Assessing the risk of magnetic interaction between auditory implants and programmable ventriculoperitoneal shunts.

PURPOSE: This study investigated whether the magnetic field of the internal magnet of cochlear implants and bone-anchored hearing aids (BAHA) would be sufficient to affect a programmable ventriculoperitoneal (VP) shunt. Current guidelines suggest against implanting these hearing devices ipsilateral to a programmable VP shunt, but the exact nature of the interaction has not been quantified. METHODS: The magnetic field strength (mT) was measured at 0 and 10 mm from the edge of both the Cochlear Implant CI512 (Cochlear Corporation) magnet and BAHA Attract magnet. Next, the hearing devices were placed into their anatomical positions in a 3-D clay model, along with three different types of programmable VP shunts. The valve setting was measured before and after exposure. RESULTS: At 10 mm, neither device generated a magnetic field sufficient to adjust the VP shunt valve. In the clay model, the valve settings were not affected by the presence of any device. CONCLUSION: Neither the cochlear implant nor the BAHA subcutaneous internal magnets generated sufficient magnetic field to reprogramme the valves of commonly used programmable VP shunts. The magnetic field from each device decreases dramatically at 10 mm. Further clinical studies to help mitigate the current restrictive guidance should consider involvement of VP shunt manufacturers to inform future shunt development and design.

Effect of exposure from iPhone 12 on programmable ventriculoperitoneal shunts.

The latest iPhone 12 model has elicited concerns over its interaction with medical devices such as pacemakers due to its integrated MagSafe technology. Historically, programmable ventriculoperitoneal (VP) shunts have been demonstrated to readjust when exposed to magnetic objects. Yet, the presence of interactions between the iPhone 12 and shunts is unknown. In this in-vitro study, we examined the effect on the programming of three VP shunts, Medtronic Strata II, Miethke ProGAV 2.0 and Codman Hakim, when exposed to the iPhone 12 model. We found that all three valves did not re-program when the iPhone was held near or moved in a swiping or rotational motion above the valves. Therefore, the risk of re-programming of these three shunts when exposed to iPhone 12 appears to be low. However, patients should take care until further work is undertaken to examine the complex interplay between programmable VP shunts with magnetic devices.

Effect of audiological testing on programmable ventriculoperitoneal shunts.

OBJECTIVE: This study aimed at measuring the magnetic field strength of commonly used types of audiological testing equipment and determine their effects on the three most commonly used programmable ventriculoperitoneal (VP) shunts to try and quantify the risk of a VP shunt being reprogrammed during audiological testing. DESIGN: In this in vitro study, magnetic field strength was measured for TDH 39 supra-aural earphones, B71 bone vibrator, ALGO 3i probe, Bio-logic Nav Pro probe, Otodynamics otoport insert earphone and Madsen Zodiac tympanometry probe. STUDY SAMPLE: Magnetic field strength associated with transducers placed on a model of a skulls having implanted Miethke ProGAV 2.0, Medtronic Strata II and Codman Hakim programmable VP shunts was measured. RESULTS: The supra-aural earphones had a magnetic field strength of 14 mT at 0 mm, which dropped to 0 mT at 10 mm away from the transducer. All other equipment had a magnetic field strength of 3.5 mT or less at 0 mm. There was no instance of reprogramming of the shunts by the transducers. CONCLUSIONS: The findings suggest that the risk of inadvertent valve-reprogramming by the transducers is extremely small. However, care should be taken to avoid placing any of the transducers directly over the shunt.

Tonsillectomy discharge information - An improvement in both patient safety and satisfaction.

Approximately 20,000 adult and 25,000 paediatric tonsillectomies are performed each year in England. 0.9% of these patients return to theatre for post-tonsillectomy bleeding. The Royal College of Surgeons of England (RCSEng) have produced guidelines regarding emergency surgery, with standards for tonsillectomy discharge information. We audited our compliance with these guidelines and patient satisfaction regarding the information currently provided. Theatre records identified all tonsillectomies carried out between December 2012 and February 2013. 71 patients and their electronic discharge information were reviewed for post-operative bleeding information. Each patient was contacted, with a second call made to those who did not answer. 35 patients took part in our telephone questionnaire. Only 35% of patients had post-operative bleeding information on their discharge summary. 51% received no written information either in clinic or on the day of surgery, 66% recalled a verbal explanation. Only 54% knew to go to A&E if they experienced bleeding. 40% were not satisfied with their discharge information, stating that they wanted to know about bleeding, recovery expectations, and information regarding oral intake. A focus group was formed to discuss potential solutions to the audit outcomes and a tonsillectomy leaflet was produced inline with the trust patient information template. It contained specific instructions regarding bleeding and the nearest A&E contact details. It was reviewed by three tonsillectomy patients and their feedback regarding further information on post-operative diet, throat appearance and pain expectations was incorporated. A second cycle of the audit took place between August and September 2013. Results showed improvement, with 83% receiving an information leaflet and 100% a verbal explanation. 100% of patients were satisfied with their discharge information and 100% knew what to do if they bled. As a result we now meet the standards set out by the RCSEng and have increased our patient safety and satisfaction rates.

Klebsiella pneumoniae liver abscess and endophthalmitis.

A 36-year-old man was referred to the general medical team with endophthalmitis. He was noted to have raised inflammatory markers and deranged liver function tests on admission. Subsequent abdominal ultrasound scan revealed a liver abscess requiring percutaneous drainage. A common human pathogen, Klebsiella pneumoniae, was cultured from multiple sites. K pneumoniae has virulent serotypes (K1 and K2) that can cause primary liver abscess with metastatic infections. Cases have previously been predominantly reported in Southeast Asia but are increasing in prevalence in Europe and North America. The main known risk factor for the disease is diabetes mellitus. Swift antibiotic therapy, ophthalmology review and percutaneous drainage of any liver abscess are essential. Early recognition of the syndrome, despite potentially few initial symptoms, can significantly reduce morbidity and mortality. The authors report the first recorded case of K pneumoniae liver abscess with endophthalmitis in the UK.