Claustrophobia, Sedation, Monitoring, MR-Conditional Equipment and Emergencies in the MR Environment — What the Guidance and the Evidence State, and Where They Stop

Claustrophobia, Sedation, Monitoring, MR-Conditional Equipment and Emergencies in the MR Environment — What the Guidance and the Evidence State, and Where They Stop

MRIninja Knowledge Base | Child Page — MRI Safety (deep dive S11) Version 1.0 — October 2026

Parent page: MRI Safety — Master Page (hazard table in Section 3; control layers in Section 6). Builds on: MR Site Zones and Access Control (zones and emergency access) · Implant and Device MR Safety Framework (labels and matching a label to the scanner) · RF Heating and Burns (heating by monitoring leads) · Acoustic Noise in MRI (acoustic noise and hearing protection) · Projectile and Torque Hazards in the Static Field (cylinders and other projectiles)

1. Scope, Status and Boundaries

This page gathers what the sources read state on five connected questions: how often anxiety and claustrophobia stop an examination and what is known about reducing them; how children and adults who cannot lie still are prepared, sedated or anaesthetised, and how the sedation is monitored; what monitoring equipment can and cannot show in the magnetic field; what equipment may be brought into the MR environment; and what the guidance says to do when a patient collapses or needs resuscitation in the examination room. The questions are grouped because the same person is often involved: an anxious patient may become a sedated patient, a sedated patient is a monitored patient, and a monitored patient needs equipment that has been shown to be safe in the room.

Topics with another home are not repeated: the mechanism of heating by leads and cables and the evidence on burns (RF Heating and Burns); acoustic noise and hearing protection (Acoustic Noise in MRI); cylinders, trolleys and other projectiles (Projectile and Torque Hazards in the Static Field); the content of labels and their matching to the scanner (Implant and Device MR Safety Framework); the zones, supervision and emergency access (MR Site Zones and Access Control); the screening questionnaire and the screening of unconscious patients (Patient Preparation, Sections 3.2 and 3.3); and gadolinium reactions as a risk (Gadolinium-Based Contrast Agent Safety). Quench, cryogens and oxygen depletion belong to Cryogens, Quench and Oxygen Depletion in MRI, and incident reporting and governance to Incident Learning, Governance, Quality and Jurisdictions in MR Safety.

Reading status. The page rests on a United States practice advisory (2015), the 2016 paediatric sedation guideline of two American academies, a 2026 best practice statement on emergencies from a United Kingdom professional association, selected sections of the fifth edition (July 2026) of the UK MHRA guidelines, and, for claustrophobia, two systematic reviews (abstracts), one prospective cohort (abstract), one conference abstract, one trial protocol and one small non-randomised study. The Association of Anaesthetists guideline of 2019 was read only as a summary page; MHRA Section 5 (including 5.3.10 on monitoring) was not read; the ACR Manual on MR Safety, the standards (IEC 60601-2-33, ASTM F2503), the 2019 update of the paediatric sedation guideline, and the guidance on sedation of adults of any anaesthetic or radiological society were not read. No randomised trial of sedation, monitoring or resuscitation technique in the MR environment was read, and no study of outcomes of resuscitation in MR units.

What this page does not do. It gives no sedation protocol, drug dose, monitoring standard or resuscitation algorithm for any facility. Statements that are the page’s own inference are marked Reasoning; where a source needed to complete a statement was not found they are marked (to be sourced).

2. Sources Read and What They State

Table 1. Documents used, what they were used for and how they were read.

3. How Often Anxiety and Claustrophobia Stop an Examination

A systematic review of 18 studies of adults pooled the proportion of scans terminated because of claustrophobia at 1.18 per cent (95 per cent confidence interval 0.79 to 1.65), with significant clinical and statistical heterogeneity, and states that health professionals working in MRI should be prepared to encounter claustrophobic patients [6]. A prospective cohort of 55,734 consecutive patients (1997 to 2005) found claustrophobia in 2.1 per cent (2.0 to 2.3) of patients on a conventional scanner and 0.7 per cent (0.6 to 0.9) on a newer scanner with a shorter, wider conical bore and 97 per cent less acoustic noise; the adjusted odds ratio was 3.1 (2.5 to 3.9), the number needed to treat 72, and head-first examination, female sex and middle age were associated with claustrophobia [10]. The protocol of a later trial quotes a prevalence of claustrophobia of 2.3 per cent (2.0 to 2.5) among patients scheduled for MRI [11]. A prospective study of 6,520 consecutive patients reported an overall event rate of 9.8 per cent [9]. Figure 1 sets the estimates side by side.

