Red Blood Cell Transfusion in the Emergency Department: An Observational Cross-Sectional Multicenter Study

Misdiagnosis of thrombotic microangiopathy in the emergency department: a multicenter retrospective study

To estimate the rate of inappropriate diagnosis in patients who visited the ED with thrombotic microangiopathy (TMA) and to assess the factors and outcomes associated with emergency department (ED) misdiagnosis. Retrospective multicenter study of adult patients admitted to the intensive care unit (ICU) for TMA from 2012 to 2021 who had previously attended the ED for a reason related to TMA. Patient characteristics and outcomes were compared in a univariate analysis based on whether a TMA diagnosis was mentioned in the ED or not. Forty patients were included. The diagnosis of TMA was not mentioned in the ED in 16 patients (40%). Patients for whom the diagnosis was mentioned in the ED had more frequently a request for schistocytes research, and therefore had more often objectified schistocytes. They also had more frequently a troponin dosage in the ED (even if the difference was not significant), an ECG performed or interpreted, and were admitted more quickly in the ICU (0 [0-0] vs 2 [0-2] days; P = 0.002). Hemoglobin levels decreased significantly in both groups, and creatinine levels increased significantly in the misdiagnosis group between ED arrival and ICU admission. In patients with a final diagnosis of TTP, the time to platelets durable recovery was shorter for those in whom the diagnosis was mentioned in the ED without reaching statistical significance (7 [5-11] vs 14 [5-21] days; P = 0.3).

Haemoglobin thresholds for transfusion: how are we doing in the era of Choosing Wisely? A retrospective cohort study

INTRODUCTION

 Clinical practice guidelines and the Choosing Wisely initiative launched in 2012 recommend a haemoglobin (Hb) threshold of 70-80 g/lfor red blood cell (RBC) transfusions in stable hospitalised patients. Data on transfusion practices and their trends in medical inpatients are limited. To address this gap, we investigated transfusion practices and their trends in general internal medicine and other clinics.

METHODS

This retrospective cohort study analysed data from all hospitalisations with RBC transfusions at a Swiss university hospital between 2012 and 2019. We included all first transfusion episodes if pretransfusion Hb was available. The primary endpoint was mean pretransfusion Hb; secondary endpoints included potentially inadequate transfusions (i.e., transfusions at Hb ≥80 g/l) and receipt of a single RBC unit. Trends in mean pretransfusion Hb over time were estimated using generalised estimating equations, and risk factors for potentially inadequate transfusions were identified using multivariable adjusted generalised estimating equations models.

RESULTS

 Of 14,598 hospitalisations with RBC transfusions, 1980 (13.6%) were discharged from general internal medicine. From 2012 to 2019, mean pretransfusion Hb decreased from 74.0 g/l to 68.8 g/l in general internal medicine (mean annual decrease -0.76 g/l, 95% confidence interval [CI] -0.51 to -1.02) and from 78.2 g/l to 72.7 g/l in other clinics (mean annual decrease -0.69, 95% CI -0.62 to -0.77; p for interaction 0.53). The overall proportion of potentially inadequate transfusions was 17.8% in general internal medicine and 24.1% in other clinics (p <0.001) and decreased over the study period from 26.9% to 5.5% in general internal medicine and from 37.0% to 15.2% in other clinics. In contrast, the proportion of cases receiving a single RBC unit increased (39.5% to 81.4% in general internal medicine, 42.7% to 66.1% in other clinics). Older age (adjusted odds ratio [aOR] 1.45, 95% CI 1.32-1.58 for ≥65 vs <65 years), having surgery (aOR 1.24, 95% CI 1.14-1.36), acute haemorrhage (aOR 1.16, 95% CI 1.02-1.33), chronic heart failure (aOR 1.17, 95% CI 1.04-1.32), ischaemic heart diseases (aOR 1.27, 95% CI 1.15-1.41), chronic pulmonary diseases (aOR 1.24, 95% CI 1.08-1.42), malignancy (aOR 1.11, 95% CI 1.01-1.21), and rheumatic disease (aOR 1.27, 95% CI 1.01-1.59) were risk factors for potentially inadequate transfusions.

CONCLUSIONS

 More restrictive transfusion practices were adopted in general internal medicine and other clinics over time, suggesting that guideline recommendations and the Choosing Wisely initiative may have been increasingly followed. Interventions to reduce potentially inadequate transfusions should target providers who care for older patients and those with surgery or chronic cardiac and pulmonary diseases.

Modelling haemoglobin incremental loss on chronic red blood cell transfusions

BACKGROUND AND OBJECTIVES

Understanding the impact of red blood cell (RBC) lifespan, initial RBC removal, and transfusion intervals on patient haemoglobin (Hb) levels and total iron exposure is not accessible for chronic transfusion scenarios. This article introduces the first model to help clinicians optimize chronic transfusion intervals to minimize transfusion frequency.

MATERIALS AND METHODS

Hb levels and iron exposure from multiple transfusions were calculated from Weibull residual lifespan distributions, the fraction effete RBC removed within 24-h (X_e ) and the nominal Hb increment. Two-unit transfusions of RBCs initiated at patient [Hb] = 7 g/dl were modelled for different RBC lifespans and transfusion intervals from 18 to 90 days, and X_e from 0.1 to 0.5.

RESULTS

Increased X_e requires shorter transfusion intervals to achieve steady-state [Hb] of 9 g/dl as follows: 30 days between transfusions at X_e  = 0.5, 36 days at X_e  = 0.4, 42 days at X_e  = 0.3, 48 days at X_e  = 0.2 and 54 days at X_e  = 0.1. The same transfusion interval/X_e pairs result in a steady-state [Hb] = 8 g/dl when the RBC lifespan was halved. By reducing transfused RBC increment loss from 30% to 10%, annual transfusions were decreased by 22% with iron addition decreased by 24%. Acute dosing of iron occurs at the higher values of X_e on the day after a transfusion event.

CONCLUSION

Systematic trends in fractional Hb incremental loss X_e have been modelled and have a significant and calculatable impact on transfusion intervals and associated introduction of iron.