- Obesity
Link:www.sobauk.co.uk
- BMI >30 obese, >35 with assd comorbidity OR > 40 without comorbidity is morbidly obese
- Absolute BMR is higher in obese individuals
- The causes are multifactorial
- Comorbidities
- Hypertension, dyslipidaemia, IHD, DM, OA, liver disease, OSAS, asthma, HH.
- Pre-op
- Limited mobility so may mask IHD
- Drug history
- OSAS or signs of CCF to be elicited
- Airway assessment
- ECG, bloods, ?pre-op NIV, echo, PFTs, pre-op teds/mechanical calf compression devices/LMWH.
- Perioperative
- Induce on table?
- Trained staff and adequate numbers
- Correct monitoring
- IV access may be difficult
- Ramping up position
- PPI prophylaxis
- Effective temperature management
- Short acting agents used
- Ensure adequate muscle paralysis reversal
- Post-op
- Extubation awake in sitting position
- Level 2/3 care if comorbidities
- CPAP
- Multimodal analgesia
- Physio
- Maintain normoglycaemia
- Pharmacokinetics
- IBW better for fat soluble drugs
- Lean body mass (IBW + 20%) for less lipid soluble drugs
- Exceptions: sux given on actual BW and propofol TCI done on actual BW.
- Consider reduced doses in epidural space and SAB
- CVS
- Absolute blood volume, co, ventricular workload, O₂ consumption and CO₂ production are all increased
- Can lead to PAH, RVH and cor pulmonale
- Hypertension is 10x commoner
- IHD more prevalent
- Diastolic dysfunction ultimately leads to elevated LVEDP and heart failure
- ECG
- Low voltage complexes
- LVH or strain
- Inferolateral T wave abnormalities
- RAD or RBBB
- p-pulmonale
- Respiratory
- OSAS
- 5 or more per hr or >30 times per night
- Classed as 10s or more of cessation of air flow despite continued effort against a closed glottis
- Snoring
- Daytime somnolence
- Polycythaemia, hypercapnoea, RVF, pulmonary vasoconstriction
- Obesity hypoventilation syndrome
- FRC low (<1L in BMI >40)
- Reduced lung and chest wall compliance
- Increased A-a gradient with shunt
- Atelectasis and secretion retention
- CEACCP
Link:ceaccp.oxfordjournals.org/content/8/5/151.full.pdf