Identifying factors to minimize phlebotomy-induced blood loss in the pediatric intensive care unit

Impact of Blood Sampling Methods on Blood Loss and Transfusion After Pediatric Cardiac Surgery: An Observational Study

OBJECTIVES

The aims of this study were to assess the impact of the closed-loop sampling method on blood loss and the need for blood transfusion in pediatric patients following cardiac surgery.

DESIGN

Retrospective observational study.

SETTING

A single tertiary center.

PARTICIPANTS

All pediatric patients younger than 4 years old who were admitted to the pediatric intensive care unit (PICU) after cardiac surgery were enrolled. The study included 100 pediatric patients in the conservative (postimplementation) group and 43 pediatric patients in the nonconservative group (preimplementation).

INTERVENTIONS

Observational.

MEASUREMENTS

The primary outcome was the volume of blood loss during the PICU follow-up period. The secondary outcomes were the requirement for blood transfusion in each group, duration of mechanical ventilation, length of intensive care unit (ICU) stay, length of hospital stay, and mortality.

MAIN RESULTS

In the conservative (postimplementation) group, blood loss during the follow-up period was 0.67 (0.33-1.16) mL/kg/d, while it was 0.95 (0.50-2.30) mL/kg/d in the nonconservative (preimplementation) group, demonstrating a significant reduction in blood loss in the conservative group (p = 0.012). The groups showed no significant differences in terms of the required blood transfusion volume postoperatively during the first 24 hours, first 48 hours, or after 48 hours (p = 0.061, 0.536, 0.442, respectively). The frequency of blood transfusion was comparable between the groups during the first 24 hours, first 48 hours, or after 48 hours postoperatively (p = 0.277, 0.639, 0.075, respectively). In addition, the groups did not show significant differences in the duration of mechanical ventilation, length of ICU stay, length of hospital stay, or mortality.

CONCLUSIONS

The closed-loop sampling method can be efficient in decreasing blood loss during postoperative PICU follow-up for pediatric patients after cardiac surgeries. However, its application did not reduce the frequency or the volume of blood transfusion in these patients.

Recommendations on Monitoring and Replacement of Antithrombin, Fibrinogen, and Von Willebrand Factor in Pediatric Patients on Extracorporeal Membrane Oxygenation: The Pediatric Extracorporeal Membrane Oxygenation Anticoagulation CollaborativE Consensus Conference

OBJECTIVES

To derive systematic review informed, modified Delphi consensus regarding monitoring and replacement of specific coagulation factors during pediatric extracorporeal membrane oxygenation (ECMO) support for the Pediatric ECMO Anticoagulation CollaborativE.

DATA SOURCES

A structured literature search was performed using PubMed, Embase, and Cochrane Library (CENTRAL) databases from January 1988 to May 2020, with an update in May 2021.

STUDY SELECTION

Included studies assessed monitoring and replacement of antithrombin, fibrinogen, and von Willebrand factor in pediatric ECMO support.

DATA EXTRACTION

Two authors reviewed all citations independently, with conflicts resolved by a third reviewer if required. Twenty-nine references were used for data extraction and informed recommendations. Evidence tables were constructed using a standardized data extraction form.

DATA SYNTHESIS

Risk of bias was assessed using the Quality in Prognosis Studies tool. The evidence was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation system. A panel of 48 experts met over 2 years to develop evidence-based recommendations and, when evidence was lacking, expert-based consensus statements. A web-based modified Delphi process was used to build consensus via the Research And Development/University of California Appropriateness Method. Consensus was defined as greater than 80% agreement. We developed one weak recommendation and four expert consensus statements.

CONCLUSIONS

There is insufficient evidence to formulate recommendations on monitoring and replacement of antithrombin, fibrinogen, and von Willebrand factor in pediatric patients on ECMO. Optimal monitoring and parameters for replacement of key hemostasis parameters is largely unknown.

Evaluation of the impact of diagnostic blood loss and red blood cell transfusion in very-low-birth-weight anaemic neonates during hospitalization: A multi-centre retrospective clinical study

BACKGROUND AND OBJECTIVES

Diagnostic blood loss is a significant factor in the development of anaemia in neonates with very low birth weight. This study aimed to assess the clinical efficacy of intervention approaches involving varying diagnostic blood loss and red blood cell transfusion volumes in neonates with very low birth weights experiencing anaemia during hospitalization.

MATERIALS AND METHODS

A total of 785 newborns with anaemia weighing less than 1500 g were enrolled from 32 hospitals in China. The study involved monitoring diagnostic blood loss and red blood cell transfusion and evaluating relevant interventions such as red blood cell transfusion and clinical outcomes. Three intervention approaches were established based on the difference between blood loss and transfusion (Intervention Approaches 0, 1 and 2). The primary outcomes measured were unsatisfactory weight gain during hospitalization and neonatal mortality. The secondary outcomes included related complications.

RESULTS

In the non-hospital-acquired anaemia group, Intervention Approach 2 had the highest incidence of below-normal weight gain (odds ratio [OR]: 3.019, 95% confidence interval [CI]: 1.081-8.431, p = 0.035). Multivariate analysis revealed that Intervention Approach 1 had a protective effect on weight gain. In the hospital-acquired anaemia group, Intervention Approach 2 had the highest incidence of below-normal weight gain (OR: 3.335, 95% CI: 1.785-6.234, p = 0.000) and mortality (OR: 5.341, 95% CI: 2.449-11.645, p = 0.000), while Intervention Approach 1 had the lowest incidence of intraventricular haemorrhage. Intervention Approach 1 demonstrated favourable outcomes in both anaemia groups.

CONCLUSION

Intervention Approach 1 improved weight gain and reduced mortality and complications in both the non-hospital-acquired and hospital-acquired anaemia groups.

