It’s been 10 years since we discussed the tragic death of a 6-year old boy due to a flying projectile in an MRI suite (see our February 19, 2008 Patient Safety Tip of the Week “MRI Safety”) .
But a recent report (Pappas 2018) of another fatality related to a projectile in an MRI unit reminds us that this danger persists despite all the attention given to safety in the MRI suite. A 32-year old man was visiting a relative, who was a patient at a hospital in Mumbai, India, and was handed a metal oxygen cylinder to carry. They were shifting the patient to another stretcher inside the MRI room (Sood 2018). The MRI apparently was on and the oxygen cylinder was pulled toward the core. The victim was standing between the stretcher and the core and was hit by the metallic cylinder, which fell and crushed his hand. As several others in the room attempted to free the victim from under the cylinder after the magnet was turned off, the victim’s finger was severed and the oxygen cylinder began to leak. He apparently inhaled a huge amount of liquid oxygen and fell unconscious and died a few hours later in an ICU. He apparently also had a pneumothorax (Forrest 2018). Relatives apparently said there was no staff outside the MRI suite to prevent the oxygen tank from being taken inside, and there were no security guards checking for metallic objects (Forrest 2018). It was thought the cylinder was damaged after hitting the machine (Guardian 2018).
Further details include that the metal detector outside the MRI room was apparently not functioning at the time of the incident (Pandit 2018). Also, a radiology resident was apparently left in charge of the MRI suite because MRI nurses are not available after 4 PM on weekends (Barnagarwala 2018). That resident apparently instructed patient and relatives to remove metallic objects and then went into the console room to check with ICU staff as to why the scan was being performed. While a nurse ordinarily monitors the removal of metallic items that a patient may be wearing, the job at that time was done by a “ward boy” who worked in the MICU ward.
Several people, including the radiology resident and a MICU resident, were arrested after the incident! Obviously, staffing and system safety issues were the major culprits here and there is a pressing need for a thorough root cause analysis (RCA).
The Pappas article also notes an incident in 2014 in which a technician at another hospital in Mumbai spent 4 hours wedged inside an MRI machine after he was pinned between a ward assistant carrying an oxygen cylinder and the scanner. The technician lost blood circulation below the waist and was temporarily paralyzed; he also suffered organ damage and internal bleeding.
The case is a stark reminder that the security and safety features surrounding your MRI unit must not lapse at all and that no one carrying ferrometallic items be allowed into the inner room. We’ve stressed in prior columns that this is particularly important to prevent people responding to an emergency from rushing into the room before the magnet is turned off. You cannot assume that staff from other areas understand they must not enter the room. We’ve also stressed that you should work with your local fire and police departments to make sure they are also aware they cannot go into the room when the magnet is active. But inservices and signage are probably not enough. You need a person to physically bar entrance to the MRI room when the magnet is active.
We hope you’ll revisit many of our MRI safety columns listed below. Fortunately, projectile injuries and fatal incidents have been relatively rare but other untoward events may occur.
Some of our prior columns on patient safety issues related to MRI:
Pappas S. Man Dies in MRI Accident: How Does This Happen? Live Science 2018; January 29, 2018
Forrest W. Indian man carrying oxygen tank dies in MRI suite. AuntMinnnie.com 2018; January 29, 2018
Sood M. Gas leak or chest injuries: What killed 32-year-old man at Mumbai hospital’s MRI room? Hindustan Times 2018; updated January 28, 2018
The Guardian. Man dies after being sucked into MRI scanner at Indian hospital. The Guardian 2018; January 29, 2018
Pandit S. Metal detector in Mumbai hospital’s MRI room was not functional, unit had piped oxygen: BMC. Hindustan Times 2018; Updated: Feb 01, 2018
Barnagarwala T. Doctors should not be punished for MRI death: Radiology body. The Indian Express 2018; February 12, 2018
There are several reasons one is concerned about implanted devices in patients undergoing MRI imaging. Certain metallic devices may overheat during MRI, leading to burns or other thermal injuries. Certain ferromagnetic implants may migrate to undesirable locations when the magnetic field is applied. And yet other devices may simply malfunction when the magnetic field is applied.
For many years implanted pacemakers and implanted defibrillators were considered contraindications to MRI procedures, forcing patients with such devices to get alternative imaging studies that might have other risks or which might provide lesser diagnostic information. So newer “MRI-conditional” devices were developed and approved by the FDA if they met certain criteria.
But a new study (Nazarian 2017) looked at MRI safety of devices that were not considered to be MRI-conditional (termed “legacy” devices). Over 1500 patients with a pacemaker (58%) or an implantable cardioverter–defibrillator (42%) underwent over 2100 thoracic or non-thoracic clinically indicated MRI’s at a magnetic field strength of 1.5 Tesla. Certain protocols were followed prior to scanning. The pacing mode was changed to asynchronous mode for pacing-dependent patients and to demand mode for other patients. Tachyarrhythmia functions were disabled.
