Respiratory Sequential Organ Failure Assessment Research Articles

Prognostic Accuracy of SpO2-based Respiratory Sequential Organ Failure Assessment for Predicting In-hospital Mortality.

In this study we aimed to investigate the prognostic accuracy for predicting in-hospital mortality using respiratory Sequential Organ Failure Assessment (SOFA) scores by the conventional method of missing-value imputation with normal partial pressure of oxygen (PaO2)- and oxygen saturation (SpO2)-based estimation methods. This was a single-center, retrospective cohort study of patients with suspected infection in the emergency department. The primary outcome was in-hospital mortality. We compared the area under the receiver operating characteristics curve (AUROC) and calibration results of the conventional method (normal value imputation for missing PaO2) and six SpO2-based methods: using methods A, B, PaO2 is estimated by dividing SpO2 by a scale; with methods C and D, PaO2 was estimated by a mathematical model from a previous study; with methods E, F, respiratory SOFA scores was estimated by SpO2 thresholds and respiratory support use; with methods A, C, E are SpO2-based estimation for all PaO2 values, while methods B, D, F use such estimation only for missing PaO2 values. Among the 15,119 patients included in the study, the in-hospital mortality rate was 4.9%. The missing PaO2was 56.0%. The calibration plots were similar among all methods. Each method yielded AUROCs that ranged from 0.735-0.772. The AUROC for the conventional method was 0.755 (95% confidence interval [CI] 0.736-0.773). The AUROC for method C (0.772; 95% CI 0.754-0.790) was higher than that of the conventional method, which was an SpO2-based estimation for all PaO2 values. The AUROC for total SOFA score from method E (0.815; 95% CI 0.800-0.831) was higher than that from the conventional method (0.806; 95% CI 0.790-0.822), in which respiratory SOFA was calculated by the predefined SpO2 cut-offs and oxygen support. In non-ICU settings, respiratory SOFA scores estimated by SpO2 might have acceptable prognostic accuracy for predicting in-hospital mortality. Our results suggest that SpO2-based respiratory SOFA score calculation might be an alternative for evaluating respiratory organ failure in the ED and clinical research settings.

Intestinal injury in cardiac arrest is associated with multiple organ dysfunction: A prospective cohort study

BackgroundThe impact of intestinal injury in cardiac arrest is not established. The first aim of this study was to assess associations between clinical characteristics in out-of-hospital cardiac arrest (OHCA) and a biomarker for intestinal injury, Intestinal Fatty Acid Binding Protein (IFABP). The second aim was to assess associations between IFABP and multiple organ dysfunction and 30-day mortality. MethodsWe measured plasma IFABP in 50 patients at admission to intensive care unit (ICU) after OHCA. Demographic and clinical variables were analysed by stratifying patients on median IFABP, and by linear regression. We compared Sequential Organ Failure Assessment (SOFA) score, haemodynamic variables, and clinical-chemistry tests at day two between the “high” and “low” IFABP groups. Logistic regression was applied to assess factors associated with 30-day mortality. ResultsSeveral markers of whole body ischaemia correlated with intestinal injury. Duration of arrest and lactate serum concentrations contributed to elevated IFABP in a multivariable model (p < 0.01 and p = 0.04, respectively). At day two, all seven patients who had died were in the “high” IFABP group, and all six patients who had been transferred to ward were in the “low” group. Of patients still treated in the ICU, the “high” group had higher total, renal and respiratory SOFA score (p < 0.01) and included all patients receiving inotropic drugs. IFABP predicted mortality (OR 16.9 per standard deviation increase, p = 0.04). ConclusionCardiac arrest duration and lactate serum concentrations were risk factors for intestinal injury. High levels of IFABP at admission were associated with multiple organ dysfunction and mortality.Trial registration: ClinicalTrials.gov: NCT02648061.

