Over to you
Aminoglycoside ototoxicity
In the September 2008 issue of Casebook we published a case report about a claim we settled following a case of ototoxicity related to the use of aminoglycoside ear drops. This attracted considerable correspondence, mostly from readers disagreeing with the expert opinion on which we based the decision to settle the claim.
Aminoglycoside ear drops are contraindicated in patients with a perforated tympanic membrane or with a grommet in situ because there is a risk of ototoxicity. Many national guidelines, however, do sanction their use if the ear drops are indicated (ie, there is an obvious or chronic infection) and the patient is fully warned about the risks and aware of the signs and symptoms of adverse side effects.1
The expert opinion we obtained for the case report in question supported these guidelines, but the wording in our report was ambiguous and, therefore, potentially misleading. Instead of saying that the ear drops “should only be used in the presence of obvious infection where there is a tympanic membrane perforation or patent grommet in situ”, it should have read, “where there is a tympanic membrane perforation or patent grommet in situ, aminoglycoside eardrops should only be used in the presence of obvious infection”. In this case, the patient had presented with “some discomfort in the ear” and the surgeon diagnosed “some mild myringitis…with no otorrhoea or evidence of infection”. He should not, therefore, have prescribed the ear drops because there was no obvious infection to justify doing so.
Thank you to all the many readers who drew this ambiguity to our attention. We are sorry for causing confusion and hope that this matter has now been clarified to everyone’s satisfaction. The advice that MPS would give to all readers regarding the use of aminoglycoside ear drops is to familiarise themselves with the guidelines pertaining to their own countries.
1. See, for example, Philips JS et al. Evidence Review and ENT-UK Consensus Report for the Use of Aminoglycoside-Containing Ear Drops in the Presence of an Open Middle Ear, Clinical Otolaryngology 32: 330–36 (2007).
The importance of occupation
Casebook 16 volume 3 mentions two cases where the patient’s functional capacity was adversely affected by minor surgery. In each case, a different choice of procedure may have been made if the patient’s occupation had been considered. This highlights the need for an occupational history to be available, and the patient’s job or significant hobbies to be considered, at all stages of medical treatment.
Some diseases and disorders are caused by work, some are made worse by work, and the ideal end point of any medical treatment should surely be a return to full “occupational” fitness. But some general practice computer systems don’t have a field for entering “occupation”, which leaves the GP at a disadvantage when considering the interaction between health and work, and many hospital doctors don’t have “quick and safe return to work” as an endpoint in their treatment plans. We all need to think “occupation” when seeing and treating patients.
Dr Gordon Park, President of The Society of Occupational Medicine, Manchester, UK
Sharp practice
I read the article “Sharp practice” (Casebook 16(3)) with interest, but I feel that a key learning point has been overlooked. Nerve damage associated with peripheral nerve cannulation is extremely rare, with only a few case reports published worldwide. It is often impractical or impossible, due to surgical requirements or anatomical variations, to avoid cannulation of a patient’s dominant hand as was suggested in the learning points.
The most sensitive sign of nerve damage during attempted cannulation is likely to be pain. Unfortunately for the vast majority of medical professionals (with the exception of anaesthetics and paediatrics), pain occurs during every cannulation, due to a failure to provide local anaesthesia of the skin. There is good evidence that topical local anaesthetics significantly reduce the pain of cannulation, even for small diameter cannulae1 and does not affect the success rate.2 The routine use of topical anaesthesia for cannulation has two important benefits: if pain does occur, this alerts the clinician to the potential for nerve damage; and the experience for the patient is improved.
Dr Matt Wiles, Clinical Lecturer & Specialist Registrar (Anaesthesia), Nottingham, UK
References
1. Harrison N, Langham BT, Bogod DG. Appropriate Use of Local Anaesthetic for Venous Cannulation, Anaesthesia 47(3): 210–2 (1992).
2. Holdgate A, Wong G, Does Local Anaesthetic Affect the Success Rate of Intravenous Cannulation? Anaesth Intensive Care 27(3): 257-9 (1999).