2026-10-12T18:25:49Z https://api.figshare.com/v2/oai

oai:figshare.com:article/34039536 2026-10-01T05:39:43Z category_393 portal_316 item_type_3 month_year_10_2026

Supplementary file 1_Temporal overlap of intraoperative hypotension and hypocapnia and postoperative outcomes after major open intracranial surgery: a time-weighted dual-hit cohort study.docx Xing Yan (434161) Xuemin Zou (17017074) Ruowen Yang (17038311) Jinyun Wang (1800799) Lemei Zhu (13984746) Foetal Development and Medicine cerebral perfusion end-tidal carbon dioxide hypocapnia intracranial surgery intraoperative hypotension perioperative outcomes temporal overlap time-weighted exposure Background<p>Intraoperative hypotension reduces cerebral perfusion pressure, whereas hypocapnia may reflect either ventilation-related cerebral vasoconstriction or reduced pulmonary perfusion during a low-flow state. We evaluated whether the time-weighted overlap of hypotension and hypocapnia was associated with adverse postoperative outcomes after major open intracranial surgery.</p>Methods<p>We conducted a retrospective cohort study using INSPIRE version 1.4.2. Adults undergoing major open intracranial surgery were included if mean arterial pressure (MAP) and end-tidal carbon dioxide (EtCO₂) had at least 80% synchronous coverage. Dual-hit cerebral hypoperfusion burden (DHCB) was defined as the proportion of synchronously valid monitoring time with simultaneous MAP <65 mmHg and EtCO₂ < 30 mmHg. The primary outcome was a composite of in-hospital death, postoperative intensive care unit stay of at least 2 days, or prolonged postoperative hospitalization. Patient-clustered multivariable logistic regression simultaneously modeled hypotension-only, hypocapnia-only, and concurrent exposure burdens.</p>Results<p>The final cohort included 2,286 operations in 2,092 patients. Concurrent hypotension and hypocapnia occurred in 708 operations (31.0%), and the composite outcome occurred after 676 operations (29.6%). Each 5-percentage-point increase in DHCB was associated with higher odds of the composite outcome (adjusted odds ratio, 1.19; 95% CI, 1.10–1.28; P < 0.001), whereas hypotension-only and hypocapnia-only burdens were not independently associated with the outcome. Adding DHCB improved model fit but only minimally increased apparent discrimination (C-statistic, 0.764 to 0.767). Results remained consistent across progressively adjusted and sensitivity analyses. Restricted cubic spline analysis showed an overall association (P < 0.001) but no significant evidence of nonlinearity (P for nonlinearity = 0.143). The standardized risk increased from 27.3% at DHCB = 0% to 45.6% at DHCB = 30%, although estimates at higher burdens were less precise.</p>Conclusions<p>Greater temporal overlap between intraoperative hypotension and hypocapnia was associated with adverse short-term postoperative outcomes beyond the corresponding non-overlapping exposure burdens. DHCB should be interpreted as a hypothesis-generating marker of concurrent physiological exposure rather than evidence of two independent causal insults, and requires external validation with neurologically specific outcomes before clinical application.</p> 2026-10-01T05:39:43Z Dataset Dataset 10.3389/fmed.2026.1946283.s001 https://figshare.com/articles/dataset/Supplementary_file_1_Temporal_overlap_of_intraoperative_hypotension_and_hypocapnia_and_postoperative_outcomes_after_major_open_intracranial_surgery_a_time-weighted_dual-hit_cohort_study_docx/34039536 CC BY 4.0