Survival and analysis of prognostic factors for severe burn patients with inhalation injury: based on the respiratory SOFA score

BackgroundIt is important to determine the severity of inhalation injury in severely burned patients. The oxygenation index PaO2/FiO2(PF) ratio is a key clinical indicator of inhalation injury. Sequential organ failure assessment (SOFA) is developed to assess the acute incidence of critical illness in the population. We hope to provide an assessment of survival or prognostic factor for severely burned patients with inhalation injury based on the respiratory SOFA score.MethodsThis is a retrospective cohort study of all admissions to Department of Burn and Plastic Surgery at West China Hospital of Sichuan University from July 2010 to March 2021. Data was analyzed using Cox regression models to determine significant predictors of mortality. Survival analysis with time to death event was performed using the Kaplan–Meier survival curve with the log-rank test. All potential risk factors were considered independent variables, while survival was considered the risk dependent variable.ResultsOne hundred eighteen severe burn patients with inhalation injury who met the inclusion and exclusion criteria were admitted, including men accounted for 76.3%. The mean age and length of stay were 45.9 (14.8) years and 44.3 (38.4) days. Flame burns are the main etiology of burn (74.6%). Patients with the respiratory SOFA score greater than 2 have undergone mechanical ventilation. Univariate Kaplan–Meier analysis identified age, total body surface area burned (TBSA), ICU admission and the respiratory SOFA score as significant factors on survival. Cox regression analysis showed that TBSA and the respiratory SOFA score were associated with patient survival (p < 0.001). In some patients with severe burns and inhalation damage, the survival probability drops to less than 10% (TBSA greater than 80%: 8.9% and respiratory SOFA score greater than 2: 5.6%). This study statistically found that the TBSA with the respiratory SOFA score model (AUROC: 0.955) and the rBaux score (AUROC: 0.927) had similar predictive value (p = 0.175).ConclusionThe study indicates that a high respiratory system SOFA score was identified as a strong and independent predictor of severely burned patients with inhalation injury during hospitalization. When combined with TBSA, the respiratory SOFA scores can dynamically assess the severity of the patient's lung injury and improve the predictive level.

A Method to Explore Variations of Ventilator-Associated Event Surveillance Definitions in Large Critical Care Databases in the United States.

Retrospective, multicenter, cross-sectional analysis. Three hundred forty critical care units across 209 hospitals, comprising 261,910 patients in both the electronic Intensive Care Unit Clinical Research Database and Medical Information Mart for Intensive Care III databases. A total of 14,517 patients undergoing MV for 4 or more days. We designed a statistical analysis framework, complemented by a custom interactive data visualization tool to depict how changes to the VAC surveillance definition alter its prognostic performance, comparing patients with and without VAC. This methodology and tool enable comparison of three clinical outcomes (hospital mortality, hospital length-of-stay, and ICU length-of-stay) and provide the option to stratify patients by six criteria in two categories: patient population (dataset and ICU type) and clinical features (minimum Fio2, minimum positive end-expiratory pressure, early/late VAC, and worst first-day respiratory Sequential Organ Failure Assessment score). Patient population outcomes were depicted by heatmaps with mortality odds ratios. In parallel, outcomes from ventilation setting variations and clinical features were depicted with Kaplan-Meier survival curves. We developed a method to examine VAC using information extracted from large electronic health record databases. Building upon this framework, we developed an interactive tool to visualize and quantify the implications of variations in the VAC surveillance definition in different populations, across time and critical care settings. Data for patients with and without VAC was used to illustrate the effect of the application of this method and visualization tool.

Personalized risk predictor for acute cellular rejection in lung transplant using soluble CD31

We evaluated the contribution of artificial intelligence in predicting the risk of acute cellular rejection (ACR) using early plasma levels of soluble CD31 (sCD31) in combination with recipient haematosis, which was measured by the ratio of arterial oxygen partial pressure to fractional oxygen inspired (PaO2/FiO2) and respiratory SOFA (Sequential Organ Failure Assessment) within 3 days of lung transplantation (LTx). CD31 is expressed on endothelial cells, leukocytes and platelets and acts as a “peace-maker” at the blood/vessel interface. Upon nonspecific activation, CD31 can be cleaved, released, and detected in the plasma (sCD31). The study included 40 lung transplant recipients, seven (17.5%) of whom experienced ACR. We modelled the plasma levels of sCD31 as a nonlinear dependent variable of the PaO2/FiO2 and respiratory SOFA over time using multivariate and multimodal models. A deep convolutional network classified the time series models of each individual associated with the risk of ACR to each individual in the cohort.

