Childhood Obesity: Anesthetic Implications

Transcription

1 Childhood Obesity: Anesthetic Implications The Changing Practice of Anesthesia 2015 UCSF Department of Anesthesia and Perioperative Care Marla Ferschl, MD Associate Professor of Anesthesia University of California-San Francisco September 25, 2014 Disclosures None 2 1

2 Overview Definition Pathophysiology Comorbid Conditions Anesthetic Implications 3 Case Scenario 6 year old male weighing 55kg presents for adenotonsillectomy in the setting of OSA How do you: 1. Manage his airway 2. Dose Medications 3. Ensure a safe yet rapid emergence 4. Provide adequate post-operative pain control 4 2

3 Obesity-Definition You know it when you see it! 5 Obesity-Definition Adults: 6 3

4 7 Obesity-Definition Childhood BMI >85%ile=overweight >95%ile=obese Rough estimate: BMI>20 in age 2-5 BMI>25 in age

5 Obesity Prevalence 9 Health, United States, U.S. Department of Health and Human Services. 10 5

6 Ogden et al. JAMA

7 Obesity-Pathophysiology 90% from excess calorie consumption 10% secondary to endocrine disorders, neurological conditions, and syndromes 13 Co-Morbid Conditions OSA 13-59% of overweight children Diagnosed by parent hx or sleep study Mild Moderate Severe Diminished ventilatory response to CO

8 Co-Morbid Conditions Pulmonary Decreased FRC, FEV1 and DLCO Asthma 30% of obese 8-18 year-olds have asthma Higher BMI correlates with higher severity More frequent URIs Lang JE et al. J Asthma Jedrychowski et al. Public Health Li AM et al. Arch Dis Child Co-Morbid Conditions Cardiovascular 20-30% incidence of HTN Obese children have increased blood volume and stroke volume increased cardiac output LVH, hypercholesterolemia and hyperlipidemia 16 8

9 Co-Morbid Conditions Type 2 Diabetes Metabolic syndrome common 24% progress to DM within 2 years 45% of pediatric patients with Diabetes are Type 2!!! Gidding SS et al. J Pediatr 2004 Craig ME et al. Pediart Diabetes Anesthetic Implications Increased relative risk of: Difficult mask ventilation Airway obstruction Desaturation Bronchospasm 18 9

10 Anesthetic Implications 19 Airway Management More difficult mask ventilation Oral airway and LMA ready Meticulous patient positioning Ramp Back-up plan if conventional DL fails 20 10

11 Pharmacology How do you know how much to give? Total Body Weight >> Lean Body Weight =IBW +0.3 x (TBW-IBW) >> Ideal Body Weight =50% BMI x height (meters 2 ) 21 Pharmacology Approximate Ideal Body Weight by Age Age (yr) Weight (Kg)

12 Pharmacology Theoretically: Lipophilic drugs have increase volume of distribution Hydrophilic drugs remain unchanged 23 Recommended Dosing Algorithm Medication Thiopental sodium Dosing Weight Lean body weight (more rapid awakening) Propofol Etomidate Succinylcholine Pancuronium Rocuronium Vecuronium Cisatracurium Fentanyl Alfentanil Remifentanil Midazolam Paracetamol Neostigmine Sugammadex Enoxaparin (VTE prophylaxis) Lean body weight (induction bolus) Total (actual) body weight (maintenance infusion) Lean body weight Total (actual) body weight Ideal body weight Ideal body weight Ideal body weight Ideal body weight Lean body weight Lean body weight Lean body weight Total (actual) body weight (bolus dose) Ideal body weight (infusion) Lean body weight Total (actual) body weight Total (actual) body weight or ideal body weight + 40% Total (actual) body weight 0.5 mg kg

13 Pharmacology General rule Initial dosing to ideal body weight; titrate to effect Succinylcholine dosed to Total Body weight Highly lipophilic drugs (midazolam, thiopental) may stick around longer Caution with opioids as ventilatory response to CO 2 may be altered 25 Emergence and Recovery Patients more prone to airway obstruction, awake extubation Caution with opioids in recovery room and for home When in doubt, admit 26 13

14 Case Discussion 6 year old male weighing 55kg presents for adenotonsillectomy in the setting of OSA IV induction unless experienced in inhalational induction Dose propofol to LBW, muscle relaxants to ideal body weight Consider Desflurane Minimize opioids until patient spontaneously ventilating, then titrate to effect Consider dexmedetomidine to smooth emergence (0.5 g-1 g/kg) Awake extubation Careful post-op observation 27 Questions? 28 14

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