Allogeneic Blood Transfusion and Risk of Postoperative Complications in Patients with Mild and Moderate Anemia of Any Cause? A Retrospective Cohort Study in Total Revision Hip Surgery

Introduction

Patients undergoing revision total hip surgery (RTHS) have a high prevalence of mild and moderate preoperative anemia, associated with adverse outcomes. The aim of this study was to investigate the association of perioperative allogeneic blood transfusions (ABT) and postoperative complications in preoperatively mild compared to moderate anemic patients undergoing RTHS who did not receive a diagnostic anemia workup and treatment before surgery.

Methods

We included 1,765 patients between 2007 and 2019 at a university hospital. Patients were categorized according to their severity of anemia using the WHO criteria of mild, moderate, and severe anemia in the first Hb level of the case. Patients were grouped as having received no ABT, 1-2 units of ABT, or more than 2 units of ABT. Need for intraoperative ABT was assessed in accordance with institutional standards. Primary endpoint was the compound incidence of postoperative complications. Secondary outcomes included major/minor complications and length of hospital and ICU stay.

Results

Of the 1,765 patients, 31.0% were anemic of any cause before surgery. Transfusion rates were 81% in anemic patients and 41.2% in nonanemic patients. The adjusted risks for compound postoperative complication were significantly higher in patients with moderate anemia (OR 4.88, 95% CI: 1.54-13.15, p = 0.003) but not for patients with mild anemia (OR 1.93, 95% CI: 0.85-3.94, p < 0.090). Perioperative ABT was associated with significantly higher risks for complications in nonanemic patients and showed an increased risk for complications in all anemic patients. In RTHS, perioperative ABT as a treatment for moderate preoperative anemia of any cause was associated with a negative compound effect on postoperative complications, compared to anemia or ABT alone.

Discussion

ABT is associated with adverse outcomes of patients with moderate preoperative anemia before RTHS. For this reason, medical treatment of moderate preoperative anemia may be considered.

[The costs of preoperative anemia in hip joint revision surgery]

BACKGROUND

Anemia is highly prevalent in patients before hip joint revision surgery (HJRS) and is associated with an increased complication rate. This paper is the first to investigate costs, real diagnosis-related group (DRG) revenues and case coverage of preoperative anemia in elective HJRS.

METHODS

Medical data, transfusions, costs, and revenues of all patients undergoing HJRS at two campuses of the Charité -Universitätsmedizin Berlin between 2010 and 2017 were used for subgroup analyses and linear regressions.

RESULTS

Of 1187 patients included 354 (29.8%) showed preoperative anemia. A total of 565 (47.6%) patients were transfused with a clear predominance of anemic patients (72.6% vs. 37.0%, p < 0.001). Costs (12,318€ [9027;20,044€] vs. 8948€ [7501;11,339€], p < 0.001) and revenues (11,788€ [8992;16,298€] vs. 9611€ [8332;10,719€], p < 0.001) were higher for preoperatively anemic patients and the coverage was deficient (-1170€ [-4467;1238€] vs. 591€ [-1441;2103€], p < 0.001). In anemic patients, case contribution margins decreased with increasing transfusion rates (p ≤ 0.001). Comorbidities had no significant economic impact.

CONCLUSION

Preoperative anemia and perioperative transfusions in HJRS are associated with increased treatment costs and a financial undercoverage for healthcare providers and health insurance companies. Concepts for the treatment of preoperative anemia (e.g. patient blood management) could reduce treatment costs in the medium term.

Pleural effusions are associated with adverse outcomes after cardiac surgery: a propensity-matched analysis

BACKGROUND

Pleural effusions commonly occur in patients recovering from cardiac surgery; however, the impact on outcomes is not well characterized. The purpose of this study is to characterize the clinical outcomes of cardiac surgery patients with pleural effusion.

METHODS

All patients undergoing cardiac surgery between 2006 and 2019 at a tertiary care university hospital were included in this observational, cross-sectional analysis using propensity matching.