Efficacy of Losartan in Hospitalized Patients With COVID-19–Induced Lung Injury

SARS-CoV-2 viral entry may disrupt angiotensin II (AII) homeostasis, contributing to COVID-19 induced lung injury. AII type 1 receptor blockade mitigates lung injury in preclinical models, although data in humans with COVID-19 remain mixed. To test the efficacy of losartan to reduce lung injury in hospitalized patients with COVID-19. This blinded, placebo-controlled randomized clinical trial was conducted in 13 hospitals in the United States from April 2020 to February 2021. Hospitalized patients with COVID-19 and a respiratory sequential organ failure assessment score of at least 1 and not already using a renin-angiotensin-aldosterone system (RAAS) inhibitor were eligible for participation. Data were analyzed from April 19 to August 24, 2021. Losartan 50 mg orally twice daily vs equivalent placebo for 10 days or until hospital discharge. The primary outcome was the imputed arterial partial pressure of oxygen to fraction of inspired oxygen (Pao2:Fio2) ratio at 7 days. Secondary outcomes included ordinal COVID-19 severity; days without supplemental o2, ventilation, or vasopressors; and mortality. Losartan pharmacokinetics and RAAS components (AII, angiotensin-[1-7] and angiotensin-converting enzymes 1 and 2)] were measured in a subgroup of participants. A total of 205 participants (mean [SD] age, 55.2 [15.7] years; 123 [60.0%] men) were randomized, with 101 participants assigned to losartan and 104 participants assigned to placebo. Compared with placebo, losartan did not significantly affect Pao2:Fio2 ratio at 7 days (difference, -24.8 [95%, -55.6 to 6.1]; P = .12). Compared with placebo, losartan did not improve any secondary clinical outcomes and led to fewer vasopressor-free days than placebo (median [IQR], 9.4 [9.1-9.8] vasopressor-free days vs 8.7 [8.2-9.3] vasopressor-free days). This randomized clinical trial found that initiation of orally administered losartan to hospitalized patients with COVID-19 and acute lung injury did not improve Pao2:Fio2 ratio at 7 days. These data may have implications for ongoing clinical trials. ClinicalTrials.gov Identifier: NCT04312009.

A Comparative Analysis of the Respiratory Subscore of the Sequential Organ Failure Assessment Scoring System.

Rationale: The Sequential Organ Failure Assessment (SOFA) tool is a commonly used measure of illness severity. Calculation of the respiratory subscore of SOFA is frequently limited by missing arterial oxygen pressure (PaO2) data. Although missing PaO2 data are commonly replaced with normal values, the performance of different methods of substituting PaO2 for SOFA calculation is unclear. Objectives: The study objective was to compare the performance of different substitution strategies for missing PaO2 data for SOFA score calculation. Methods: This retrospective cohort study was performed using the Weill Cornell Critical Care Database for Advanced Research from a tertiary care hospital in the United States. All adult patients admitted to an intensive care unit (ICU) from 2011 to 2019 with an available respiratory SOFA score were included. We analyzed the availability of the PaO2/fraction of inspired oxygen (FiO2) ratio on the first day of ICU admission. In those without a PaO2/FiO2 ratio available, the ratio of oxygen saturation as measured by pulse oximetry to FiO2 was used to calculate a respiratory SOFA subscore according to four methods (linear substitution [Rice], nonlinear substitution [Severinghaus], modified respiratory SOFA, and multiple imputation by chained equations [MICE]) as well as the missing-as-normal technique. We then compared how well the different total SOFA scores discriminated in-hospital mortality. We performed several subgroup and sensitivity analyses. Results: We identified 35,260 unique visits, of which 9,172 included predominant respiratory failure. PaO2 data were available for 14,939 (47%). The area under the receiver operating characteristic curve for each substitution technique for discriminating in-hospital mortality was higher than that for the missing-as-normal technique (0.78 [0.77-0.79]) in all analyses (modified, 0.80 [0.79-0.81]; Rice, 0.80 [0.79-0.81]; Severinghaus, 0.80 [0.79-0.81]; and MICE, 0.80 [0.79-0.81]) (P < 0.01). Each substitution method had a higher accuracy for discriminating in-hospital mortality (MICE, 0.67; Rice, 0.67; modified, 0.66; and Severinghaus, 0.66) than the missing-as-normal technique. Model calibration for in-hospital mortality was less precise for the missing-as-normal technique than for the other substitution techniques at the lower range of SOFA and among the subgroups. Conclusions: Using physiologic and statistical substitution methods improved the total SOFA score's ability to discriminate mortality compared with the missing-as-normal technique. Treating missing data as normal may result in underreporting the severity of illness compared with using substitution. The simplicity of a direct oxygen saturation as measured by pulse oximetry/FiO2 ratio-modified SOFA technique makes it an attractive choice for electronic health record-based research. This knowledge can inform comparisons of severity of illness across studies that used different techniques.

