Patient harm associated with serial phlebotomy and blood waste in the intensive care unit: A retrospective cohort study

Background

Intensive care unit (ICU) patients are at high risk of anemia, and phlebotomy is a potentially modifiable source of blood loss. Our objective was to quantify daily phlebotomy volume for ICU patients, including blood discarded as waste during vascular access, and evaluate the impact of phlebotomy volume on patient outcomes.

Methods

This was a retrospective observational cohort study between September 2014 and August 2015 at a tertiary care academic medical-surgical ICU. A prospective audit of phlebotomy practices in March 2018 was used to estimate blood waste during vascular access. Multivariable logistic regression was used to evaluate phlebotomy volume as a predictor of ICU nadir hemoglobin < 80 g/L, and red blood cell transfusion.

Results

There were 428 index ICU admissions, median age 64.4 yr, 41% female. Forty-four patients (10%) with major bleeding events were excluded. Mean bedside waste per blood draw (144 draws) was: 3.9 mL from arterial lines, 5.5 mL central venous lines, and 6.3 mL from peripherally inserted central catheters. Mean phlebotomy volume per patient day was 48.1 ± 22.2 mL; 33.1 ± 15.0 mL received by the lab and 15.0 ± 8.1 mL discarded as bedside waste. Multivariable regression, including age, sex, admission hemoglobin, sequential organ failure assessment score, and ICU length of stay, showed total daily phlebotomy volume was predictive of hemoglobin <80 g/L (p = 0.002), red blood cell transfusion (p<0.001), and inpatient mortality (p = 0.002). For every 5 mL increase in average daily phlebotomy the odds ratio for nadir hemoglobin <80 g/L was 1.18 (95% CI 1.07–1.31) and for red blood cell transfusion was 1.17 (95% CI 1.07–1.28).

Conclusion

A substantial portion of daily ICU phlebotomy is waste discarded during vascular access. Average ICU phlebotomy volume is independently associated with ICU acquired anemia and red blood cell transfusion which supports the need for phlebotomy stewardship programs.

Reducing Phlebotomy Utilization With Education and Changes to Computerized Provider Order Entry

INTRODUCTION

Daily phlebotomy is often a standard procedure in hospitalized patients. Recently, this practice has begun receiving attention as a potential target for efforts focused on eliminating overuse. Several organizations have published their efforts in this arena. Interventions have included education, feedback, and changes to computerized provider order entry (CPOE) but have yielded mixed results.

METHODS

A quality improvement initiative to reduce the utilization of daily phlebotomy was conducted at a 505-bed Academic Medical Center. This project involved a combination of educational interventions and changes to CPOE. The primary end point evaluated was the daily performance of complete blood counts (CBCs) and basic metabolic profiles (BMPs) on medical and surgery units relative to the corresponding hospital census.

RESULTS

Over the course of this project from August 1, 2013, to September 23, 2016, there was a 15.2% reduction in CBCs (p < .001 for linear trend) and 13.1% reduction in BMPs.

DISCUSSION

Our results suggest that layering multimodal interventions that involve both "hard-wired" changes to CPOE and education and performance feedback can result in decreased utilization of phlebotomy.

Collection and laboratory methods for dried blood spots for hemoglobin A1c and total and high-density lipoprotein cholesterol in population-based surveys

BACKGROUND

The Health Measures at Home Study was a study designed to evaluate the feasibility of incorporating dried blood spots (DBS) collection into the National Health Interview Survey and to compare the proficiencies between field interviewers and health technicians in obtaining DBS.

METHODS

DBS collection and venipuncture were attempted on 125 participants. The DBS were collected in the participant's home and venous blood was collected in the National Health and Nutrition Examination Survey (NHANES) mobile examination center. The DBS results were compared to venous results in the NHANES for the measurements of hemoglobin A1c (HbA1c) and total and high-density lipoprotein (HDL) cholesterol.

RESULTS

Field interviewers and health technicians were able to collect the DBS for greater than 95% of participants. For DBS, health technicians and field interviewers were highly correlated for HbA1c (r=0.92) and total cholesterol (r=0.89), but not for HDL cholesterol (r=0.72). The DBS results of interviewers and health technicians compared to the venous method for HbA1c (r=0.90), but did not compare well for HDL cholesterol (r=0.64-0.66) and total cholesterol (r=0.65-0.67).

CONCLUSION

DBS was comparable to venous HbA1c, but not for total and HDL cholesterol. Health technicians and field interviewers had similar performance for DBS methods, except HDL cholesterol.

Incidence of hepatocellular carcinoma reduced by phlebotomy treatment in patients with chronic hepatitis C

OBJECTIVE

To determine the impact of phlebotomy on the laboratory values and the incidence of hepatocellular carcinoma (HCC) in patients with hepatitis C.

