ABSTRACT
PURPOSE: This empirical study aims to investigate the efficacy of pre-emptive cryotherapy in reducing pain that is caused by the deltoid intramuscular (IM) injection of long-acting injectable (LAI) antipsychotics in clinical settings. PATIENTS AND METHODS: This study included 29 outpatients receiving LAI antipsychotic treatment. The evaluations of pain during (1) the usual procedure (control), (2) pre-emptive use of ice pack cryotherapy (pre-cooling), and (3) pre-emptive use of a room-temperature ice pack (pre-touching) were conducted using a numerical rating scale (NRS) for comparison. All patients were administered with LAI antipsychotics via deltoid IM. Furthermore, the results of the Positive and Negative Symptom Scale (PANSS), clinical global impressions (CGI) scale, and Global Assessment of Functioning (GAF) scale that were administered during the control procedure were evaluated. RESULTS: The median NRS pain scores during the IM injection of LAI antipsychotics were 4.0 (3.0-5.0), 2.0 (1.0-3.0), and 3.0 (2.5-6.0) for the control, pre-cooling, and pre-touching conditions, indicating a significant difference (p = 6.0 × 10-6). The NRS pain scores for the pre-cooling condition were significantly lower than those for the control and pre-touching conditions (p = 2.5 × 10-5 and 6.7 × 10-5, respectively). No significant correlation was observed between the NRS pain scores for the control condition and the PANSS, CGI scale, or GAF scale scores. Furthermore, no adverse events were recorded during the study period. CONCLUSION: Pain during the deltoid IM injection of LAI antipsychotics was found to be reduced by pre-emptive skin cooling. To date, this is the first study to confirm the effectiveness of pre-emptive cryotherapy for relieving such pain in clinical situations.