<title>Abstract</title><sec id="S1049023X20000138_as1"><title>Introduction:</title>The Nankai Trough, which marks the boundary between the Eurasian and Philippine Sea plates, is forecasted to create a catastrophic earthquake and tsunami within 30 years. The Japanese government believes that the number of casualties would be huge. However, the exact number of severely injured (SI) people who would need emergency and intensive care has not been identified.

</sec><sec id="S1049023X20000138_as2"><title>Objective:</title>This study, therefore, aimed to clarify the gap between medical supplies and forecasted demand.

</sec><sec id="S1049023X20000138_as3"><title>Methods:</title>The official data estimating the number of injured people were collected, together with the number of intensive care unit (ICU) and high care unit (HCU) beds from each prefecture throughout Japan. The number of SI cases was recalculated based on official data. The number of hospital beds was then compared with the number of SI people.

</sec><sec id="S1049023X20000138_as4"><title>Results:</title>The total number of hospitals in Japan is 8,493 with 893,970 beds, including 6,556 ICU and 5,248 HCU beds. When the Nankai Trough earthquake occurs, 187 of the 723 disaster base hospitals (DBHs) would be located in the areas with a seismic intensity of an upper six on the Japanese Seismic Intensity Scale (JSIS) of seven, and 79 DBHs would be located in the tsunami inundation area. The estimated total number of injured people would be 661,604, including 26,857 severe, 290,065 moderate, and 344,682 minor cases.

</sec><sec id="S1049023X20000138_as5"><title>Conclusion:</title>Even if all ICU and HCU beds were available for severe patients, an additional 15,053 beds would be needed. If 80% of beds were used in non-disaster times, the available ICU and HCU beds would be only 2,361. The Cabinet Office of Japan (Chiyoda City, Tokyo, Japan) assumes that 60% of hospital beds would be unavailable in an area with an upper six on the JSIS. The number of ICU and HCU beds that would be usable during a disaster would thus further decrease. The beds needed for severe patients, therefore, would be significantly lacking when the Nankai Trough earthquake occurs. It would be necessary to start the treatment of those severe patients who are “more likely to be saved.”

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