Table 1 Details of the seals, anaesthetic protocol and monitoring

Age, sex, wt

6 weeks, female, 12 kg

8 weeks, male, 16 kg

2 weeks, female, 20 kg

Presenting complaint

Open mandibular fracture >1 week duration

5^th metatarsal bone fracture

Left tibia and fibula fracture > 4 days

Premedication

Pethidine¹ (2 mg.kg^-1), midazolam² (0.2-0.3 mg.kg^-1), atropine³ (0.02-0.04 mg.kg^-1) IM

Induction

Propofol⁴ (1.25-2 mg.kg^-1) IV 30-40 minutes after premedication

Endotracheal tube

6.5 mm cuffed

7 mm cuffed

8 mm cuffed

Maintenance

Sevoflurane⁵ in 100% O₂, IPPV

Sevoflurane in 100% O₂, IPPV

Isoflurane⁶ in 100% O₂, IPPV

End tidal anaesthetic agent

ET sevo 3-3.3%

ET sevo 1.7-2.7%

ET iso 0.5-1.4%

ETCO₂

6.0-7.4 kPa

4.6-6.0 kPa

4.6-6.0 kPa

Fluid therapy

CSL + 2.5% glucose (10 ml.kg^-1h^-1)

CSL (10 ml.kg^-1h^-1) Bolus of 2.5% glucose (5 ml.kg^-1)

CSL (10 ml.kg^-1h^-1) CSL + 2.5% glucose (10 ml.kg^-1h^-1) Hetastarch (1 ml.kg^-1h^-1) Hetastarch boluses (total 12 ml.kg^-1)

Analgesia

Bupivacaine⁷ (1 mg.kg^-1) bilateral mandibular nerve block

Meloxicam⁹ (0.1 mg.kg^-1) IV

Meloxicam (0.1 mg.kg^-1) IV Lidocaine¹¹ (3.75 mg.kg^-1) splash block

Butorphanol¹⁰ (0.1 mg.kg^-1) IV 90 minutes after premedication

Haemoglobin saturation (SpO₂)

96% during surgery; 78% at the end of surgery

97-99%

97-99%

Heart rate

85-125 bpm

100-130 bpm

100-130 bpm

Body temperature

33.9-37°C

35.2-35.3°C

34.4-36.2°C

Blood glucose (minutes post induction)

7.6 mmol.l^-1 (10) 9.3 mmol.l^-1 (55) 10.3 mmol.l^-1 (100) 5.7 mmol.l^-1 (145)

6.6 mmol.l^-1 (20) 5.8 mmol.l^-1 (50) 5.1 mmol.l^-1 (80) 3.1 mmol.l^-1 (110)

6.1 mmol.l^-1 (15) 3.2 mmol.l^-1 (60) 3.1 mmol.l^-1 (105)

Duration of surgery

60 minutes

75 minutes

80 minutes

Duration of anaesthesia

90 minutes

125 minutes

150 minutes

Return to spontaneous breathing (minutes after end of anaesthesia)

Died

25 minutes

25 minutes