Obstetric Obesity: Anesthesia Implications and Management,Outline,Definition and prevalence Physiological changes on the top of pregnancy Pregnancy complications Maternal complications Fetal complications Anesthesia problems and management,Definition,BMI=kg/m2 Normal: 18.5-24.9 Overweight: 25-29.9 Obesity: 30 The revised pregnancy weight gain guideline by IOM 2009 NOT differentiate bw Class I 30-34.99 Class II 35-39.99 Class III or morbidly obese 40 Obesity in pregnancy, ACOG, 2013,No data in China yet,What will happen when people get big?,Physiological changes of obesity on pregnancy,Airway,Pregnancy & obesity, risk factors for difficult airway In pregnancy: Breast enlargement, Adipose tissue deposition, Mucosa engorgement Failed intubation is 8 times more,Airway,Difficult airway in obesity Difficult intubation 15.5% vs. 2.2% (BMI 35 vs. Lean people) (Juvin et al) 6/17 (total 117 morbidly obese pregnant women) difficult intubation in obese parturients for c/s (Hood and Dewan) Implication: pre-labor anesthesia consultation,Respiration,Decreased RV, ERV, FRC in pregnancy Reduced pulmonary and chest wall compliance in obesity Increased oxygen consumption and CO2 production FRC can fall below closing capacity (early airway closure and shunting Importance of preoxygenation,OSA,Risk of OSA doubles in overweight parturients Increased risk for HTN, DM, preterm labor and operative intervention and adverse fetal outcomes. Early diagnosis and treatment can improve maternal and fetal outcomes,Cardiovascular,In Pregnancy: CO, 50% higher after 2nd trimester First stage25% more than the prelabor 2nd stage 40% more Postpartum, 75% above the prelabor,Cardiovascular,Obesity: 30-50 ml/min/100g increase in CO 60% obese pts may have mild to mod HTN Obese parturients: exacerbated increase in blood volume, impaired afterload reduction b/o increased PVR Neuroendocrine activation, renal sodium retention and increased systemic oxidative stress due to comorbidities in obesity lead to cardiac remodeling and myocardial dysfunction. Supine Hypotensive Syndrome is exacerbated,GI,Pregnancy leads to GERD: hormonal and mechanical mechanism GERD symptoms exacerbated in obese parturients “Full stomach” precautious, RSI, “Triple Rx”: Sodium Bicitrate, Metoclopramide, famotidine,Pregnancy complications,Maternal Complications,Gestational DM Gestational HTN Preeclampsia Fetal macrosomia OSA Asthma,Fetal complications,Prematurity Still-birth Congenital abnormalities Macrosomia Childhood and adolescent obesity,MC Vallejo, SOAP, 2013,Intrapartum Complications,Big baby, uterine atony Shoulder dystocia Increased C-section rate Increased instrumental delivery,Maternal Risks,Hypertensive disorders, including preE Gestational diabetes Asthma OSA,L. Ellinas, openanesthesia.org, 2013,L. Ellinas, openanesthesia.org, 2013,Anesthesia considerations,Pre-anesthesia Considerations,Pre-admission consultation is preferred Early thorough physical examination Good anesthesia plan IV may be difficult Equipment: BP cuff, operating table, video scope Evaluate ability to lie supine For OSA patients, where is the CPAP machine,Labor Analgesia,Will be difficult Prefer to place early Make sure it works Do anything possible to prevent failure of conversion to C-section epidural,Labor Analgesia,Catheter placement Position Location Technique,What predicts difficult?,Could NOT feel anything when touch Could NOT sit still Scoliosis Previous lower back surgery,Depth to space,Failure rate,Unilateral block Failure from the beginning Later failure Every back can make the catheter in and out 4 cm in the epidural space in obese patients,Techniques,Direct insertion Needle mapping Ultrasound,Ultrasound technique for epidural placement,5 basic planes,KJ Chin, ISURA, 2012,Cesarean Delivery Anesthesia,Conversion Labor Epidural to C/D anesthesia,With existing working epidural catheter Dose through the catheter 2% lidocaine with epinephrine 15-25 ml Sodium Bicarbonate 1 in 10 ml 3% 2-chloroprocaine 15-25 ml 0.5% bupivacaine 15-30 Fentanyl 50-100 mcg through epidural Preservative-free morphine 3 mg after umbilical cord is clamped Level: T4,Without An Epidural,Spinal CSE (combined spinal and epidural) Hyperbaric bupivacaine 12-15mg Fentanyl 10-15mcg Epinephrine 100-200 mcg Preservative-free morphine 100 mcg,GETA,The anesthesia of choice for real OB emergency Pre-meds: sodium bitrate, famotidine, metoclopramide Position, alignment of the axis RSI Video scope, FOI, LMA,HE Shobary, MEJ Anesth 2011,187 KG, BMI 70, OSA, DMII,MC Vallejo, SOAP, 2013,Induction drugs,Propofol 2.5 mg/kg Methohexital (Brevital), 1-2 mg/kg, or 50-120 mg Ketamine 1 mg/kg up to 100 mg Etomidate 0.3 mg/kg Fentanyl 50-100 mcg Succinylcholine 1-2 mg/kg, ok to use rocurronium instead, but be cautious in obese patients Half MAC of gas + 50/50 nitrous oxide Ventilate to normo-carbia, DO NOT OVERVENTILATE,Emergence,Michigan series 1985-2003, 7 anesthesia contributing maternal death None during induction of GA Five resulted fr