'True Blood' The Critical Care Story: An audit of blood sampling practice across three adult, paediatric and neonatal intensive care settings

Blood-sparing techniques prevalence in adult intensive care units: A multicentre survey study

INTRODUCTION

Anaemia is a common condition in patients admitted to intensive care units (ICUs). It is also well known that a significant amount of the carbon dioxide produced by health services is likely attributable to blood donation, testing, and the manufacture, storage, and distribution of blood components. To mitigate this, prevention strategies such as blood-sparing techniques are available. There is a lack of knowledge regarding the use of such techniques in ICUs in Spain and Latin America, healthcare systems with very different health expenditures per capita. The aim is to assess the degree of implementation of blood-sparing techniques in these regions.

METHODS

Cross-sectional online multicentre survey. 251 ICUs in Spain and 53 in Latin America (20 in Argentina, 20 in Colombia, 13 in Ecuador) participated. A 20-item survey on the use of point-of-care, small-volume tubes (SVT), and closed-blood sampling devices (CBSD) was validated. Effect sizes were calculated using Phi (φ) or Cramer's V (V).

RESULTS

A response rate of 77% was obtained for Spain and 96% for Latin America. In Spain, the majority of ICUs were affiliated with public hospitals (88.1%, 171/194) while in Latin America, most were associated with private hospitals (56.9%, 29/51). Regarding the use of point-of-care testing, 67.5% of Spanish ICUs, compared to 35.3% of Latin Americans, reported frequent use (V=0.343). In 91.7% of Spanish ICUs and 58.9% of Latin Americans, SVTs were rarely or never used (V=0.380). The use of CBSD was significantly lower in Spain for both arterial and central venous catheters (V=0.336). Private hospitals used more CBSD in arterial catheter than public ones (27% vs 8.3%, V=0.278).

CONCLUSION

Point-of-care testing can be improved in Latin America, while the use of CBSD and small-volume tubes can be enhanced in Spain. Private hospitals tend to implement blood-sparing techniques more effectively than public hospitals.

Blood gas sampling in the intensive care unit: A prospective before-and-after interventional study on the effect of an educational program on blood gas testing frequency

BACKGROUND

Blood gas analysis is the most commonly ordered test in the intensive care unit. Each investigation, however, comes with risks and costs to the patient and healthcare system. Evidence suggests that many tests are performed with no appropriate clinical indication.

OBJECTIVES

The primary aim of our prospective interventional study was to investigate the proportion of blood gases undertaken with a valid clinical indication before and after an educational intervention. A secondary aim was to examine sleep interruption secondary to blood gas sampling.

METHODS

A prospective, before-and-after interventional study was conducted across two metropolitan intensive care units in Melbourne, Australia. Adults aged ≥18 years who were admitted to intensive care were eligible for inclusion. Two observation periods were conducted across a 2-week period in May and September 2022 (Periods 1 and 2), where clinicians were encouraged to record the purpose of blood gas sampling and other relevant data via an electronic questionnaire. These data were reviewed with corresponding electronic medical records. In between these periods, an interventional educational program to inform the clinical rationale for blood gas testing was delivered during July and August 2022, including introduction of a clinical guideline.

RESULTS

There were 68 patients with 688 tests included in Period 1 compared to 69 patients with 756 tests in Period 2. There was no significant difference between the median number of blood gas analyses performed per patient before and after the educational intervention (6.0 tests per patient vs 5.0 tests per patient, p = 0.609). However, there was a significant increase in the percentage of tests with a valid clinical indication (49.0% vs 59.7%, p = 0.0025). The most common indications selected were routine measurement, monitoring a clinical value, change in ventilator settings/oxygen therapy, and clinical deterioration. In addition, there were a large number of patients who were awakened upon drawing of a blood sample for analysis (26.1% for Period 1 and 37.6% for Period 2, p = 0.06).

CONCLUSION

The implementation of an educational program resulted in a significant increase in the proportion of blood gases performed with an appropriate clinical indication. There was, however, no reduction in the overall number of blood gases performed.

Environmental impact of a blood test reduction intervention in adult intensive care units: A before and after quality improvement project

BACKGROUND

Pathology testing is a very common investigation in the intensive care unit (ICU). Many tests are ordered on a routine basis rather than for a specific clinical indication, resulting in potential patient harm and unnecessary financial and environmental costs.

