Infective endocarditis

A patient with an aortic valve replacement on warfarin came to see her GP for removal of a lesion on her back. Initially, it was thought that the lesion was benign, but the GP in the practice who was to perform the surgery, an MDU member, suspected that it might be a basal cell carcinoma and elected to do a full excision rather than curettage as had initially been suggested.

In accordance with local practice for minor surgery in patients on warfarin, the patient’s INR was checked the day before the procedure. It was 3.3 (the target was 3–4). The GP did a full excision of the 4mm lesion and advised the patient to continue her warfarin as usual. She was not given peri-operative prophylactic antibiotics. Histology showed the lesion to be benign.

Five days later the patient returned as the wound was oozing. A practice nurse cleaned it with saline. The sutures were removed on day seven but the day afterwards, the patient was admitted to hospital as the wound was now bleeding. It was re-sutured and as the INR was found to be 6 warfarin was stopped. Clexane was administered.

The following day, the wound was noted to be oozing serosanguinous fluid and to have infected adjacent hair follicles. The patient was started on oral flucloxacillin by the hospital.

Over the next two weeks, the patient returned to her GP twice as she felt unwell with a sore throat. As she was not improving her GP admitted her to hospital. Infective endocarditis due to staphylococcus aureus was confirmed. The patient went on to have a re-do aortic valve replacement some months later.

The GP received a complaint. She responded explaining that she had followed guidelines both for the continuation of the warfarin and for not offering prophylactic antibiotics. A year later the patient brought a claim against the GP, alleging that she should have been given prophylactic antibiotics before excision of the skin lesion and that the INR had been too high for the procedure to be carried out. Furthermore, she claimed she had not been warned of the potential risks associated with excision of the skin lesion due not only to bleeding but also infection of her prosthetic heart valve.

The doctor confirmed that she had followed local guidelines for minor surgery for patients on warfarin – that is, that INR should be checked the day before the procedure to ensure it was not above the target range for the patient. This had certainly been discussed with the patient. Regarding giving prophylactic antibiotics for minor skin surgery, it was the member’s understanding that this was not necessary for a clean, minor, non-invasive procedure and was in accordance with 2008 NICE guidance.

The MDU sought independent GP expert advice which confirmed the continuation of warfarin during minor dermatological surgery in a primary care setting, provided the INR is within the target range. The expert also confirmed that up to 2008 traditional practice would have been to offer antibiotic cover to high risk patients for a range of invasive procedures, but this did not include cutaneous surgery. However, the final decision was to be left to individual clinicians. Subsequent NICE guidance in 2008 suggested the previous practice of prescribing prophylactic antibiotics for patients at risk of infective endocarditis undergoing interventional procedures involving teeth, aero-oesophageal, lower GI or urogenital tracts, was mistaken. In the circumstances, therefore, the expert believed the member was under no obligation to offer the patient antibiotic prophylaxis.

Even if antibiotics had been given, the expert stated in the report, they would not have prevented the infective endocarditis as the infection probably occurred a week after the original surgery, following the resuture by the hospital. Likewise even if the warfarin had been stopped (which was not recommended) it would have been restarted by the time the patient bled eight days later.

The MDU sent a letter of response on behalf of the member denying liability for the subsequent infective endocarditis, and as a result the claim was successfully defended.

This page was correct at publication on 01/08/2012. Any guidance is intended as general guidance for members only. If you are a member and need specific advice relating to your own circumstances, please contact one of our advisers.