METHODS

Study patients with chronic hepatitis C were treated with glycyrrhizin injection and oral ursodeoxycholic acid and either with (n=52) or without (n=50) phlebotomy during the period of 2005-2012. Six phlebotomized patients had previously received interferon therapy and were subsequently excluded from the data analysis. The serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), total bilirubin, alkaline phosphatase, gamma-glutamyl transpeptidase, lactate dehydrogenase, ferritin, iron and albumin, as well as the hemoglobin concentration, platelet count and prothrombin time, were determined. We compared the long-term outcomes based on the incidence of HCC and laboratory values, including the baseline serum ferritin levels, in patients treated with versus without phlebotomy.

RESULTS

In the phlebotomy group, the mean AST and ALT levels decreased significantly at each one-year interval over five years (p<0.01), whereas the platelet counts did not. The incidence of HCC in the phlebotomized patients was significantly lower than that observed in the patients treated without phlebotomy: 10.3% vs. 43.7%, respectively, during the 8-year observation period (p=0.04). The incidence of HCC was also lower in the phlebotomized patients with a normal baseline ferritin level: 0.0% vs. 36.0% in the matched subgroup treated without phlebotomy at year 8. Phlebotomy offered a risk ratio of 0.13, thus suggesting protection against the development of HCC.

CONCLUSION

The incidence of HCC can be reduced by phlebotomy treatment, which should be performed in patients with chronic hepatitis C not receiving or not responding to antiviral therapy.

The effect of ongoing blood loss on human serum concentrations of perfluorinated acids

Perfluorinated alkyl acids (PFAAs) have been detected in serum at low concentrations in background populations. Higher concentrations haven been observed in adult males compared to females, with a possible explanation that menstruation offers females an additional elimination route. In this study, we examined the significance of blood loss as an elimination route of PFAAs. Pooled serum samples were collected from individuals undergoing a medical procedure involving ongoing blood withdrawal called venesection. Concentrations from male venesection patients were approximately 40% lower than males in the general population for perfluorohexane sulfonate (PFHxS), perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). A simple pharmacokinetic model was used to test the hypothesis that blood loss could explain why adult males have higher concentrations of PFAAs than females, and why males undergoing venesections had lower concentrations compared to males in the general population. The model application generally supported these hypotheses showing that venesection might reduce blood serum concentrations by 37% (PFOA) and 53% (PFOS) compared to the observed difference of 44% and 37%. Menstruation was modeled to show a 22% reduction in PFOA serum concentrations compared to a 24% difference in concentrations between males and females in the background population. Uncertainties in the modeling and the data are identified and discussed.

Is it useful to repeat an adrenal venous sampling in patients with primary hyperaldosteronism?

Adrenal venous sampling (AVS) is a challenging technical procedure and few patients had AVS procedure twice.

AIM

To evaluate the reproducibility of the AVS, why AVS were repeated and the conclusions drawn from them.

PATIENTS AND METHODS

From 1997-2012, 12 patients underwent two AVS. A cortisol level in the adrenal vein greater than or equal to 1.1 to inferior vena cava defined a successful catheterization and a lateralization of secretion corresponded to an aldosterone-to-cortisol vein ratio greater than or equal to 2 between the one side to another.

RESULTS

The same side of lateralization of secretion was found in 75% of them. The second AVS were due to technical failure (n=4), unproven lateralization (n=2), a lateralization opposite to the main nodule and ipsilateral to hyperplasia (n=4) on first AVS. For two patients, as the CT was normal, AVS was required again. The second AVS was successful in all patients, including those with an initial technical failure but only patient with technical failure underwent surgery, as BP and kaliemia were controlled. Lateralization on the side of hyperplasia or opposite to the biggest nodule was confirmed in two of four cases.

CONCLUSION

When AVS is unsuccessful for technical reasons, it is worth doing it again but after being sure that surgery is still possibly indicated.

[Effect of frequency donations of plasma standard dose on immune reactivity of regular donors]

For the date of investigation, regular donation standard dose of plasma have minimally influence on the immune reactivity of regular donors organism. Uniform enhance humoral response indicating the accumulation of reserve capacity immunity. Most likely, the planned removal from the blood plasma of stimulated local humoral response, it manifestation by protective activity of endothelial adhesion properties.

Office-based procedures among urban and rural family physicians in Ontario

OBJECTIVE

To compare FP and GP performance of office-based procedures between urban and rural practices.

DESIGN

Descriptive cohort study using health administrative data.

SETTING

Ontario.

PARTICIPANTS

All FPs and GPs who billed the Ontario Health Insurance Plan for at least 1 office-based procedure between January 1 and December 31, 2006 (N = 8648).

MAIN OUTCOME MEASURES

Ontario Health Insurance Plan billings for office-based procedures were adjusted by full-time equivalent (FTE) so that the means are for 1 FTE. Office-based procedures were grouped into 1) surgical procedures, 2) injections and immunizations, 3) electrocardiograms (ECGs), and 4) venipunctures and laboratory tests. The analyses were stratified for FP and GP age, sex, rurality of practice, and participation in a primary care model.

RESULTS

There were no substantial differences between FPs and GPs in rural practices compared with those in more urban practices with respect to surgical procedures. Rural FPs and GPs had lower mean numbers of injections and immunizations, ECGs, and venipunctures and laboratory tests than FPs and GPs practising in urban areas. Family physicians and GPs in primary care models had a lower mean number of surgical procedures but a higher adjusted mean number of injections and immunizations, ECGs, and venipunctures and laboratory tests.