OBJECTIVE

The objective of this study was to determine whether a multifaceted intervention based on the principles of education, audit, and feedback can result in a decrease in unnecessary pathology tests without a commensurate increase in adverse patient outcomes and to measure this decrease in terms of the associated reduction in environmental and financial costs.

METHODS

A before and after quality improvement project was conducted between 2017 and 2019 across four ICUs in three 12-month phases, divided according to baseline, intervention implementation, and follow-up. Local clinician champions from each site partnered with the project coordinating centre to develop and implement a range of interventions based on the principles of education, audit, and feedback. Data were collected for the number of pathology tests performed and the clinical characteristics of patients admitted to a participating ICU across the three phases.

RESULTS

A total of 196 323 arterial blood gases and 460 258 other tests across eight categories were performed on the 22 210 patients admitted to participating ICUs during the project. A decrease in testing was observed across all but one category, with the greatest reduction seen in arterial blood gases (31.2% reduction in tests per bed-day). Across all categories, this equated to a mean reduction of 1.8 tCO2e (tonnes of carbon dioxide equivalent), a potential estimated total saving of Australian dollar $918 497.50. No increase in adverse clinical outcomes was observed.

CONCLUSION

A multifaceted intervention based on the principles of education, audit, and feedback can produce a significant decrease in the number of unnecessary pathology tests performed. This reduction translates to substantial environmental and financial savings without any associated increase in adverse patient outcomes.

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.

Clotted blood samples in the neonatal intensive care unit: A retrospective, observational study to evaluate interventions to reduce blood sample clotting

BACKGROUND

Blood draws for laboratory investigations are essential for patient management in neonatal intensive care units (NICU). When blood samples clot before analysis, they are rejected, which delays treatment decisions and necessitates repeated sampling.

AIMS

To decrease the incidence of rejected blood samples taken for laboratory investigation as a result of clotted sample.

STUDY DESIGN

This retrospective observational study used routine data on blood draws from preterm infants collected between January 2017 and June 2019 in a 112-cot NICU in Qatar. Quality improvement interventions to reduce the rate of clotted blood samples included: awareness raising and safe sampling workshops with NICU staff, involvement of the neonatal vascular access team, development of a complete blood count (CBC) sample collection pathway, review of sample collection equipment, introducing the Tenderfoot® heel lance, establishment of benchmarks and provision of dedicated blood extraction equipment.

RESULTS

First attempt blood draw occurred in 10 706 cases, representing a 96.2% success rate. In 427 (3.8%) cases, the samples were clotted requiring repeat collection. The overall rate of clotted specimens decreased from 4.8% in 2017 and 2018 to 2.4% in 2019, with odds ratios of 1.42 (95% confidence interval [CI] 1.13-1.78, p = .002), 1.46 (95% CI 1.17-1.81, p < .001) and 0.49 (95% CI 0.39-0.63, p < .001), respectively. The majority (87%-95%) of blood samples were by venepuncture using an intravenous (IV) catheter or the NeoSafe™ blood sampling device. Heel prick sampling was the second (2%-9%) most common method. Clotted samples were most frequently associated with needle use, 228 of 427 (53%), and IV cannula, 162 of 427 (38%), with odds ratios of 4.14 (95% CI 3.34-5.13, p < .001) and 3.11 (95% CI 2.51-3.86, p < .001), respectively.

CONCLUSIONS

Our interventions over 3 years were associated with reduced rates of sample rejection due to clotting, and this led to improved patient experience through fewer repeated samplings.

RELEVANCE TO CLINICAL PRACTICE

The insights gained from this project can help to improve patient care. Interventions that reduce the rate of blood sample rejection by clinical laboratories can lead to economic savings, timelier diagnostic and treatment decisions, and contribute to an improved quality care experience for all critical care patients, irrespective of age, by reducing the need for repeated phlebotomy and the risk of related complications.

