CANCARE RESEARCH
Explore previously published research highlights by topic, study type or publication date.
An automated research-discovery feed. Summaries are based on published abstracts and are not clinical recommendations.
Safety and Efficacy of Acute Normovolemic Hemodilution in Female Patients: A Secondary Analysis of the ANH Trial.
Clinical takeaway This exploratory analysis found no clear transfusion benefit in women, alongside signals of more hypotension and longer ICU and hospital stays with ANH. Confirmation in adequately powered studies is needed.
Summary & abstract
Study summary
This post hoc analysis included 405 women undergoing elective cardiac surgery with cardiopulmonary bypass, comparing acute normovolemic hemodilution (ANH) with usual care. Index-hospitalization red-cell transfusion occurred in 38.8% versus 44.6% (RR 0.87; 95% CI 0.69-1.10), without a statistically significant difference. Intraoperative hypotension was more frequent with ANH (16.0% versus 4.8%; RR 3.30; 95% CI 1.62-6.74). ANH was also associated with longer ICU stays (mean difference 21.13 hours; 95% CI 1.89-40.38) and hospital stays (1.92 days; 95% CI 0.14-3.70), while mortality and other postoperative complications did not differ significantly.
Study limitation: This post hoc female subgroup analysis is exploratory and requires confirmation in studies specifically powered for this population.
Published abstract
IMPORTANCE: Female patients undergoing cardiac surgery have a higher transfusion burden, yet they remain underrepresented in randomized clinical trials. Although the ANH trial showed no significant reduction in the proportion of patients receiving allogeneic blood transfusions with acute normovolemic hemodilution, evidence regarding its efficacy and safety specifically in female patients remains limited. OBJECTIVE: To evaluate the efficacy and safety of acute normovolemic hemodilution (ANH) compared with usual care in female patients undergoing elective cardiac surgery with cardiopulmonary bypass. DESIGN, SETTING, AND PARTICIPANTS: This was a post hoc secondary analysis of the multicenter, randomized ANH trial, which was conducted at 32 centers in 11 countries from April 2019 to December 2024. Of 2010 patients in the original ANH trial, 405 were women and were included in this analysis; 219 had been randomized to receive ANH and 186 to usual care. This secondary analysis was conducted from August 2025 to January 2026. INTERVENTION: Withdrawal of at least 650 mL whole blood with crystalloids replacement and reinfusion after cardiopulmonary bypass. MAIN OUTCOMES AND MEASURES: The primary outcome was the occurrence of at least 1 allogeneic packed red blood cell (pRBC) transfusion during the index hospitalization. Safety outcomes included intraoperative hypotension, intensive care unit (ICU) length of stay, hospital length of stay, mortality, and other perioperative complications. RESULTS: The median (IQR) age of the participants was 62 (54-69) years. The occurrence of allogeneic pRBC transfusion was similar in the ANH and usual care groups (38.8% vs 44.6%, respectively; relative risk [RR], 0.87; 95% CI, 0.69-1.10; P = .24). Intraoperative hypotension occurred more frequently with ANH (16.0% vs 4.8% in usual care; RR, 3.30; 95% CI, 1.62-6.74; P = .02). Patients receiving ANH also had longer ICU stays (mean difference, 21.13 hours; 95% CI, 1.89-40.38; P = .03) and hospital stays (mean difference, 1.92 days; 95% CI, 0.14-3.70; P = .04). No significant differences were observed in mortality or other postoperative complications. CONCLUSIONS AND RELEVANCE: In this post hoc secondary analysis of a randomized clinical trial, ANH was not associated with a reduction in allogeneic pRBC transfusion among women undergoing cardiac surgery and was associated with more frequent intraoperative hypotension and longer ICU and hospital stay. These exploratory findings warrant confirmation in adequately powered studies specifically designed to evaluate female patients undergoing cardiac surgery. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03913481.
AI summary and clinical bottom line, with automated source checks. Consult the original paper before applying findings.
Association Between Relative Plasma Hyperosmolality and Postoperative Delirium Following Cardiac Surgery: A Post Hoc Analysis.
Clinical takeaway These exploratory findings link postoperative hyperosmolality and accumulated perioperative factors with delirium after cardiac surgery. They do not establish causality or demonstrate that modifying osmolality prevents delirium.
Summary & abstract
Study summary
This post hoc analysis of a randomized trial included 195 cardiac-surgery patients aged 65 years or older at one Swedish tertiary hospital. Postoperative delirium occurred in 36% (70/195), with postoperative assessments on days 1 and 3. Relative plasma hyperosmolality on postoperative day 3 was identified as a potentially independent correlate of delirium in multivariable analysis. More than two concurrent perioperative factors were reported to be associated with an eightfold greater likelihood of delirium, although the abstract provided neither confidence intervals nor a numerical effect estimate for hyperosmolality.
Study limitation: Single-centre post hoc associations, without reported confidence intervals or clear temporal ordering, limit causal interpretation and precision.
Published abstract
PURPOSE: To determine whether relative plasma hyperosmolality is independently associated with postoperative delirium (POD) and to explore the relationship between the cumulative number of concurrent perioperative variables and POD in patients aged greater than or equal to 65 years undergoing cardiac surgery. DESIGN: Post hoc analysis. METHODS: This post hoc analysis of a randomized controlled trial included 195 consecutive patients enrolled between March 2019 and June 2020 at a tertiary hospital in Sweden. The incidence of POD was 36% (70/195). POD was assessed preoperatively and postoperatively on days 1 and 3, based on the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. Plasma osmolality was measured on five occasions and coordinated with POD assessments. Potential perioperative variables associated with POD were analyzed using a multivariable logistic regression model. FINDINGS: The main findings indicate that relative hyperosmolality on the third postoperative day may represent a biochemical factor independently associated with the development of POD, and the presence of more than two concurrent perioperative factors, which may increase the likelihood of POD eightfold. CONCLUSIONS: Relative plasma hyperosmolality may be associated with POD after cardiac surgery. The accumulation of concurrent perioperative variables also appears important and supports further investigation of multicomponent prevention strategies. Multicenter studies are needed to confirm these findings.
AI summary and clinical bottom line, with automated source checks. Consult the original paper before applying findings.