Figure 1 — Reported rates of claustrophobia in MRI differ by definition and population (not comparable estimates)

Reasoning. The estimates are not comparable: they use different definitions (terminated scans, claustrophobia, claustrophobic events), populations (all patients, patients at increased risk by questionnaire) and eras of scanner design. The order of magnitude for terminated scans in unselected adults is one to two in 100 in the sources read, but the sources do not allow a figure to be given for any single facility, and the 9.8 per cent figure should not be read as the proportion of scans that fail. The definition of an event in the 6,520-patient study was not available in the text read.

Prediction by questionnaire. In the 6,520-patient study, 4,288 patients completed the 26-item Claustrophobia Questionnaire before the examination. Patients who had an event scored higher; the negative predictive value was 0.99 in men and 0.97 in women, the positive predictive value 0.01 in men and 0.16 in women, and completing the questionnaire was not associated with more events; the authors conclude that it is suitable as a screening tool for the absence of a subsequent claustrophobic event but not as a predictor in individual patients [9]. The questionnaire score correlated with events in the randomised trial reported by a news item [15]. Reasoning. A test with a high negative and a very low positive predictive value is useful to exclude, not to select; a positive result identifies mostly patients who will cope.

4. Interventions in Adults and Scanner Design

A systematic review (21 studies, Joanna Briggs Institute method) of interventions to reduce anxiety, distress and the need for sedation in adults assessed MRI design features, cognitive-behavioural strategies, prone positioning, information provision, fragrance administration and team training, and states in its abstract that all showed some positive effect; the abstract gives no effect sizes or certainty ratings [7]. A second systematic review (12 studies, 1,604 participants; seven MRI, three nuclear medicine, two PET/CT) found that information beyond the appointment letter reduced anxiety in five of eight studies, had no effect in two and increased anxiety in one (detailed information about radiation and risks), that all three studies of cognitive strategies and one study of music reported reductions, that certainty was low and risk of bias mostly poor, and that anxious and claustrophobic patients and sedated patients were excluded from the included studies [8].

On scanner design, the 55,734-patient cohort is non-randomised and the newer scanner differed from the conventional one in noise as well as in bore shape, so the effect cannot be assigned to bore dimensions alone [10]. A randomised comparison of an open vertical 1.0-T scanner with a closed short-bore 1.5-T scanner in patients at increased risk, known here only from a news report, found claustrophobic events in 39 per cent with the short-bore scanner and 26 per cent with the open scanner, a difference described as not statistically significant, and 56 per cent in earlier examinations on conventional scanners [15][11]. A small non-randomised study of a psychological programme in high-risk patients reported claustrophobia in 18 per cent (14 of 77) against 46 per cent (67 of 146) with routine intervention and sedation in 3 per cent against 10 per cent, with no significant change in the questionnaire score in either group [12].

Table 2. Interventions for adults: what the sources read support.

Reasoning. The sources support the use of information, cognitive and relaxation techniques as low-risk measures with some benefit and low certainty; they do not allow a ranking of measures, a statement on the size of an effect, or the claim that a wider bore or an open scanner reliably prevents claustrophobia in patients at high risk. Positioning (feet-first entry), a companion in the room, ventilation, lighting, music and virtual reality are listed on the Patient Preparation page without a source that was read for this page; they are neither confirmed nor refuted here (to be sourced).

5. Children: Preparation and the Decision to Sedate

A scoping review of 36 studies, mainly of MRI, lists mock scanners, play therapy, storybooks, videos and animations, applications, virtual reality and colouring books as preparation methods, with the need for sedation or general anaesthesia, scan completion and anxiety among the outcomes [17]; only the extraction table was read, so no finding is stated here. A guide for referring children to general anaesthesia for MRI was assessed in an interrupted time series of 11,530 local sedation records of a registry (July 2008 to March 2013): referrals to general anaesthesia rose and fewer children of ASA class III or more were sedated, but serious adverse events (P = 0.874) and failed sedation (P = 0.169) did not change [13]. The AAP and AAPD guideline notes that sedation of a child for MRI purely for screening of preterm infants is discouraged when the result is unlikely to change medical management [2].