Routine Versus On-Demand Blood Sampling in Critically Ill Patients: A Systematic Review

OBJECTIVES

We aimed to provide an overview of the current evidence on routine versus on-demand blood sampling in critical care. We assessed the reported proportion of patients exposed to daily routine blood sampling, the tests performed, characteristics associated with more frequent blood sampling, and the reported benefits and harms of routine blood sampling compared with on-demand sampling.

DATA SOURCES

We systematically searched the Cochrane Library, the Excerpta Medica Database, and the Medical Literature Analysis and Retrieval System Online for studies assessing routine versus on-demand blood testing in critically ill patients from inception to September 2022.

STUDY SELECTION

Abstracts and full texts were assessed independently and in duplicate by two reviewers.

STUDY EXTRACTION

Data were extracted independently and in duplicate by two reviewers using predefined extraction forms.

DATA SYNTHESIS

Of 12,212 records screened, 298 full-text articles were assessed for eligibility. We included 70 studies; 50 nonrandomized interventional studies and 20 observational studies. Exposure to routine blood testing was 52-100% (very low certainty of evidence). Blood testing seemed to occur more frequently in medical intensive care settings with a median of 18 blood tests per patient day (interquartile range, 10-33) (very low certainty of evidence). Mixed biochemistry seemed to be the most frequently performed blood tests across all settings (five tests per patient day; interquartile range, 2-10) (very low certainty of evidence). Reductions in routine blood testing seemed to be associated with reduced transfusion rates and costs without apparent adverse patient outcomes (low certainty of evidence).

CONCLUSIONS

In this systematic review, routine blood testing in critically ill patients was common and varied considerably. A reduction in routine blood testing appeared to be associated with reduced transfusion rates and costs without adverse effects, but the evidence was very uncertain.

Evaluation of a closed loop-blood sampling system in intensive care: A pilot randomised controlled trial. The ENCLOSE trial

OBJECTIVE

To test the feasibility of conducting a randomised controlled trial to evaluate the impact of a closed-loop blood sampling system and blood conservation bundle.

METHODS

Single site, parallel group, pilot randomised control trial comparing open system sampling to closed system sampling and conservation bundle aligned with national guidelines. Randomisation sequence was generated by an independent statistician and allocation concealment maintained via sealed opaque envelopes. The study setting was the general intensive care unit of a major metropolitan public hospital in Queensland, Australia. Participants were ≥ 18 years who had an arterial catheter inserted in intensive care. Main outcome measures included trial feasibility, blood sample loss, haematocrit (HCT) change, and packed red blood cell transfusion use.

RESULTS

Eighty patients were randomised (n = 39 open group, n = 41 closed group). Characteristics in each group were equal at baseline with overall median age 60 years (IQR 48.6-70.4), 58 % male, and median APACHE II score 16 (IQR 11-22). The proportion of patients eligible was 29 % and missed eligible was 65 %. Otherwise, feasibility criteria were met with proportion of eligible patients agreeing to enrolment 99 %, 100 % of patients receiving allocated treatment; only 1 % of data missing. Analysis demonstrated a significant reduction in mean daily blood sample losses (open 32.7 (SD 1.58) mL vs closed 15.5 (SD 5.79) mL, t = -8.454, df = 78, p < 0.001).

CONCLUSIONS

A large, multi-site trial is feasible with enhanced eligibility criteria, increased recruitment support. The intervention reduced daily blood sample volumes and transfusion use. Further trials are required to provide both effectiveness and implementation outcomes.

Patient blood management in critically ill children undergoing cardiac surgery: A cohort study

OBJECTIVE

The objective of this study was to audit current patient blood management practice in children throughout cardiac surgery and paediatric intensive care unit (PICU) admission.

DESIGN

This was a prospective observational cohort study.

SETTING

This was a single-centre study in the cardiac operating room (OR) and PICU in a major tertiary children's hospital in Australia.

PATIENTS

Children undergoing corrective cardiac surgery and requiring admission to PICU for postoperative recovery were included in the study.

