Significance of body temperature in elderly patients with sepsis
Authors: Shimazui Takashi , Nakada Taka-aki , Walley Keith R. , Oshima Taku , Abe Toshikazu , Ogura Hiroshi , Shiraishi Atsushi , Kushimoto Shigeki , Saitoh Daizoh , Fujishima Seitaro , Mayumi Toshihiko , Shiino Yasukazu , Tarui Takehiko , Hifumi Toru , Otomo Yasuhiro , Okamoto Kohji , Umemura Yutaka , Kotani Joji , Sakamoto Yuichiro , Sasaki Junichi , Shiraishi Shin-ichiro , Takuma Kiyotsugu , Tsuruta Ryosuke , Hagiwara Akiyoshi , Yamakawa Kazuma , Masuno Tomohiko , Takeyama Naoshi , Yamashita Norio , Ikeda Hiroto , Ueyama Masashi , Fujimi Satoshi , Gando Satoshi ,   on behalf of the JAAM FORECAST Group, Shimazui Takashi , Nakada Taka-aki , Walley Keith R. , Oshima Taku , Abe Toshikazu , Ogura Hiroshi , Shiraishi Atsushi , Kushimoto Shigeki , Saitoh Daizoh , Fujishima Seitaro , Mayumi Toshihiko , Shiino Yasukazu , Tarui Takehiko , Hifumi Toru , Otomo Yasuhiro , Okamoto Kohji , Umemura Yutaka , Kotani Joji , Sakamoto Yuichiro , Sasaki Junichi , Shiraishi Shin-ichiro , Takuma Kiyotsugu , Tsuruta Ryosuke , Hagiwara Akiyoshi , Yamakawa Kazuma , Masuno Tomohiko , Takeyama Naoshi , Yamashita Norio , Ikeda Hiroto , Ueyama Masashi , Fujimi Satoshi , Gando Satoshi , Tasaki Osamu , Mizobata Yasumitsu , Funakoshi Hiraku , Okuyama Toshiro , Yamashita Iwao , Kanai Toshio , Yamada Yasuo , Aibiki Mayuki , Sato Keiji , Yamashita Susumu , Yoshida Kenichi , Kasaoka Shunji , Kon Akihide , Rinka Hiroshi , Kato Hiroshi , Okudera Hiroshi , Narimatsu Eichi , Fujiwara Toshifumi , Sugita Manabu , Shichinohe Yasuo , Nakae Hajime , Iiduka Ryouji , Nakamura Mitsunobu , Murata Yuji , Sato Yoshitake , Ishikura Hiroyasu , Myojo Yasuhiro , Tsujita Yasuyuki , Kinoshita Kosaku , Yamaguchi Hiroyuki , Sakurai Toshihiro , Miyatake Satoru , Saotome Takao , Yasuda Susumu , Abe Toshikazu , Ogura Hiroshi , Umemura Yutaka , Shiraishi Atsushi , Kushimoto Shigeki , Saitoh Daizoh , Fujishima Seitaro , Sasaki Junichi , Mayumi Toshihiko , Shiino Yasukazu , Nakada Taka-aki , Tarui Takehiko , Hifumi Toru , Otomo Yasuhiro , Kotani Joji , Sakamoto Yuichiro , Shiraishi Shin-ichiro , Takuma Kiyotsugu , Tsuruta Ryosuke , Hagiwara Akiyoshi , Yamakawa Kazuma , Takeyama Naoshi , Yamashita Norio , Ikeda Hiroto , Mizushima Yasuaki , Gando Satoshi 
Published: June 2020

Abstract
Background
Elderly patients have a blunted host response, which may influence vital signs and clinical outcomes of sepsis. This study was aimed to investigate whether the associations between the vital signs and mortality are different in elderly and non-elderly patients with sepsis.

Methods
This was a retrospective observational study. A Japanese multicenter sepsis cohort (FORECAST, n = 1148) was used for the discovery analyses. Significant discovery results were tested for replication using two validation cohorts of sepsis (JAAMSR, Japan, n = 624; SPH, Canada, n = 1004). Patients were categorized into elderly and non-elderly groups (age ≥ 75 or < 75 years). We tested for association between vital signs (body temperature [BT], heart rate, mean arterial pressure, systolic blood pressure, and respiratory rate) and 90-day in-hospital mortality (primary outcome).

Results
In the discovery cohort, non-elderly patients with BT < 36.0 °C had significantly increased 90-day mortality (P = 0.025, adjusted hazard ratio 1.70, 95% CI 1.07–2.71). In the validation cohorts, non-elderly patients with BT < 36.0 °C had significantly increased mortality (JAAMSR, P = 0.0024, adjusted hazard ratio 2.05, 95% CI 1.29–3.26; SPH, P = 0.029, adjusted hazard ratio 1.36, 95% CI 1.03–1.80). These differences were not observed in elderly patients in the three cohorts. Associations between the other four vital signs and mortality were not different in elderly and non-elderly patients. The interaction of age and hypothermia/fever was significant (P < 0.05).

Conclusions
In septic patients, we found mortality in non-elderly sepsis patients was increased with hypothermia and decreased with fever. However, mortality in elderly patients was not associated with BT. These results illuminate the difference in the inflammatory response of the elderly compared to non-elderly sepsis patients.