CONCLUSION

For those procedures that are not dependent on specialist backup or access to more advanced technology, there were no substantial differences between rural and urban FPs and GPs. All comprehensive FPs and GPs should be able to provide these services to their patients. Training programs for all family medicine residents should ensure future FPs and GPs are able to perform these procedures.

Phlebotomy patterns in haemochromatosis patients and their contribution to the blood supply

AIMS

To determine venesection patterns in hereditary haemochromatosis (HC) patients in Christchurch, New Zealand, their contribution to the blood supply, and reasons for deferral.

METHODS

Review of clinical records of 412 HC patients venesected by the NZ Blood Service at least once during 2009.

RESULTS

Of 275 males and 137 females, 384 had been tested for HFE gene mutations--76% were C282Y homozygotes, 12.8%, C282Y/H63D compound heterozygous, 8.6%, either H63D homozygotes, C282Y heterozygotes or H63D heterozygotes. Small numbers had no detectable mutations, were not iron overloaded but had been venesected for isolated hyperferritiniaemia. 53% were donors. C282Y homozygotes required significantly more venesections than patients of other genotypes. Eligible HC patients donated 3 units/donor/year compared to 1.63/person/year by healthy donors (p<0.001). HC patients contributed 3.4% of whole blood collections in 2009. There were 212 permanent or temporary donation deferrals--common reasons were abnormal liver functions, chronic or malignant disease, or immigration from vCJD risk countries.

CONCLUSIONS

HC donors donate at nearly twice the rate of healthy donors but contribute only a small amount to the blood pool. Revision of selection criteria may increase this contribution without compromising blood safety.

Adrenal venous sampling in primary aldosteronism: a low dilution of adrenal venous blood is crucial for a correct interpretation of the results

OBJECTIVE

In primary aldosteronism, adrenal venous sampling (AVS) is essential for subtype differentiation as it evaluates aldosterone secretion from both adrenals. Selectivity of adrenal sampling is assessed by the ratio of cortisol concentrations in adrenal venous blood and inferior vena cava blood (C(adrenal)/C(ivc)). Since the criteria for selective adrenal sampling differ among the reported literature, we performed a study to evaluate the influence of different selectivity criteria on AVS results.

DESIGN AND METHODS

Reports of AVS were screened retrospectively. All AVS were performed with cosyntrophin infusion. Reports containing samples with C(adrenal)/C(ivc)>or=10 taken from both adrenals and at least one other adrenal sample characterised by C(adrenal)/C(ivc)>or=1.1 were enrolled. For each individual, we chose reference samples that were defined by the highest C(adrenal)/C(ivc) achieved from each adrenal. The significance of the remaining samples with C(adrenal)/C(ivc)>or=1.1 was analysed in regard to their respective reference samples. We assessed the impact of analysed samples on identification of lateralisation of aldosterone secretion that is crucial for decisions concerning adrenalectomy.

RESULTS

AVS reports of 87 patients were enrolled. A total of 225 adrenal samples were analysed and divided into five groups according to C(adrenal)/C(ivc):1.1-1.99, 2-2.99, 3-4.99, 5-9.99 and >or=10. By comparing reference with analysed samples, a concordant assessment with respect to lateralisation of aldosterone secretion was observed in 39, 52, 72, 85 and 94% of the respective groups of analysed samples.

CONCLUSION

AVS provides consistent information when adrenal samples with high cortisol concentrations are used.

Analysis of turnaround time by subdividing three phases for outpatient chemistry specimens

The Department of Laboratory Medicine at Asan Medical Center provides a special one-stop service to allow both doctors and outpatients to receive routine outpatient test results in a timely manner within 1 hr. We developed a new Laboratory Information System (LIS)-based monitoring system that records the laboratory turnaround time (TAT) in 3 phases and analyzes the time to complete each phase with relevant specimens. TAT is subdivided into preanalytical, analytical, and postanalytical phases based on the 4 time points when data are entered automatically into the LIS. The average TAT for 13,594 outpatient routine chemistry specimens with the one-stop service was 43.6+/-7.7 min. Completion times of the preanalytical, analytical, and postanalytical phases were 29.7+/-6.9, 13.9+/-4.1, and 0.02+/-0.13 min, respectively; 98.0% of the specimens were reported within 60 min. The remaining 2.0% were reported after 60 min with an average TAT of 68.7+/-11.3 min. Preanalytical phase delays were primarily responsible for the specimens reported between 60 and 90 min, and analytical phase delays were largely responsible for the few specimens (0.2%) reported after 90 min. For specimens reported between 60 and 90 min, the preanalytical phase was found to need improvement in order to shorten TAT; the main target for improvement was identified as the "waiting time for phlebotomy" step.

Fainting and hemolysis during blood sampling in youngsters: Prevalence study

OBJECTIVE

To assess the incidence of fainting and hemolysis in taking blood samples from adolescents in a school setting.

