Morbid obesity and anaesthesia



·         40 year old man

·         180kg 170cm BMI+++

·         Not known to any doctors

·         SBO requiring urgent laparotomy




·      Major comorbidity + major surgery

·      Risky anaesthetic and surgery

·      Risky intra-op and post-op

Obesity itself

·      Airway: difficulty bag-mask ventilation due to obstruction; difficult intubation due to positioning

·      Breathing: difficulty ventilating due to restriction, difficulty oxygenating due to shunt

·      Circulation: difficult vascular access and BP monitoring

·      Logistics: difficulty positioning and transferring

Secondary pathology

·      Airway and breathing: sleep-disordered breathing

·      Circulation: AF, coronary artery disease, cardiomyopathy, cor pulmonale

·      Other: diabetes, GORD




·      What is the severity of obesity?

·      What secondary pathologies are present?

·      What needs testing?

·      What needs optimizing?





What to do pre-op:

-Assessment (HxExIx)

                Severity of illness: evidence of hypovolaemia, sepsis, organ dysfunction

Presence and severity of comorbidities

Prev anaes esp airway


                Time to test anything? e.g. sleep studies (?OSA), TTE (?PHTN, RV dysfx)

                Needs review by anyone? e.g. peri-op med

                Need treatment of anything? e.g. diabetes

-Planning for the entire stay:

                People: second anaesthetist to help me, peri-op physician of some sort

                Equipment: hover mat, oxford ramp, HFNP, locked analgesic infusion pumps

                Facilities: HDU




                Access: 2 x 18g IV and arterial line

Monitoring: standard + 5 lead ECG + arterial

-Induction: modified rapid-sequence

                2nd anaesthetist!

                Positioning: oxford ramp + HFNP 50L/min highest FiO2

                Say airway plan: 1)video scope size 8 ETT with stylet 2) iGel size 4 3) BMV with red guedel 4) scalpel bougie cric

                Give drugs: alfentanil 15mcg/kg LBW + propofol 2g/kg LBW + rocuronium 1.2mg/kg


                Anaesthetic: deflurane to minimize uptake

                Analgesia: ketamine 0.3mg/kg + infusion 0.1mg/kg/h + lignocaine 1mg/kg + infusion 1mg/kg/h + titrated fentanyl 0.5mcg/kg + paracetamol 1g + parecoxib 40mg

                Fluid: CSL how much?



                Bite block

                Reversal: sugammadex + TOF >0.9 confirmation

                On bed

                Sitting up

                Obeying commands

                Ensure all systems good: airway/breathing/circ/neuro/neuromusc/acid-base/temp



-Disposition: HDU due to risk of airway obstruction and death

-Analgesic plan: paracetamol + ketamine infusion + fentanyl PCA +/- rectus sheath catheters + APS referral

-Rectus sheath catheters: load ropiv 0.75% 10mL each, infuse ropiv 0.2% 6mL/h each