What blood conservation practices are effective at reducing blood sampling volumes and other clinical sequelae in intensive care? A systematic review

OBJECTIVES

The objective of this study was to critically appraise and synthesise evidence for blood conservation strategies in intensive care. Blood sampling is a critical aspect of intensive care to guide clinical decision-making. Repeated blood sampling can result in blood waste and contamination, leading to iatrogenic anaemia and systemic infection.

REVIEW METHOD USED

Cochrane systematic review methods were used including meta-analysis, and independent reviewers.

DATA SOURCES

A systematic search was conducted in Medline, CINAHL, PUBMED and EMBASE databases. The search was limited to randomised controlled trials (RCTs) and cluster RCTs, published in English between 2000 and 2021.

REVIEW METHODS

Paired authors independently assessed database search results and identified eligible studies. Trials comparing any blood conservation practice or product in intensive care were included. Primary outcomes were blood sample volumes and haemoglobin change. Secondary outcomes included proportion of patients receiving transfusions and infection outcomes. Quality appraisal employed the Cochrane Risk of Bias tool. Meta-analysis using random effects approach and narrative synthesis summarised findings.

RESULTS

Eight studies (n = 1027 patients), all RCTs were eligible. Six studies included adults, one studied paediatrics and one studied preterm infants. Seven studies evaluated a closed loop blood sampling system, and one studied a conservative phlebotomy protocol. Studies were of low to moderate quality. Meta-analysis was not possible for interventions targeting blood sample volumes or haemoglobin. Decreased blood sample volumes reported in four studies were attributable to a closed loop system or conservative phlebotomy. No study reported a significant change in haemoglobin. Meta-analysis demonstrated that use of a closed system (compared to open system) reduced the proportion of patients receiving transfusion [Risk Ratio (RR) 0.65, 95% CI 0.46-0.92; 287 patients] and reduced intraluminal fluid colonisation [RR 0.25, 95% CI 0.07-0.58; 500 patients].

CONCLUSIONS

Limited evidence demonstrates closed loop blood sampling systems reduced transfusion use and fluid colonisation. Simultaneous effectiveness-implementation evaluation of these systems and blood conservation strategies is urgently required.

PROSPERO PROTOCOL REGISTRATION REFERENCE

CRD42019137227.

Every Tube Counts: reducing extra tubes drawn in the emergency department

A common practice exists in hospitals where extra tubes of blood are collected for possible add-on testing, this practice contributes to wastage of consumables. Baseline estimates from a 5-month local lab information system audit revealed that ~65 extra tubes per day were being collected, with an additional 2-week manual audit of all extra tubes received in the laboratory confirming the practice. The audits showed that the majority of the tubes (~99%) were being drawn from the adult emergency department (ED). Furthermore, only 5% of the extra tubes were being used for add-on testing, whereas the remaining tubes had no testing performed on them and were discarded at the end of the day. This translates to over 23 000 extra tubes being wasted annually.After initial discussion with ED leadership, the practice was identified as primarily nurse driven. An educational intervention was created and entitled 'Every Tube Counts', with the aim to reduce extra tube collections in the adult ED by 50% within the first month of intervention. First, a memo with initial findings and a request to stop the practice of extra tube collection was sent out to all ED staff. After 2 weeks of additional data collection, it was noticed that extra tubes were still being collected. A second intervention, which consisted of another communication and utilisation of nurse educators to disseminate the information to nursing staff, saw a remarkable ~80% reduction in collection of extra tubes in the following few months after the second intervention. The practice was followed for an additional 15 months, which saw a slight increase of extra tube collections over time with a levelling off towards the latter period of the study. However, the target goal was maintained over the entire study period.

Comparison of Clinical, Economic, and Humanistic Outcomes Between Blood Collection Approaches: A Systematic Literature Review

BACKGROUND

A systematic literature review was performed to understand the prevalence, advantages, and disadvantages of blood collection using different approaches (direct venipuncture or vascular access devices), and interventions used to mitigate the disadvantages.

METHODS

The review included a broad range of study designs and outcomes. Database searches (Embase, MEDLINE, Cochrane library, and Centre for Reviews and Dissemination) were conducted in March 2021 and supplemented by hand searching.

RESULTS

One hundred forty-one publications were included. The data indicate that blood sampling from vascular access devices is common in emergency departments, trauma centers, and intensive care units. Studies showed that hemolysis and sample contamination place a considerable economic burden on hospitals. Significant cost savings could be made through enforcing strict aseptic technique, or using the initial specimen diversion technique.

CONCLUSIONS

Hemolysis and sample contamination are far from inevitable in vascular access device-collected or venipuncture samples; both can be reduced through adherence to strict blood sampling protocols and utilization of the initial specimen diversion technique. Needle-free blood collection devices offer further hope for reducing hemolysis. No publication focused on the difficult venous access population; insertion success rates are likely to be lower (and the benefits of vascular access devices higher) in these patients.

Risk Factors Analysis for Hemoglobin Decline Caused by Diagnostic Blood Collection in Respiratory Department in North China: A Case-Control Study

Purpose

This study aimed to investigate the correlation between hemoglobin decline and diagnostic blood collection in the respiratory department and analyze the decline's risk factors.

Patients and Methods

A case-control study in the respiratory department of a national tertiary hospital in north China, multivariable logistic regression analysis was used to find the risk factors. Patients excluding other factors affecting hemoglobin other than blood collection in the year 2021 were enrolled and divided into two groups according to the D-value of hemoglobin. The degree of hemoglobin decline caused by diagnostic blood collection between discharge and admission and its risk factors were analyzed.

Results

Among the 530 patients screened in the study, ΔHb (the D-value of hemoglobin between discharge and admission) showed a skewed distribution with an average value of -4.38±0.514 g/L. We defined the D-value less than mean-2SD (ΔHb<-5.408) as a significant hemoglobin decline, by which the patients were categorized into two groups. Some variables had apparent differences between the two groups. By multivariable logistic regression analysis on these variables, the independent risk factors for significant hemoglobin decline (ΔHb<-5.408g/L) were revealed: age (OR=1.020, 95% CI 1.008-1.032, p=0.001), Male gender (OR=1.544, 95% CI 1.011-2.358, p=0.044), hemoglobin value at admission (OR=1.052, 95% CI 1.039-1.065, p<0.001), total blood collection volume (OR=1.021, 95% CI 1.010-1.032, p<0.001).

