A new frontier: magnetic resonance imaging-operating room

Anesthetic challenges and outcomes for procedures in the intraoperative magnetic resonance imaging suite: A systematic review

BACKGROUND AND OBJECTIVE

Hybrid operating room suites with intraoperative magnetic resonance imaging enable image guided surgery in a fully functional operating room environment. While this environment creates challenges to anesthetic care, the effects on anesthetic adverse events and outcomes are largely unknown. This systematic scoping review aims to map the existing knowledge about anesthetic care in advanced imaging hybrid operating rooms.

METHODS

A broad-based literature search was performed using the PubMed (Medline), Embase, Cochrane Library, Web of Science, and Google Scholar databases. References published in English between January 1994 and August 2017 were included. Quality of evidence was assessed using the GRADE guidelines.

RESULTS

Forty-seven manuscripts were eligible for data collection. Adverse events were heterogeneously defined across 17 manuscripts and occurred in 0 to 100% (quality of evidence mostly very low). Monitoring difficulty was reported in 4 manuscripts of very low data quality. Interference between the magnet and the electrocardiogram was investigated in 2 manuscripts (quality of evidence low and very low, respectively). None of the reported events appeared to result in long-term patient harm. Author recommendations or a narrative review of the literature were provided in 40 manuscripts. Common safety concerns included lower equipment reliability, inaccessibility of the patient and airway, and the relative isolation of the suite (in relationship to other anesthesia care areas). Most authors also emphasized the importance of safety checklists, protocols, and provider training.

DISCUSSION

While intraoperative magnetic resonance imaging hybrid operating rooms are increasingly utilized, the existing literature does not allow estimating adverse event rates in this location. Prospective studies quantifying the effect of the environment on anesthesia outcomes are lacking. Despite this, there is a broad consensus regarding the anesthetic and safety concerns. More research is needed to inform practice standards and training requirements for this challenging environment.

Challenges in pediatric neuroanesthesia: awake craniotomy, intraoperative magnetic resonance imaging, and interventional neuroradiology

This article gives a review of 3 challenges in caring for children undergoing neurosurgical and neurointerventional procedures. Anesthesiologists may have experience with certain aspects of these situations but may not have extensive experience with each clinical setting. This review addresses issues with awake craniotomy, intraoperative magnetic resonance imaging, and neurointerventional procedures in children with neurologic disease. Familiarization with these complex clinical scenarios and their unique considerations allows the anesthesiologist to deliver optimal care and helps facilitate the best possible outcome for these patients.

Anesthetic concerns for pediatric patients in an intraoperative MRI suite

PURPOSE OF REVIEW

Intraoperative magnetic resonance imaging (iMRI) is an evolving technology used to provide precise intraoperative navigation during a variety of neurosurgical and other types of surgical procedures. Anesthesiologists need to be aware of the unique challenges created by this environment. Failure to recognize the differences between the diagnostic MRI environment and the iMRI environment can compromise the safety of the patient and operating room staff and present logistical problems.

RECENT FINDINGS

Recent surgical reports herald the uses and benefits of iMRI. However, there are a few in the anesthesia literature addressing the significant benefits and the anesthesia-specific issues this technology creates. We will review recent reports describing anesthetic care of patients in this environment as well as examine the recent surgical and radiologic literature as they relate to issues faced by anesthesiologists.

SUMMARY

We describe the design of different iMRI suites as well as provide a breakdown of both patient and equipment issues encountered by anesthesiologists practicing in this environment. Finally, we offer our ongoing experience in this environment and provide suggestions to optimize patient outcomes.

Detection of unanticipated intracranial hemorrhage during intraoperative magnetic resonance image-guided neurosurgery. Report of two cases

The authors report unanticipated intraoperative intracranial hemorrhaging in two pediatric neurosurgical patients. Both children were undergoing elective craniotomies with the aid of intraoperative magnetic resonance (iMR) imaging. In both cases, the ability of iMR imaging to aid in diagnosis allowed prompt and definitive treatment of potentially life-threatening complications. These cases illustrate the ability of iMR imaging to aid in differentiating unexpected and/or unexplained intraoperative events in pediatric neurosurgery.

Quelle anesthésie pour les IRM en pédiatrie? Résultats d'une enquête par Internet dans les CHU de France

OBJECTIVE

To investigate the procedures used by French anaesthesiologists in children undergoing MRI.

METHODS

A questionnaire was sent by Internet to every university hospital in France. Information concerning the specialty of the doctor in charge of the child, the age of the children, premedication, airway control, the agents used, presence of a specific recovery room, length of hospitalization and number of children undergoing MRI was obtained.

