Managing anesthesia for cesarean section in obese patients: current perspectives

Figures & data

Table 1 Common comorbidities associated with obesity

Comorbidity	Odds ratio (95% confidence interval)
Type 2 diabetes	12.41 (9.03, 17.06)
Hypertension	2.42 (1.59, 3.67)
Coronary artery disease	3.1 (2.81, 3.43)
Congestive heart failure	1.78 (1.07, 2.95)
Pulmonary embolism	3.51 (2.61, 4.73)
Stroke	1.49 (1.27, 1.74)
Asthma	1.78 (1.36, 2.32)
Gallbladder disease	2.32 (1.17, 4.57)
Chronic back pain	2.81 (2.27, 3.48)

Note: Data from a previous study.¹¹⁰

Table 2 Obstetric complications in the obese compared with the nonobese parturients

Obstetric complication	Odds ratio (95% confidence interval)
Gestational diabetes^Citation111	2.4 (2.2, 2.7)
Hypertensive disorders^Citation111	3.3 (2.7, 3.9)
Venous thromboembolism^Citation112	9.7 (3.1, 30.8)
Induction of labor^Citation113	1.84 (1.53, 2.21)
Total cesarean delivery^Citation113	2.42 (2.02, 2.91)
Emergency cesarean delivery^Citation113	2.15 (1.78, 2.58)
Postpartum hemorrhage^Citation111	2.3 (2.1, 2.6)
Wound infection^Citation114	2.24 (1.91, 2.64)
Macrosomia^Citation113	3.39 (2.78, 4.18)
Shoulder dystocia ^Citation115	2.9 (1.4, 5.8)
Prematurity^Citation111	1.2 (1.1, 1.4)
Still birth^Citation116	2.1 (1.5, 2.7)
Neonatal death^Citation117	2.6 (1.2, 5.8)

Table 3 General anesthesia considerations in obese parturients

Preinduction

Premedication

Histamine-2 receptor antagonist

Nonparticulate antacid

Standard ASA monitors

Pulse oximetry

Noninvasive blood pressure cuff of appropriate size

Electrocardiogram

Capnography

Temperature

Difficult airway cart/presence of trained assistant

Short handles and multiple blades

Video laryngoscope

Fiberoptic laryngoscope

Laryngeal mask airways

Large bore intravenous access

Position

Align oral, pharyngeal, and tracheal axes

Neck in sniffing position

Back ramped on folded blankets or padded ramp

Left uterine displacement

Preoxygenation

100% oxygen for 3 minutes tidal volume breaths or eight deep breaths over 1 minute

Induction and intubation

Rapid sequence induction with cricoid pressure

Propofol: 2–2.8 mg/kg based on LBW

Etomidate: 0.2 mg/kg based on LBW

Thiopentone: 4–5 mg/kg based on LBW

Succinylcholine: 1 mg/kg based on total body weight

Rocuronium: 1–1.2 mg/kg based on ideal body weight

Maintenance

Volatile agents: isoflurane, desflurane, or sevoflurane with or without nitrous oxide (higher inspired oxygen concentrations may be needed)

Fentanyl: administered based on LBW

Emergence

Beware of risks of aspiration, hypoventilation, and airway obstruction

Tracheal extubation with patient fully awake

Full reversal of muscle relaxation

Semi-sitting position

Note: Data from previous studies.^42,118

Abbreviations: ASA, American Society of Anesthesiologists; LBW, lean body weight.

Table 4 Relative infant dose of some analgesic agents

Analgesic agent	Relative infant dose (%)
Acetaminophen	8.81
Ibuprofen	0.65
Naproxen	3.3
Celecoxib	0.3
Ketorolac	0.2
Hydromorphone	<1
Hydrocodone	2.4
Morphine	9–35
Oxycodone	3.5
Gabapentin	6.5

Notes: Relative infant dose is calculated by dividing the infant’s dose via milk (in mg/kg/day) by the mother’s dose (in mg/kg/day). Data from a previous study.¹⁰⁷

Table 5 Different guidelines for thromboprophylaxis in the parturient

American College of Chest Physicians^Citation119

Recommendation: Low molecular weight heparin for one major or ≥2 minor risk factors (mechanical prophylaxis if contraindications to pharmacologic prophylaxis)

Major risk factors

Cesarean delivery with ≥1,000 mL postpartum hemorrhage

Immobility >7 days antepartum

History of venous thromboembolism

Medical comorbidities: sickle-cell disease, systemic lupus erythematosus, heart disease

Thrombophilia: antithrombin deficiency, Factor V Leiden, prothrombin G20210A

Preeclampsia with fetal growth restriction

Blood transfusion

Postpartum Infection

Minor risk factors

Multiple pregnancy

Obesity BMI >30 kg/m^2

Emergency cesarean section

Smoking >10 cigarettes/day

Fetal growth restriction

Thrombophilia: protein C or protein S deficiency

Preeclampsia

Royal College of Obstetricians and Gynaecologists^Citation120

Recommendation: Assess risk factors to decide high, intermediate, or lower risk

Risk factors

High risk (low molecular weight heparin for at least 6 weeks)

History of venous thromboembolism

Antenatal anticoagulation

High-risk thrombophilia

Low-risk thrombophilia with a family history

Intermediate risk (low molecular weight heparin for at least 10 days)

Cesarean delivery in labor

BMI ≥40 kg/m^2

Readmission or prolonged admission (≥3 days) postpartum

Any postpartum surgical procedure except for perineal repair

High-risk medical comorbidities: Systemic lupus erythematosus, cancer, heart or lung disease, inflammatory conditions, sickle-cell disease, nephrotic syndrome, IV drug user

Other risk factors (treat as intermediate risk if 2 or more, if <2 factors consider as lower risk, early mobilization and avoid dehydration)

Obesity: BMI ≥30kg/m^2

Gross varicose veins

Elective cesarean delivery

Family history of venous thromboembolism

Advanced maternal age (>35 years)

Immobility such as paraplegia

Parity ≥3

Current smoking

Preeclampsia

Multiple pregnancy

Cesarean delivery

Postpartum hemorrhage >1,000 mL or blood transfusion

Labor >24 hours

Preterm delivery

Stillbirth

American College of Obstetricians and Gynecologists^Citation121

Recommendation 1: Perioperative mechanical thromboprophylaxis for all women undergoing cesarean delivery

Recommendation 2: Low molecular weight heparin for any of the following

History of venous thromboembolism

Family history of venous thromboembolism and a thrombophilia

High-risks thrombophilias

Abbreviations: BMI, body mass index; IV, intravenous.

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