Premedication for Claustrophobic Patients for MRI Scan

Claustrophobia is an irrational fear of constraint, restriction, immobility, smothering and suffocation. Claustrophobia is a specific phobia, according to the Diagnostic and Statistical Manual 5 (DSM 5). The disorder affects 5% of the general population. Claustrophobic patients may fear that the restriction of their limbs will hinder their ability to move quickly towards perceived safety. Magnetic resonance imaging (MRI) may trigger claustrophobia, because this diagnostic procedure involves a patient staying immobile in a narrow and noisy tube. Anxiolytic premedication before MRI scan, using Lorazepam, may occasionally help to reduce claustrophobia.

This is a prospective observational crossover study of claustrophobic adult patients who are undergoing MRI scan as part of chronic pain management. At alternate MRI scan sessions, each patient receives rotational premedication using Lorazepam 1mg; or Clonidine tablet 0.2mg; or combined Clonidine 0.2mg + Lorazepam 1mg.

The patient will use the Claustrophobia Questionnaire (CLQ), a special validated tool, to collect data on the days before and after each MRI scan. The CLQ is a patient-administered tool that is used to record the severity and presence of claustrophobia symptoms, on a measurement range of 0 to 104. A change in the CLQ scores by 12-points is considered significant. In addition, the patient will use the General Anxiety Disorder Questionnaire (GAD-7), a special validated tool, to collect data on the days before and after each MRI scan. The GAD-7 is a patient-administered tool that is used to record the severity and presence of anxiety symptoms, on a measurement range of 0 to 21. A change in the GAD-7 scores by 3-points is considered significant.

Data analyzed with IBM® SPSS® Statistics 25 (IBM Corp, Armonk, NY); using Student's t-test, ANOVA, Pearson Chi-square test, and regression analysis. P-value <0.05 is considered significant.

Inclusion criteria

• diagnosed with claustrophobia
• previous incomplete MRI because of claustrophobia
• adult patients
• good treatment compliance
• reliable Claustrophobia Questionnaire (CLQ) diary
• reliable General Anxiety Disorder Questionnaire (GAD) diary
• informed consent for diary review
• consent for clinical record quality assurance review

Exclusion criteria

• poor treatment compliance
• cognitive disorder
• inability to provide consent
• major neuropsychiatric disorder
• unreliable diary
• cannabis use
• excessive alcohol intake
• previous adverse/allergic reactions to clonidine
• previous adverse/allergic reactions to lorazepam