Frequency of Nucleated Red Blood Cells in the Peripheral Blood of ICU-Admitted Patients

Background Nucleated red blood cells (NRBCs) are not normally found in the peripheral blood of normal healthy individuals. The presence of NRBCs on an adult peripheral blood smear indicates that there is an extremely high demand for the bone marrow to manufacture RBCs and that immature red blood cells are being released into the bloodstream. Anemia, myelofibrosis, thalassemia, miliary tuberculosis, malignancies of the bone marrow (myelomas, leukemias, lymphomas), and prolonged hypoxemia are a few possible pathogenic reasons. Critically ill patients who have NRBCs have a high mortality rate and a worse prognosis.

OBJECTIVE

To evaluate the clinical significance of NRBCs in the peripheral blood of critically ill patients admitted to the ICU to find a cut-off to predict mortality.

MATERIALS AND METHODS

A cross-sectional study was carried out over a period of six months September 1, 2020, to March 31, 2021, in Lahore, Pakistan. A total of 800 critically ill patients of both sexes in the age group of 18-70 years were included. Patients younger than 18 years and patients who underwent surgery were excluded. A quantity of 3 ml of whole blood sample in an ethylenediamine tetraacetic acid (EDTA) vial from each patient was run on SYSMEX XN-9000 (Sysmex Corporation, Kobe, Hyogo, Japan) and the results were reviewed on peripheral smears.

RESULTS

The incidence of NRBCs in ICU-admitted patients was 62.5% (500/800). The total number of NRBC-positive patients recovering after the treatment was 364 (72.8%). The overall mortality of NRBC-positive patients was 30% (150/500). It was significantly higher (p<0.001) than that of NRBC-negative patients (14%; 44/300). During treatment, the highest mortality rate was seen in patients due to malignancy (100%), followed by sepsis (58.8%). It was observed that the disease pattern and number of NRBCs were significantly different (p<0.001) among all disease groups. However, there was no statistically significant difference in NRBCs on the basis of gender (p >0.05). In our study, a cutoff of NRBCs of 2.50 showed a high risk of mortality with a sensitivity of 91%.

CONCLUSION

The presence of NRBCs may predict mortality in critically ill ICU-admitted patients. Their presence in the blood may be regarded as a marker of severity suggesting a high risk of ICU death.

Improvement of mortality prediction accuracy in critically ill patients through combination of SOFA and APACHE II score with markers of stress haematopoiesis

INTRODUCTION

In critically ill patients nucleated red blood cells (NRBC) and immature granulocytes (IG) appear in the peripheral blood as the consequence of stress haematopoesis. The aim of this retrospective study was to evaluate the diagnostic value of NRBC and IG and to propose a model of improved mortality prediction including these parameters in the assessment of critically ill patients.

METHODS

The study included 338 critically ill adult patients hospitalized at Department of Anaesthesiology and Intensive Medicine, Louis Pasteur University Hospital in Kosice. As NRBC positive patients were considered patients with peripheral NRBC > 0.01 × 10⁹ /L and IG positivity as >0.03 × 10⁹ /L. Apache II index was calculated 24 hours after admission and Systemic Organ Failure Assessment (SOFA) on the day with the worst clinical condition.

RESULTS

NRBC positivity was found in 27.6% of patients. The mortality of NRBC positive patients was 48.38%, significantly higher than 23.7% of NRBC negative patients. IG positivity was 79.0% and their mortality was also higher as compared with that of IG negative patients (69.3% vs 33.8%). Three regression models predicting mortality including stress haematopoiesis markers, APACHE II, SOFA scores and age had sufficient level of sensitivity and specificity.

CONCLUSION

The presence of NRBC in the peripheral blood and the IG increase are available early risk predictors of mortality in critically ill patients. Regression models designed by combination of SOFA, APACHE II, and the new haematological parameters increase the accuracy and effectivity of diagnostic process in predicting prognosis and risk of mortality with high sensitivity and specificity.

Mortality prediction models in the adult critically ill: A scoping review

BACKGROUND

Mortality prediction models are applied in the intensive care unit (ICU) to stratify patients into different risk categories and to facilitate benchmarking. To ensure that the correct prediction models are applied for these purposes, the best performing models must be identified. As a first step, we aimed to establish a systematic review of mortality prediction models in critically ill patients.

METHODS

Mortality prediction models were searched in four databases using the following criteria: developed for use in adult ICU patients in high-income countries, with mortality as primary or secondary outcome. Characteristics and performance measures of the models were summarized. Performance was presented in terms of discrimination, calibration and overall performance measures presented in the original publication.