Results from a safety standpoint were very reassuring. No long-term clinically significant adverse events were reported. In nine MRI examinations the patient’s device reset to a backup mode. The reset was transient in eight of the nine examinations. In one case, a pacemaker with less than 1 month left of battery life reset to ventricular inhibited pacing and could not be reprogrammed and was subsequently replaced. The most common notable change in device parameters (>50% change from baseline) immediately after MRI was a decrease in P-wave amplitude, which occurred in 1% of the patients.
And CMS (Centers for Medicare & Medicaid Services) just issued a Proposed Decision Memo for Magnetic Resonance Imaging (MRI) (CMS 2018). It proposes that the evidence is sufficient to conclude that magnetic resonance imaging (MRI) for Medicare beneficiaries with an implanted pacemaker (PM), implantable cardioverter defibrillator (ICD), cardiac resynchronization therapy pacemaker (CRT-P), or cardiac resynchronization therapy defibrillator (CRT-D) is reasonable and necessary for the diagnosis or treatment of illness or injury or to improve the functioning of a malformed body member. Thus, CMS is proposing to modify its national coverage determination to eliminate the collection of additional information.
So it looks like patients having these older devices will now be eligible to have clinically indicated MRI studies that they previously would have been excluded from. Perhaps our one caveat would be to note that the safety study performed by Nazarian and colleagues was done using a relatively weak magnetic field. Many facilities are now using much higher magnetic field strength MRI’s and we’d be somewhat reluctant to extrapolate the current safety data to those units.
As above, a more common problem is that certain metallic devices may overheat during MRI, leading to burns or other thermal injuries. Now may be an appropriate time to raise again a warning about unexpected ingestion of metallic items in children. In our August 2012 What's New in the Patient Safety World column “Newest MRI Hazard: Ingested Magnets” we cited a case in which an MRI done on a 5-year old who had unexpectedly swallowed magnets resulted in a bowel perforation (Bailey 2012).
Ingestion of rare earth magnets subsequently was recognized as a serious ongoing hazard for pediatric patients and led to a 2012 Consumer Product Safety Commission (CPSC) policy action and efforts from consumer and physician advocacy groups. A recent study (Reeves 2017) showed that the frequency of magnet ingestions continued to rise from 2010 and then peak in 2012, followed by a decline in magnet ingestion ED visits during the post-federal action years.
But a new hazard has popped up: the popular “fidget spinner”! Ingestion of components (such as the fidget spinner cap or the button batteries) by small children have recently been reported (Khalaf 2018, Tipnis 2018). While we have not yet heard of any incidents involving MRI in children with such ingestions, it would not be surprising if such occur.
In the 2012 Bailey article relating to ingested magnets, the hospital changed their MRI screening protocol. While they still do a written and verbal questionnaire of the children and parents for presence of metallic objects, they now also have all children change into a hospital gown and undergo screening using a hand-held ferromagnetic detection scanner. Given the new hazard related to fidget spinners, that sort of protocol may not be a bad idea for small children prior to MRI.
Some of our prior columns on patient safety issues related to MRI:
Nazarian S, Hansford R, Rahsepar AA, et al. Safety of Magnetic Resonance Imaging in Patients with Cardiac Devices. N Engl J Med 2017; 377: 2555-2564
CMS (Centers for Medicare & Medicaid Services). Proposed Decision Memo for Magnetic Resonance Imaging (MRI) (CAG-00399R4). CMS 2018; January 11, 2018
Bailey JR, Eisner EA, Edmonds EW. Unwitnessed magnet ingestion in a 5 year-old boy leading to bowel perforation after magnetic resonance imaging: case report of a rare but potentially detrimental complication. Patient Safety in Surgery 2012; 6: 16 (19 July 2012)
Reeves PT, Nylund CM, Krishnamurthy J, et al. Trends of Magnet Ingestion in Children, an Ironic Attraction. Journal of Pediatric Gastroenterology and Nutrition 2017; Published Ahead of Print: November 7, 2017
Khalaf RT, Gurevich Y, Marwan AI, et al. Button Battery Powered Fidget Spinners: A Potentially Deadly New Ingestion Hazard for Children. Journal of Pediatric Gastroenterology and Nutrition 2018; Published Ahead of Print: January 24, 2018
Tipnis NA, Ciecierega T. Fidget Spinner Ingestion. Journal of Pediatric Gastroenterology and Nutrition 2018; Published Ahead of Print: January 24, 2018
In our March 2014 What's New in the Patient Safety World column “New ASGE Endoscopy Safety Guidelines” we noted that the ASGE (American Society for Gastrointestinal Endoscopy) position (Calderwood 2014) on use of capnography was that there was inadequate data to support the routine use of capnography when moderate sedation is the target. Our own warning was that the “target” of moderate sedation is often overshot and some patients inadvertently receive deep sedation. While the evidence base for use of capnography in this setting may be limited, it only takes one case of a disaster related to oversedation to destroy whatever other good work you’ve done. Capnography is rapidly becoming a standard of care whenever patients are being given intravenous sedation or opioids.