Reasoning. The sources read show that preparation methods exist and are studied and that a referral guide did not, in one setting, change serious adverse events or failed sedation; they give no basis for an age below which sedation is or is not needed, for a success rate of non-sedated scanning, or for choosing between sedation and general anaesthesia in a given child. The general points on children in the preparation of patients are in Patient Preparation (Section 14.1).

6. Sedation and Anaesthesia in the MR Environment

6.1 What the documents state

The AAP and AAPD guideline states that non-painful imaging such as MRI generally calls for sedatives or hypnotics rather than analgesics, that imaging facilities are among the non-hospital settings where sedation has increased and where immediate backup may be lacking, that the response of a sedated patient to stimuli usually cannot be assessed during MRI without defeating the purpose of sedation so that the patient should be treated as deeply sedated, and that everyone entering the suite, including parents, must be screened for ferromagnetic items [2]. The ASA advisory states that every case needs an individual anaesthetic plan with the support staff covering scan requirements, equipment position, patient-specific issues, staff and patient positioning and emergency planning, that lighter anaesthesia may be appropriate because MRI is non-painful but can cause airway complications that may require interrupting the scan, that patients receiving moderate or deep sedation should be monitored according to the institution’s protocol for similarly sedated patients elsewhere, and that complex airway procedures such as fibreoptic intubation should be performed outside Zone IV in a controlled setting [1]. The Association of Anaesthetists summary suggests that hospitals develop and audit governance procedures to ensure that anaesthetists of all grades are competent to work in MR [3].

6.2 Minimum monitoring and personnel

Table 3. Minimum monitoring and personnel in the paediatric sedation guideline (2016 text).

The same guideline states that if capnography is not feasible because of agitation the reason should be documented, and that for uncooperative children it may be started once the child is sedated [2]. The ASA advisory states that patients should be monitored according to the ASA Standards for Basic Anesthesia Monitoring, that exhaled carbon dioxide monitoring should be considered for all deep sedation and for moderate sedation when ventilation cannot be directly observed, and that pulse oximetry does not replace ventilation monitoring [1].

6.3 Fasting

The AAP and AAPD guideline states that elective sedation generally follows general-anaesthesia fasting intervals (clear liquids 2 hours, human milk 4 hours, infant formula 6 hours, non-human milk 6 hours, light meal 6 hours) and that for emergency sedation the risk of aspiration is weighed against the urgency [2]. A registry of 139,142 sedation or anaesthesia encounters outside the operating room at 42 institutions found no deaths, 10 aspirations and 75 major complications, aspiration in 0.97 per 10,000 nil-per-os patients against 0.79 per 10,000 in others (odds ratio 0.81, 95 per cent confidence interval 0.08 to 4.08), and no independent association of nil-per-os status with major complications; the authors state that aspiration is uncommon [14]. Reasoning. The two sources are consistent in showing that guidelines require fasting and that the registry could not identify a measurable difference in the rare outcomes; the confidence interval for aspiration is wide enough to be compatible with a large effect in either direction, and the registry is observational and not specific to MRI. The adult intervals quoted on the Patient Preparation page are not sourced in the documents read for this page (to be sourced).

7. Monitoring in the Magnetic Field

The AAP and AAPD guideline states that capnography is especially useful in patients who are hard to observe, such as those in an MRI scanner or a darkened room, that MRI-compatible pulse oximeters and capnographs that function continuously during scanning should be used for any sedated or restrained child, that oximeter and ECG wires should not be coiled, that the oximeter probe should be placed as far from the magnet coil as possible, and that ECG monitoring has been linked to thermal injury so that MRI-compatible ECG pads are essential [2]. The ASA advisory states that ECG information may be unreliable in the high magnetic field, including the interpretation of the ST segment, that every monitor used in Zone IV must be MR Safe or MR Conditional for the scan, that a monitor should show the vital signs in Zone III when the anaesthesia provider is not in Zone IV, and that care must be taken with ECG and other monitor leads to prevent burns even when the leads are non-ferromagnetic [1]. The MHRA text read refers the choice of patient monitoring equipment to the MR operator and to Section 5.3.10, which was not read [5].

The mechanisms by which leads and cables heat tissue, the factors that decide the temperature rise and the evidence on burns are in RF Heating and Burns; the hearing protection of a sedated patient is in Acoustic Noise in MRI. Reasoning. The documents agree that monitoring must continue in the room and that its equipment must itself be shown to be safe; they do not give measured performance of any monitor in any field, and the statement that the ECG may be unreliable is a caution without a stated magnitude. No comparison of monitoring modalities for outcomes in MRI was read.