RESULTS

Of 11,037 patients that underwent cardiac surgery during the study period, 6461 (58.5%) had no pleural effusion (Group 0), 3322 (30.1%) had pleural effusion only (Group 1), and 1254 (11.4%) required at least one secondary drainage procedure after the index operation (Group 2). After propensity matching, the mortality of patients who underwent secondary drainage procedures was 6.1% higher than in Group 1 (p < 0.001). Intensive care unit (ICU) stay was longer for those with pleural effusions (18 [IQR 9-32] days in Group 2, 10 [IQR 6-17] days for Group 1, and 7 [IQR 4-11] days for Group 0, p < 0.001). Patients with pleural effusions had a higher incidence of hemodialysis (246 [20.0%] in Group 2, 137 [11.1%] in Group 1, 98 [7.98%] in Group 0), and a longer ventilation time in the ICU (57 [IQR 21.0-224.0] hours in Group 2, 25.0 [IQR 14.0-58.0] hours in Group 1, 16.0 [IQR 10.0-29.0] hours in Group 0).

CONCLUSION

Pleural effusions, especially those that require a secondary drainage procedure during recovery, are associated with significantly worse outcomes including increased mortality, longer length of stay, and higher complication rates. These insights may be of great interest to scientists, clinicians, and industry leaders alike to foster research into innovative methods for preventing and treating pleural effusions with the aim of improving outcomes for patients recovering from cardiac surgery.

Outcomes in Critically Ill Patients Sedated with Intravenous Lormetazepam or Midazolam: A Retrospective Cohort Study

The benzodiazepine, midazolam, is one of the most frequently used sedatives in intensive care medicine, but it has an unfavorable pharmacokinetic profile when continuously applied. As a consequence, patients are frequently prolonged and more deeply sedated than intended. Due to its distinct pharmacological features, including a cytochrome P450-independent metabolization, intravenous lormetazepam might be clinically advantageous compared to midazolam. In this retrospective cohort study, we compared patients who received either intravenous lormetazepam or midazolam with respect to their survival and sedation characteristics. The cohort included 3314 mechanically ventilated, critically ill patients that received one of the two drugs in a tertiary medical center in Germany between 2006 and 2018. A Cox proportional hazards model with mortality as outcome and APACHE II, age, gender, and admission mode as covariates revealed a hazard ratio of 1.75 [95% CI 1.46–2.09; p < 0.001] for in-hospital mortality associated with the use of midazolam. After additionally adjusting for sedation intensity, the HR became 1.04 [95% CI 0.83–1.31; p = 0.97]. Thus, we concluded that excessive sedation occurs more frequently in critically ill patients treated with midazolam than in patients treated with lormetazepam. These findings require further investigation in prospective trials to assess if lormetazepam, due to its ability to maintain light sedation, might be favorable over other benzodiazepines for sedation in the ICU.

Patient Monitoring Alarms in an Intensive Care Unit: Observational Study With Do-It-Yourself Instructions

BACKGROUND

As one of the most essential technical components of the intensive care unit (ICU), continuous monitoring of patients' vital parameters has significantly improved patient safety by alerting staff through an alarm when a parameter deviates from the normal range. However, the vast number of alarms regularly overwhelms staff and may induce alarm fatigue, a condition recently exacerbated by COVID-19 and potentially endangering patients.

OBJECTIVE

This study focused on providing a complete and repeatable analysis of the alarm data of an ICU's patient monitoring system. We aimed to develop do-it-yourself (DIY) instructions for technically versed ICU staff to analyze their monitoring data themselves, which is an essential element for developing efficient and effective alarm optimization strategies.

