Evaluation of Total Intravenous Anaesthesia for Intraocular Operations in Day Surgery

P-A Laloë, Dr A A Samaan

Department of Anaesthesia, Diana Princess of Wales Hospital, Grimsby, UK

 Introduction

General anaesthesia (GA) is indicated for some patients undergoing cataract phacoemulsification and the triple procedure (phacoemulsification, intraocular lens implantation and deep sclerectomy). Most of these patients are elderly with significant cardio-respiratory disease. Total intravenous anaesthesia (TIVA) with propofol and remifentanil alone provides optimum operating conditions and fast recovery for day surgery.

Methods

Observational prospective study of 301 consecutive patients who required GA for ophthalmic surgery between Jan. 2001 and May 2007. GA was induced and maintained with propofol (Target Controlled Infusion 4 µg/ml for induction followed by 2.5-3.5 µg/ml for maintenance) and remifentanil (loading dose 1 µg/kg followed by maintenance of 0.05 - 0.1 µg/kg/min; Minto model TCI after 2004). No other analgesic was given. Controlled mechanical ventilation with oxygen/air was carried out with a classical LMA without neuromuscular blockade. No prophylactic anti-emetic was given. Most patients received ephedrine 30 mg. Operative conditions, haemodynamic changes, ease of ventilation, recovery time, nausea, vomiting and hospital admissions were recorded.

Results

Age: mean of 71.0 years (range 4 to 97, SD 13.8)

Weight: mean of 70.3 kg (range 20 to 135, SD 16.6)

ASA grade: ASA I: 17%, ASA II: 50%, ASA III: 34%

The values in the table are mean (range). 255 cases were planned as day cases: one patient (0.4%) required an overnight admission (angina in recovery). Seventeen patients (5.6%) required >30mg of ephedrine (maximum 90mg). Fourteen patients had dystonic movements at induction, 1 had hiccups during surgery and 10 patients had eye movement upon eye squeezing which resolved with a TCI increase. Ten patients (3.3%) had LMA difficulties (1 laryngospasm, 2 required atracurium 15mg, 4 re-inserted, 7 leaks). Three patients (1%) had PONV on the ward (none in recovery).

Discussion

Using the Marsh model to calculate induction doses (Induction [mg] = Target 0.004 [mg/ml] * V₁ 228 [ml/kg] * Mass [kg]) we can estimate each patients’ propofol maintenance dose. This narrows the difference between the two groups. Our patients recovered quicker than both groups studied by Moffat et al. underlining advances in technique (we used a lower TCI and no nitrous oxide)¹. Controlled ventilation with a LMA contributes to the good recovery profile seen in these patients². The absence of neuromuscular blockade further improves patient experience.

Conclusion

TIVA with propofol and remifentanil, controlled mechanical ventilation with a LMA without neuromuscular blockade, additional analgesia or anti-emetics provides good operative and postoperative conditions for intraocular day surgery.

References

1 Moffat A, Cullen PM. Comparison of two standard techniques of general anaesthesia for day-case cataract surgery. British Journal of Anaesthesia 1995; 74: 145-8.

2 Akhtar TM, McMurray, Kerr WJ, Kenny G. A comparison of laryngeal mask airway with tracheal tube for intra-ocular ophthalmic surgery. Anaesthesia 1992; 47: 668-71.