence of post-operative blood loss > 1000 mL by POD #2 or RBC transfusion[3].

Emergence

Postoperative management

Disposition

Pain management

Potential complications

Procedure variants

Neuraxial General
Unique considerations
  • Decreased BP common with spinal anesthesia
  • Given fluid pre-load or co-load
  • Be prepared to provide bolus as vasopressors as needed
  • GA normally used with regional technique contraindicated or when there is not enough time to perform a block due to obstetric emergency
  • Rapid sequence induction (RSI)
Position
Surgical time
EBL
Postoperative disposition
Pain management
Potential complications

References

  1. "Births: Provisional Data for 2017" (PDF). CDC. May 2018. Retrieved 18 May 2018.
  2. Tita, Alan T.N.; Szychowski, Jeff M.; Boggess, Kim; Saade, George; Longo, Sherri; Clark, Erin; Esplin, Sean; Cleary, Kirsten; Wapner, Ron; Letson, Kellett; Owens, Michelle (2016-09-29). "Adjunctive Azithromycin Prophylaxis for Cesarean Delivery". New England Journal of Medicine. 375 (13): 1231–1241. doi:10.1056/NEJMoa1602044. ISSN 0028-4793. PMC 5131636. PMID 27682034.CS1 maint: PMC format (link)
  3. Sentilhes, Loïc; Sénat, Marie V.; Le Lous, Maëla; Winer, Norbert; Rozenberg, Patrick; Kayem, Gilles; Verspyck, Eric; Fuchs, Florent; Azria, Elie; Gallot, Denis; Korb, Diane (2021-04-29). "Tranexamic Acid for the Prevention of Blood Loss after Cesarean Delivery". New England Journal of Medicine. 384 (17): 1623–1634. doi:10.1056/NEJMoa2028788. ISSN 0028-4793.