Predictive value of individual Sequential Organ Failure Assessment sub-scores for mortality in the cardiac intensive care unit.

PurposeTo determine the impact of Sequential Organ Failure Assessment (SOFA) organ sub-scores for hospital mortality risk stratification in a contemporary cardiac intensive care unit (CICU) population.Materials and methodsAdult CICU admissions between January 1, 2007 and December 31, 2015 were reviewed. The SOFA score and organ sub-scores were calculated on CICU day 1; patients with missing SOFA sub-score data were excluded. Discrimination for hospital mortality was assessed using area under the receiver-operator characteristic curve (AUROC) values, followed by multivariable logistic regression.ResultsWe included 1214 patients with complete SOFA sub-score data. The mean age was 67 ± 16 years (38% female); all-cause hospital mortality was 26%. Day 1 SOFA score predicted hospital mortality with an AUROC of 0.72. Each SOFA organ sub-score predicted hospital mortality (all p <0.01), with AUROC values of 0.53 to 0.67. On multivariable analysis, only the cardiovascular, central nervous system, renal and respiratory SOFA sub-scores were associated with hospital mortality (all p <0.01). A simplified SOFA score containing the cardiovascular, central nervous system and renal sub-scores had an AUROC of 0.72.ConclusionsIn CICU patients with complete SOFA sub-score data, risk stratification for hospital mortality is determined primarily by the cardiovascular, central nervous system, renal and respiratory SOFA sub-scores.

Mobilization of Mechanically Ventilated Patients in Switzerland.

Growing evidence suggests that early mobilization benefits intensive care unit (ICU) patients. However, national practices and the culture of individual ICUs influence mobilization activities. In a 1-day, Swiss point prevalence study conducted in 35 ICUs (representing 45% of all ICUs), the highest level of mobilization for mechanically ventilated patients was characterized using the validated ICU Mobility Scale, along with data collection for potential safety events and mobilization barriers. Among 161 mechanically ventilated patients, a total of 33% (n = 53) had active mobilization, with walking achieved by only 2% (n = 4). More severe organ failure was associated with lower mobilization (respiratory Sequential Organ Failure Assessment score: P = .037, cardiac: P = .008, neurology: P < .001). Barriers to mobilization were reported in 71% (n = 115), with deep sedation significantly higher among patients receiving passive versus active mobilization (14% vs 0%, P = .005). Potential safety events occurred in 20% (n = 33) of patients without significant differences between passive and active mobilization. Availability of physiotherapists and appropriate equipment were not reported barriers. Mobilization during mechanical ventilation occurred infrequently with greater organ failure associated with lower mobilization. Addressing the identified modifiable barriers via structured efforts to achieve multidisciplinary culture change is essential to decrease the common use of bed rest in Swiss ICUs.

Daily Lowest Hemoglobin and Risk of Organ Dysfunctions in Critically Ill Patients.

To determine the association between hemoglobin levels and the daily risk of individual organ dysfunctions in critically ill patients. Post hoc analysis of prospectively collected data. Vanderbilt University Medical Center and Saint Thomas Hospital Medical and Surgical ICUs. Medical and surgical ICU patients admitted with respiratory failure or shock. Baseline demographic data, and detailed in-ICU and hospital data, including daily lowest hemoglobin, were collected up to hospital day 30. We assessed patients daily for brain dysfunction (delirium, using Confusion Assessment Method for ICU), for renal and respiratory dysfunction (using the ordinal renal and respiratory Sequential Organ Failure Assessment score), and for ICU mortality. Associations between the lowest hemoglobin on a given day and organ dysfunctions the following day were assessed using multivariable regressions, adjusting for age, Acute Physiology and Chronic Health Evaluation II score, Charlson comorbidity index, Framingham Stroke Risk Profile, ICU day, ICU type, sepsis, and current organ dysfunction status. A sensitivity analysis further adjusted for daily transfusions and fluid balance in a subset of our patients. We enrolled 821 patients with a median (interquartile range) age of 61 (51-71) years, Acute Physiology and Chronic Health Evaluation II score of 25 (19-31), and hemoglobin level of 10.0 (9.0-11.1) g/dL. There was no evidence of an association between lowest daily hemoglobin and brain dysfunction (p = 0.69 for delirium), renal dysfunction (p = 0.30), or ICU mortality (p = 0.95). The lowest hemoglobin on a given day was significantly associated with the respiratory Sequential Organ Failure Assessment score the following day; for each increasing hemoglobin unit, the odds of worsened respiratory Sequential Organ Failure Assessment score the following day were decreased by 36% (OR, 0.64; 95% CI, 0.53-0.77; p < 0.001). The sensitivity analysis including daily transfusions and fluid balance (in a subset of 518 patients) did not qualitatively change any of these associations. In this study in ICU patients, lower hemoglobin was associated with a higher probability of worsening respiratory dysfunction scores the following day. There was no evidence of association between hemoglobin and brain or renal dysfunction, or ICU mortality. The possible differential effects of anemia on organ dysfunctions seen in this hypothesis-generating study will have to be studied in a larger prospective study before any alterations to present restrictive transfusion guidelines can be recommended.