MEASUREMENTS AND MAIN RESULTS

Fifty-six patients and 1779 blood sampling episodes were audited over a 7-month period. The median age was 9 months (interquartile range [IQR] = 1-102), with the majority (n = 30 [54%]) younger than 12 months. The median number of blood sampling episodes per patient per day was 6.6 (IQR = 5.8-8.0) in total, with a median of 5.0 (IQR = 4.0-7.5) episodes in the OR and 5.0 (IQR = 3.4-6.2) episodes per day throughout PICU admission. The most common reason for blood tests across both OR and PICU settings was arterial blood gas analysis (total median = 86%, IQR = 79-96). The overall median blood sampling volume per kg of bodyweight, patient, and day was 0.63 mL (IQR = 0.20-1.14) in total. Median blood loss for each patient was 3.5 mL/kg per patient per day (IQR = 1.7-5.6) with negligible amounts in the OR and a median of 3.6 mL/kg (IQR = 1.7-5.7) in the PICU. The median Cell Saver® transfusion volume was 9.9 mL/kg per patient per day (IQR = 4.0-19.1) in the OR. The overall median volume of other infusion products (albumin 4%, albumin 20%, packed red blood cells) received by each patient was 20.1 mL/kg (IQR = 10.7-36.4) per day. Sampling events and blood loss were positively associated with PICU stay.

CONCLUSIONS

Patient blood management practices observed in this study largely conform to National Blood Authority guidelines. Further implementation projects and research are needed to accelerate implementation of known effective blood conservation strategies within paediatric critical care environments.

Reducing unnecessary diagnostic phlebotomy in intensive care: a prospective quality improvement intervention

BACKGROUND

Critically ill patients receive frequent routine and recurring blood tests, some of which are unnecessary.

AIM

To reduce unnecessary routine phlebotomy in a 30-bed tertiary medical-surgical intensive care unit (ICU) in Toronto, Ontario.

METHODS

This prospective quality improvement study included a 7-month preintervention baseline, 5-month intervention and 11-month postintervention period. Change strategies included education, ICU rounds checklists, electronic order set modifications, an electronic test add-on tool and audit and feedback. The primary outcome was mean volume of blood collected per patient-day. Secondary outcomes included the number blood tubes used and red cell transfusions. Balancing measures included the timing and types of blood tests, ICU length of stay and mortality. Outcomes were evaluated using process control charts and segmented regression.

RESULTS

Patient demographics did not differ between time periods; total number of patients: 2096, median age: 61 years, 60% male. Mean phlebotomy volume±SD decreased from 41.1±4.0 to 34.1±4.7 mL/patient-day. Special cause variation was met at 13 weeks. Segmental regression demonstrated an immediate postintervention decrease of 6.6 mL/patient-day (95% CI 1.8 to 11.4 p=0.009), which was sustained. Blood tube consumption decreased by 1.4 tubes/patient-day (95% CI 0.4 to 2.4, p=0.005) amounting to 13 276 tubes (95% CI 4602 to 22 127 tubes) saved over 11 months. Red blood cell transfusions decreased from 10.5±5.2 to 8.3±4.4 transfusions/100 patient-days (incident rate ratio 0.56, 95% CI 0.35 to 0.88, p=0.01). There was no impact on length of stay (2 days, IQR 1-5) and mortality (18.1%±2.0%).

CONCLUSION

Iterative improvement interventions targeting clinician test ordering behaviour can reduce ICU phlebotomy and may impact red cell transfusions. Frequent stakeholder consultation, incorporating stewardship into daily workflow, and audit and feedback are effective strategies.

Every treasured drop! Blood transfusion requirements in very preterm neonates after implementation of blood conservation strategies: an observational analytical study

BACKGROUND

Certain morbidities are inevitable in preterm infants; the challenge lies in minimizing them. Anemia of prematurity is multifactorial. Therapy largely depends on adult red blood cell transfusions (RBCT); which inherently, are not without problems. Most literature in this respect are retrospective or evaluate individual stratagems to reduce RBCT.

METHODS

This observational analytical study was planned to compare need for RBCT, before and after institution of blood conservation strategies (BCS). All those ≤30 weeks gestation at birth during two-time epochs were included (Before BCS: retrospective; After BCS: prospective). BCS constituted of delayed cord clamping (DCC), strict sampling indications, micro-sampling with point-of-care testing (MS-POCT) and adherence to RBCT thresholds.