RESULTS

In total, 43 mortality prediction models were included in the final analysis. In all, 15 models were only internally validated (35%), 13 externally (30%) and 10 (23%) were both internally and externally validated by the original researchers. Discrimination was assessed in 42 models (98%). Commonly used calibration measures were the Hosmer-Lemeshow test (60%) and the calibration plot (28%). Calibration was not assessed in 11 models (26%). Overall performance was assessed in the Brier score (19%) and the Nagelkerke's R² (4.7%).

CONCLUSIONS

Mortality prediction models have varying methodology, and validation and performance of individual models differ. External validation by the original researchers is often lacking and head-to-head comparisons are urgently needed to identify the best performing mortality prediction models for guiding clinical care and research in different settings and populations.

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.

Decreased high density lipoprotein cholesterol is an independent predictor for persistent organ failure, pancreatic necrosis and mortality in acute pancreatitis

High density lipoprotein cholesterol (HDL-C) has been reported as a significant indicator of systemic inflammation. The association underlying HDL-C and persistent organ failure (POF), pancreatic necrosis (PNec) and mortality in acute pancreatitis (AP) has not been evaluated. From 2007 to 2016, consecutive AP patients with admission lipid profiles assessment were included in this study. The association of HDL-C value and other lipids with outcomes was explored with Cox proportional regression models, which were adjusted for confounding factors. 1131 consecutive AP patients were clinically eligible. Overall, 17.9% of the patients developed with POF, 27.1% experienced PNec, and 6.7% died during hospitalization. Lower HDL-C median (<1.06 mmol/L) was identified as an independent prognostic factor of the outcomes. Moreover, there was a positive trend for the association across increasing HDL-C quartiles and POF, PNec and mortality after multivariable analysis (p values were <0.001, <0.001 and 0.043, respectively). The AUC of HDL-C for the outcomes were comparable to that of Ranson score for diagnosing POF (0.778 vs. 0.678; P < 0.001), PNec (0.734 vs. 0.701; P = 0.143) and mortality (0.768 vs. 0.745; P = 0.516). Decreased HDL-C value is an independent risk factor for the incidence of POF, PNec and in-hospital mortality in AP.

Prospective comparison of three risk score models at three different surgical intensive care units

PURPOSE

Although risk score models are of great value, their use is restricted because of the additional effort involved. The aim of this study was to compare three different score systems. Each of these requires a different degree of effort by the medical staff. One of the score systems is solely based on routine laboratory parameters. Data were collected on three different ICUs units, with each showing a large variety in patients' health conditions.

METHODS

Prospective data of 588 surgical patients were collected by means of Acute Physiology and Chronic Health Evaluation II (APACHE II), Dense Laboratory Whole Blood Applied Risk Estimation (DELAWARE), and Simplified Acute Physiology Score II (SAPS II) score systems. These patients were admitted to three different intensive care units over a period of 12 months. On the day of admission, predicted hospital survival and mortality were evaluated.

RESULTS

With a cutoff value of 0.6, the sensitivity of the APACHE II, DELAWARE, and SAPS II was at 0.19, 0.24, and 0.21; the specificity was at 0.98, 0.92, and 0.98; and the correct classification rate at 0.86, 0.83, and 0.86. The r(2) value was 0.35 for the APACHE II, 0.12 for the DELAWARE, and 0.21 for the SAPS II. The hospital mortality rate was overestimated in all three score systems.

CONCLUSIONS

The results of this first multicenter study comparing three risk score systems indicate that it is possible to establish a general risk score for surgical intensive care patients on admission date. Such a risk score is solely based on quality-controlled, low-cost routine laboratory parameters.

Risk stratification tools for predicting morbidity and mortality in adult patients undergoing major surgery: qualitative systematic review

Risk stratification is essential for both clinical risk prediction and comparative audit. There are a variety of risk stratification tools available for use in major noncardiac surgery, but their discrimination and calibration have not previously been systematically reviewed in heterogeneous patient cohorts.Embase, MEDLINE, and Web of Science were searched for studies published between January 1, 1980 and August 6, 2011 in adult patients undergoing major noncardiac, nonneurological surgery. Twenty-seven studies evaluating 34 risk stratification tools were identified which met inclusion criteria. The Portsmouth-Physiology and Operative Severity Score for the enUmeration of Mortality and the Surgical Risk Scale were demonstrated to be the most consistently accurate tools that have been validated in multiple studies; however, both have limitations. Future work should focus on further evaluation of these and other parsimonious risk predictors, including validation in international cohorts. There is also a need for studies examining the impact that the use of these tools has on clinical decision making and patient outcome.

Nucleated red blood cells are associated with a higher mortality rate in patients with surgical sepsis

BACKGROUND

Nucleated red blood cells (NRBCs) are present in certain non-oncologic disease states and are associated with a poor prognosis. The purpose of this study was to evaluate NRBCs as an early prognostic marker for death in patients with surgical sepsis.