Innate Immune Function and Organ Failure Recovery in Adults With Sepsis.

Sepsis stimulates pro- and anti-inflammatory immune responses. The innate immune response is critical to organ injury repair. We tested for an association between innate immune function and organ function recovery in a prospective cohort of immune-competent adults with sepsis. We conducted a prospective observational cohort study enrolling immune-competent adults with sepsis. We tested innate immune function by quantification of lipopolysaccharide (LPS)-stimulated tumor necrosis factor (TNF) α production capacity in whole blood samples on hospital days 1, 4, and 6. The primary outcome was organ function recovery on day 4 defined as a 4-point decrease in the composite cardiovascular and respiratory Sequential Organ Failure Assessment (SOFA) score components or a SOFA score ≤2. Patients with sepsis who recovered organ function by day 4 (n = 11) had similar baseline characteristics when compared to those with ongoing organ failure (n = 13). Tumor necrosis factor α production capacity was similar between the 2 groups on hospital days 1 and 4 but significantly different on day 6. Patients who regained organ function recovery had significantly higher TNF-α production capacity on day 6 ( P = .01), which persisted after adjustment for age, Acute Physiology and Chronic Health Evaluation III score, and steroid administration ( P = .03). There was no difference in TNF-α production capacity over time in those who survived to hospital discharge versus nonsurvivors. Increasing TNF-α production capacity is associated with improved organ failure recovery. Further studies are needed to evaluate a causal association between innate immune suppression and organ failure recovery as well as predictive accuracy for hospital survival. Impaired TNF-α production as a marker of sepsis-associated innate immune dysfunction may be a feasible target for immune stimulation to decrease time to organ failure recovery.

Comparison of alternating pressure mattresses and overlays for prevention of pressure ulcers in ventilated intensive care patients: a quasi‐experimental study

To compare the effectiveness of alternating pressure air mattresses vs. overlays to prevent pressure ulcers in mechanically ventilated patients in intensive care units. Pressure ulcers prevention is an important issue in the nursing of critically ill patients. It is not clear whether alternating pressure air mattresses are more effective than overlays to prevent pressure ulcers. Prospective quasi-experimental study. A prospective quasi-experimental study was conducted among patients in the medical-surgery intensive care unit of a university hospital on mechanical ventilation ≥24hours during two time periods (2001 and 2006). Overlays were used in 2001 and mattresses in 2006. Primary outcome was the incidence of pressure ulcers grade ≥II (according to the European Pressure Ulcer Advisory Panel) during intensive care unit stay. The study included 221 patients (116 in 2001 and 105 in 2006). Baseline characteristics were similar between groups except for a higher Acute Physiology and Chronic Health Evaluation III score, total and first-day respiratory Sequential Organ Failure Assessment Score on day 1 in overlay group. There was significantly lower incidence density in the mattress vs. overlay group (12·41 cases/1000days vs. 18·67 cases/1000days of stay). The multivariate analyses showed the use of the mattress to be a protective factor against pressure ulcer onset. This quasi-experiment study that alternative pressure air mattresses were more effective than alternating pressure air overlays in preventing pressure ulcers in mechanically ventilated critical care patients.

