1、Obstetric Obesity: Anesthesia Implications and Management,Yunhong Zhang, MD, PhDAnesthesia Associates of St. LouisJune, 2015,Outline,Definition and prevalence Physiological changes on the top of pregnancy Pregnancy complicationsMaternal complicationsFetal complicationsAnesthesia problems and managem
2、ent,Definition,BMI=kg/m2Normal: 18.5-24.9 Overweight: 25-29.9Obesity: 30The revised pregnancy weight gain guideline by IOM 2009NOT differentiate bwClass I 30-34.99Class II 35-39.99Class III or morbidly obese 40Obesity in pregnancy, ACOG, 2013,No data in China yet,What will happen when people get big
3、?,Physiological changes of obesity on pregnancy,Airway,Pregnancy & obesity, risk factors for difficult airwayIn pregnancy: Breast enlargement, Adipose tissue deposition,Mucosa engorgementFailed intubation is 8 times more,Airway,Difficult airway in obesityDifficult intubation 15.5% vs. 2.2% (BMI 35 v
4、s. 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 pregnancyReduced pulmonary and chest wall compliance in obesityIncreased
5、oxygen consumption and CO2 productionFRC can fall below closing capacity (early airway closure and shuntingImportance of preoxygenation,OSA,Risk of OSA doubles in overweight parturientsIncreased risk for HTN, DM, preterm labor and operative intervention and adverse fetal outcomes.Early diagnosis and
6、 treatment can improve maternal and fetal outcomes,Cardiovascular,In Pregnancy:CO, 50% higher after 2nd trimesterFirst stage25% more than the prelabor 2nd stage 40% morePostpartum, 75% above the prelabor,Cardiovascular,Obesity:30-50 ml/min/100g increase in CO60% obese pts may have mild to mod HTNObe
7、se parturients: exacerbated increase in blood volume, impaired afterload reduction b/o increased PVRNeuroendocrine activation, renal sodium retention and increased systemic oxidative stress due to comorbidities in obesity lead to cardiac remodeling and myocardial dysfunction.Supine Hypotensive Syndr
8、ome is exacerbated,GI,Pregnancy leads to GERD: hormonal and mechanical mechanismGERD symptoms exacerbated in obese parturients“Full stomach” precautious, RSI, “Triple Rx”: Sodium Bicitrate, Metoclopramide, famotidine,Pregnancy complications,Maternal Complications,Gestational DMGestational HTNPreecla
9、mpsiaFetal macrosomiaOSAAsthma,Fetal complications,PrematurityStill-birthCongenital abnormalitiesMacrosomiaChildhood and adolescent obesity,MC Vallejo, SOAP, 2013,Intrapartum Complications,Big baby, uterine atonyShoulder dystociaIncreased C-section rateIncreased instrumental delivery,Maternal Risks,
10、Hypertensive disorders, including preEGestational diabetesAsthmaOSA,L. Ellinas, openanesthesia.org, 2013,L. Ellinas, openanesthesia.org, 2013,Anesthesia considerations,Pre-anesthesia Considerations,Pre-admission consultation is preferredEarly thorough physical examinationGood anesthesia planIV may b
11、e difficultEquipment: BP cuff, operating table, video scopeEvaluate ability to lie supineFor OSA patients, where is the CPAP machine,Labor Analgesia,Will be difficultPrefer to place earlyMake sure it worksDo anything possible to prevent failure of conversion to C-section epidural,Labor Analgesia,Cat
12、heter placementPositionLocationTechnique,What predicts difficult?,Could NOT feel anything when touchCould NOT sit stillScoliosisPrevious lower back surgery,Depth to space,Failure rate,Unilateral blockFailure from the beginningLater failureEvery back can make the catheter in and out 4 cm in the epidu
13、ral space in obese patients,Techniques,Direct insertionNeedle mappingUltrasound,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 catheterDose through the catheter2%
14、lidocaine with epinephrine 15-25 mlSodium Bicarbonate 1 in 10 ml 3% 2-chloroprocaine 15-25 ml0.5% bupivacaine 15-30 Fentanyl 50-100 mcg through epiduralPreservative-free morphine 3 mg after umbilical cord is clampedLevel: T4,Without An Epidural,SpinalCSE (combined spinal and epidural)Hyperbaric bupi
15、vacaine 12-15mgFentanyl 10-15mcgEpinephrine 100-200 mcgPreservative-free morphine 100 mcg,GETA,The anesthesia of choice for real OB emergencyPre-meds: sodium bitrate, famotidine, metoclopramidePosition, alignment of the axisRSIVideo scope, FOI, LMA,HE Shobary, MEJ Anesth 2011,187 KG, BMI 70, OSA, DM
16、II,MC Vallejo, SOAP, 2013,Induction drugs,Propofol 2.5 mg/kgMethohexital (Brevital), 1-2 mg/kg, or 50-120 mgKetamine 1 mg/kg up to 100 mgEtomidate 0.3 mg/kgFentanyl 50-100 mcgSuccinylcholine 1-2 mg/kg, ok to use rocurronium instead, but be cautious in obese patientsHalf MAC of gas + 50/50 nitrous ox
17、ideVentilate to normo-carbia, DO NOT OVERVENTILATE,Emergence,Michigan series 1985-2003, 7 anesthesia contributing maternal deathNone during induction of GAFive resulted from hypoventilation or airway obstruction during emergence, extubation, or recoveryFully wake upObesity increases the risk signifi
18、cantly,JM Mhyre, Anesthesiology, 2007,Summary,OB anesthesia is NOT just pain controlObesity put patients on various risksAvoid GA if possibleStart earlyPrepare for the worstTeach your patients to lose weight whenever is appropriate,The 2016 SOAP Annual MeetingMay 18-22, 2016Seaport Hotel Boston, MA,Etherdome!,THANK YOU!,