RESULTS

Of 45 enrolled neonates in each group, proportion of those requiring even 1 RBCT was significantly reduced after BCS [51.1% vs. 26.7%, p = 0.02, OR 0.35, 95%CI (0.14, 0.84)]. Calculated cumulative blood volume losses (35.3 ml vs. 21.9 ml) and loss per kilogram birth weight (35.3 ml/kg vs. 20.12 ml/kg) were significantly lower after BCS (p = 0.0036). Need for &gt;1 RBCT, mean lowest Hb, mean maximum-hemoglobin drop, need for arterial lines were reduced. Adherence to RBCT thresholds were acceptably good in both time epochs. However, the compliance to DCC was low in both groups, identifying one area of focus with scope for massive improvement.

CONCLUSIONS

Need for RBCT transfusions largely attributable to reduced blood losses for lab analysis were reduced after BCS. Installation of in-house MS-POCT seemed to be the pivotal factor. Units that care for very preterm infants must make attempts to procure MS-POCT equipment.

Avoidable Blood Loss in Critical Care and Patient Blood Management: Scoping Review of Diagnostic Blood Loss

Background: Anemia remains one of the most common comorbidities in intensive care patients worldwide. The cause of anemia is often multifactorial and triggered by underlying disease, comorbidities, and iatrogenic factors, such as diagnostic phlebotomies. As anemia is associated with a worse outcome, especially in intensive care patients, unnecessary iatrogenic blood loss must be avoided. Therefore, this scoping review addresses the amount of blood loss during routine phlebotomies in adult (>17 years) intensive care patients and whether there are factors that need to be improved in terms of patient blood management (PBM). Methods: A systematic search of the Medline Database via PubMed was conducted according to PRISMA guidelines. The reported daily blood volume for diagnostics and other relevant information from eligible studies were charted. Results: A total of 2167 studies were identified in our search, of which 38 studies met the inclusion criteria (9 interventional studies and 29 observational studies). The majority of the studies were conducted in the US (37%) and Canada (13%). An increasing interest to reduce iatrogenic blood loss has been observed since 2015. Phlebotomized blood volume per patient per day was up to 377 mL. All interventional trials showed that the use of pediatric-sized blood collection tubes can significantly reduce the daily amount of blood drawn. Conclusion: Iatrogenic blood loss for diagnostic purposes contributes significantly to the development and exacerbation of hospital-acquired anemia. Therefore, a comprehensive PBM in intensive care is urgently needed to reduce avoidable blood loss, including blood-sparing techniques, regular advanced training, and small-volume blood collection tubes.

Dynamic Monitoring of Systemic Biomarkers with Gastric Sensors

Continuous monitoring in the intensive care setting has transformed the capacity to rapidly respond with interventions for patients in extremis. Noninvasive monitoring has generally been limited to transdermal or intravascular systems coupled to transducers including oxygen saturation or pressure. Here it is hypothesized that gastric fluid (GF) and gases, accessible through nasogastric (NG) tubes, commonly found in intensive care settings, can provide continuous access to a broad range of biomarkers. A broad characterization of biomarkers in swine GF coupled to time-matched serum is conducted . The relationship and kinetics of GF-derived analyte level dynamics is established by correlating these to serum levels in an acute renal failure and an inducible stress model performed in swine. The ability to monitor ketone levels and an inhaled anaesthetic agent (isoflurane) in vivo is demonstrated with novel NG-compatible sensor systems in swine. Gastric access remains a main stay in the care of the critically ill patient, and here the potential is established to harness this establishes route for analyte evaluation for clinical management.

Role of the nurse in patient blood management and treating anaemia

Patient blood management has been defined as a patient-focused and evidence-based approach to optimising the management of patients during the transfusion of blood components. This article explores the complex factors that can influence clinical decisions and enhance patient safety in the administration of blood components, particularly red blood cell transfusions in patients with anaemia. The article also explores the nurse's role in acting as a patient advocate and considering alternatives to the use of blood components. While this article focuses on anaemia-related transfusions, the author relates the principles of patient blood management to all transfusion care.

Staff awareness and bundling reduce skin breaks and blood tests in neonatal intensive care

AIM

Skin breaks (SBs) for procedures and blood sampling are common in neonatal intensive care units (NICU), contributing to pain, infection risk and anaemia. We aimed to document their prevalence, identify areas for improvement and, through staff awareness, reduce their frequency.