METHODS

Retrospective evaluation of data collected prospectively from 275 patients from our Investigational Review Board-approved surgical sepsis database over a 27-mo period. The NRBC values were correlated with patient outcomes. The χ(2) test was used for testing of categorical variables and the Mann-Whitney U was used for testing of continuous variables. The level of significance was set at 0.05.

RESULTS

At sepsis recognition, 48 patients (17.5%) were NRBC-positive. The mortality rate was greater in patients who were NRBC positive while in the intensive care unit (ICU); (27% vs. 12%; p=0.007) and during the hospital stay (35.4% vs. 15%; p=0.001). When NRBC-values at all time points are considered, 116 patients (42.2%) were NRBC-positive. The mortality rate was greater in patients who were NRBC-positive in both the ICU (23.3% vs. 8.2%; p<0.001) and during the hospital stay (31% vs. 9.4%; p<0.001). In-hospital and ICU mortality rates increased with increasing NRBC-concentration. For the 153 patients with severe sepsis, NRBC positivity at any time was associated with a higher ICU mortality rate (20% vs. 3.2%; p=0.001). Significant mortality differences did not occur between NRBC-positive and NRBC-negative patients with sepsis (n=48) or septic shock (n=74).

CONCLUSIONS

Surgical sepsis patients with detectable NRBCs are at higher risk of ICU and in-hospital death than those with non-detectable NRBCs. The mortality difference is underscored in surgical patients with severe sepsis. This study suggests NRBCs may be a biomarker of outcomes in patients with surgical sepsis.

Long-term comparison of a routine laboratory parameter-based severity score with APACHE II and SAPS II

BACKGROUND

Risk score models predicting mortality have tremendous value, but because of the additional effort involved, their clinical use remains low. The aim of this study is to compare three different scores that each requires different levels of effort during admission and throughout treatment: the Acute Physiology and Chronic Health Evaluation II (APACHE II), the Simplified Acute Physiology Score II (SAPS II), and the Dense Laboratory Whole Blood Applied Risk Estimation (DELAWARE) score. Of the three, only the DELAWARE is based solely on routine laboratory parameters.

METHODS

Prospective data of the three scores were collected for 268 surgical patients admitted to the intensive care unit over 1 year. The predicted hospital mortality and survival were evaluated for the first 14 days.

RESULTS

With a cutoff value of 0.65, the sensitivity of the DELAWARE was 71.6%, the specificity, 92.5%, and the correct classification rate, 87.3%. The APACHE II and SAPS II showed values of 41.2%/96.8%/86.2% and 62.7%/87.1%/82.5%, respectively. The r2 value was 0.884 for the DELAWARE, 0.876/0.814 for the APACHE II and SAPS II. Hospital mortality rate was overestimated by 20% to 65% in all scores. The discriminatory ability of the APACHE II and SAPS II increased throughout the course of treatment.

CONCLUSIONS

The routine laboratory-based DELAWARE provides a reliable, valid risk assessment of the surgical intensive care patient at admission. It also provides additional information without added effort or poor interobserver reliability, which leads to better data comparability. We have to state that until now the data have been collected in a single-center and their general validity is therefore limited. By the end of treatment, the SAPS II and APACHE II had increased discriminatory ability and are therefore useful as process parameters.

An Update on C-reactive Protein for Intensivists

This review aims to summarise the physiology of C-reactive protein (CRP), its possible roles and limitations as an inflammatory and infective marker in intensive care medicine, and also the emerging roles of CRP in the pathogenesis of cardiovascular and autoimmune diseases. Observational and animal studies on uses of CRP were retrieved from the PubMed database without any language restrictions. Quantitative data were not pooled because of the heterogeneity of patient characteristics and disparate ways in which CRP was studied. Serum CRP concentrations are determined by the synthetic rate of its production in the liver regulated predominantly by interleukin-6. It has a half-life of 19 hours and is relatively slow in its onset and offset in response to an acute inflammatory process when compared to procalcitonin. It has some favourable properties and limitations as an inflammatory marker. An elevated CRP concentration is not specific to infections and the absolute CRP concentrations cannot be used to differentiate between bacterial, fungal and severe viral infections. The dynamic response of CRP to therapy that aims to modify the underlying inflammatory process and the clinical context of a patient are of pivotal importance when CRP concentrations are interpreted. CRP is found to be a significant partaker and prognostic factor in a wide range of cardiovascular and chronic diseases. In summary, CRP concentration is an important prognostic factor of many acute and chronic diseases. Serial CRP measurements may be useful to reflect a patient's response to therapy that aims to modify the underlying inflammatory process.