+ + I have nothing to disclose. Perioperative Considerations in - - PowerPoint PPT Presentation

10/19/2018 1

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Perioperative Considerations in the Obese Gynecologic Patient

Stefanie M. Ueda, M.D. Associate Clinical Professor UCSF Division of Gynecologic Oncology

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I have nothing to disclose.

I counsel patients about weight loss or the effects of obesity on their health at “well woman,” annual, or obstetric visits?

• A. Yes
• B. No

Y e s N

• 10%

90%

+ Obesity in the United States

 40.4% prevalence in U.S.

women with 6-12 fold mortality risk

 Age adjusted prevalence  57% Blacks  46.9% Hispanics  38% Whites

 Only 36% of OB-GYNs

reportedly counsel patients about obesity

 5-10% weight reduction

among PCOS women associated with improved insulin resistance, hyperinsulinemia, and hyperglycemia

 Maternal obesity associated

with increased risk of diabetes, hypertension, neural tube defects, thromboembolism, cesarean, and stillbirth

Kahan S et al, Clin Obstet Gyn 2017

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Weight Loss Reverses Co-Morbidities

 5-10%sustained

weight loss improves glycemic control, triglycerides, blood pressure, LFTs,and chronic pain

 Medicare began

reimbursing obesity counseling in primary care in 2011

 Maximum 22 visits

(15 min) over 1 year contingent on patients achieving 3 kg weight loss

 Reducing caloric

intake by 500-750 calories/day

Kahan S et al, Clin Obstet Gyn 2017

5A’s Approach to Counseling ASSESS Measure BMI Identify co-morbidities Discuss readiness for change ADVISE Counseling benefits AGREE Establish goals Monitor nutrition & activity ASSIST Problem solve barriers Identify contributors/causes ARRANGE Refer to dietitians, hospital based programs, behavioral providers

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Pharmacotherapy and Surgery

 4 FDA approved medications1  Lorcaserin (Belviq)  Phentermie-topiramate (Qsymia)  Naltrexone-buproprion (Contrave)  Liraglutide (Saxenda)  Pharmacotherapy as adjunct to behavioral

counseling

 Continued long term if obtain at least 5%

weight loss after 3 months

 Bariatric surgery indicated in patients with

BMI>40 or >35 with 1 comorbidity2

 Average 2 year weight loss of 25% for

sleeve gastrectomy and 32% for Roux-en Y bypass

 Meta-analysis shows weight loss in range

• f 10-15%

1Kahan S et al, Clin Obstet Gyn 2017 2Jensen MD et al, J Am Coll Cardiolo 2014

+ Cardiopulmonary Physiology in the Obese

 Cardiovascular  Increase in oxygen demand, cardiac

• utput and stroke volume

 Decrease in vascular volume increasing

risk for heart failure, hypertension, peripheral edema arrhythmia, and sudden death

 Respiratory

 Reduced lung compliance, functional

residual capacity, total lung volume, and expiratory reserve

 Increase work of breathing, oxygen

consumption, and CO2 production

 Increase adipose deposition increases

upper airway resistance

 Higher likelihood of OSA Louie M et al, Curr Opin Obstet Gynecol 2016

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Physiologic Changes of Obesity

 Renal

 Higher inflammatory

cytokines and endothelial dysfunction

 Gastrointestinal

 Larger gastric volumes  Lower gastric pH  Delayed stomach

emptying

 Higher intra-abdominal

pressures with increased risk of aspiration

Louie M et al, Curr Opin Obstet Gynecol 2016

10/19/2018 3

+ Preoperative Evaluation

 Exercise capacity assessment (<4 metabolic equivalents)

 Preoperative EKG and CXR  Possible referral to cardiology (echo and stress test)

 COPD or severe reactive airway disease

 PFTs (FEV1/FVC<70% and FEV1>12% poorer prognosticators)  OSA testing (6.7% vs 2.6% complication rate)  Elevated serum bicarbonate sensitive for elevated PaC02 levels  Anesthesia evaluation

 Screening for Type II DM if >45

 HgbA1C (6.5-7%)  Fasting blood sugar (<110)  2 hour postprandial (<140) Leonard KL et al, Surg Clin North Am 2015

+ Pulmonary Optimization

 Inspiratory muscle training

may decrease postoperative complications1

 STOP-BANG serves as

validated OSA screening tool2

 Score 5-8 high risk for

moderate to severe OSA

 Higher risk for difficult

intubation (20%), mask ventilation (23%), and 1 year mortality (7.45%)