DESIGN

A cross-sectional school-based survey. All blood samples and data were collected during September and October 2005.

SUBJECTS

A community sample of 869 youngsters attending third grade secondary education in 14 secondary schools in the Flemish province of Antwerp, Belgium (mean age: 17.3 years, +/-1.2 years).

MEASUREMENTS

Fasting blood samples were obtained on-site for measurement of levels of glucose, high density lipoprotein cholesterol and triglycerides. The incidence of fainting and hemolysis was assessed.

RESULTS

In 60% of the total sample a blood sample was taken, 15% refused. In the remaining 25%, taking a blood sample was not possible due to problems in drawing blood from the vein (4%) or not fasting (21%). The incidence of fainting was 2.5%. Hemolysis occurred in 2.4% of the blood samples.

CONCLUSION

When taking blood samples in this age group, there seems to be a great willingness to participate. Precaution should be taken though when taking blood samples in youngsters. In this study, about 1 in 40 students fainted. When blood samples are taken on-site and transported to a laboratory, an incidence of hemolysis of 2.4% should be taken into account.

[Performance analysis of venous puncture, and nasogastric and nasointestinal tube placement in a pediatric ward]

This article is an observational study that analyzes the performance of venous punctures and nasogastric and nasointestinal tube placement in pediatric patients, performed by nurses in a pediatric ward. This exploratory descriptive study was carried out at a teaching hospital in Porto Alegre, Rio Grande do Sul, Brazil, and its purpose is to identify frequency and time spent in the performance of these procedures, as well as to provide data for the management of nursing human resources. Two nurses were selected intentionally and an observation structured record was used to collect the data. The average time spent in the performance of venous punctures was 17.62 minutes, and tube placement, 10.8 minutes. The outcomes provided an understanding of the processes complexity, whose elements are related to the nurse's work process, as well as to the other professionals involved, the family and the child who underwent the procedures.

Blood, sweat, and tears: embedding biological samples in social science research on children

In the first decade of the 21st Century, calls for interdisciplinary research are commonplace. Yet, relatively few papers discuss how to complete such research successfully. In this paper, I describe the details of data collection focused on five, six and seven-year old children. The project examined the effect of environmental contaminants on children's educational outcomes. It included a primary caregiver interview, a skill test with the child, and a venous blood draw from the child to test for lead, mercury, cadmium, arsenic, nicotine, and cotinine. This paper describes key issues and the solutions I adopted. Challenges discussed here include navigating the Institutional Review Board Process, analyzing the blood, obtaining the supplies needed to draw blood, banking blood for future research, hiring a phlebotomist, and recruiting subjects. While not all details will apply directly to other research projects, this paper provides some perspective on the current realities facing social scientists who decide to collect biological samples.

Diagnostic blood loss in mechanically ventilated patients

BACKGROUND

Concern for the volume of blood loss resulting from diagnostic phlebotomy has been expressed in the literature for decades. Blood conservation strategies have been found to reduce the volume withdrawn for laboratory tests, but some patient populations may remain at risk.

OBJECTIVE

This study examines the frequency of phlebotomy and volume of diagnostic blood loss for critically ill mechanically ventilated patients in a small community hospital.

METHODS

The subjects were 43 critically ill adults who received mechanical ventilation for at least 24 hours during the first quarter of 2005. Data were collected from computerized medical records and included the frequency and types of laboratory tests performed over the course of hospitalization.

RESULTS

The mean total number of blood samples withdrawn was 69 (standard deviation = 59). The mean amount withdrawn per day was 16 mL (standard deviation = 7) with mean total volumes ranging from 57 to 1120 mL per patient. Four patients had more than 500 mL withdrawn. Chemistry analyses accounted for both the highest frequency of phlebotomy and the highest volume.

CONCLUSIONS

The daily volume of diagnostic blood loss for this population was less than the amounts previously reported in the literature, so there is some evidence of effectiveness of blood conservation strategies. However, some patients were still experiencing blood loss as the result of phlebotomy that may have been clinically significant. Additional strategies for reducing phlebotomy volumes are recommended.

A repeated measures concordance correlation coefficient

The concordance correlation coefficient is commonly used to assess agreement between two raters or two methods of measuring a response when the data are measured on a continuous scale. However, the situation may arise in which repeated measurements are taken for each rater or method, e.g. longitudinal studies in clinical trials or bioassay data with subsamples. This paper proposes a coefficient for measuring agreement between two raters or two methods of measuring a response in the presence of repeated measurements. We illustrate the methodology with examples comparing (1) 1-hr versus 2-hr blood draws for measuring cortisol in an asthma clinical trial and (2) two measurements of percentage body fat, from skinfold calipers and dual energy X-ray absorptiometry.