METHODS

Quality improvement project via prospective audit at a tertiary-level NICU in Australia was conducted. All infants admitted to the NICU for >24 h during two audit periods were included in the study. A specifically designed bedside audit tool was used to prospectively document all SB and blood tests performed on infants during a 4-week audit period (audit 1). Results were reviewed to identify areas for improvement, and disseminated to staff at unit meetings, shift handover and email. Following education and awareness, the audit was repeated (audit 2), and data were compared. Frequency of SB and blood tests performed was measured. Data were tested for normality and analysed using parametric or non-parametric tests where appropriate.

RESULTS

There were 52 NICU admissions during each audit period (104 total), with 34 (65%) and 31 (60%) having audit sheets completed, respectively. Median (interquartile range) gestational age and mean (standard deviation) birthweight were 29 (26.3-35) weeks and 1836 (1185) g for audit 1, 30 (28.5-31.5) weeks and 1523 (913) g for audit 2. The reduction in total blood tests (mean) was 36.3%, skin breaks per admitted baby day reduced by 60% and total blood volume sampled (mean) by 37.7%.

CONCLUSIONS

A quality improvement project by prospective audit and staff education was associated with reductions in frequency of skin breaks and blood tests in the NICU.

The Comparison of Hemoglobin Values Measured by Blood and Continuous Non-Invasive Monitoring (SpHb) in Newborn Infants

OBJECTIVE

Hemoglobin (Hb) measurement is one of the most commonly used laboratory tests in medical practice. Unnecessary blood sampling, especially in neonatal intensive care units (NICUs), contributes to iatrogenic anemia. Continuous non-invasive monitoring of total Hb (SpHb) was compared with invasive venous blood samples (tHb) in NICU patients.

METHODS

Three hundred and ten patients were identified in NICU. Non-invasive Hb measurement was performed immediately before venous blood sampling and comparison of invasive with non-invasive values was undertaken.

RESULTS

There was a strongly positive correlation between SpHb and tHb (r = 0.965, p < 0.001). Bland-Altman analysis was performed in 95% limits of agreement for Hb values measured by both methods. The mean bias between tHb and SpHb measurements was 0.05 g/dl (-1.85 to 1.96). In Passing-Bablok regression analysis, the CUSUM test p value was found to be 0.98 for Hb levels measured by SpHb and tHb; and the difference between the methods was not significant.

CONCLUSION

In newborns, SpHb method offers reliable Hb values, which are comparable with the more traditional tHb method. Continuous non-invasive monitoring of total Hb may help prevent unnecessary blood sampling and iatrogenic anemia. Further clinical studies are required for the effectiveness of the method in critically ill patients with circulatory disorders.

Reducing inappropriate arterial blood gas testing in a level III intensive care unit: a before-and-after observational study

Background: Arterial blood gas (ABG) analysis is the most frequently performed test in intensive care units (ICUs), often without a specific clinical indication. This is costly and contributes to iatrogenic anaemia. Objectives: To reduce the number of ABG tests performed and the proportion that are inappropriate. Design, setting and participants: The indications for ABG analysis were surveyed at a 58-bed level III ICU during fortnightly periods before and after a multifaceted educational intervention which included the introduction of a clinical guideline. The number of ABG tests performed during the period July-December 2017 was compared with that for the period July-December 2018. Tests were predefined as inappropriate if performed at regular time intervals, at change of shift, concurrently with other blood tests or after a treatment was ceased on a stable patient or after ventilatory support or oxygen delivery was decreased in an otherwise stable patient. The study was enrolled on the Quality Improvement Projects Register and ethics approval was waived by the local ethics committee. Results: There was a 31.3% bed-day adjusted decrease in number of ABG tests performed (33 005 v 22 408; P < 0.001), representing an annual saving of A$770 000 and 100 litres of blood. The proportion of inappropriate ABG tests decreased by 47.3% (54.2% v 28.6%; P < 0.001) and the number of inappropriate ABG tests per bed-day decreased by 71% (2.8 v 0.8; P < 0.001). Patient outcomes before and after the intervention did not differ (standardised mortality ratio, 0.65 v 0.63; P = 0.22). Conclusion: Staff education and implementation of a clinical guideline resulted in substantial decreases in the number of ABG tests performed and the proportion of inappropriate ABG tests.

