A wireless remote controlled infusion pump for anaesthesia during magnetic resonance imaging

Abstract

Editor—The use of ferromagnetic devices in magnetic resonance imaging (MRI) suites represents a life-threatening hazard for patients and healthcare providers.1Zimmer C Jenssen MN Treschan TA Peters J Near-miss accident during magnetic resonance imaging by a flying sevoflurane vaporizer due to ferromagnetism undetectable by handheld magnet.Anesthesiology. 2004; 100: 1329-1330Crossref PubMed Scopus (12) Google Scholar 2Chaljub G Kramer LA Johnson RA Singh H Crow WN Projectile cylinder accidents resulting from the presence of ferromagnetic nitrous oxide or oxygen tanks in MR suite.Am J Roengentol. 2001; 177: 27-30Crossref PubMed Scopus (96) Google Scholar In the past, the lack of compatible infusion pumps has led to the use of conventional pumps, placed outside the MRI scanner with long tubing for drug delivery.3Wynnychenko TM Szokol JW Murphy GS Infusion pump use in the MRI.Anesth Analg. 2000; 91: 249-250PubMed Google Scholar 4Burgogyne LL de Armendi AJ The Baxter AS50 syringe driver can be used safely in the MRI suite.J Clin Anesth. 2005; 17: 404-406Abstract Full Text Full Text PDF Scopus (3) Google Scholar These long infusion lines can be trapped in the closed door3Wynnychenko TM Szokol JW Murphy GS Infusion pump use in the MRI.Anesth Analg. 2000; 91: 249-250PubMed Google Scholar and cause false flow rates.5Kasai T Hirose M Yaegashi K Fugita T Hirai Y Tanaka Y Influence of microcatheter length on flow rates of disposable infusion kits.Eur J Anaesth. 2004; 21: 858-860Crossref PubMed Google Scholar The MRidium™ (Iradimed Corp, USA) is a new MRI-compatible infusion pump with a wireless remote control system. We report its use for propofol infusion in a 1.5 Tesla MRI environment. Twenty critically ill and intubated patients undergoing MRI were sedated with propofol 1% using the MRidium™, placed 20 cm from the MRI scanner bore. After a bolus injection of 5 ml, the infusion rate was maintained at 15 ml h−1. An additional bolus of 5 ml was used if the patient appeared agitated. The occlusion pressures of the pump were tested at 5 and 10 psi. The modifications were made via the remote system placed in the control room. The Maglife C™ (Schiller, USA) was used for patient monitoring (Fig. 1). All the patients were ventilated using the Parapac™ ventilator (Smiths Medical, UK). Additionally 20 anaesthetists and nurse anaesthetists rated their satisfaction of the device using a 10-point numeric scale (0, not satisfied, to 10, highly satisfied). The results yielded seven occlusion alarms at 5 psi and none at 10 psi. It was rated highly (satisfaction score >7) by 17/20 (85%) of users mainly because of its remote control whereas 12/20 (60%) considered the syringe adaptor as unstable. We conclude that the Mridium™ remote controlled system is feasible for propofol infusion in patients undergoing MRI. However, the syringe adaptor needs further improvements.