METHODS

This observational study was conducted using alarm log data extracted from the patient monitoring system of a 21-bed surgical ICU in 2019. DIY instructions were iteratively developed in informal interdisciplinary team meetings. The data analysis was grounded in a framework consisting of 5 dimensions, each with specific metrics: alarm load (eg, alarms per bed per day, alarm flood conditions, alarm per device and per criticality), avoidable alarms, (eg, the number of technical alarms), responsiveness and alarm handling (eg alarm duration), sensing (eg, usage of the alarm pause function), and exposure (eg, alarms per room type). Results were visualized using the R package ggplot2 to provide detailed insights into the ICU's alarm situation.

RESULTS

We developed 6 DIY instructions that should be followed iteratively step by step. Alarm load metrics should be (re)defined before alarm log data are collected and analyzed. Intuitive visualizations of the alarm metrics should be created next and presented to staff in order to help identify patterns in the alarm data for designing and implementing effective alarm management interventions. We provide the script we used for the data preparation and an R-Markdown file to create comprehensive alarm reports. The alarm load in the respective ICU was quantified by 152.5 (SD 42.2) alarms per bed per day on average and alarm flood conditions with, on average, 69.55 (SD 31.12) per day that both occurred mostly in the morning shifts. Most alarms were issued by the ventilator, invasive blood pressure device, and electrocardiogram (ie, high and low blood pressure, high respiratory rate, low heart rate). The exposure to alarms per bed per day was higher in single rooms (26%, mean 172.9/137.2 alarms per day per bed).

CONCLUSIONS

Analyzing ICU alarm log data provides valuable insights into the current alarm situation. Our results call for alarm management interventions that effectively reduce the number of alarms in order to ensure patient safety and ICU staff's work satisfaction. We hope our DIY instructions encourage others to follow suit in analyzing and publishing their ICU alarm data.

Epidural Anesthesia in Liver Surgery-A Propensity Score-Matched Analysis

OBJECTIVE

To assess the effects of epidural anesthesia (EA) on patients who underwent liver resection.

DESIGN

Secondary analysis of a prospective randomized controlled trial.

SETTING

This single-center study was conducted at an academic medical center.

METHODS

A subset of 110 1:1 propensity score-matched patients who underwent liver resection with and without EA were analyzed. Outcome measures were pain intensity ≥5 on a numeric rating scale (NRS) at rest and during movement on postoperative days 1-5, analyzed with logistic mixed-effects models, and postoperative complications according to the Clavien-Dindo classification, length of hospital stay (LOS), and one-year survival. One-year survival in the matched cohorts was compared using a frailty model.

RESULTS

EA patients were less likely to experience NRS ≥5 at rest (odds ratio = 0.06, 95% confidence interval [CI] = 0.01 to 0.28, P < 0.001). These findings were independent of age, sex, Charlson comorbidity index, baseline NRS, and surgical approach (open vs laparoscopic). The number and severity of postoperative complications and LOS were comparable between groups (P = 0.258, P > 0.999, and P = 0.467, respectively). Reduced mortality rates were seen in the EA group one year after surgery (9.1% vs 30.9%, hazard ratio = 0.32, 95% CI = 0.11 to 0.90, P = 0.031). No EA-related adverse events occurred. Earlier recovery of bowel function was seen in EA patients.

CONCLUSIONS

Patients with EA had better postoperative pain control and required fewer systemic opioids. Postoperative complications and LOS did not differ, although one-year survival was significantly improved in patients with EA. EA applied in liver surgery was effective and safe.

Hyperferritinemia in Critically Ill Patients

OBJECTIVE

Hyperferritinemia is frequently seen in critically ill patients. A rather rare though life-threatening condition related to severely elevated ferritin is hemophagocytic lymphohistiocytosis. We analyze ferritin levels to differentiate hemophagocytic lymphohistiocytosis from other causes of hyperferritinemia in a mixed cohort of critically ill patients.

DESIGN

Retrospective observational study.

SETTING

Adult surgical, anesthesiologic, and medical ICUs of a university hospital.

