Reactions 702 - 23 May 1998

SMepivacaine

Respiratory tract disorders in an elderly patient:case report

A 90-year-old woman experienced asymptomatic, profoundoxyhaemoglobin desaturation after she underwent a routineinterscalene block prior to total shoulder arthroplasty.

The interscalene block was achieved by the injection of40ml of mepivacaine 1.4% with 1:200 000 epinephrine[adrenaline] and alkalinised with sodium bicarbonate.Immediately after completing the block, the patient had anSpO2 level of 94–96%. This decreased over the next 3 minutesto 75–85% and the woman became cyanotic. Her SpO2 levelincreased to 85–90% after she received increased oxygen flowvia a face mask. A chest x-ray showed an elevated ipsilateralhemidiaphragm.

25 minutes after completing the block, it was elected toinduce general anaesthesia. Arterial blood gas analysis showed89% oxyhaemoglobin saturation with an inspired oxygenfraction (FiO2) of 0.4. Thirty minutes later, with controlledventilation, 100% oxyhaemoglobin saturation with 0.9 FiO2

was observed. Surgery proceeded uneventfully and the patientwas eventually extubated without incident. A repeat chest x-ray showed her left hemidiaphragm returning to the pre-blockposition.

Author comment: ‘The case highlights the need to closelyobserve geriatric patients after the onset of interscalene blockprior to surgical preparation. It also emphasises the need tohave the ability to administer positive pressure ventilation andto have the means to intubate immediately when performingany regional anesthetic.’Smith MP, et al. Asymptomatic profound oxyhemoglobin desaturation followinginterscalene block in a geriatric patient. Regional Anesthesia and Pain Medicine23: 210-213, Mar-Apr 1998 - USA 800671714

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Reactions 23 May 1998 No. 7020114-9954/10/0702-0001/$14.95 Adis © 2010 Springer International Publishing AG. All rights reserved