 CPAP and multimodal pain

regimen to reduce opioids that induce intermittent hypoxia

 30-40º position with ISP

1Pouwels S et al, Resp Med 2016 2Nagappa M et al, Curr Opin Anesthiol 2017

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Bowel Preparation

 No routine bowel prep  Exacerbates cardiovascular and renal

dysfunction

 2012-15 review of ACS-NSQIP in elective

colorectal resections

 Mechanical bowel prep alone showed no

significant benefit

 Antibiotic bowel prep lowered  Surgical site infection (OR 0.63, p= 0.01)  Anastomotic leak (OR 0.53, p=0.002)  Combination of mechanical and antibiotic

bowel prep reduced

 Surgical site infection (OR 0.39, p<0.001)  Wound dehiscence (OR 0.43, p=0.001)  Anastomotic leak (OR 053, P<0.001) Klinger AL et al, Ann Surg 2017

+ Thromboembolic Prophylaxis

 Obese patient with at least moderate risk (3%)

 VTE incidence 2% and PE 0.5%  Intraoperative sequential compression devices recommended  Addition of heparin prophylaxis1  Cancer  Age>40  Pulmonary dysfunction  History of VTE  Thrombophilia

 Systematic literature review of postoperative prophylaxis2

 LMWH 3000-4000 anti-Xa IU SC Q12 hours or SCDs acceptable for

low risk obese patients

 LMWH 4000-6000 anti-Xa IU SC Q12 hours for higher risk patients

and consider extending for 10-15 days (age >55, BMI>50, history VTE, OSA, venous disease, pulmonary hypertension)

 Heterogeneous efficacy for IVC filter placement

1Gould MK et al, Chest 2012 2Venclauskas L et al, Eur J Anaesthesiol 2018

10/19/2018 4

+ Antibiotic Prophylaxis

 Current recommendations for 3g

for patient >120 kg

 60 minutes prior to incision  Re-dose every 4 hours

 Pharmacokinetic study of 63

patients who received 2g cefazolin as surgical prophylaxis

 Fewer patients with BMI>35 achieved

therapeutic levels (58% vs 75%, p=0.20)

 Less patients with total body

weight>120 kg achieved therapeutic levels (55% vs 68%, p=0.28)

 BMI and TBW cut-offs poor indicators

• f benefit

Hites M et al, Int J Antimicrobial Agents 2016

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Intraoperative Positioning

 Higher risk for pressure

ulcers and nerve injuries if >6-8 hours

 Lithotomy safe with

padded boot type stirrups

 Buttocks slightly lower

than edge of bed when shifted in Trendelenburg

 Tucking both arms with

padding at elbows

 Bed extenders preferable

to arm sleds

 Anti-slide pad or bean

bag with padded strap across chest

 Maintaining pannus in

caudad position or laterally to prevent port interference

Scheib SA et al, J Minim Invasive Gynecol 2014

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Laparoscopic Entry

Scheib SA et al, J Minim Invasive Gynecol 2014

 No entry clearly superior and

no difference in complication rates

 Orogastric tube to prevent

stomach distention

 Left upper quadrant entry if

prominent pannus

 Hasson open technique requires

more extensive dissection

 Veress needle (150 mm) entry

associated with higher rate of failed entry and preperitoneal insufflation

 90 degree insertion relative to

abdominal wall

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Port Placement and Insufflation

 More cephalad and lateral

placement with longer trocars up to 150 mm1

 Consider reducing

insufflation pressures to 9-12 mm Hg and less Trendelenburg to 30-50º to improve ventilation

 Increased intra-abdominal

pressure leads to increased venous stasis, portal venous blood flow, and airway pressure with decreased cardiac function and respiratory compliance2

1Scheib SA et al, J Minim Invasive Gynecol 2014 2Demirel I et al, Obes Surg 2018

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+ Anesthetic Agents

 Use of short acting anesthetics like

propofol, desflurane, and sevoflurane because of rapid elimination

 Propofol dosed according to lean

body weight

 Desflurane may reduce mean time to

extubation over sevoflurane1

 Use of succinylcholine over other

muscle relaxants

 Increases tidal volumes  Dilates pharyngeal isthmus  Dosed by total body weight

Kiss T et al, Curr Opin Crit Care 2016

+ Intraoperative Ventilation

 Higher risk of difficult intubation

(15.8% with BMI>30 compared to 5.8% in general population)1

 Awake videolaryngoscopy (up to

96% success rate)