Several studies suggest that capnography monitoring during gastrointestinal endoscopic procedures reduces the incidence of hypoxemia, but the impact on other adverse outcomes has been less clear. Now new study (Jopling 2017) retrospectively looked at a large database of patients undergoing gastrointestinal endoscopic procedures with sedation. Patients were put in one of 4 categories: (1) pulse oximetry (SpO2) only, (2) capnography only, (3) SpO2 with capnography, and (4) neither SpO2 nor capnography. Propensity-score matching was done to make groups comparable. For inpatients, capnography monitoring was associated with a 47% estimated reduction in the odds of death at discharge (OR: 0.53) and a non-significant 10% estimated reduction in the odds of pharmacological rescue event at discharge (OR: 0.91). For outpatients, capnography monitoring was associated with a 61% estimated reduction in the odds of pharmacological rescue event at discharge (OR: 0.39) and a non-significant 82% estimated reduction in the odds of death at discharge (OR: 0.18). The authors conclude that, despite the retrospective nature of the study, use of capnography during these procedures is recommended.
The ASGE guidelines for sedation and anesthesia in GI endoscopy have also recently been updated (Early 2018). They have been reviewed and endorsed by the American Association for the Study of Liver Diseases, the American College of Gastroenterology, and the American Gastroenterological Association, in addition to the Governing Board of the American Society for Gastrointestinal Endoscopy.
Those guidelines state “capnography has been demonstrated to detect depressed respiratory activity before transient hypoxemia, but a clear link between transient hypoxemia and serious cardiopulmonary unplanned events during sedated endoscopy has not been established. Integrating capnography into patient monitoring protocols for endoscopic procedures with moderate sedation has not been shown to improve patient safety; however, there is evidence supporting itsuse in procedures targeting deep sedation.”
However, under its recommendations for propofol use during endoscopy, it does state “Capnography should be considered because it may decrease the risks during deep sedation.” And under their summary recommendations they “suggest that capnography monitoring be considered for patients undergoing endoscopy targeting deep sedation.”
We’re glad to see these recommendations for increased use of capnography during procedures using sedation n the GI lab. Capnography monitoring is rapidly becoming the standard of care for patients undergoing procedures under sedation in a wide variety of settings.
Calderwood AH, Chapman FJ, Cohen J, et al for the ASGE Ensuring Safety in the Gastrointestinal Endoscopy Unit Task Force. Guidelines for safety in the gastrointestinal endoscopy unit. Gastrointestinal Endoscopy 2014; article in press published 30 Jan 2014
Jopling MW, Qiu J. Capnography Sensor Use Is Associated With Reduction of Adverse Outcomes During Gastrointestinal Endoscopic Procedures With Sedation Administration. BMC Anesthesiol 2017; 17: 157 Published: 28 November 2017
Early DS, Lightdale JR, Vargo JJ, et al. Guidelines for sedation and anesthesia in GI endoscopy. Gastrointest Endosc 2018; 87(2): 327-337
Contact precautions are an important component of our interventions to reduce the transmission of MDRO’s (multi-drug-resistant organisms) and other potentially contagious diseases in hospitals. But contact precautions, in particular contact isolation, are not without potential downsides. We’ve done several columns (listed below) on the unintended consequences of contact isolation.
The SHEA (Society for Healthcare Epidemiology of America) expert guidance on duration of contact precautions for acute care settings was recently published (Banach 2018). Most prior guidelines for contact precautions for MDRO’s (multi-drug-resistant organisms) have addressed when to use such precautions but have paid less attention to how long such precautions should be used.
SHEA notes that expert guidance documents are developed to address areas of relatively narrow scope that lack the level of evidence required for a formal guideline but are important for the provision of safe and effective healthcare.
The SHEA guidance provides recommendations regarding discontinuation of contact precautions (CP) at the individual patient level in acute-care hospitals employing CP for the following organisms:
You’ll have to go to the actual SHEA document for details of the recommendations for each organism. The guidance also has good discussion about sites of colonization and groups at risk for prolonged colonization and discussion about microbiology testing, including molecular testing.
Some of our prior columns on the unintended consequences of contact isolation:
Banach D, Bearman G, Barnden M, et al. Duration of Contact Precautions for Acute-Care Settings. Infection Control & Hospital Epidemiology 2018; 1-18. Published online: 11 January 2018
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