Highly conservative phlebotomy in adult intensive care--a prospective randomized controlled trial

Anaemia in critically ill patients is common and phlebotomy associated blood loss may contribute towards this anaemia. The aims of this study were twofold. Firstly, a survey was conducted to provide a summary of current phlebotomy practices within Australian intensive care units. A standardized telephone survey was aimed at Australian intensive care units registered with Australia and New Zealand Intensive Care Society (ANZICS) and questions regarding phlebotomy procedures directed at nursing staff. Secondly, a prospective randomized controlled trial aimed to assess the impact of a highly conservative phlebotomy procedure on haemoglobin concentration in intensive care patients. Patients admitted to our own intensive care unit were randomized using a sealed envelope technique to either a highly conservative phlebotomy group, or standardized controls. Blood was taken according to strict protocols and recorded along with haemoglobin concentration daily. The survey demonstrated that 16% of Australian units return deadspace volumes from in-line arterial sets and no unit routinely used paediatric-sized blood collection tubes. Using our highly conservative protocol, median phlebotomy-associated blood loss was reduced by over 80% (40 ml vs 8 ml P<0.001). Mean haemoglobin fell from 13.7 g/dl to 11.7 g/dl in controls (P=0.002) and from 12.7 g/dl to 11.5 g/dl (P=0.074) in our study group. We conclude that highly conservative phlebotomy is feasible in a critical care unit and is associated with a reduction in blood loss.

Venous stasis and routine hematologic testing

Prolonged venous stasis, as generated by a long tourniquet placement, produces spurious variations in several measurable analytes. To verify to what extent venous stasis influences routine hematologic testing, we assessed routine hematologic parameters, including hemoglobin, hematocrit, red blood cell count (RBC), main cell hemoglobin (MHC), main cell volume (MCV), platelet count (PLT), main platelet volume (MPV), white blood cell count (WBC) and WBC differential on the Advia 120 automated hematology analyzer in 30 healthy volunteers, either without venous stasis (no stasis) or after application of a 60 mmHg standardized external pressure by a sphygmomanometer, for 1 (1-min stasis) and 3 min (3-min stasis). Although the overall correlation between measures was globally acceptable, the mean values for paired samples were significantly different in all parameters tested, except MCV, MHC, PLT, MPV, eosinophils, basophils and large unstained cells after 1-min stasis and all parameters except MCV, MHC, MPV and basophils after 3-min venous stasis. As expected RBC, hemoglobin and hematocrit displayed a significant trend towards increase, whereas WBC and the WBC subpopulations were decreased. Difference between measurements by Bland and Altman plots exceeded the current analytical quality specifications for desirable bias for WBC, RBC, hemoglobin, hematocrit, lymphocytes and monocytes in samples collected after either 1- and 3-min stasis. These results provide clear evidence that venous stasis during venipuncture might produce spurious and clinically meaningful biases in the measurement of several hematologic parameters, prompting further considerations on the usefulness of adopting appropriate preventive measures for minimizing such influences.

Reducing unnecessary inpatient laboratory testing in a teaching hospital

After an inpatient phlebotomy-laboratory test request audit for 2 general inpatient wards identified 5 tests commonly ordered on a recurring basis, a multidisciplinary committee developed a proposal to minimize unnecessary phlebotomies and laboratory tests by reconfiguring the electronic order function to limit phlebotomy-laboratory test requests to occur singly or to recur within one 24-hour window. The proposal was implemented in June 2003. Comparison of fiscal year volume data from before (2002-2003) and after (2003-2004) implementation revealed 72,639 (12.0%) fewer inpatient tests, of which 41,765 (57.5%) were related directly to decreases in the 5 tests frequently ordered on a recurring basis. Because the electronic order function changes did not completely eliminate unnecessary testing, we concluded that the decrease in inpatient testing represented a minimum amount of unnecessary inpatient laboratory tests. We also observed 17,207 (21.4%) fewer inpatient phlebotomies, a decrease sustained in fiscal year 20042005. Labor savings allowed us to redirect phlebotomists to our understaffed outpatient phlebotomy service.

Audit of phlebotomy turnaround time in a private hospital setting

An audit on the turnaround time (TAT) of a hospital phlebotomy service was undertaken to assess whether or not the existing service standards can satisfy the needs and expectations of both the external and internal customers. A job request survey form was designed and implemented in June 2005 to be used by the day shift to record the number of phlebotomy cases and the corresponding TAT. The success rate and complaints related to phlebotomy were also recorded. Phlebotomists provided the data for this study on an honor system basis. Out of 2,118 test requests received by the laboratory, 1,867 (88.1 percent) were phlebotomy requests. Approximately 62 phlebotomy requests were recorded, on average, per day shift. The average time, expressed in mean +/- standard deviation (SD) needed for response, arrival, and job completion was 7.4 +/- 1.5 minutes, 5.6 +/- 1.6 minutes, and 10.4 +/- 2.4 minutes respectively, with an average overall TAT of 23.4 +/- 4.1 minutes per phlebotomy request. The success rate at first phlebotomy attempt was 97 percent, and only one complaint was received during the audit period. This study may help hospital management identify possible bottlenecks that delay phlebotomy TAT, thus improving service standards in this area.