 25º head up induction  Apneic oxygenation with nasal O2  PEEP with recruitment maneuvers

decreases atelectasis and improves PaO2/FiO2 ratio as well as lung compliance

 No significant differences in PaO2

• r FiO2 with pressure or volume

controlled strategies

 CPAP postoperatively reduces

reduces atelectasis and pneumonia

• n Cochrane review

Pouwels S et al, Resp Med 2016

+ Fluid Management

 No need to administer extra volume to

• bese patients

 Goal urine output 0.5-1 ml/kg/h  Each extra liter of fluid increases risk of

postoperative symptoms ~16-32%

 Goal directed fluid therapy with

hemodynamic parameters decreases

 Length of stay  Incidence of respiratory failure  Surgical site infection  Postoperative nausea and vomiting  Dynamic indicators such as pleth

variability index (PVI) may be superior to CVP or PCWP

 250-500 mL boluses  Less fluid infusion intraoperatively  No difference in renal function 24-48

hours postoperatively

Demirel I et al, Obes Surg 2018

+ Wound Closure

 Wound separation and

infection rate as high as 37% in gynecology patients

 No difference in wound

complications in obese women undergoing cesarean

• r gynecologic surgery with

staple or subcuticular closure1,2

 Worse cosmetic score,

darker scar color, and more skin marks with staples

 Overall patient satisfaction

similar

1Zaki MN al, AJOG 2018 2Kuroki LM et al, Obes Surg 2018

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+ Panniculectomy

 Increase visualization of

pelvis and improve node sampling1

 Infection rates of 3-56%

when done with gynecologic surgery2

 Extended antibiotic

prophylaxis did not reduce surgical site infection

 Higher risk if additional

comorbidities including hypertension, diabetes, and smoking

 Possible decrease risk of

infection with closure of subcutaneous tissue in 3-4 layers

1Rasmussen RW al, Gyn Obstet 2016 2Patibandla JR al, J Surg Onc 2017

+ Perioperative Analgesia

 77% morbidity due to opioids occurs in

1st postoperative day

 Obese patients may have higher basal

endogenous opioid levels and may be more sensitive to opioids

 Nocturnal hypoxemia of OSA increases

potency of opioids

 Multimodal treatment  NSAIDS  Toradol in first 24 hours improves

patient satisfaction and is comparable to fentanyl while reducing nausea, sedation, and slowing of bowel function

 Tylenol IV with higher, faster peak

concentration

 Alpha-2 agonists (also suppress PONV)  Dexmedetomidine 0.2-0.8 µg/kg/min  Pregabalin 150 mg PO preoperatively  Tramadol (caution with seizure history) Alvarez A et al, Obes Surg 2014

+ NMDA Antagonists

 Ketamine

 Anti-inflammatory effects  Lowers opioid hyperalgesia  0.5 mg/kg bolus followed by

continuous 2-2.5 µg/kg/min

 Magnesium (blocks NMDA at

sites other than ketamine)

 Additional 50 mg/kg at time of

induction improves postoperative analgesia

 Mild sedation but lowers

intraoperative anesthetic requirements

Alvarez A et al, Obes Surg 2014

+ Regional Anesthesia

 Reduces opioid requirements, pulmonary

complications, airway intervention, cardiopulmonary depression, and PONV

 94.3% success rate of epidural placement in

• bese patients (compared to 97.3%)

 Transverse abdominis plane (TAP) blocks

(T6-L1) may decrease opioid use

 Thoracic epidural with higher efficacy to

TAP block

 Incisional-site anesthetic infiltration

associated with decreased morphine consumption and less pain within 1st hour

 Recommend using ideal body weight in

dosing of peripheral blocks

 0.125% bupivacaine or 0.2% ropivacaine Alvarez A et al, Obes Surg 2014

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Lifestyle and Perioperative Modifications

 Identify and initiate open

communication about obesity

 Assess willingness to lose weight  Discuss risks associated with excess

weight

 Perform appropriate preoperative

evaluation and optimization including OSA assessment

 Attempt minimally invasive surgery

when able and ensure appropriate intraoperative positioning, ventilation, and fluid management

 Consider regional anesthesia and

multimodal treatment to reduce

• pioids

A patient with BMI 32, COPD, and IDDM has failed medical and conservative management for a symptomatic fibroid uterus. In preparation for her surgery, I would MOST want

• A. Preoperative echo and PFTs

B.

Goal directed fluid management

• C. Multimodal pain regimen
• D. Postoperative anticoagulation

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