RESULTS

Out of the 28 hospitals contacted, one did not reply and two did not perform anaesthesia for MRI. In 80% of cases, paediatric anaesthesiologists were in charge of the children. Only one team applied an age limit and performed sedation only in children over 10 kg. Specific monitoring for MRI was used by all teams. Premedication was given in 52% of cases. Parents were present during induction in 52% of cases. Sevoflurane was used in 52%, propofol in 40% and propofol with sufentanil in 8%. Presence of a venous line is systematic in 92% of cases. Intubation is systematic in 36% of cases, laryngeal mask in 20%, one or the other in 24%, and face mask and/or oral canula in 20%. The most widely used ventilation mode is spontaneous breathing (52%). All children go to the recovery room, which was close to the MRI unit in only 48% of cases and was less than 1 hour away in 72%. In 83% of cases, MRI is performed on a day-case basis and the number of procedures varies from 4 to 30 per week.

CONCLUSION

While there is no standard anaesthetic protocol in France for children undergoing MRI, only specialist teams undertake such procedures.

Anesthesia for magnetic resonance imaging

PURPOSE OF REVIEW

This review focuses on the technological principles, safety considerations, monitors and equipment, patient issues, and a general overview of the anesthetic management of both conventional and intraoperative magnetic resonance imaging based on the most recent literature.

RECENT FINDINGS

As a diagnostic imaging modality, magnetic resonance imaging remains unparalleled in its diagnostic and clinical value. The clinical applications for magnetic resonance imaging continue to evolve, and include its latest use in minimally invasive procedures as well as in the operating room. Intraoperative magnetic resonance imaging is steadily gaining acceptance for neurosurgical procedures. The safety considerations, monitor and equipment issues for intraoperative magnetic resonance imaging are similar to the conventional setting. However, they differ in their focus on anesthesia management. Most monitoring compatible with magnetic resonance imaging has been available for many years. In the USA, the newest available monitoring option during magnetic resonance imaging is for temperature. This option has been available in other countries for a number of years. A fiberoptic surface sensor provides a safe and accurate monitor of adult, pediatric, and neonatal body temperature.

SUMMARY

The magnetic resonance imaging suite is a challenging environment for the anesthesiologist, and carries inherent risks. Several factors account for this, including the remote location, the unique features of the magnetic resonance imaging scanner, and patient-related factors. Understanding the implications of the magnetic resonance imaging environment will facilitate ensuring the safety of the patient and personnel.

Intraoperative mobile magnetic resonance imaging for craniotomy lengthens the procedure but does not increase morbidity

PURPOSE

To evaluate anesthetic aspects of care provided for craniotomy using mobile intraoperative magnetic resonance imaging (iMRI).

METHODS

Anesthetic factors were studied using a retrospective case-control design. The primary outcome measures were the duration of the surgical intervention; the recovery score and body temperature on arrival; and length of stay in the post-anesthetic care unit. Secondary outcome measures were estimated blood loss, perioperative transfusion requirements, and fluids administered.

RESULTS

Seventy-six patients undergoing craniotomy in the MRI theatre were compared with a case-matched control group of patients who underwent neurosurgical interventions in the conventional operating room during the same time period. The only outcome measure that differed between the two groups of patients was the duration of surgery: the mean duration of procedures for patients who underwent imaging was 407 +/- 143 min compared to 285 +/- 122 min in the conventional operating theatre (P < 0.000). Actual time spent imaging accounted for approximately 100 min (83%) of the increased duration.

CONCLUSION

Our results do not support concerns that the iMRI suite is a "hostile" environment for the delivery of anesthesia for craniotomy. With the exception of an increased duration of the procedure, patients undergoing anesthesia with iMRI showed no differences from those operated in the conventional operating theatres.

Anesthesia for magnetic resonance guided neurosurgery: initial experience with a new open magnetic resonance imaging system

The authors present their initial experience with a compact open magnetic resonance (MR) image-guided system, (PoleStar N-10, Odin Medical Technologies, Yokneam, Israel) used in a standard operating room, modified for radio frequency (RF) shielding. The low intensity of the magnetic field (0.12T), and the ability to lower the magnet from the operative field during surgery allows for an almost routine surgical procedure, in addition to the benefits of using intraoperative MR imaging. Although an MR compatible anesthesia machine and monitoring system are used, the system offers anesthesiologists access to the patient at all times during the procedure, and the ability to use conventional surgical equipment, syringe pumps, and warming devices. Propofol and remifentanil, used for maintaining anesthesia, allow early extubation and neurological evaluation at the end of surgery. Electrocorticographic monitoring can be used during surgery for epilepsy, and awake craniotomy can be performed. More experience with this new imaging system is required to assess its influence on clinical decision making and outcome.