Punção venosa periférica: avaliação de desempenho dos profissionais de enfermagem

Estudo comparativo inferencial que teve o objetivo de avaliar o desempenho dos profissionais de enfermagem na execução da punção venosa periférica; verificar as convergências e identificar os fatores de risco a complicações. Constou de 55 profissionais de um hospital geral de grande porte. Para a coleta dos dados, foi utilizado um instrumento de observação do tipo "check-list", contendo 25 itens. Na avaliação da média de acertos das três categorias profissionais, foi utilizado o teste estatístico não-paramétrico Krush Kal-Wallis com nível de significância a = 5%. Nos casos onde houve diferença foram procedidos testes de comparações múltiplas. Obtive-se 78% de média de acerto global para todas as categorias: 82% enfermeiros, 80% técnicos e 77% auxiliares de enfermagem. Dos itens do procedimento, 10 apresentaram erros significativos, sendo que 4 desses obtiveram p < 0,05. Os dados apontam a necessidade de intensificar as atividades educativas que promovam a mudança de comportamento dos profissionais de enfermagem em prol da qualidade do desempenho da punção venosa periférica.

[Can patients treated with therapeutic bloodletting become blood donors?]

BACKGROUND

Blood letting is an important form of treatment in some diseases, e.g. haemochromatosis and polycytaemia rubra vera. In our hospital, this treatment takes place in the blood bank. If the blood collected from these patients could be used for transfusion, it would help reduce the present blood shortage.

MATERIAL AND METHODS

We examined the referral letters for all patients treated with blood letting during a twelve-month period in two hospitals to see how often the referrals gave information that would exclude the patient as a blood donor.

RESULTS

1,116 units of blood were collected from 177 patients. 122 patients treated with 696 bloodlettings did have information in their referral letter which indicated that they would be unsuitable as blood donors.

DISCUSSION

55 of 177 patients treated with blood letting could have been further evaluated in order to determine whether they fulfilled the criteria for blood donors. The impact of accepting patients as blood donors could be significant. Patients in need of blood letting are not voluntary, unpaid donors and additional steps are required to compensate for this fact.

Phlebotomy overdraw in the neonatal intensive care nursery

OBJECTIVE

Because blood loss attributable to laboratory testing is the primary cause of anemia among preterm infants during the first weeks of life, we quantified blood lost attributable to phlebotomy overdraw, ie, excess that might be avoided. We hypothesized that phlebotomy overdraw in excess of that requested by the hospital laboratory was a common occurrence, that clinical factors associated with excessive phlebotomy loss would be identified, and that some of these factors are potentially correctable. DESIGN, OUTCOME MEASURES, AND ANALYSIS: Blood samples drawn for clinical purposes from neonates cared for in our 2 neonatal special care units were weighed, and selected clinical data were recorded. The latter included the test performed; the blood collection container used; the infant's location (ie, neonatal intensive care unit [NICU] and intermediate intensive care unit); the infant's weight at sampling; and the phlebotomist's level of experience, work shift, and clinical role. Data were analyzed by univariate and multivariate procedures. Phlebotomists included laboratory technicians stationed in the neonatal satellite laboratory, phlebotomists assigned to the hospital's central laboratory, and neonatal staff nurses. Phlebotomists were considered experienced if they had worked in the nursery setting for >1 year. Blood was sampled from a venous or arterial catheter or by capillary stick from a finger or heel. Blood collection containers were classified as tubes with marked fill-lines imprinted on the outside wall, tubes without fill-lines, and syringes. Infants were classified by weight into 3 groups: <1 kg, 1 to 2 kg, and >2 kg. The volume of blood removed was calculated by subtracting the weight of the empty collection container from that of the container filled with blood and dividing by the specific gravity of blood, ie, 1.050 g/mL. The volume of blood withdrawn for individual laboratory tests was expressed as a percentage of the volume requested by the hospital laboratory.

RESULTS

The mean (+/- standard error of the mean) volume of blood drawn for the 578 tests drawn exceeded that requested by the hospital laboratory by 19.0% +/- 1.8% per test. The clinical factors identified as being significantly associated with greater phlebotomy overdraw in the multiple regression model included: 1) collection in blood containers without fill-lines; 2) lighter weight infants; and 3) critically ill infants being cared for in the NICU. Because the overall R(2) of the multiple regression for these 3 clinical factors was only.24, the random factor of individual phlebotomist was added to the model. This model showed that there was a significant variation in blood overdraw among individual phlebotomists, and as a result, the overall R(2) increased to.52. An additional subset analysis involving 2 of the 3 groups of blood drawers (ie, hospital and neonatal laboratory phlebotomists) examining the effect of work shift, demonstrated that there was significantly greater overdraw for blood samples obtained during the evening shift, compared with the day shift when drawn using unmarked tubes for the group of heavier infants cared for in the NICU.