PATIENTS

Critical care patients (≥ 18 yr old) admitted to any of the adult ICUs at Charité - Universitätsmedizin Berlin between January 2006 and August 2018 with at least one ferritin value and hyperferritinemia (≥ 500 µg/L).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Patients were categorized into hemophagocytic lymphohistiocytosis, sepsis, septic shock, and other diagnoses. These were further categorized into 17 subgroups. Hemophagocytic lymphohistiocytosis diagnosis was based on Hemophagocytic Lymphohistiocytosis-2004 criteria and the HScore. Of 2,623 patients with hyperferritinemia, 40 were considered to have hemophagocytic lymphohistiocytosis (1.52%). Maximum ferritin levels were highest in hemophagocytic lymphohistiocytosis patients compared with all other disease groups (each p < 0.001). Sepsis and septic shock patients had higher maximum ferritin levels than patients with other diagnoses (each p < 0.001). A maximum ferritin value of 9,083 µg/L was at 92.5% sensitivity and 91.9% specificity for hemophagocytic lymphohistiocytosis (area under the curve, 0.963; 95% CI, 0.949-0.978). Of all subgroups with other diagnoses, maximum ferritin levels were highest in patients with varicella-zoster virus, hepatitis, or malaria (median, 1,935, 1,928, and 1,587 µg/L, respectively). Maximum ferritin levels were associated with increased in-hospital mortality (odds ratio, 1.518 per log µg/L [95% CI, 1.384-1.665 per log µg/L]; p < 0.001).

CONCLUSIONS

This is the largest study of patients with ferritin available in a mixed ICU cohort. Ferritin levels in patients with hemophagocytic lymphohistiocytosis, sepsis, septic shock, and other conditions were distinctly different, with the highest ferritin levels observed in hemophagocytic lymphohistiocytosis patients. Maximum ferritin of 9,083 µg/L showed high sensitivity and specificity and, therefore, may contribute to improved diagnosis of hemophagocytic lymphohistiocytosis in ICU. The inclusion of ferritin into the sepsis laboratory panel is warranted.

C-reactive protein for risk prediction of post-operative delirium and post-operative neurocognitive disorder

BACKGROUND

Post-operative delirium (POD) and post-operative neurocognitive disorder (NCD) are frequently seen in the elderly. Development of biomarkers for pre-operative risk prediction is of major relevance. As inflammation present before surgery might predispose to POD and post-operative NCD development, we aim to determine associations between pre-operative C-reactive protein (CRP) and the incidence of POD and post-operative NCD.

METHODS

In this observational study, we analyzed 314 patients enrolled in the SuDoCo trial, who had a pre-operative CRP measurement the day before surgery. Primary outcomes were POD assessed according DSM-4 from day 1 until day 7 after surgery and post-operative NCD assessed 3 months after surgery. We conducted multivariable logistic regression analysis adjusted for age, sex, randomization, body mass index, MMSE, ASA status, infection/autoimmune disease/malignoma and types of surgery to determine associations between CRP with POD and post-operative NCD, respectively.

RESULTS

Pre-operative CRP was independently associated with POD [OR 1.158 (95% CI 1.040, 1.291); P = .008]. Patients with CRP values ≥5 mg/dL had a 4.8-fold increased POD risk [OR 4.771 (95% CI 1.765, 12.899; P = .002)] compared to patients with lower CRP values. However, no association was seen between pre-operative CRP and post-operative NCD [OR 0.552 (95% CI 0.193, 1.581); P = .269].

CONCLUSIONS

Pre-operative CRP levels were independently associated with POD but not post-operative NCD after three months. Moreover, higher pre-operative CRP levels showed higher risk for POD. This strengthens the role of inflammation in the development of POD. Assessment of CRP before surgery might allow risk stratification of POD.

TRIAL REGISTRATION

This study was registered with ISRCTN Register 36437985 on 02 March 2009.