Conclusion

In the respiratory department, older male and more diagnostic blood collection mean higher risks of significant hemoglobin decline. Surprisingly, the lower the hemoglobin value at admission, the lower the risk.

Capillary Refill Time and Serum Lactate as Predictors of Mortality and Postoperative Extracorporeal Membrane Oxygenation Requirement in Congenital Heart Surgery

Multiple tissue perfusion markers are described to guide therapy in critically ill pediatric patients undergoing congenital heart surgery. Given the advantages of capillary refill time, our goal is to determine its predictive capacity for mortality and postoperative extracorporeal oxygenation requirements in congenital heart surgery and compare it to serum lactate. We conducted a prospective cohort observational study in a single high-complexity university hospital. Serum lactate and capillary refill time were measured at five predetermined time points: preoperative, immediate postoperative, 6, 12, and 24 h after the surgery. Prolonged immediate postoperative, 6 h, and 12 h capillary refill time measurements turned out to be independent risk factors for both outcomes. The capillary refill time area under the curve ranged between 0.70 and 0.80, while the serum lactate resulted between 0.79 and 0.92 for both outcomes. Both tissue perfusion markers resulted in mortality and extracorporeal oxygenation requirement predictors. Given the advantages of capillary refill time over serum lactate, a monitoring strategy including these two perfusion markers should be considered for congenital heart surgeries.

Impact of Blood Sampling on Anemia in the PICU: A Prospective Cohort Study

OBJECTIVES

Fifty percent of children are anemic after a critical illness. Iatrogenic blood testing may be a contributor to this problem. The objectives of this study were to describe blood sampling practice in a PICU, determine patient factors associated with increased sampling, and examine the association among blood sampling volume, anemia at PICU discharge, and change in hemoglobin from PICU entry to PICU discharge.

DESIGN

Prospective observational cohort study.

SETTING

PICU of Sainte-Justine University Hospital.

PATIENTS

All children consecutively admitted during a 4-month period.

MEASUREMENTS AND MAIN RESULTS

Four hundred twenty-three children were enrolled. Mean blood volume sampled was 3.9 (±19) mL/kg/stay, of which 26% was discarded volume. Children with central venous or arterial access were sampled more than those without access (p < 0.05). Children with sepsis, shock, or cardiac surgery were most sampled, those with a primary respiratory diagnosis; the least (p < 0.001). We detected a strong association between blood sample volume and mechanical ventilation (H, 81.35; p < 0.0001), but no association with severity of illness (Worst Pediatric Logistic Organ Dysfunction score) (R, -0.044; p = 0.43). Multivariate analysis (n = 314) showed a significant association between the volume of blood sampled (as continuous variable) and anemia at discharge (adjusted OR, 1.63; 95% CI, 1.18-2.45; p = 0.003). We lacked power to detect an association between blood sampling and change in hemoglobin from PICU admission to PICU discharge.

CONCLUSIONS

Diagnostic blood sampling in PICU is associated with anemia at discharge. Twenty-five percent of blood losses from sampling is wasted. Volumes are highest for patients with sepsis, shock, or cardiac surgery, and in patients with vascular access or ventilatory support.

Performance evaluation of the XT MicroSlide assay pairs on the Vitros XT 7600 compared to VITROS single microslide assays on Vitros 5600

Objectives

Pediatric hospitals are always challenged by specimen volumes and thus any innovation in this realm is very welcome. With the introduction of Microslide assay pairs, we aimed to evaluate the analytical performance of the Vitros XT MicroSlide assay pairs on the Vitros XT 7600 compared to single MicroSlides.

Design

Performance characteristics included within-run precision, analytical measurable range, method comparison, and interference verification. We compared six XT MicroSlide pairs on the Vitros XT 7600 with twelve corresponding single slide assays on the Vitros 5600 system.

Results

The XT MicroSlides on Vitros XT 7600 demonstrated excellent precision, equivalent analytical measurable range, and strong method correlation with single slide assays on Vitros 5600 for most of the assays tested. Within-run CVs of the analytes ranged between 0.32% and 2.93% with between-run CV of less than 8.8% and linearity for all analytes was within the manufacturer's specified range. Interference studies showed comparable effects of hemolysis, lipemia, and bilirubin on both instruments.

Conclusions

The XT MicroSlides are comparable to the single MicroSlide assays with improved efficiency, turnaround times and lower sample volumes.

Potential Role of Serum Intestinal Fatty Acid-Binding Protein as a Marker for Early Prediction and Diagnosis of Necrotizing Enterocolitis in Preterm Neonates

Introduction:

Intestinal fatty acid-binding protein (I-FABP) is located in the apex of mature enterocytes and released into circulation; once the injury of enterocyte happens, its circulating levels are considered an early and sensitive marker of intestinal ischemia as in necrotizing enterocolitis (NEC); because of its small molecular weight, it can be detected in urine.

Aims:

The aim was to study the usefulness of both serum and urine I-FABP in early diagnosis of NEC and to correlate the serum and urinary levels.

Settings and Design:

This study was case–control design.

Methods:

Simultaneous serum and urine samples obtained at the onset of symptoms, in 40 preterms with suspected NEC, with gestational age ± 27.70 weeks and birth weight ± 1.11 kg, i.e., 20 preterms diagnosed at Stage I, 12 preterms at Stage II, and 8 preterms at Stage III, were compared with age- and weight-matched preterms with no NEC.

Statistical Analysis:

The collected data were tabulated, coded, and then analyzed using the computer program Statistical Package for the Social Science (SPSS version 22).