8. MR-Conditional Equipment

The MHRA guidelines state that normally no equipment is to be taken into the MR environment unless it has been labelled MR Safe or MR Conditional, that ferromagnetic objects such as tools, gas cylinders, trolleys and life-support systems must not be allowed in, that where risks cannot be removed mitigation such as tethering equipment appropriately should be considered, and that equipment that is MR Conditional under one set of conditions may not be safe under other conditions [5]. The ASA advisory states that anaesthesia equipment should be labelled as safe, unsafe or conditional for each scanner and its safety and effectiveness confirmed at each MRI location, that equipment must not interfere with image acquisition, that an MR Safe or MR Conditional anaesthesia machine is always preferred and should be installed in newly built or renovated facilities, that when none is available inhalational agents may be delivered from a machine in Zone III through an elongated circuit and wave guide (described as cumbersome and mishap-prone), and that for total intravenous anaesthesia MR Safe or MR Conditional pumps may be used in Zone IV, traditional pumps in Zone III with tubing through a wave guide, or periodic bolus injections; equipment for positive-pressure ventilation with oxygen must be immediately available even without an anaesthesia machine [1]. The AAP and AAPD guideline states that an infusion pump must be either MRI-compatible or placed outside the room with long tubing, that all equipment in the suite must be MRI-compatible, including laryngoscope blades and handles and oxygen tanks [2]. A committee of the Anesthesia Patient Safety Foundation advises that an MRI-compatible laryngoscope, blades and non-magnetic lithium batteries be kept available [16].

The meaning of the terms MR Safe, MR Conditional and MR Unsafe, the conditions on a label and the need to match them to the scanner are in Implant and Device MR Safety Framework; projectile incidents with cylinders and other equipment are in Projectile and Torque Hazards in the Static Field. Reasoning. The documents agree that the label of an item applies to the scanner and conditions it was tested for and that an item that is not labelled must stay out; they do not list items that are acceptable, which depends on the label of each item. The cost and availability of conditional equipment, and the consequences of using an extended circuit or long tubing for the quality of ventilation or infusion, were not described in the sources read (to be sourced).

9. Emergencies and Resuscitation in the MR Environment

The best practice statement of the British Association of MR Radiographers states that a permanent magnetic field is always present and cannot be turned off even during a cardiac arrest; that no one may enter the controlled access area without MRI safety screening, regardless of urgency; that resuscitation equipment must not be taken to the patient in the scan room while the magnet is energised unless it is MR Safe or MR Conditional; that all clinical staff who may respond must understand the field hazards and the local procedures and know where the scanners are; that regular multidisciplinary drills, including extrication simulations, are strongly recommended because suite designs vary; and that in exceptional circumstances resuscitation team members who must enter shall be accompanied by trained MRI personnel [4].

The ASA advisory states that for a medical emergency such as cardiopulmonary arrest the patient should be removed from Zone IV while CPR is started if indicated, help called and the patient moved to a designated resuscitation area outside Zone IV and as close to it as possible, which should have a defibrillator, vital-sign monitors and a code cart with drugs, airway equipment, oxygen and suction; that for a projectile incident the patient should be removed from Zone IV if possible and the scan stopped; that in a quench the patient should if possible be removed and oxygen given, that a controlled quench may be needed to free a patient, and that after a quench or fire static fields may persist so that emergency responders should not enter Zone IV; and that education should include how to respond to a code blue in Zones III and IV within the code team’s protocols [1]. The Anesthesia Patient Safety Foundation committee recommends a policy for failed airways and cardiac arrest based on the four-zone system, a predetermined magnetically safe location, and a stretcher kept in the scanner room to move the patient [16]. The MHRA text read states that procedures (local rules and standard operating procedures) should be established for emergencies in the controlled access area and that contacts with external services, particularly for first aid, should be arranged [5]. The AAP and AAPD guideline states that where backup may be lacking emergency medical services may need to be activated and that the practitioner remains responsible for life support until they arrive [2].

Table 4. Emergency response: statements by source (Zone IV in the ASA and APSF texts corresponds to the scan room).

Reasoning. The documents converge on the sequence screen first, remove the patient from the scan room, resuscitate outside it with equipment that has not been brought into the field, and train for it. None of the sources read reports measured times to compressions or defibrillation in MR units, outcomes of arrests in MR suites, or an evaluation of drills, and the BAMRR text read gives no instruction on the location of CPR or on defibrillation; the ASA text is the only source read that names a resuscitation area and its contents. Terminology differs: the zones of the ACR model are used by ASA and APSF, the “controlled access area” by the MHRA and BAMRR (see MR Site Zones and Access Control). The detail of quench, venting and oxygen depletion is not held here (Cryogens, Quench and Oxygen Depletion in MRI).

