ChiCTR‐IOR‐17010508.

Methods	Elderly individuals undergoing spinal surgery were randomly allocated to one of two groups. Randomisation was performed using a random number table. It is unclear how allocation concealment was performed and maintained. The blinding status of participants, personnel, and outcome assessors is not described.
Participants	The study aimed to randomise 60 elderly individuals, between 60 and 80 years of age and of both sexes, undergoing spinal surgery, to one of two groups: Group 1 (Autotransfusion group): N = 30 Group 2 (Control group): N = 30
Interventions	Group 1 (Autotransfusion group): underwent perioperative cell salvage using leucocyte depletion filter and autotransfusion Group 2 (Control group): received allogeneic blood transfusion
Outcomes	Outcomes reported: oxygenation index (OI), respiratory index (RI), alveloar surface‐active substances related proteins‐A concentration (SP‐A) (primary outcome), serum malondialdehyde (MDA), superoxide dismutase (SOD), interleukin 6 (IL‐6), tumour necrosis factor (TNF)‐alpha concentration, blood transfusion reactions, postoperative respiratory complications within 72 hours
Notes	Transfusion protocol: a transfusion protocol is not described Prospective registration status: the study was reported to be prospectively registered on the Chinese Clinical Trials registry. Ethical approval: the study was approved by the Ethics Committee of Second Affiliated Hospital of Zhejiang Chinese Medical University (No. 20156) on 14 January 2015. Language: study information on the Chinese Clinical Trials registry in Chinese and English languages Reason for awaiting classification status: this study corresponds to a trial registration only and lacks sufficient information about intervention and comparator to assess for inclusion.