Results:

Serum levels of I-FABP in NEC cases were significantly higher than the control group, with a mean of 6005.77 ± 6384.77 and 1480.79 ± 1276.48 pg/ml, respectively (P < 0.001). Urine levels of I-FABP in NEC cases were significantly higher than the control group, with a mean of 5009.22 ± 3941.64 and 2677.62 ± 2257.29 pg/ml, respectively (P = 0.04). Both serum and urine I-FABP levels not only in Stage II are significantly higher than Stage I but also in Stage III are significantly higher than Stage I and II (P < 0.001, P = 0.03, respectively), which showed significant positive correlation with stages of NEC (r = 0.618; P < 0.001; r = 0.306; P = 0.049, respectively). Both serum and urine I-FABP levels had a highly significant positive correlation with each other (r = 0.406 P < 0.0001). Receiving operating characteristic curve showed an area under the curve of 0.92 and 0.81 for serum and urine I-FABP, respectively.

Conclusions:

Whether serum or urinary I-FABP is valuable in the diagnosis and prediction of NEC and strongly correlated with the disease severity and with each other.

Predicting abnormal laboratory blood test results in the intensive care unit using novel features based on information theory and historical conditional probability: Observational Study (Preprint)

Background

Redundancy in laboratory blood tests is common in intensive care units (ICUs), affecting patients’ health and increasing health care expenses. Medical communities have made recommendations to order laboratory tests more judiciously. Wise selection can rely on modern data-driven approaches that have been shown to help identify low-yield laboratory blood tests in ICUs. However, although conditional entropy and conditional probability distribution have shown the potential to measure the uncertainty of yielding an abnormal test, no previous studies have adapted these techniques to include them in machine learning models for predicting abnormal laboratory test results.

Objective

This study aimed to address the limitations of previous reports by adapting conditional entropy and conditional probability to extract features for predicting abnormal laboratory blood test results.

Methods

We used an ICU data set collected across Alberta, Canada, which included 55,689 ICU admissions from 48,672 patients. We investigated the features of conditional entropy and conditional probability by comparing the performances of 2 machine learning approaches for predicting normal and abnormal results for 18 blood laboratory tests. Approach 1 used patients’ vitals, age, sex, and admission diagnosis as features. Approach 2 used the same features plus the new conditional entropy–based and conditional probability–based features. Both approaches used 4 different machine learning models (fuzzy model, logistic regression, random forest, and gradient boosting trees) and 10 metrics (sensitivity, specificity, accuracy, precision, negative predictive value [NPV], F₁ score, area under the curve [AUC], precision-recall AUC, mean G, and index balanced accuracy) to assess the performance of the approaches.

Results

Approach 1 achieved an average AUC of 0.86 for all 18 laboratory tests across the 4 models (sensitivity 78%, specificity 84%, precision 82%, NPV 75%, F₁ score 79%, and mean G 81%), whereas approach 2 achieved an average AUC of 0.89 (sensitivity 84%, specificity 84%, precision 83%, NPV 81%, F₁ score 83%, and mean G 84%). We found that the inclusion of the new features resulted in significant differences for most of the metrics in favor of approach 2. Sensitivity significantly improved for 8 and 15 laboratory tests across the different classifiers (minimum P<.001 and maximum P=.04). Mean G and index balanced accuracy, which are balanced performance metrics, also improved significantly across the classifiers for 6 to 10 and 6 to 11 laboratory tests. The most relevant feature was the pretest probability feature, which is the probability that a test result was normal when a certain number of consecutive prior tests was already normal.

Conclusions

The findings suggest that conditional entropy–based features and pretest probability improve the capacity to discriminate between normal and abnormal laboratory test results. Detecting the next laboratory test result is an intermediate step toward developing guidelines for reducing overtesting in the ICU.

Avoidable Serum Potassium Testing in the Cardiac ICU: Development and Testing of a Machine-Learning Model

OBJECTIVES

To create a machine-learning model identifying potentially avoidable blood draws for serum potassium among pediatric patients following cardiac surgery.

DESIGN

Retrospective cohort study.

SETTING

Tertiary-care center.

PATIENTS

All patients admitted to the cardiac ICU at Boston Children's Hospital between January 2010 and December 2018 with a length of stay greater than or equal to 4 days and greater than or equal to two recorded serum potassium measurements.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We collected variables related to potassium homeostasis, including serum chemistry, hourly potassium intake, diuretics, and urine output. Using established machine-learning techniques, including random forest classifiers, and hyperparameter tuning, we created models predicting whether a patient's potassium would be normal or abnormal based on the most recent potassium level, medications administered, urine output, and markers of renal function. We developed multiple models based on different age-categories and temporal proximity of the most recent potassium measurement. We assessed the predictive performance of the models using an independent test set. Of the 7,269 admissions (6,196 patients) included, serum potassium was measured on average of 1 (interquartile range, 0-1) time per day. Approximately 96% of patients received at least one dose of IV diuretic and 83% received a form of potassium supplementation. Our models predicted a normal potassium value with a median positive predictive value of 0.900. A median percentage of 2.1% measurements (mean 2.5%; interquartile range, 1.3-3.7%) was incorrectly predicted as normal when they were abnormal. A median percentage of 0.0% (interquartile range, 0.0-0.4%) critically low or high measurements was incorrectly predicted as normal. A median of 27.2% (interquartile range, 7.8-32.4%) of samples was correctly predicted to be normal and could have been potentially avoided.

CONCLUSIONS

Machine-learning methods can be used to predict avoidable blood tests accurately for serum potassium in critically ill pediatric patients. A median of 27.2% of samples could have been saved, with decreased costs and risk of infection or anemia.

The Prevalence and Clinical Significance of Preoperative Thrombocytopenia in Adults Undergoing Elective Surgery: An Observational Cohort Study

BACKGROUND

Preoperative thrombocytopenia is associated with inferior outcomes in surgical patients, though concurrent anemia may obfuscate these relationships. This investigation assesses the prevalence and clinical significance of preoperative thrombocytopenia with thorough consideration of preoperative anemia status.

