Kendiss Olafson

Intensive care unit-acquired weakness (ICU-AW) research focuses predominantly on intrinsic muscle pathology rather than integrated systemic interactions, which are commonly studied in exercise science. Peak oxygen uptake (V˙O2peak), V˙O2 on/off kinetics, and skeletal muscle oxygenation provide a quantitative evaluation of exercise capacity and are infrequently measured in intensive care unit (ICU) survivors. Routine cardiopulmonary exercise test (CPET) research separates V˙O2peak and V˙O2 kinetics assessments into multiple sessions. Yet, a combined experimental approach may enhance diagnosis, follow-up retention, and mechanistic insight for patients with ICU-AW. This prospective cross-sectional observational study aims to develop a standardized, single-session CPET protocol for combined assessment of V˙O2peak, V˙O2 kinetics, and skeletal muscle microvascular oxygenation in ICU survivors, enabling quantitative and integrated assessment of ICU-AW. Adults mechanically ventilated for ≥7 days will be recruited to participate 6 months post-ICU discharge in a modified CPET exercise session on an upright cycle ergometer. The proposed standardization will involve (1) the estimation of V˙O2peak using a priori formulas with a V˙O2peak correction factor for the ICU population, (2) V˙O2 on-kinetics (constant work rate) targeting relative 30% V˙O2reserve, (3) an incremental ramp exercise based on self-reported functional status, and (4) a 10-minute recovery to quantify V˙O2 off-kinetics. In addition, near-infrared spectroscopy will be placed on the vastus lateralis muscle to simultaneously collect tissue saturation index and deoxyhemoglobin during each phase of the protocol. Recruitment is anticipated to begin in June 2026 and is expected to be completed in 2029/2030. The anticipated sample size will be approximately 48 participants based on the feasibility of recruiting 1 participant per month and a sample size calculation based on Bland-Altman limits of agreement between predicted and measured V˙O2peak. The intensive care unit combined assessment of cardiorespiratory exercise (ICU-CARE) CPET protocol will enable the quantitative evaluation of V˙O2peak, V˙O2 on/off kinetics, and local microvascular skeletal muscle oxygenation during a single exercise session, facilitating the integrated physiological study of ICU-AW.

BACKGROUND ICU-acquired weakness (ICU-AW) research focuses predominantly on intrinsic muscle pathology rather than integrated systemic interactions, commonly studied in exercise science. Peak oxygen uptake (V ̇O_2peak), V ̇O_2 on/off kinetics, and skeletal muscle oxygenation provide quantitative evaluation of exercise capacity, and are infrequently measured in ICU survivors. Routine cardiopulmonary exercise test (CPET) research separates V ̇O_2peak and V ̇O_2 kinetics assessments into multiple sessions. Yet, a combined experimental approach may enhance diagnosis, follow-up retention, and mechanistic insight for patients with ICU-AW. OBJECTIVE This prospective cross-sectional observational study aims to develop a standardized, single-session CPET protocol for combined assessment of V ̇O_2peak, V ̇O_2 kinetics, and skeletal muscle microvascular oxygenation in ICU survivors, enabling quantitative and integrated assessment of ICU-AW. METHODS Adults mechanically ventilated ≥ 7 days will be recruited to participate 6 months post-ICU discharge, in a modified CPET exercise session on an upright cycle ergometer. The proposed standardization will involve (i) the estimation of V ̇O_2peak using a priori formulae with a V ̇O_2peak correction factor for the ICU population, (ii) V ̇O_2 on-kinetics (constant-work-rate [CWR]) targeting relative 30% V ̇O_2reserve, (iii) an incremental ramp exercise based on self-reported functional status, and (iv) a 10-minute recovery to quantify V ̇O_2 off-kinetics. In addition, near-infrared spectroscopy (NIRS) will be placed on the vastus lateralis muscle to simultaneously collect tissue saturation index (TSI) and deoxy-hemoglobin (HHb) during each phase of the protocol. RESULTS Recruitment is anticipated to begin in June 2026, and is expected to be completed in 2028. Anticipated sample size will be approximately 25 participants based on convenience sampling and recruitment of 1 participant per month. CONCLUSIONS The ICU-CARE CPET protocol will enable the quantitative evaluation of V ̇O_2peak, V ̇O_2 on/off kinetics, and local microvascular skeletal muscle oxygenation during a single exercise session, facilitating the integrated physiological study of ICU-AW. CLINICALTRIAL Registered at clinicaltrials.gov under the clinical study ID NCT06193980