Clinicians at the bore. A letter to the journal that published the ASA advisory proposed that providers stay as far as possible from the scanner, avoid leaning into the bore, avoid rapid movements and have back-up personnel for intense vertigo; the Task Force replied that it could not recommend these statements without more compelling evidence and intended to address the issue in a future update [1]. The mechanism of movement-induced effects is in Static Magnetic Field Contours.

10. Where the Documents Differ and Open Questions

Table 5. Differences and unresolved questions.

11. Practice: the Pathway the Sources Support

Reasoning. The following arrangement is the page’s synthesis of statements in the sources and is not itself a recommendation of any one source. For the anxious patient: (1) provide information and relaxation or cognitive strategies, which show some benefit with low certainty [7][8]; (2) use a questionnaire, if at all, to exclude rather than to select [9]; (3) decide on sedation in advance, not during an incomplete scan, because a sedated patient needs monitoring, personnel and equipment (items 4 to 7). For the sedated or anaesthetised patient: (4) treat the patient as deeply sedated, monitor with MR Safe or Conditional pulse oximetry and capnography, add ECG according to the depth of sedation, and keep the vital signs visible from outside the room [2][1]; (5) use ECG and oximeter leads that are labelled for the scanner, uncoiled, away from the coil, and refer to RF Heating and Burns for the mechanism of heating [2][1]; (6) bring into the room only equipment whose label matches the scanner, and plan how infusions and ventilation will be delivered before the patient arrives [5][1]; (7) have a named person responsible for the patient who has no other task during deep sedation [2]. For an emergency: (8) screen responders, remove the patient to the designated resuscitation area, and resuscitate there with equipment that has not been in the field [4][1]; (9) rehearse the sequence, including extrication, with the personnel who would be called [4]. The sources read do not say who must hold which competence in an adult service, how often drills should occur, or what records should be kept (to be sourced).

12. Limits of the Evidence and What Was Not Read

The documents on sedation, monitoring and emergencies are consensus or expert statements without a stated evidence grading; the evidence on claustrophobia is observational, heterogeneous and mostly at abstract level; no randomised trial of a sedation regimen, a monitor or a resuscitation technique in the MR environment was read, and no study of outcomes of resuscitation in MR suites. The ASA advisory (2015) and the AAP and AAPD guideline (2016 text) are older than the 2026 documents, and their individual statements may have been updated; the advisory’s sentence on pacemakers and defibrillators is not carried forward (see Cardiac Implantable Electronic Devices in MRI and Implant and Device MR Safety Framework). The Association of Anaesthetists guideline, MHRA Section 5, the ACR Manual on MR Safety, the standards, the 2019 paediatric update, guidance on adult sedation from any society, and any national guidance outside the United Kingdom and the United States were not read. All statements are those of the documents as returned by summarising tools or in abstracts, and were not checked page by page.

13. Topics Not Covered

Drug choice, dosing and regimens for sedation of adults and children; the technique of general anaesthesia and of ventilation in the MR environment beyond the statements quoted; the treatment of a reaction to a contrast agent in progress (the ACR Manual on Contrast Media was not read); extravasation; the monitoring of patients with implanted devices (Cardiac Implantable Electronic Devices in MRI); quench, venting and oxygen depletion (Cryogens, Quench and Oxygen Depletion in MRI); incident reporting, learning and the rules of individual jurisdictions (Incident Learning, Governance, Quality and Jurisdictions in MR Safety); interventional and intraoperative MRI suites; research volunteers; and the screening of unconscious patients (Patient Preparation, Section 3.3).

14. Evidence-Based References

No randomised trial of sedation, monitoring or resuscitation in the MR environment was read; the sections below follow the hierarchy of the sources actually read, and the guidance documents rest on consensus without stated evidence grading.

A. Guidelines, Consensus, Standards and Regulation

B. Systematic Reviews

C. Primary Studies, Registries, Protocols and Scoping Review

D. Results Known Only from a News Report, and Expert Opinion

End of document — Claustrophobia, Sedation, Monitoring, Equipment and Emergencies (S11) — MRIninja v1.0 — October 2026. Parent: MRI Safety master.