METHODS

This is an observational cohort study of adults undergoing elective surgery with planned postoperative hospitalization from January 1, 2009 to May 3, 2018. Patients were designated into 4 groups: normal platelet and hemoglobin concentrations, isolated thrombocytopenia (ie, platelet count <100 × 109/L), isolated anemia (ie, hemoglobin <12 g/dL women, <13.5 g/dL men), and thrombocytopenia with anemia. Thrombocytopenia was further defined as incidental (ie, previously undiagnosed) or nonincidental. Multivariable regression analyses were utilized to assess the relationships between thrombocytopenia status and clinical outcomes, with a primary outcome of hospital length of stay.

RESULTS

A total of 120,348 patients were included for analysis: 72.3% (95% confidence interval [CI], 72.1-72.6) normal preoperative laboratory values, 26.3% (26.1-26.6) isolated anemia, 0.80% (0.75-0.86) thrombocytopenia with anemia, and 0.52% (0.48-0.56) isolated thrombocytopenia (0.38% [0.34-0.41] nonincidental, 0.14% [0.12-0.17] incidental). Thrombocytopenia was associated with longer hospital length of stay in those with concurrent anemia (multiplicative increase of the geometric mean 1.05 [1.00, 1.09] days; P = .034) but not in those with normal preoperative hemoglobin concentrations (multiplicative increase of the geometric mean 1.02 [0.96, 1.07] days; P = .559). Thrombocytopenia was associated with increased odds for intraoperative transfusion regardless of anemia status (nonanemic: 3.39 [2.79, 4.12]; P < .001 vs anemic: 2.60 [2.24, 3.01]; P < .001). Thrombocytopenia was associated with increased rates of intensive care unit (ICU) admission in nonanemic patients (1.56 [1.18, 2.05]; P = .002) but not in those with preoperative anemia (0.93 [0.73, 1.19]; P = .578).

CONCLUSIONS

Preoperative thrombocytopenia is associated with clinical outcomes in elective surgery, both in the presence and absence of concurrent anemia. However, isolated thrombocytopenia is rare (0.5%) and is usually identified before preoperative testing. It is unlikely that routine thrombocytopenia screening is indicated for most patients.

Diagnostic blood loss from phlebotomy and hospital acquired anemia in patients with severe burns

PURPOSE

The study was performed to estimate the diagnostic blood loss (DBL) volume during hospitalization and investigate its relationship with the development of moderate to severe hospital acquired anemia (HAA) and increased number of red blood cell (RBC) transfusion following extensive burns.

MATERIALS AND METHODS

This was a retrospective study of adult burned patients with total body surface area (TBSA) burn larger than 40%, who were admitted to burn center of Changhai hospital between January 2005 and December 2017.

RESULTS

We included a final number of 157 patients in the present study. Moderate to severe HAA within the fourth week postburn was developed in 46 of 121 patients who stayed over 28-day hospitalization. Patients with moderate to severe HAA had both significantly higher total DBL volume [245 (IQR: 183.75, 325.25) mL vs 168 (119, 163) mL ; P = 0.001] and DBL volume per day [10.22 (IQR: 8.57, 12.38) mL vs 6.63 (5.22, 10.42) mL/day; P = 0.005]. Logistic regression analysis revealed that both DBL volume per day and TBSA burn were independent risk factors for the development of moderate to severe HAA.

CONCLUSIONS

Severely burned patients appear to be prone to develop HAA during hospitalization. The DBL volume contribute to the occurrence of moderate to severe HAA, which might be a modifiable target for preventing HAA.

Association between anemia and postoperative complications in infants undergoing pyloromyotomy

BACKGROUND

Although preoperative anemia has been suggested to predict postsurgical morbidity and mortality among infants <1 year of age, the data were drawn from heterogeneous patient cohorts including severely ill infants undergoing complex, high-risk procedures. We aimed to determine whether untreated preoperative anemia was associated with increased risk of postoperative complications in infants <1 year of age who underwent pyloromyotomy, a common and relatively simple surgery.

METHODS

Infants <1 year of age undergoing pyloromyotomy were identified from the American College of Surgeons (ACS) National Surgical Quality Improvement Program-Pediatric database. Preoperative anemia was defined as a hematocrit ≤40% for infants 0-30 days of age and ≤30% for infants more than 30 days of age. Patients who received pre- or postoperative blood transfusions were excluded.

RESULTS

We identified 2948 patients who met our inclusion criteria, of whom 843 were anemic (29%). The overall rate of complications in this cohort was 6%. The most common postoperative complications were readmission (97 cases), surgical site infection (43), reoperation (39), prolonged hospital stay (24), urinary tract infection (3), 30-day mortality (3) and cardiac arrest (2). We found no differences in the incidence of complications in anemic versus nonanemic patients on bivariate analysis or multivariable logistic regression (adjusted odds ratio = 1.2; 95% confidence interval: 0.8-1.7; P = 0.319).

CONCLUSIONS

In relatively healthy infants undergoing pyloromyotomy, untreated preoperative anemia was not associated with postoperative compilations and should not be considered a significant risk factor. Level of evidence III.

Patient Blood Management in Pediatric Cardiac Surgery: A Review

Efforts to reduce blood product transfusions and adopt blood conservation strategies for infants and children undergoing cardiac surgical procedures are ongoing. Children typically receive red blood cell and coagulant blood products perioperatively for many reasons, including developmental alterations of their hemostatic system, and hemodilution and hypothermia with cardiopulmonary bypass that incites inflammation and coagulopathy and requires systemic anticoagulation. The complexity of their surgical procedures, complex cardiopulmonary interactions, and risk for inadequate oxygen delivery and postoperative bleeding further contribute to blood product utilization in this vulnerable population. Despite these challenges, safe conservative blood management practices spanning the pre-, intra-, and postoperative periods are being developed and are associated with reduced blood product transfusions. This review summarizes the available evidence regarding anemia management and blood transfusion practices in the perioperative care of these critically ill children. The evidence suggests that adoption of a comprehensive blood management approach decreases blood transfusions, but the impact on clinical outcomes is less well studied and represents an area that deserves further investigation.