[Laboratory testing in intensive care medicine]

Despite the tremendous technological developments in medicine, careful history-taking and clinical examination remain the cornerstones of diagnostics. Numerous laboratory tests are ordered in intensive care and emergency medicine. The rate of overutilization of these tests during initial patient admission is almost 50%. Patient history may be frequently insufficient for conducting targeted laboratory testing, and concern about not overlooking a pathology also contributes to laboratory test overutilization. On the other hand, laboratory test profiles are frequently defined a priori to simplify the management process. However, these profiles are commonly based on symptoms rather than on a suspected diagnosis. Several laboratory variables are outside the normal range in critically ill patients. However, normal ranges are defined on the basis of data from healthy subjects, and these do not allow for a clear distinction between stress adaptation and clinically relevant changes that require correction. Pathophysiological changes due to the acute injury in critically ill patients and the reaction of the organism to the injury or even to the treatment itself can lead to changes in laboratory values. Untargeted laboratory tests contribute to iatrogenic anemia and increased costs. The results of such tests are either hardly noticed or, in the worst case, lead to further unnecessary diagnostic steps and unjustified therapeutic measures. Point-of-care laboratory tests, including blood gas analysis, blood count, serum electrolytes, and lactate, to assess the patient's homeostatic state and laboratory data for the relevant critical care scores are uniformly required. Beyond that, every laboratory test should be chosen wisely based on a concrete clinical question.

Customisation and validation of a low-volume plasma renin activity immunoassay: Enabling of regulatory compliant determination in paediatric trials

Objectives

Investigations of plasma renin activity (PRA) in children are urgently required. Small-volume, regulatory guideline compliant, bioanalytical assays tailored for paediatric application could facilitate to overcome this hurdle. Ethical constraints given e.g. by the European Medicines Agency need to be addressed and reliable data generation in line with Good Clinical Laboratory Practice must be ensured.

Methods

A PRA enzyme-linked immunosorbent assay (ELISA) was tailored for paediatric application and validated in the context of the U.S. Food and Drug Administration bioanalytical guideline. Performance verification of the assay was conducted by participation in an interlaboratory ring test, evaluation of incurred sample reanalysis and an application-orientated approach in children.

Results

A five-fold reduction of required plasma volume to 100 μL was achieved without limiting the calibration range. Between-run accuracy and precision varied no more than 5.0% and 6.3%, respectively. No substantial matrix effect was detected and the inter-run precision for parallelism was 11.1%. Stability experiments approved the freeze-thaw stability, short-term stability as well as 37 weeks of long-term stability. The assay successfully participated in the interlaboratory ring test, showing non-inferiority regarding radioimmunoassay (RIA). Moreover, PRA in plasma samples of neonates was successfully determined. Conducted incurred sample reanalysis confirmed the comparability and reliability of the assay with regard to international regulatory bioanalytical guidelines.

Conclusion

A fit-for-purpose PRA ELISA characterised by low-volume application was successfully established, indicating non-inferiority regarding commonly applied RIAs. Reliability of the regulatory-compliant PRA assay was proven by participation in an interlaboratory ring test and its application in a paediatric population.

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A small-volume PRA ELISA was successfully validated regarding FDA guideline.

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Performance of the presented ELISA showed non-inferiority to corresponding RIAs.

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Substantial reduction in plasma volume enables application in vulnerable population.

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Application in diseased children and incurred sample reanalysis successfully proven.