Diagnostic biomarkers for adult haemophagocytic lymphohistiocytosis in critically ill patients (HEMICU): a prospective observational study protocol

INTRODUCTION

Haemophagocytic lymphohistiocytosis (HLH) in adults is characterised by toxic immune activation and a sepsis-like syndrome, leading to high numbers of undiagnosed cases and mortality rates of up to 68%. Early diagnosis and specific immune suppressive treatment are mandatory to avoid fatal outcome, but the diagnostic criteria (HLH-2004) are adopted from paediatric HLH and have not been validated in adults. Experimental studies suggest biomarkers to sufficiently diagnose HLH. However, biomarkers for the diagnosis of adult HLH have not yet been investigated.

METHODS AND ANALYSIS

The HEMICU (Diagnostic biomarkers for adult haemophagocytic lymphohistiocytosis in critically ill patients) study aims to estimate the incidence rate of adult HLH among suspected adult patients in intensive care units (ICUs). Screening for HLH will be performed in 16 ICUs of Charité - Universitätsmedizin Berlin. The inclusion criteria are bicytopaenia, hyperferritinaemia (≥500 µg/L), fever or when HLH is suspected by the clinician. Over a period of 2 years, we expect inclusion of about 100 patients with suspected HLH. HLH will be diagnosed if at least five of the HLH-2004 criteria are fulfilled, together with an expert review; all other included patients will serve as controls. Second, a panel of potential biomarker candidates will be explored. DNA, plasma and serum will be stored in a biobank. The primary endpoint of the study is the incidence rate of adult HLH among suspected adult patients during ICU stay. Out of a variety of measured biomarkers, this study furthermore aims to find highly potential biomarkers for the diagnosis of adult HLH in ICU. The results of this study will contribute to improved recognition and patient outcome of adult HLH in clinical routine.

ETHICS AND DISSEMINATION

The institutional ethics committee approved this study on 1 August 2018 (Ethics Committee of Charité - Universitätsmedizin Berlin, EA4/006/18). The results of the study will be disseminated in an international peer-reviewed journal and presented at international conferences.

TRIAL REGISTRATION NUMBER

NCT03510650.

Intraoperative hyperglycemia increases the incidence of postoperative delirium

BACKGROUND

Hyperglycemia frequently occurs during major surgery and is associated with adverse postoperative outcomes. This study aimed to investigate the influence of intraoperative hyperglycemia on incidences of postoperative delirium (POD) and postoperative cognitive dysfunction (POCD).

METHODS

Eighty-seven patients aged ≥65 years undergoing elective surgery were included in this prospective observational subproject of the BioCog study. Blood glucose (BG) levels were measured every 20 minutes intraoperatively. Hyperglycemia was defined as BG levels ≥150 mg·dL-1. Patients were assessed for POD twice daily until postoperative day 7. The occurrence of POCD was determined three months after surgery. Multivariable logistic regression was used to identify associations between hyperglycemia and POD as well as POCD. Secondary endpoints comprised duration of hyperglycemia, maximum glucose level (Glucosemax) and differences between diabetic and non-diabetic patients.

RESULTS

POD occurred in 41 (47.1%), POCD in five (15.2%) patients. In two separate multivariable logistic regression models, hyperglycemia was significantly associated with POD (OR 3.86 [CI 95% 1.13, 39.49], P=0.044) but not POCD (3.59 [NaN, NaN], P=0.157). Relative duration of hyperglycemia was higher in POD patients compared to patients without POD (20 [0; 71] % versus 0 [0; 55] %, P=0.075), whereas the maximum glucose levels during surgery were similar between the two groups. Considering only non-diabetic patients, relative duration of hyperglycemia (P=0.003) and Glucosemax (P=0.015) were significantly higher in patients with POD.

CONCLUSIONS

Intraoperative hyperglycemia was independently associated with POD but not POCD. Relative duration of hyperglycemia appeared thereby to also play a role. Especially hyperglycemic non-diabetic patients might be at high risk for POD.