A Standard Push-Pull Protocol for Waste-Free Sampling in the Pediatric Intensive Care Unit

Blood sampling is a major source of blood loss in the pediatric intensive care unit (PICU). Blood-sparing sampling techniques such as the push-pull method can significantly reduce sampling-related blood loss and protect patients from anemia and blood transfusions. The push-pull method is supported by research evidence for central venous catheter (CVC) sampling, but research protocols differ and not all CVCs and laboratory tests have been studied. A standard push-pull protocol for the PICU was developed, implemented, and evaluated in this evidence-based practice project. Results show that the protocol can be used safely and reliably as a standard waste-free sampling method in the PICU.

Patient blood management, what does this actually mean for neonates and infants?

Patient blood management (PBM) refers to an evidence-based package of care that aims to improve patient outcomes by optimal use of transfusion therapy, including managing anaemia, preventing blood loss and improving anaemia tolerance in surgical and other patients who may need transfusion. In adults, PBM programmes are well established, yet the definition and implementation of PBM in neonates and children lags behind. Neonates and infants are frequently transfused, yet they are often under-represented in transfusion trials. Adult PBM programmes may not be directly applicable to these populations. We review the literature in neonatal (and applicable paediatric) transfusion medicine and propose specific neonatal PBM definitions and elements.

Engineering of a miniaturized, robotic clinical laboratory

The ability to perform laboratory testing near the patient and with smaller blood volumes would benefit patients and physicians alike. We describe our design of a miniaturized clinical laboratory system with three components: a hardware platform (ie, the miniLab) that performs preanalytical and analytical processing steps using miniaturized sample manipulation and detection modules, an assay-configurable cartridge that provides consumable materials and assay reagents, and a server that communicates bidirectionally with the miniLab to manage assay-specific protocols and analyze, store, and report results (i.e., the virtual analyzer). The miniLab can detect analytes in blood using multiple methods, including molecular diagnostics, immunoassays, clinical chemistry, and hematology. Analytical performance results show that our qualitative Zika virus assay has a limit of detection of 55 genomic copies/ml. For our anti-herpes simplex virus type 2 immunoglobulin G, lipid panel, and lymphocyte subset panel assays, the miniLab has low imprecision, and method comparison results agree well with those from the United States Food and Drug Administration-cleared devices. With its small footprint and versatility, the miniLab has the potential to provide testing of a range of analytes in decentralized locations.

Controlling Phlebotomy Volume Diminishes PICU Transfusion: Implementation Processes and Impact

BACKGROUND AND OBJECTIVES

Phlebotomy excess contributes to anemia in PICU patients and increases the likelihood of red blood cell transfusion, which is associated with risk of adverse outcomes. Excessive phlebotomy reduction (EPR) strategies may reduce the need for transfusion, but have not been evaluated in a PICU population. We hypothesized that EPR strategies, facilitated by implementation science methods, would decrease excess blood drawn and reduce transfusion frequency.

METHODS

Quantitative and qualitative methods were used. Patient and blood draw data were collected with survey and focus group data to evaluate knowledge and attitudes before and after EPR intervention. The Consolidated Framework for Implementation Research was used to interpret qualitative data. Multivariate regression was employed to adjust for potential confounders for blood overdraw volume and transfusion incidence.

RESULTS

Populations were similar pre- and postintervention. EPR strategies decreased blood overdraw volumes 62% from 5.5 mL (interquartile range 1-23) preintervention to 2.1 mL (interquartile range 0-7.9 mL) postintervention (P < .001). Fewer patients received red blood cell transfusions postintervention (32.1% preintervention versus 20.7% postintervention, P = .04). Regression analyses showed that EPR strategies reduced blood overdraw volume (P < .001) and lowered transfusion frequency (P = .05). Postintervention surveys reflected a high degree of satisfaction (93%) with EPR strategies, and 97% agreed EPR was a priority postintervention.

CONCLUSIONS

Implementation science methods aided in the selection of EPR strategies and enhanced acceptance which, in this cohort, reduced excessive overdraw volumes and transfusion frequency. Larger trials are needed to determine if this approach can be applied in broader PICU populations.

Noninvasive hemoglobin monitoring in critically ill pediatric patients at risk of bleeding

OBJECTIVE

To determine the accuracy and usefulness of noninvasive continuous hemoglobin (Hb) monitoring in critically ill patients at risk of bleeding.

DESIGN

An observational prospective study was made, comparing core laboratory Hb measurement (LabHb) as the gold standard versus transcutaneous hemoglobin monitoring (SpHb).

SETTING

Pediatric Intensive Care Unit of a tertiary University Hospital.

PATIENTS

Patients weighing >3kg at risk of bleeding.

INTERVENTIONS

SpHb was measured using the Radical7 pulse co-oximeter (Masimo Corp., Irvine, CA, USA) each time a blood sample was drawn for core laboratory analysis (Siemens ADVIA 2120i).

VARIABLES

Sociodemographic characteristics, perfusion index (PI), pleth variability index, heart rate, SaO₂, rectal temperature, low signal quality and other events that can interfere with measurement.

RESULTS

A total of 284 measurements were made (80 patients). Mean LabHb was 11.7±2.05g/dl. Mean SpHb was 12.32±2g/dl (Pearson 0.72, R² 0.52). The intra-class correlation coefficient was 0.69 (95%CI 0.55-0.78)(p<0.001). Bland-Altman analysis showed a mean difference of 0.07 ±1.46g/dl. A lower PI and higher temperature independently increased the risk of low signal quality (OR 0.531 [95%CI 0.32-0.88] and 0.529 [95%CI 0.33-0.85], respectively).