Multiple Organ Dysfunction After Return of Spontaneous Circulation in Postcardiac Arrest Syndrome

Recent guidelines for the treatment of postcardiac arrest syndrome recommend optimization of vital organ perfusion after return of spontaneous circulation to reduce the risk of postresuscitation multiple organ injury. However, the prevalence of extracerebral multiple organ dysfunction in postcardiac arrest patients and its association with in-hospital mortality remain unclear. Single-center, prospective observational study. Urban academic medical center. Postcardiac arrest patients. Inclusion criteria were as follows: age older than 17 years, nontrauma cardiac arrest, and comatose after return of spontaneous circulation. We prospectively captured all extracerebral components of the Sequential Organ Failure Assessment score over the first 72 hours after return of spontaneous circulation. The primary outcome measure was in-hospital mortality. We used multivariate logistic regression to determine if multiple organ dysfunction (defined as the highest extracerebral Sequential Organ Failure Assessment score) was an independent predictor of death, after adjustment for the presence of cerebral injury (defined as not following commands at any point over 0-72 hr). We enrolled 203 postcardiac arrest patients; 96% had some degree of extracerebral organ dysfunction and 66% had severe dysfunction in two or more extracerebral organ systems. The most common extracerebral organ failures were cardiovascular (i.e., vasopressor dependence) and respiratory (i.e., oxygenation impairment). The highest extracerebral Sequential Organ Failure Assessment score over 72 hours had an independent association with in-hospital mortality (odds ratio 1.95 [95% CI, 1.15-3.29]). Of the individual organ systems, only the cardiovascular and respiratory Sequential Organ Failure Assessment scores had an independent association with in-hospital mortality. The results of this study support the hypothesis that extracerebral organ dysfunction is common and associated with mortality in postcardiac arrest syndrome. This association appears to be driven by postresuscitation hemodynamic dysfunction and oxygenation impairment. Further research is needed to determine the value of hemodynamic and oxygenation optimization as a part of treatment strategies for patients with postcardiac arrest syndrome.

Is worsening multiple organ failure the cause of death in patients with severe sepsis?*

Although the mortality of severe sepsis is easily quantified, the actual cause and timing of death from severe sepsis are less defined. We used the INDEPTH (International Integrated Database for the Evaluation of Severe Sepsis and Drotrecogin alfa activated) database to investigate the reported cause of death in patients with severe sepsis. Retrospective database analysis. Data from 4459 patients with severe sepsis (drotrecogin alfa activated, n = 3228; placebo, n = 1231) included in five clinical trials conducted in tertiary care institutions in 28 countries. We examined the cause of death and the pattern of Sequential Organ Failure Assessment scores near the time of death. We also evaluated the time course of biomarker levels at this late stage. A total of 1201 (27.0%) patients died during the 28-day study period. The main causes of death were as follows: sepsis-associated multiple organ failure (43.1%), refractory septic shock (22.6%), and respiratory failure (13.0%). There were no significant differences in the distributions of cause of death between drotrecogin alfa activated and placebo patients, so that all patients were combined for analysis. The mean cardiovascular Sequential Organ Failure Assessment score increased from 2.4, 4 days before death, to 2.9, 1 day before death, and the mean respiratory Sequential Organ Failure Assessment score increased from 2.6, 4 days before death, to 2.9, 1 day before death. The increase in these individual Sequential Organ Failure Assessment scores was more prominent in patients who died early (day 0-5). Protein C levels decreased and interleukin-6 levels increased in the days before death. Patients with severe sepsis typically die of multiple organ failure, refractory shock, or respiratory failure. Persistent, more than worsening, organ failure is the more common pattern before death.

Pressure ulcer incidence and risk factors in ventilated intensive care patients

Purpose The aim of this study was to determine the incidence of pressure ulcers (PUs) in ventilated patients in all intensive care units (ICUs) in Granada (Spain) and identify risk factors for their development. Materials and Methods A prospective cohort study in 9 medical-surgical ICUs was conducted. Two hundred ninety-nine patients with more than 24 hours on mechanical ventilation (MV) were enrolled during 2 periods in a 5-month study. Pressure ulcers of patients were measured according to the European Pressure Ulcer Advisory Panel. Results Of the 299 patients initially enrolled, 47 (16%) developed PUs of at least grade II severity. The incidence density of PUs was 13.4 cases per 1000 patient-days of ICU stay and 19.6 cases per 1000 patient-days on MV. Logistic regression identified first-day respiratory sequential organ failure assessment (odds ratio [OR], 1.56; 95% confidence interval [CI], 1.026-2.360; P = .037), fourth-day cardiovascular sequential organ failure assessment (OR, 1.33; 95% CI, 1.066-1.664; P = .012), age (OR, 1.042; 95% CI, 1.013-1.072; P = .004), winter period (OR, 4.60; 95% CI, 1.99-10.59; P < .001), and length of MV before PUs (OR, 1.042; 95% CI, 1.005-1.080; P = .024) as significant independent predictors of PU development. Conclusions Among other factors previously known in ventilated patients, duration of MV and winter period were identified as risk factors for PUs.