Purpose The interplay between critical illness and mental disorders is poorly understood. The purpose of this study is to measure both the treated prevalence of mental disorders and psychotropic medication use before and after hospitalization and the impact of intensive care unit (ICU) admission on these outcomes. Methods Using a population-based administrative database in Manitoba, Canada, 49,439 ICU patients admitted between 2000 and 2012 were compared to two matched comparison groups (hospitalized; n = 146,968 and general population; n = 141,937). Treated prevalence of mental disorders and psychotropic medication prescriptions were measured in the 5-year periods before and after the hospitalization. Multivariable models compared adjusted prevalence ratios (APRs) between populations. Results The 5-year treated mental disorder prevalence in the ICU population increased from 41.5% pre-hospitalization to 55.6% post-hospitalization. Compared to non-ICU hospitalized patients, the adjusted treated mental disorder prevalence in ICU patients was lower prior to hospitalization (1-year APR 0.94, 95% CI 0.92–0.97, p < 0.0001; 5-year APR 0.99, 95% CI 0.98–1.00, p = 0.1), but higher following discharge (1-year APR 1.08, 95% CI 1.05–1.11, p < 0.0001, 5-year APR 1.03, 95% CI 1.01–1.05, p < 0.0001). A high proportion of ICU patients received antidepressant, anxiolytic and sedative-hypnotic prescriptions before and after their hospitalization. In multivariable analyses, ICU exposure was associated with an increase in mood, anxiety and psychotic disorders, and sedative-hypnotics use (p < 0.0001 for all Time × Group interactions). Conclusions During the 5 years after admission to ICU, there is a significant increase in treated prevalence of mental disorders and psychotropic medication use compared to the 5 years prior to ICU and compared to general population and hospital cohorts. Prevention and intervention programs that identify and treat mental disorders among survivors of critical illness warrant further study.

The consistently observed male predominance of patients in intensive care units (ICUs) has raised concerns about gender-based disparities in ICU access. Comparing rates of ICU admission requires choosing a normalizing factor (denominator), and the denominator usually used to compare such rates between subpopulations is the size of those subpopulations. However, the appropriate denominator is the number of people whose medical condition warranted ICU care. We devised an estimate of the number of critically ill people in the general population, and used it to compare rates of ICU admission by gender and income. This population-based, retrospective analysis included all adults in the Canadian province of Manitoba, 2004–2015. We created an estimate for the number of critically ill people who warrant ICU care, and used it as the denominator to generate critical illness-normalized rates of ICU admission. These were compared to the usual population-normalized rates of ICU care. Men outnumbered women in ICUs for all age groups; population-normalized male:female rate ratios significantly exceed 0 for every age group, ranging from 1.15 to 2.10. Using critical-illness normalized rates, this male predominance largely disappeared; critically ill men and women aged 45–74 years were admitted in equivalent proportions (critical-illness normalized rate ratios 0.96–1.01). While population-normalized rates of ICU care were higher in lower income strata (p < 0.001), the gradient for critical illness-based rates was reversed (p < 0.001). Across a 30-year adult age span, the male predominance of ICU patients was accounted for by higher estimated rates of critical illness among men. People in lower income strata had lower critical-illness normalized rates of ICU admission. Our methods highlight that correct inferences about access to healthcare require calculating rates using denominators appropriate for this purpose.

Objective: To compare methods of characterizing intensive care unit (ICU) bed use and estimate the number of beds needed.Study Setting: Three geographic regions in the Canadian province of Manitoba.Study Design: Retrospective analysis of population‐based data from April 1, 2000, to March 31, 2007.Methods: We compared three methods to estimateICUbed requirements. Method 1 analyzed yearly patient‐days. Methods 2 and 3 analyzed day‐to‐day fluctuations in patient census; these differed by whether each hospital needed to independently fulfill its own demand or this resource was shared across hospitals.Principal Findings: Three main findings were as follows: (1) estimates based on yearly average usage generally underestimated the number of beds needed compared to analysis of fluctuations in census, especially in the smaller regions where underestimation ranged 25–58 percent; (2) 4–29 percent fewer beds were needed if it was acceptable for demand to exceed supply 18 days/year, versus 4 days/year; and (3) 13–36 percent fewer beds were needed if hospitals within a region could effectively shareICUbeds.Conclusions: Compared to using yearly averages, analyzing day‐to‐day fluctuations in patient census gives a more accurate picture ofICUbed use. Failing to provide adequate “surge capacity” can lead to demand that frequently and severely exceeds supply.

Prior studies of patients leaving hospital against medical advice (AMA) have been limited by not being population-based or assessing only one type of patient.

Introduction: Epidemiologic assessment of critically ill people in Intensive Care Units (ICUs) is needed to ensure the health care system can meet current and future needs. However, few such studies have been published. Methods: Population-based analysis of all adult ICU care in the Canadian province of Manitoba, 1999 to 2007, using administrative data. We calculated age-adjusted rates and trends of ICU care, overall and subdivided by age, sex and income. Results: In 2007, Manitoba had a population of 1.2 million, 118 ICU beds in 21 ICUs, for 9.8 beds per 100,000 population. Approximately 0.72% of men and 0.47% of women were admitted to ICUs yearly. The age-adjusted, male:female rate ratio was 1.75 (95% CI 1.64 to 1.88). Mean age was 64.5 ± 16.4 years. Rates rose rapidly after age 40, peaked at age 75 to 80, and declined for the oldest age groups. Rates were higher among residents of lower income areas, for example declining from 7.9 to 4.4 per 100,000 population from the poorest to the wealthiest income quintiles (p <0.0001). Rates of ICU admission slowly declined over time, while cumulative yearly ICU bed-days slowly rose; changes were age-dependent, with faster declines in admission rates with older age. There was a high rate of recidivism; 16% of ICU patients had received ICU care previously. Conclusions: These temporal trends in ICU admission rates and cumulative bed-days used have significant implications for health system planning. The differences by age, sex and socioeconomic status, and the high rate of recidivism require further research to clarify their causes, and to devise strategies for reducing critical illness in high-risk groups.