CONCLUSIONS

SpHb shows a good overall correlation to LabHb, though with wide limits of agreement. Its main advantage is continuous monitoring of patients at risk of bleeding. The reliability of the method is limited in cases with poor peripheral perfusion.

Hematocrit Levels, Blood Testing, and Blood Transfusion in Infants After Heart Surgery

OBJECTIVE

To determine whether judicious blood testing impacts timing or amount of packed RBC transfusions in infants after heart surgery.

DESIGN

A retrospective study comparing before and after initiation of a quality improvement process.

SETTING

A university-affiliated cardiac ICU at a tertiary care children's hospital.

PATIENTS

Infants less than 1 year old with Risk Adjustment for Congenital Heart Surgery category 4, 5, 6, or d-transposition of great arteries (Risk Adjustment for Congenital Heart Surgery 3) consecutively treated during 2010 through 2013.

INTERVENTION

A quality improvement process implemented in 2011 to decrease routine laboratory testing after surgery.

MEASUREMENTS AND MAIN RESULTS

Fifty-two infants preintervention and 214 postintervention had similar age, weight, proportion of cyanotic lesions, and surgical complexity. Infants with single versus biventricular physiology were compared separately. The number of laboratory tests per patient adjusted for cardiac ICU length of stay (laboratory tests/patient/day) was significantly lower in postintervention populations for single and biventricular groups (9 vs 15 and 10 vs 15, respectively; p < 0.001). The proportion of single ventricle patients transfused post- and preintervention was not statistically different (72% vs 90%; p = 0.130). Transfusion in the biventricular groups was the same over time (65% vs 65%). Time to first transfusion was significantly longer in the postintervention single ventricle group (4 vs 1 d; p < 0.001), and was not statistically different in the biventricular patients (4 vs 7 d; p = 0.058). The median hematocrit level at first transfusion was significantly lower (37% vs 40%; p = 0.004) postintervention in the cyanotic population, but did not differ in the biventricular group (31% vs 31%; p = 0.840).

CONCLUSION

In infants after heart surgery, blood testing targeted to individual needs significantly decreased the number of blood tests, but did not significantly decrease postoperative blood transfusion.

Development of anemia, phlebotomy practices, and blood transfusion requirements in 45 critically ill cats (2009-2011)

OBJECTIVE

To describe the incidence of the development of anemia, the number of phlebotomies performed daily, the approximate volume of blood withdrawn, the transfusion requirements and their association with duration of hospitalization and survival to discharge in critically ill cats.

DESIGN

Retrospective study from January 2009 to January 2011.

SETTING

University teaching hospital.

ANIMALS

Cats hospitalized in the intensive care unit (ICU) for >48 hours.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Medical records of cats hospitalized for >48 hours in the ICU were examined. Of the 45 cats included, 60% (27/45) were not anemic upon admission to the ICU. Of these, 74.1% (20/27) developed anemia during their ICU stay. Development of anemia was associated with a longer duration of hospitalization (P = 0.002) but not with survival (P = 0.46). Fourteen cats (31.1%; 14/45) received one or more packed red blood cell transfusions and had significantly longer ICU stays (P < 0.001). Transfusion requirements were not associated with survival (P = 0.66). The median number of phlebotomies per day for all cats in the ICU was 3 (range 1-6). This was significantly associated with the development of anemia (P = 0.0011) and higher transfusion requirements (P = 0.16) in the 14 cats that received a transfusion. The estimated volume phlebotomized was significantly (P < 0.001) greater in cats that required a transfusion (median volume 3.32 mL/kg/ICU stay) compared to cats that did not require a transfusion (median volume 1.11 mL/kg/ICU stay) but was not associated with survival to discharge (P = 0.84).

CONCLUSIONS

Development of anemia necessitating blood transfusions is common in critically ill cats and leads to significantly longer duration of ICU hospitalization. Iatrogenic anemia from frequent phlebotomies is an important cause for increased transfusion requirement. Fewer phlebotomies and other blood conserving strategies in these patients may help reduce the incidence of anemia and decrease transfusion requirements, as well as result in shorter hospital stays.

Intestinal fatty acid-binding protein as a diagnostic marker for complicated and uncomplicated necrotizing enterocolitis: a prospective cohort study

Background

Early NEC symptoms are non-specific and diagnostic tests lack discriminative power. Intestinal fatty acid-binding protein (I-FABP), mainly located in small bowel enterocytes, is released into the blood following NEC-associated enterocyte disruption. Aim of this prospective cohort trial was to determine the diagnostic value of I-FABP measured in plasma (I-FABPp) and urine (I-FABPu) for the presence of NEC, to evaluate I-FABP levels during NEC development, and to assess its prognostic value for the progression from suspected to complicated disease.

Methods

Between 2010 and 2012 we prospectively enrolled neonates with suspected NEC. We measured I-FABP levels eight-hourly from onset of suspected NEC for at least 48 hours, or until surgery. NEC diagnosis was confirmed radiologically or during operation. We defined NEC as complicated if it resulted in surgery and/or death. We determined disease course and diagnostic I-FABP cut-off points.

Results

The study comprised 37 neonates (24M, 13F), gestational age 28 (24–36) weeks, birth weight 1190 (570–2,400) grams. We found significantly higher I-FABPp and I-FABPu levels in NEC patients (n = 22) than in patients with other diagnoses (n = 15). Cut-off values for diagnosing NEC were 9 ng/mL I-FABPp and 218 ng/mL I-FABPu, with corresponding likelihood ratios (LRs) of 5.6 (95% CI 0.89–35) and 5.1 (95% CI 0.73–36), respectively. I-FABP levels were highest in the first eight hours after symptom onset and gradually decreased over time. Cut-off values for complicated disease were 19 ng/mL I-FABPp and 232 ng/mL I-FABPu, with LRs of 10 (95% CI 1.6–70) and 11 (95% CI 1.6–81), respectively.