Risk Factors of Intraoperative Dysglycemia in Elderly Surgical Patients

BACKGROUNDː Dysglycemia is associated with adverse outcome including increased morbidity and mortality in surgical patients. Acute insulin resistance due to the surgical stress response is seen as a major cause of so-called stress hyperglycemia. However, understanding of factors determining blood glucose (BG) during surgery is limited. Therefore, we investigated risk factors contributing to intraoperative dysglycemia. METHODSː In this subgroup investigation of the BIOCOG study, we analyzed 87 patients of ≥ 65 years with tight intraoperative BG measurement every 20 min during elective surgery. Dysglycemia was defined as at least one intraoperative BG measurement outside the recommended target range of 80-150 mg/dL. Additionally, all postoperative BG measurements in the ICU were obtained. Multivariable logistic regression analysis adjusted for age, sex, American Society of Anesthesiologists (ASA) status, diabetes, type and duration of surgery, minimum Hemoglobin (Hb) and mean intraoperative norepinephrine use was performed to identify risk factors of intraoperative dysglycemia. RESULTSː 46 (52.9%) out of 87 patients developed intraoperative dysglycemia. 31.8% of all intraoperative BG measurements were detected outside the target range. Diabetes [OR 9.263 (95% CI 2.492, 34.433); p=0.001] and duration of surgery [OR 1.005 (1.000, 1.010); p=0.036] were independently associated with the development of intraoperative dysglycemia. Patients who experienced intraoperative dysglycemia had significantly elevated postoperative mean (p<0.001) and maximum BG levels (p=0.001). Length of ICU (p=0.007) as well as hospital stay (p=0.012) were longer in patients with dysglycemia. CONCLUSIONSː Diabetes and duration of surgery were confirmed as independent risk factors for intraoperative dysglycemia, which was associated with adverse outcome. These patients, therefore, might require intensified glycemic control. Increased awareness and management of intraoperative dysglycemia is warranted.

Nucleated red blood cells as predictors of mortality in patients with acute respiratory distress syndrome (ARDS): an observational study

Background

Nucleated red blood cells (NRBCs) in critically ill patients are associated with increased mortality and poor outcome. The aim of the present study was to evaluate the predictive value of NRBCs in patients with acute respiratory distress syndrome (ARDS).

Methods

This observational study was conducted at an ARDS referral center and included patients from 2007 to 2014. Daily NRBC counts were assessed and the predictive validity of NRBCs on mortality was statistically evaluated. A cutoff for prediction of mortality based on NRBCs was evaluated using ROC analysis and specified according to Youden’s method. Multivariate nonparametric analysis for longitudinal data was applied to prove for differences between groups over the whole time course. Independent predictors of mortality were identified with multiple logistic and Cox’ regression analyses. Kaplan–Meier estimations visualized the survival; the corresponding curves were tested for differences with the log-rank test.

Results

A total of 404 critically ill ARDS patients were analyzed. NRBCs were found in 75.5% of the patients, which was associated with longer length of ICU stay [22 (11; 39) vs. 14 (7; 26) days; p < 0.05] and higher mortality rates (50.8 vs. 27.3%; p < 0.001). Logistic regression analysis with mortality as response showed NRBC positivity per se to be an independent risk factor for mortality in ARDS with a doubled risk for ICU death (OR 2.03; 95% CI 1.16–3.55; p < 0.05). Also, NRBC value at ICU admission was found to be an independent risk factor for mortality (OR 3.25; 95% CI 1.09–9.73, p = 0.035). A cutoff level of 220 NRBC/µl was associated with a more than tripled risk of ICU death (OR 3.2; 95% CI 1.93–5.35; p < 0.0001). ARDS patients below this threshold level had a significant survival advantage (median survival 85 days vs. 29 days; log rank p < 0.001). Presence of a severe ARDS was identified as independent risk factor for the occurrence of NRBCs > 220/µl (OR 1.81; 95% CI 1.1–2.97; p < 0.05).

Conclusions

NRBCs may predict mortality in ARDS with high prognostic power. The presence of NRBCs in the blood might be regarded as a marker of disease severity indicating a higher risk of ICU death.