Claustrophobia, Anxiety, and Emotional Distress

The increasing availability and capabilities of magnetic resonance (MR) studies to improve medical diagnosis and prognosis has dramatically increased the number of procedures performed worldwide. Thus, many more first-time and repeat patients are undergoing MR examinations for an ever-widening spectrum of indications. Increasing proportions of these MR procedures are performed on patients suffering from unstable medical and psychological illnesses. For certain patients that undergo MR examinations, the experience may cause great emotional distress. Referring physicians, radiologists, and technologists can best manage affected patients by understanding the etiology of the problem and knowing the appropriate maneuver or intervention to implement in order to handle the condition.

The experience of "psychological distress" in the MR environment includes all subjectively unpleasant experiences that are directly attributable to the procedure. Distress for the patient undergoing an MR examination can range from mild anxiety that can be handled with minimal reassurance to a more serious panic attack that may require psychiatric intervention. Severe psychological distress reactions to MR examinations, namely anxiety and panic attacks, are characterized by the rapid onset of at least four of the following: nausea, paresthesias, palpitations, chest pain, faintness, dyspnea, choking sensation, sweating, trembling, vertigo, depersonalization, and fear of losing control or dying.

Many symptoms of panic attack mimic over activity of the sympathetic nervous system, prompting concern that catecholamine responses may precipitate cardiac arrhythmias and/or ischemia in susceptible patients. However, this has not been reported in a clinical MR setting. Nevertheless, it is advisable that, in a medically unstable patient, physiologic monitoring be a routine component of the MR examination.

In the mildest form, distress is the normal amount of anxiety any reasonable person will experience when undergoing a diagnostic procedure. Moderate distress severe enough to be described as a dysphoric psychological reaction has been reported by as many as 65% of the patients examined by MR imaging. The most severe forms of psychological distress described by patients are anxiety, claustrophobia, or panic attacks.

Claustrophobia is a disorder characterized by the marked, persistent and excessive fear of enclosed spaces. In such affected individuals, exposure to an enclosed space such as that found with certain MR systems, almost invariably provokes an immediate anxiety response that in it's most extreme form is indistinguishable from the panic attack described above.

The actual incidence of distress in the MR environment is highly variable across studies due to differences in outcome measures used to determine distress. Some studies indicated that as many as 20% of individuals attempting to undergo an MR procedure can't complete it secondary to serious distress such as claustrophobia or other similar sensation. In contrast, other investigators have reported that as few as 0.7% of individuals have incomplete or failed MR procedures due to distress.

THE IMPACT OF EMOTIONAL DISTRESS
Patient distress can contribute to adverse outcomes for the MR procedure. These adverse outcomes include unintentional exacerbation of patient distress, a compromise in the quality and, thus, the diagnostic aspects of the imaging study and decreased efficiency of the imaging facility due to delayed, prematurely terminated, or cancelled studies. Patient compliance during an MR procedure, such as the ability to remain in the MR system and to hold still long enough to complete the study, is of paramount importance to achieve a diagnostically acceptable examination. If a good quality study cannot be obtained, the patient may require an invasive diagnostic examination in place of the safer, less painful and risky MR procedure. Thus, for the distressed patient unable to undergo an MR procedure, there are typically clinical, medico-legal, and economic related considerations implications.

Increasing pressure to use MR system time efficiently to cover the costs of expensive diagnostic imaging equipment puts greater stress on both staff and patients. The ability of referring physicians, radiologists, and MRI technologists to detect patient distress at the earliest possible time, to discover the source of the distress, and then to provide appropriate intervention can greatly improve patient comfort, quality of imaging studies, and efficiency of the MRI facility.

FACTORS THAT CONTRIBUTE TO DISTRESS
Many factors contribute to distress experienced by certain patients undergoing MR procedures. Most commonly cited are concerns about the physical environment of the MR system. Also well documented are the anxieties associated with the underlying medical problem necessitating the MR procedure. Certain individuals, such as those with psychiatric illnesses, may be predisposed to suffer greater distress due to MR procedures.

The physical environment of the MR system is clearly one important source of distress to patients. Sensations of apprehension, tension, worry, claustrophobia, anxiety, fear, and even panic attacks have been directly attributed to the confining dimensions of the interior of the MR system. For example, for certain MR systems, the patient's face may be three to ten inches from the inner portion of the scanner, prompting feelings of uncontrolled confinement and detachment.

Similar distressing sensations have been attributed to other aspects of the MR environment including the prolonged duration of the examination, the acoustic noise, the temperature and humidity within the MR system, and the distress related to restriction of movement. Additionally, the MR system may produce a feeling of sensory deprivation, which is also known to be a precursor of severe anxiety states.