CONCLUSION

Significant volumes of blood loss are attributable to overdraw for laboratory testing. This occurrence likely exacerbates the anemia of prematurity and may increase the need for transfusions in some infants. Attempts should be made to correct the factors involved. Common sense suggests that blood samples drawn in tubes with fill-lines marked on the outside would more closely approximate the volumes requested than those without. Conversely, the use of unmarked tubes could lead to phlebotomy overdraw because phlebotomists may overcompensate to avoid having to redraw the sample because of an insufficient volume for analysis. We were surprised to observe that the lightest and most critically ill infants experienced the greatest blood overdraw. (ABSTRACT TRUNCATED)

Venipuncture versus central venous access: a comparison of methotrexate levels in pediatric leukemia patients

Patients receiving methotrexate (MTX) therapy for treatment of acute lymphocytic leukemia (ALL) consistently have venipuncture MTX levels drawn twice during each hospitalization. The purpose of this study was to compare MTX levels drawn from central venous catheters (CVCs) with those drawn by venipuncture. A convenience sample of 14 pediatric patients was used, with a total of 33 peak levels and 33 trough level sample pairs collected. Venipuncture and CVC levels were compared by using the paired t-test and analyzing the peak and trough data pairs separately. Results confirmed there was no difference in MTX level results (peak, p = .502; trough, p = .114). However, the CVC trough levels would have changed clinical management for 5 of the 33 patients. Therefore, it is recommended that all MTX levels be drawn from the CVC but that trough MTX levels that would alter clinical management be verified by a venipuncture sample. This method will safely minimize the number of venipunctures for children with ALL.

Blood gas analysis: a study of blood loss in intensive care

This paper describes a quantitative study conducted on an intensive care unit in the north of England. It involved the collection of data from the existing records of 65 patients consecutively sampled from a predetermined date provided that they stayed more than 24 hours and had an arterial line in situ. As patient records were used, ethical approval was not necessary. The objectives of the study were to quantify the mean number of blood gas samples taken per patient and estimate the mean blood loss resulting from this, including discard volume. Limitations include reliance on records and lack of an economic evaluation. The results show that blood loss in this study was greater than that reported elsewhere. Patients who were ventilated for 24 hours or more had a statistically significant greater blood loss when compared to those who were not (P < 0.001). A subgroup of patients undergoing renal replacement therapy had the greatest blood loss (mean 55.18 ml per day). This loss was statistically significant when compared to patients not in acute renal failure (P=0.007). When patients undergoing multiple therapies normally associated with increased sampling were compared to patients not receiving such therapies, there was no statistically significant difference in blood loss. The need to change current nursing practice to reduce iatrogenic anaemia is emphasized.

Hemochromatosis probands as blood donors

BACKGROUND

There has been no estimate of the potential eligibility of hemochromatosis probands or patients as blood donors or the suitability for transfusion of their blood that was removed by therapeutic phlebotomy.

STUDY DESIGN AND METHODS

According to guidelines of the American Association of Blood Banks, a retrospective estimate of these factors in 211 adult white hemochromatosis probands diagnosed during routine medical care was performed. The findings were compared to those in volunteer white whole-blood donors.

RESULTS

Before diagnosis of hemochromatosis, 49 probands had voluntarily donated 597 units of blood; 88 percent were donated by men. After diagnosis, 142 (67%) of 211 probands were potentially eligible. Data on each unit removed during iron-depletion therapy and during the first year of maintenance therapy (therapeutic phlebotomy) were available in 86 eligible probands. Of 1592 units, 1029 (65%) obtained during iron-depletion therapy in eligible probands were potentially suitable; 86 percent were from men. During maintenance therapy, 106 (88%) of 121 units from eligible probands were potentially suitable. In volunteer donors, 255,567 (94%) of 273,302 presenting donors were accepted. After testing and laboratory losses, 239,300 (94%) units were acceptable for transfusion.

CONCLUSIONS

In comparison with normal volunteers, hemochromatosis probands at diagnosis are less likely to be eligible as blood donors. The percentage of units obtained from patients during iron-depletion therapy that are suitable for transfusion is also lower, although the percentage increases during maintenance therapy.

Variations in transfusion practice in neonatal intensive care

OBJECTIVE

To compare the transfusion practices between two neonatal intensive care units (NICUs) to assess the impact of local practice styles on the timing, number, and total volume of packed red cell transfusions in very low birth weight infants. To derive multivariate models to describe practice and to identify potential areas for improvement in the future.

METHODOLOGY

We reviewed phlebotomy losses and transfusion rates between two NICUs (A and B) for 270 consecutive admissions of birth weight < 1500 g. We stratified for birth weight and for illness severity by the Score for Neonatal Acute Physiology (SNAP). Measures of short-term outcome were compared. We derived multivariate models to describe and compare the practices in the two NICUs.

RESULTS

Patients in NICU A had smaller phlebotomy losses than those in NICU B. A lower percentage of the patients in NICU A (65% vs 87%) received transfusions, but they tended to receive a greater total volume per kg per patient (67 mL/kg vs 54.8 mL/kg). Transfusion timing differed between the NICUs; in NICU A only approximately one-half of their transfusions occurred in the first 2 weeks, whereas in NICU B almost 70% of the transfusions were given in this time period. Multivariate models showed that phlebotomy losses were significantly related to lower gestational age (GA) and higher SNAP. Hospitalization in NICU B resulted in 10.7 cc of additional losses relative to NICU A for a comparable GA and illness severity score. The volume of blood transfused per kilogram of body weight was a function of GA, SNAP, and hospital. Care practices in NICU A added an additional 19 cc of transfused volume in the first 14 days of life, and an additional 26 cc thereafter when adjusted for GA and SNAP. These differences in phlebotomy and transfusion were not associated with differences in the days of oxygen therapy or mechanical ventilation, the oxygen requirement at 28 days, the incidence of chronic lung disease, or the rate of growth by day 28.

