Avogadro

Anaesthetic costs calculator, by Dr Lawrence Rowe, Norfolk and Norwich University Hospital

Vapour MWt Density 1ml liquidoccupies: Price/bottle mls
Halothane 197.4 1.86 227.30 ml vapour $20.57 250 BNF prices 2007
Enflurane 184.5 1.52 198.74 (at 21deg C$24.00 250 (discontinued 2006)
Isoflurane 184.5 1.50 196.12 using Avogadro's $30.00 250 (Baxter)
Desflurane 168.0 1.45 208.21Hypothesis*) $44.41 240 (Baxter)
Sevoflurane 200.0 1.52 183.34 $250.00 250 (Abbott)

% FGF(l/min) ml/min vap ml/min liq liq p/ml Costp/min £/hr ml/hr
Halothane 1.5 6 90 0.40 8.2 3.3 $1.95 Excluding soda-lime
Enflurane 3 6 180 0.91 9.6 8.7 $5.22 (£1 per hrapprox)
Isoflurane 2 6 120 0.61 12.0 7.3 $4.41
Desflurane 5 6 300 1.44 18.5 26.7 $16.00
Sevoflurane 2 2 40 0.22 100.0 21.8 $13.0913.2

Propofol:
Cost/50ml: $1.55 or 3.1 p/ml** **NNUH price for generic propofol 50ml vial
Rate 14 mg/kg/hr £/hr
Body wt 65 kgie: 91 ml/hr = 4.7 p/min or $2.82

Propofol:
Cost/50ml: $1.55 or 3.1 p/ml
Rate 6 mg/kg/hr £/hr
Body wt 65 kgie: 39 ml/hr = 2.0 p/min or $1.21


* Avogadro's hypothesis states that 1 gram mole of a liquid when vapourisedoccupies 22.4 litres at Standard Temperature and Presure (STP)
STP = 273 degrees Kelvin or 0 degrees Celcius and 760mmHg pressure