MR systems that have an architecture that utilizes a vertical magnetic field offer a more open design that is presumed to reduce the frequency of distress associated with MR procedures. The latest versions of these open MR systems, despite having static magnetic field strengths of 0.3-Tesla or lower have improved technology (i.e., faster gradient fields, optimized surface coils, etc.) that permit acceptable image quality for virtually all types of standard, diagnostic imaging procedures. High-field open MR systems operating at 0.7-Tesla and 1.0-Tesla are now commercially available and these systems may be more acceptable to patients with feelings of distress. Also, the latest generation, high-field-strength (1.5-Tesla and 3-Tesla) MR systems have shorter-and wider bore configurations that likely mitigate feelings of being enclosed that may be experienced by patients undergoing MR procedures.

In 1993, a specially designed, low-field-strength (0.2-Tesla) MR system (Artoscan, Lunar Corporation/General Electric Medical Systems, Madison, WI and Esaote, Genoa, Italy) became commercially available for MR imaging of extremities. The use of this dedicated extremity MR system provides an accurate, reliable, and relatively inexpensive means (i.e., in comparison to the use of a whole-body MR system) of evaluating musculoskeletal abnormalities. In fact, utilization of the extremity MR system to assess musculoskeletal pathology is an acceptable alternative to whole-body MR systems since the diagnostic capabilities for evaluation of the knee, shoulder, and other extremities has been reported to be comparable to mid- or high-field-strength MR systems.

The architecture of the extremity MR system has no confining features or other aspects that would typically create patient-related problems. This is because only the body part that requires imaging is placed inside the bore of the magnet during the MR examination. A report indicated that 100% of the MR examinations that were initiated were completed without being interrupted or cancelled for patient-related problems. The unique design of the extremity MR system is believed to have contributed to the successful completion of MR procedures in the patients of this study. Furthermore, these findings represent a dramatic improvement compared with the published incidence of patient distress that tends to interrupt or prevent the completion of MR procedures using whole-body MR systems. Another dedicated-extremity MR system with an open design permits MR imaging of the shoulder. There is also a high-field-strength extremity MR system (OrthOne, ONI) that has a configuration that may also be conducive to preventing psychological distress.

Adverse psychological reactions are sometimes associated with MR procedures simply because the examination may be perceived by the patient as a "dramatic" medical test that has an associated uncertainty of outcome, such that there may be fear of the presence of disease or other condition. In fact, any type of diagnostic imaging procedure may produce anxiety for the patient.

Patients with pre-existing psychiatric disorders may be at greater risk for experiencing distress in the MR environment. Accordingly, patients with pre-existing anxiety disorders or similar conditions should be identified prior to MR examinations in order to increase anxiety-minimizing efforts (see below). Patients with other psychiatric illnesses such as depression and any illness complicated by thought disorder such as schizophrenia and manic-depressive disorder may also be at increased risk for distress in the MR environment.

Patients with psychiatric illnesses may, under normal circumstances, be able to tolerate the MR environment without a problem, as is clear form the thousands who participate in clinical neuroimaging research studies each year. However, the increased stress due to their medical illness or fear of medical illness may exacerbate their psychiatric symptoms to such an extent that they may have difficulty complying with MR procedures. At the very least, patients with psychiatric illnesses may require more time and patience to provide the appropriate level of preparatory information for the MR examination.

TECHNIQUES TO MINIMIZE PATIENT DISTRESS
Various procedures exist for minimizing distress or anxiety in patients undergoing MR procedures (Table 1). Certain measures should be employed for all studies, while others may be required only if the patient experiences distress due to the factors described above.

Table 1. Techniques to manage patients with distress associated with MR procedures.
1. Prepare and educate the patient concerning specific aspects of the MR examination (e.g., MR system dimensions, gradient noise, intercom system, constant presence of the technologist etc.).
2. Allow an appropriately screened relative or friend to remain with the patient during the MR procedure.
3. Maintain verbal, visual, and/or physical contact with the patient during the MR procedure.
4. Use an MR-compatible stereo system to provide music to the patient.
5. Use an MR-compatible video monitor to provide a visual distraction to the patient.
6. Use a virtual reality environment system to provide audio and visual distraction.
7. Place the patient prone for the examination.
8. Position the patient feet-first instead of head-first into the MR system.
9. Use special mirrors or prism glasses to redirect the patient's line of sight.
10. Use a blindfold so that the patient is not aware of the surroundings.
11. Use bright lights inside of the MR system.
12. Use a fan inside of the MR system.
13. Use vanilla scented oil or other similar aroma therapy.
14. Use relaxation techniques such as controlled breathing or mental imagery.
15. Use systematic desensitization.
16. Use medical hypnosis.
17. Use a sedative or other similar medication.

For All Patients Undergoing MR Procedures
Referring clinicians should take the time to explain the rationale for the MR procedure and what he/she expects to learn from the results with respect to the implications for treatment and prognosis. Importantly, the clinician should schedule time with the patient to communicate the results of the MR procedure.