Conclusions

Both plasma and urinary I-FABP levels specifically identify NEC in preterm infants prior to appearance of diagnostic radiological signs suggestive for NEC. Moreover, serial I-FABP measurements accurately predict development of complicated disease.

Impact of an educational intervention on the frequency of daily blood test orders for hospitalized patients

OBJECTIVES

During hospitalizations, blood is drawn for diagnostic laboratory tests to help guide patient care. Often, blood tests continue to be ordered even in the face of clinical and laboratory stability. Blood draws are painful and costly, and they may be associated with anemia. We hypothesized that provider education could reduce the frequency of daily blood tests ordered for hospitalized patients.

METHODS

During a 2-month intervention period, internal medicine providers were educated through flyers displayed in providers' offices and periodic email communications reminding them to order daily blood tests only if the results would change patient care. Two-month preintervention data from 982 patients and 2-month postintervention data from 988 patients were analyzed. The primary outcome measured was the number of daily blood tests ordered per patient per day.

RESULTS

Mean orders of CBC decreased from 1.46 to 1.37 tests per patient per day (P < .05) after the intervention. Basic metabolic panel orders were reduced from 0.91 to 0.83 tests per patient per day (P < .05). Cost analyses showed a reduction of $6.33 per patient day based on the decrease in the number of daily laboratory tests ordered.

CONCLUSIONS

Provider education and reminders can reduce the frequency of daily blood tests ordered by providers for hospitalized patients. This can decrease health care costs and may reduce the risk of complications such as anemia.

A practical approach to risk-benefit estimation in pediatric drug research

One of the most difficult challenges in pediatric drug research is in exposing children to risk, often without a balanced chance of benefits. While the concept of risk is similar in adult research, the adult patient can decide for himself/herself on an acceptable level of risk, whereas children have to accept the decisions of their guardians. This paper attempts to put the complexities of estimating risk in pediatric drug research into their practical perspective, and to familiarize the reader with the way such processes are conducted in different parts of the world. Although there are regional differences, all authorities typically quantify risks of pediatric research in general, and drug research in particular, in three levels: those experienced in day-to-day life; risks slightly above this 'baseline' risk; and risks substantially above 'baseline risk'. Proportionally, the diligence of the ethics process depends on these levels, as well as on the potential benefits (or lack of) to the child involved in the research. Importantly, risk is context dependent, and a particular intervention may be effective or safe in one setting but not in another, based on local experience, staffing levels, and similar variabilities.

A survey of some pre-analytical errors identified from the Biochemistry Department of a Scottish hospital

Background

It is estimated that 70% of all health care decisions affecting diagnosis or treatment involve laboratory testing. The pre-analytical phase of the testing process shows the highest prevalence of errors accounting for 70% of all mistakes in laboratory diagnostics. It is recommended that laboratories collect statistics on pre-analytical error rates. This survey examined some mistakes in blood collection, i.e. specimen haemolysis, and EDTA contamination.

Methods

Survey was from June 2011 to May 2012. Haemolysis was detected by analysers’ automated haemolysis index function. Plasma EDTA was measured by an automated system. Data were captured from our laboratory information management system.

Results

For a total workload of 763,577 blood specimens, the overall haemolysis rate was 3.2%. Much higher rates of both specimen haemolysis and EDTA contamination were observed when blood was not collected by trained phlebotomists.

Conclusions

Better training in blood collection, achieving the standard of professional phlebotomists, will improve validity of diagnostic information; reduce risks of dangerous misinterpretation of results, unwanted anaemia and needlestick injury and decrease laboratory supplies costs. This type of audit could be replicated in other Scottish Health Boards with some benefit and thereby better target future training needs.

Intestinal fatty acid-binding protein in neonates with imminent necrotizing enterocolitis

BACKGROUND

Intestinal fatty acid-binding protein (I-FABP) is a promising marker for necrotizing enterocolitis (NEC). It can be measured in plasma (I-FABPp) and urine (I-FABPu). Data on the best way to measure I-FABP (in plasma or urine) and the necessity of simultaneous measurement of the urinary creatinine concentration to correct for physiological variations in urine concentration are not available. This holds also true for the reciprocal relation between I-FABPp, I-FABPu and other more conventional laboratory parameters.

OBJECTIVES

To evaluate the above-mentioned correlations of I-FABP measurements in neonates with suspected NEC.

METHODS

All neonates with suspected NEC were prospectively included. I-FABPp and I-FABPu were analyzed at regular intervals during the first 24 h after onset of symptoms. Correlation and agreement were assessed between these and other parameters (i.e., IL-6, WBC, platelet count, CRP, pH and lactate).

RESULTS

Included were 24 boys, 13 girls [median (range) GA 28 weeks (24-36), median birth weight 1,190 g (570-2,400)]. I-FABPu correlated strongly with I-FABPp (r 0.80, p < 0.001) with an adequate agreement. A very strong correlation between I-FABPu and I-FABPu/urine creatinine ratio (r 0.98, p < 0.001) existed. Correlations between I-FABPp/u and conventional parameters were moderate to strong until 8 h after onset of symptoms.

CONCLUSION

In neonates with suspected NEC, I-FABPu correlates strongly with I-FABPp, offering an opportunity to choose the most appropriate way of measuring I-FABP. Calculating urinary IFABP/creatinine ratio seems redundant. Moderately strong correlations between I-FABPu and IL-6, WBC and lactate were found.

Anemia and transfusion in critically ill pediatric patients: a review of etiology, management, and outcomes

This article describes the incidence and etiology of anemia in critically ill children. In addition, the article details the pathophysiology and clinical ramifications of anemia in this population. The use of transfused packed red blood cells as a therapy for anemia in critically ill patients is also discussed, including the indications for and complications associated with this practice as well as potential reasons for these complications. Finally, the article lists some therapeutic practices that may lessen the risks associated with transfusion, and briefly discusses the use of blood substitutes.