Derivation and validation of Spo2/Fio2 ratio to impute for Pao2/Fio2 ratio in the respiratory component of the Sequential Organ Failure Assessment score*

The Sequential Organ Failure Assessment (SOFA) score is validated to measure severity of organ dysfunction in critically ill patients. However, in some practice settings, daily arterial blood gas data required to calculate the respiratory component of the SOFA score are often unavailable. The objectives of this study were to derive Spo2/Fio2 (SF) ratio correlations with the Pao2/Fio2 (PF) ratio to calculate the respiratory parameter of the SOFA score, and to validate the respiratory SOFA obtained using SF ratios against clinical outcomes. We obtained matched measurements of Spo2 and Pao2 from two populations: group 1-patients undergoing general anesthesia and group 2-patients from the acute respiratory distress syndrome network-low-vs. high-tidal volume for the acute respiratory management of acute respiratory distress syndrome database. Using a linear regression model, we first determined SF ratios corresponding to PF ratios of 100, 200, 300, and 400. Second, we evaluated the contribution of positive end-expiratory pressure (PEEP) on the relationship between SF and PF, for patients on PEEP in centimeters of water (cm H2O) of <8, 8-12, and >12. Third, we calculated the SOFA scores in a separate cohort of intensive care unit patients using the derived SF ratios and validated them against clinical outcomes. The total SOFA scores calculated using SF ratios and PF ratios were highly correlated (Spearman's rho 0.85, p < 0.001) in all patients and in the three stratified PEEP categories (<8 cm H2O, Spearman's rho 0.87, p < 0.001; PEEP 8-12 cm H20, Spearman's rho 0.85, p < 0.001; PEEP >12 cm H2O, Spearman's rho 0.85, p < 0.001). The respiratory SOFA scores based on SF ratios and PF ratios correlated similarly with intensive care unit length of stay and ventilator-free days, when validated in a cohort of critically ill patients. The total and respiratory SOFA scores obtained with imputed SF values correlate with the corresponding SOFA score using PF ratios. Both the derived and original respiratory SOFA scores similarly predict outcomes.

Organ system dysfunction following open cholecystectomy for acute acalculous cholecystitis in critically ill patients

Acute acalculous cholecystitis (AAC) refers to cholecystitis without gallstones and is a serious complication of critical illness. We describe the time course of organ system dysfunction associated with cholecystectomy in critically ill patients with AAC. The data of all intensive care unit (ICU) patients who had operatively confirmed AAC during their ICU stay between 2003 and 2004 were analyzed. Patients who also had other intra-abdominal pathologies were excluded. The Sequential Organ Failure Assessment (SOFA) scores were recorded 3 days before, on the day of operation and on the first, second, third and seventh post-operative day after cholecystectomy. The impact of open cholecystectomy on organ dysfunction was evaluated on the basis of the change in the total and individual organ SOFA scores. Twenty-four patients underwent open cholecystectomy for AAC with no other intra-abdominal pathology. Sepsis was the most common admission diagnosis, followed by cardiovascular surgery. The mean (standard deviation, SD) Acute Physiology and Chronic Health Evaluation (APACHE II), Simplified Acute Physiology Score (SAPS) II and SOFA scores on admission were 24.7 (5.8), 44.3 (12.3) and 9.4 (3.2), respectively. The median (25th, 75th percentiles) total SOFA score 3 days before cholecystectomy was 7.5 (1.3, 8.0), which increased to 10.5 (8.3, 13.0) (P < 0.0001) by the day of cholecystectomy, indicating developing multiorgan dysfunction. After the operation, the score decreased to 5.5 (3.3, 10.8) (P = 0.004) by the seventh post-operative day. The change was most obvious in cardiovascular and respiratory SOFA scores. AAC is associated with multiorgan dysfunction in critically ill patients. Open cholecystectomy seems to alter the course of multiorgan dysfunction in these patients.