The single most important step is to educate the patient about the specific aspects of the MR examination that are known to be particularly difficult. This includes conveying, in terms that are understandable to the patient, the internal dimensions of the MR system, the level of gradient magnetic field-induced acoustic noise to expect, and the estimated time duration of the examination.

Studies have documented a decrease in the incidence of premature termination of examinations when patients were provided with detailed information about the MR procedure. Accordingly, patients should be provided with an appropriate brochure or video presentation supplemented by a question and answer session with an MR-trained healthcare worker prior to the examination.

Many details of patient positioning in the MR system can increase comfort and, thus, minimize distress. Taking time to ensure comfortable positioning with adequate padding and blankets to alleviate undue discomfort or pain is also important. Adequate ear protection should be provided routinely to decrease acoustic noise from the MR system, as needed (i.e., this is typically not required for low-field-strength MR systems). Demonstration of the two-way intercom system or other monitoring technique to reassure the patient that the MR staff is readily available during the examination is vital for proper patient management.

For Mildly-to-Moderately Distressed Patients
If a patient continues to experience distress after the afore-mentioned measures are implemented, additional interventions are required. Frequently, all that is necessary to successfully complete an MR examination is to allow an appropriately screened relative or friend to remain with the patient. A familiar person in the MR system room will often help an anxious patient develop an increased sense of security. If a supportive companion is not present, a staff member can maintain contact with the patient during the examination to decrease psychological distress.

Placing the patient prone so that the opening of the MR system can be seen will provide a sensation of being in a device that is more spacious. As such, prone positioning can alleviate the "closed-in" feelings frequently associated with being supine. Unfortunately, prone positioning may not be practical if the patient has certain underlying medical conditions (e.g., shortness of breath, the presence of chest tubes, etc.). Another method of positioning the patient that may help is to place the individual feet-first instead of head-first into the MR system.

MR system-mounted mirrors or prism glasses can be used to permit the patient to maintain a vertical view of the outside of the MR system in order to minimize phobic responses. Using a blindfold so that the patient is unaware of the close surroundings has also been suggested to be an effective technique for enabling anxious patients to successfully undergo MR procedures.

The environment of the MR system may be changed to optimize the management of apprehensive patients. For example, the presence of higher lighting levels tends to make most individuals feel less anxious. Therefore, the use of bright lights at either end and inside of the MR system can produce a less imposing environment for the patient. Using a fan inside of the MR system to increase airflow will also help reduce the sensation of confinement. In addition, aroma therapy (e.g., placing a cotton pad moistened with a few drops of essential lemon or vanilla oil in the MR system) can help reduce distress by providing the patient with pleasant olfactory stimulation.

Specialized systems that transmit music or audio communication through headphones have been developed specifically for use with MR systems. Reports have indicated that these devices successfully reduced symptoms of anxiety in patients during MR procedures. Furthermore, it is now possible to provide visual stimulation to the patient via monitors or special goggles. Use of visual stimuli to distract patients tends to reduce distress. Finally, a system has been developed to provide a calming virtual reality environment for the patient that may likewise serve as an acceptable means of audio and visual distraction from the MR procedure (this device is also used for fMRI studies).

For Severely Distressed or Claustrophobic Patients
Patients who are at high risk for severe distress in the MR environment and can be identified as such by their referring clinician or by the scheduling MR staff person should be offered the opportunity to have pre-MR procedure behavioral therapy. MR procedures conducted in patients that previously refused or were unable to tolerate the MR environment have been reported to be successful as a result of treatment with relaxation techniques, systematic desensitization, and medical hypnosis.

In the majority of MRI facilities, patients that are severely affected by claustrophobia, anxiety, or panic attacks in response to MR procedures usually need sedation when attempts to counteract their distress fail. Using short-acting sedatives such as lorazepam, diazepam, alprazolam, or intranasal midazolam or one of the newer anxiolytic medications may be the only means of managing a patient with a high degree of anxiety. However, the use of sedatives in patients prior to and during MR procedures may not be required in all instances, nor is it always practical.

Obviously, the use of sedation in the MR environment requires special preparation, involving several important patient management considerations. For example, the time when the patient is administered the medication for optimal effect prior to the examination must be considered along with the possibility that an adverse reaction may occur. In addition, proper MR-compatible monitoring equipment operated by appropriately trained personnel must be used to ensure patient safety. Provisions should be available for an area to permit adequate recovery of the patient after an MR procedure that involves sedation.

[*Portions of this content were excerpted with permission from Gollub RL and Shellock FG. Claustrophobia, Anxiety, and Emotional Distress in the Magnetic Resonance Environment. In, Magnetic Resonance Procedures: Health Effects and Safety. FG Shellock, Editor, CRC Press, Boca Raton, FL, 2001.]

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