CONCLUSIONS

We identified significant differences in phlebotomy and transfusion practices between two NICUs. We found no differences in short-term outcome, suggesting that the additional use of blood in one of the NICUs was discretionary rather than necessary. Our multivariate models can be used to characterize and quantify transfusion and phlebotomy practices. By predicting which patients are likely to require multiple transfusions, clinicians can target patients for erythropoietin therapy and identify those patients for whom donor exposure can be reduced by a unit of blood for multiple use. The models may help in monitoring changes in practice as they occur.

Correlates of pain-related responses to venipunctures in school-age children

Guided by the Roy Adaptation Model of Nursing, the relationship of children's age, gender, exposure to past painful experiences, temperament, fears, and child-rearing practices to their pain responses to a venipuncture was examined. A sample of 94 children aged 8 to 12 years and their female caregivers were recruited from three outpatient clinics. During the venipuncture, children's behavioral and heart rate responses were monitored; immediately after, their subjective responses were recorded. Canonical correlation revealed two variates. In the first, age and threshold (temperamental dimension) correlated with pain quality, behavioral responses, and heart rate responses, explaining 12% of the variance. In the second, age, the temperamental dimensions of distractibility and threshold, and medical fears explained only 5.7% of the variance in pain quality and heart rate magnitude. Significant correlations between pain intensity, quality, behavioral responses, and heart rate responses support the multidimensionality of pain.

Intravenous access in newborn infants: impact of extended umbilical venous catheter use on requirement for peripheral venous lines

Central venous lines are used to care for critically ill neonates in cases of limited peripheral venous access. This prospective, randomized study evaluated the risks and benefits of the use of single- and double-lumen umbilical venous catheters for up to 14 days. Patients were randomized to one of three treatment arms: (1) single-lumen umbilical catheter, (2) double-lumen umbilical catheter, or (3) no umbilical catheter; peripheral intravenous lines only. Infants in the groups treated with an umbilical venous catheter had significantly fewer venipunctures and peripheral intravenous lines placed during their first 2 weeks of life than those in the peripheral line only group. Less time and money were spent obtaining peripheral line placement in the umbilical venous catheter groups. The incidence rates of sepsis and complications were not higher in treated patients than in control patients. The double-lumen catheter further reduced peripheral venipunctures and lines. We conclude that an umbilical venous catheter used during the first 2 weeks of life is a relatively safe, less stressful, cost-effective means of providing intravenous therapy to neonates.

Lower blood pressure values in blood donors?

594 blood donors were studied to define the influence of regular blood donation on blood pressure. Blood pressures were compared at the first phlebotomy performed at the Padova Blood Unit, the 13-year phlebotomy, and the median between the two. As a control population, a cohort of 594 non-donors from the same general population similar to the blood donors was studied twice at a 15-year interval. Subjects had made on average 7.3 +/- 0.4 donations at the first step, 23 +/- 0.6 at the second, and 30.9 +/- 0.7 at the last step. Unadjusted systolic blood pressure regularly and significantly increased by 1.6% from the first phlebotomy to the second one and by 2.3% from the first to third. Adjusted systolic blood pressure, on the contrary, significantly decreased by 2.1% and by 2.7% respectively. Diastolic blood pressure tended to increase insignificantly, while the adjusted one did not change at all. The increase of systolic blood pressure from the first to second step directly correlated with the number of donations, and this also applied to differences between the first and the third. When the increase in age was introduced in the multiple regression analysis, systolic blood pressure rise from the first to third step showed an inverse correlation with the number of phlebotomies. Our data render suspect the results of epidemiological investigations which took into consideration cohorts of blood donors; although these cohorts may be anagraphically representative of a general population, repeated phlebotomies introduce a bias leading to the detection of misleadingly low blood pressure values in regular blood donors.

Prothrombin time: one tube or two

This study compares the prothrombin times (PTs) and calculated international normalized ratios (INRs) from first and second evacuation blood tubes to determine the clinical importance of using a second tube specimen for protime coagulation studies. The National Committee for Clinical Laboratory Standards (NCCLS) currently recommends that all coagulation studies be done on a second or later drawn blood tube. For patients on long-term anticoagulation therapy, this often requires that first blood tubes be drawn and discarded at each prothrombin evaluation. In this prospective study, a first and second evacuation blood tube was drawn from 343 outpatients who had a physician-ordered prothrombin time test performed. There was no statistically significant difference in the paired PT or calculated INR from any of the first and second tubes. The average difference in the INR from tube 1 to tube 2 was 2% (standard deviation [SD] 1.1%). In this sample of outpatients, the use of a second tube for PT testing was not clinically justified.