EPO 2 Evaluation of the preoxygenation in! morbidly obese. Optimal position and ventilation mode! Antony Carrier-Boucher! PGY 3 Anesthesiology! Laval University!
None! Conflict of interest!
2. Anesth Analg 2003;97:595 600. 3. Br. J. Anaesth. 1991;67(4): 464-466. Introduction! context! Airway management in obese is riskier than in thin patients 1.! More difficulty with tracheal intubation 2.! Less apnea time before hypoxemia 3.! 1. Br. J. Anaesth. 2011;106(5):617-31.
Introduction! context! Non hypoxic apnea time:! Is prolonged by a preoxygenation before general anesthesia induction 4.! Can be optimized by changes in position 6 and ventilation mode 7 during preoxygenation.! Its length is proportional to the functional residual capacity 5.! 4 Anesthesiology 1999; 91 :603 5! 5 Anesth Analg 1991,72 :89-93! 6 Obesity Surgery 2003, 13 : 4-9! 7 Anesth Analg 2005;100 :580 4!
Introduction! EPO 2 :PV! Physiologic study April-June 2014! = p < 0,001! Variation between :! - Beach Chair + SV - PEEP 0! - Reverse Trendelenburg + PSV 8 - PEEP 10!
! Introduction! Goal! 1. Find a combination of position and ventilation mode that lengthens non-hypoxic apnea time in morbidly obese patients.! Non Hypoxic Apnea Time between:! - General Anesthesia induction and! - Saturation of 92%. Primary outcome!
Hypothesis! We think that GA induction in:! Reverse Trendelenburg (RT) position! - with a positive pressure ventilation (PP) comparatively to! Beach Chair (BC) position! - without positive pressure ventilation (ZEEP) gives a longer non hypoxic apnea time.
Material & methods! Approved by the local REB! REB: #21211 IUCPQ! Protocol registered! clinicaltrials.gov: #NCT02590406! Prospective randomized control trial! September - December 2015!
Material & methods! Eligibility Criteria! Inclusion! Bariatric surgery! BMI > 40 kg/m 2! Central obesity phenotype! Waist circumference! Men > 130 cm! Women > 115 cm! Exclusion! Asthma! moderate or severe COPD! NYHA > 2! Active smoker! important GERD! Facial pilosity! Suspected or known difficulty with intubation! Anesthesiologist refusal
Material & methods! Groups! BC/ZEEP! PSV 0 cm H20! PEEP 0 cm H2O! Randomization! RT/PP! PSV 8 cm H20! PEEP 10 cm H2O!
Material & methods! Interventions!
Material & methods! Primary outcome! Time to SpO2 92 %!
Material & methods! secondary outcomes! Time EtO2 > 0,90! Maximal EtO2!
Material & methods! secondary outcomes! minimal saturation! Time SpO2 97 %!
Results! Table 1: Population description (n=48)! Data ± Standard Deviation!
Results! Non Hypoxic Apnea Time! BC/ZEEP! PSV 0 cm H2O! PEEP 0 cm H2O! RT/PP! PSV 8 cm H2O! PEEP 10 cm H2O! 216,7 ± 16,9 seconds! 258,2 ± 22,0 seconds! Difference 41,5 seconds (16%) p=0,0053!
Results! Secondary outcomes! BC/ZEEP! PSV 0 cm H2O! PEEP 0 cm H2O! RT/PP! PSV 8 cm H2O! PEEP 10 cm H2O! Time for EtO2 > 0,9! 145,3 ± 16,3 sec! 85,1 ± 19,1 sec! p<0,0001! Maximal EtO2! Minimal Saturation! Time for SpO2 > 97%!
Results! Secondary outcomes! BC/ZEEP! PSV 0 cm H2O! PEEP 0 cm H2O! RT/PP! PSV 8 cm H2O! PEEP 10 cm H2O! Time for EtO2 > 0,9! 145,3 ± 16,3 sec! 85,1 ± 19,1 sec! p<0,0001! Maximal EtO2! 0,89 ± 0,01! 0,91± 0,05! p=0,0003! Minimal saturation! Time for SpO2 > 97%!
Results! Secondary outcomes! BC/ZEEP! PSV 0 cm H2O! PEEP 0 cm H2O! RT/PP! PSV 8 cm H2O! PEEP 10 cm H2O! Time for EtO2 > 0,9! 145,3 ± 16,3 sec! 85,1 ± 19,1 sec! p<0,0001! Maximal EtO2! 0,89 ± 0,01! 0,91 ± 0,05! p=0,0003! Minimal Saturation! 84,4 ± 2,9 %! 85,3 ± 1,8 %! p= 0,3722! Time for SpO2 > 97%!
Results! Secondary outcomes! BC/ZEEP! PSV 0 cm H2O! PEEP 0 cm H2O! RT/PP! PSV 8 cm H2O! PEEP 10 cm H2O! Time for EtO2 > 0,9! 145,3 ± 16,3 sec! 85,1 ± 19,1 sec! p<0,0001! Maximal EtO2! 0,89 ± 0,01! 0,91 ± 0,05! p=0,0003! Minimal Saturation! 84,4 ± 2,9 %! 85,3 ± 1,8 %! p= 0,3722! Time for SpO2 > 97%! 88,4 ± 17,3 sec! 68,0 ± 10,6 sec! p=0,0290!
Discussion! Reverse Trendelenburg position with! Positive Pressure ventilation! Lengthens time before hypoxemia following GA induction! Unsuspected difficulty with airway management! Safer Rapid Sequence Intubation when needed!!
Shorter time to obtain an adequate preoxygenation (60 seconds less)! Defined as EtO2 > 0,90 9! Discussion! Reverse Trendelenburg position with! Positive Pressure ventilation! Higher EtO2 at the end of preoxygenation period! Higher O2 concentration in the FRC 9! Shorter time to return to an adequate saturation after a desaturation (20 seconds less)! 9. Can J Anesth. 2009, 56 449-466!
Discussion! Strengths! Randomized trial! Adequate power! First time that positions and ventilatory modes are compared in the same clinical trial! Limits! No blinding! Objective outcomes! Changes in position AND ventilation mode!
Thanks!! Research Director! Dr Jean S. Bussières, MD, FRCPC! Coauthors! Étienne Couture PGY5 anesthesiology! Dr Steeve Provencher MD, MSc, FRCPC! Nathalie Gagné PHD, inh! Simon Marceau, MD, FRCSC! All the anesthesiologists & RT of l IUCPQ!
Hemodynamics! Start PreO2! Induction!
Induction! Group 1 (n=24) Group 2 (n=24) Sufentanyl (µg)! 29! 37! Propofol (mg)! 250! 246! Muscle! Relaxant:! Succynilcholine (n)! Rocuronium (n)! 18! 6! 21! 2! Cisatracurium (n)! 0! 1!
Intubation! Comparaison de:! Position «Sniff» (élévation de la tête de 7 cm) vs! «Ramped» (Alignement méat auditif externe et sternum)! Amélioration du grade d intubation dans la position «ramped»! Grade Intubation Sniff Ramped Grade 1! 18! 29! Grade 2! 9! 3! Grade 3! 0! 1! Grade 4! 0! 0!
Intubation! Analysis! Group 1 (n=25) Group 2 (n=25) Grade 1! 15! 16! Grade 2! 4! 2! Grade 3! 1! 2! Grade 4! 0! 0! Vidéolaryngoscopie facile! 5! 5! Vidéolaryngoscopie difficile! 0! 1*! Nécessité Fibre optique! 0! 1*!