Can the blood gas analyser results be believed? A prospective multicentre study comparing haemoglobin, sodium and potassium measurements by blood gas analysers and laboratory auto-analysers

Blood gas analysers are point-of-care testing devices used in the management of critically ill patients. Controversy remains over the agreement between the results obtained from blood gas analysers and laboratory auto-analysers for haematological and biochemistry parameters. We conducted a prospective analytical observational study in five intensive care units in Western Australia, in patients who had a full blood count (FBC), urea, electrolytes and creatinine (UEC), and a blood gas performed within 1 h of each other during the first 24 h of their intensive care unit admission. The main outcome measure was to determine the agreement in haemoglobin, sodium, and potassium results between laboratory haematology and biochemistry auto-analysers and blood gas analysers. A total of 219 paired tests were available for haemoglobin and sodium, and 215 for potassium. There was no statistically significant difference between the results of the blood gas and laboratory auto-analysers for haemoglobin (mean difference –0.35 g/L, 95% confidence interval (CI) –1.20 to 0.51, P = 0.425). Although the mean differences between the two methods were statistically significant for sodium (mean difference 1.49 mmol/L, 95% CI 1.23–1.76, P < 0.0001) and potassium (mean difference 0.19 mmol/L, 95% CI 0.15–0.24, P < 0.0001), the mean biases on the Bland–Altman plots were small and independent of the magnitude of the measurements. The two methods of measurement for haemoglobin, sodium and potassium agreed with each other under most clinical situations when their values were within or close to normal range suggesting that routine concurrent blood gas and formal laboratory testing for haemoglobin, sodium and potassium concentrations in the intensive care unit is unwarranted.

Impact of Nursing Education on Phlebotomy Blood Loss and Hospital-Acquired Anemia: A Quality Improvement Project

BACKGROUND

Phlebotomy blood loss resulting in hospital-acquired anemia remains a significant problem in the critically ill population. A quality improvement project focused on decreasing phlebotomy blood loss and increasing nursing knowledge regarding blood conservation strategies was undertaken in the intensive care unit of a community hospital.

METHODS

The project followed a quasi-experimental design. Data were gathered using electronic chart review and surveys before and after educational sessions. Intensive care unit nurses attended educational sessions focused on increasing knowledge regarding phlebotomy blood loss, hospital-acquired anemia, blood conservation strategies, and utilization of blood conservation devices.

RESULTS

The study showed a statistically significant increase in nursing knowledge regarding hospital-acquired anemia, phlebotomy blood loss, and blood conservation device use (P < .001) and a statistically significant change in blood conservation device application practice in the posteducation period when compared with the preeducation period (P = .016).

CONCLUSION

The findings of this project support the added value of dedicated blood conservation education to nurses to promote increased knowledge, increased blood conservation device utilization, and decreases in phlebotomy blood loss.

Anaemia and transfusion triggers in critically ill patients - What we have learnt thus far

Anaemia is a common finding in critically ill patients, the cause of which is multi-factorial including: sepsis, haemolysis (and disseminated intravascular coagulation), iatrogenic blood loss secondary to laboratory sampling, post-operative anaemia, bone marrow suppression/failure, decreased production of erythropoietin, anaemia secondary to drugs/toxins, overt or occult blood loss, functional iron deficiency, poor nutrition and haemodilution. Anaemia is associated with deleterious outcomes including increased risk of cardiac-related morbidity and mortality and decrease in oxygen-carrying capacity in the face of increased metabolic demands. There is a growing body of evidence, which demonstrates that packed red blood cell transfusions are associated with poorer outcomes. Clinicians therefore need to weigh the potential benefit of treating anaemia against the desire to avoid unnecessary transfusions. We explored current literature regarding transfusion triggers and morbidity and mortality associated with packed red blood cell transfusions transfusion, concentrating on studies that have been conducted in critical care patients. In addition, we reflected on trials which considered the viability of iron transfusion and erythropoietin in critically unwell patients.

Closed arterial lab sampling devices: a study of compliance and best practice

As the quality of patient care continues to improve, nursing professionals are continuously tasked with researching, implementing, and evaluating best practices. The practice of obtaining blood samples from paediatric patients, using a conventional three-way stopcock method, has been associated with peripheral arterial catheter intraluminal contamination and catheter-related bloodstream infections. A paediatric cardiac intensive care unit (PCICU), in a large medical centre in the USA, set an objective to mitigate the risk of possible contamination by implementing the use of closed arterial lab sampling devices. The project extensively reviewed comparative literature of studies between conventional three-way stopcock methods and closed arterial lab sampling devices. Furthermore, it successfully implemented the recommended best practice with sustained compliance. This article discusses appraising current literature, translating into practice, and evaluating compliance throughout the PCICU over a 2-year period.