Douglas Chesher

SHOULD SERUM PANCREATIC LIPASE REPLACE SERUM AMYLASE AS A BIOMARKER OF ACUTE PANCREATITIS

Background:  Serum pancreatic lipase may improve the diagnosis of pancreatitis compared to serum amylase. Both enzymes have been measured simultaneously at our hospital allowing for a comparison of their diagnostic accuracy.

Restricted versus continued standard caloric intake during the management of refeeding syndrome in critically ill adults: a randomised, parallel-group, multicentre, single-blind controlled trial

BACKGROUND Equipoise exists regarding the benefits of restricting caloric intake during electrolyte replacement for refeeding syndrome, with half of intensive care specialists choosing to continue normal caloric intake. We aimed to assess whether energy restriction affects the duration of critical illness, and other measures of morbidity, compared with standard care. METHODS We did a randomised, multicentre, single-blind clinical trial in 13 hospital intensive care units (ICUs) in Australia (11 sites) and New Zealand (two sites). Adult critically ill patients who developed refeeding syndrome within 72 h of commencing nutritional support in the ICU were enrolled and allocated to receive continued standard nutritional support or protocolised caloric restriction. 1:1 computer-based randomisation was done in blocks of variable size, stratified by enrolment serum phosphate concentration (>0·32 mmol/L vs ≤0·32 mmol/L) and body-mass index (BMI; >18 kg/m(2)vs ≤18 kg/m(2)). The primary outcome was the number of days alive after ICU discharge, with 60 day follow-up, in a modified intention-to-treat population of all randomly allocated patients except those mistakenly enrolled. Days alive after ICU discharge was a composite outcome based on ICU length of stay, overall survival time, and mortality. The Refeeding Syndrome Trial was registered with the Australian and New Zealand Clinical Trials Registry (ANZCTR number 12609001043224). FINDINGS Between Dec 3, 2010, and Aug 13, 2014, we enrolled 339 adult critically ill patients: 170 were randomly allocated to continued standard nutritional support and 169 to protocolised caloric restriction. During the 60 day follow-up, the mean number of days alive after ICU discharge in 165 assessable patients in the standard care group was 39·9 (95% CI 36·4-43·7) compared with 44·8 (95% CI 40·9-49·1) in 166 assessable patients in the caloric restriction group (difference 4·9 days, 95% CI -2·3 to 13·6, p=0·19). Nevertheless, protocolised caloric restriction improved key individual components of the primary outcome: more patients were alive at day 60 (128 [78%] of 163 vs 149 [91%] of 164, p=0·002) and overall survival time was increased (48·9 [SD 1·46] days vs 53·65 [0·97] days, log-rank p=0·002). INTERPRETATION Protocolised caloric restriction is a suitable therapeutic option for critically ill adults who develop refeeding syndrome. We did not identify any safety concerns associated with the use of protocolised caloric restriction. FUNDING National Health and Medical Research Council of Australia.

An effective automated nutrition screen for hospitalized patients

OBJECTIVE Screening for malnutrition-related complications (MRCs) in hospitalized patients would identify those requiring nutritional intervention and improve resource allocation. Bruglers simplified screening tool (MRCS) ranks the binary pattern of six readily available variables (categorical cutoff values for serum albumin [<31.5 g/L], lymphocyte count [<1.202 x 10(9)/L], and hemoglobin [<99.5 g/L], the presence of high-risk illness, poor nutritional intake and the presence of a wound) to enable automated computerized screening. This study compared the MRCS with a simpler Automated Nutrition Score (ANS; the number of abnormal results from the six variables) and ANS(B) (the number of abnormal results from the three blood measurements) with the Subjective Global Assessment (SGA) for prediction of complications. METHODS Of 148 consecutive surgical patients, 143 underwent the SGA on admission. Morbidity was prospectively recorded. The six variables of the MRCS were tabulated and correlated with the frequency of complications. Receiver operating characteristic analysis compared the MRCS with the SGA, ANS, and ANS(B). RESULTS Twenty-two patients had moderate to severe complications, a pretest probability of 15.3%. Patients stratified as higher risk by the SGA, ANS(B), and ANS had post-test probabilities of complications of 28.7%, 37.8%, and 29.3%, respectively. However, a clinically useful prediction of low risk (post-test probability of 1.5%) was demonstrated when the ANS was <or=1. Receiver operating characteristic analysis indicated that the predictability of complications increased with SGA < ANS(B) < ANS < MRCS to an area under the curve of 0.78 (confidence interval 0.68-0.88). CONCLUSIONS The MRCS was more predictive of postoperative complications than the SGA. ANS scores are useful tools at the bedside and their utility should also be tested in non-surgical patient groups.

The impact of reporting incidental findings from exome and whole-genome sequencing: predicted frequencies based on modeling

Purpose:The American College of Medical Genetics and Genomics released practice guidelines recommending reporting of incidental findings from exome and whole-genome sequencing by massively parallel (next-generation) sequencing for multiple conditions. Policy statements from other agencies are still being developed, and many attempt to take into consideration the predicted increase in workload caused by reporting incidental findings. We describe the effects of changing the sensitivity and the specificity, as well as the implications of varying diagnostic criteria and a priori prevalence, and those of increasing the number of included conditions, on rates of incidental findings.Methods:We developed a simple mathematical model based on binomial probability for predicting rates of incidental findings. We primed and validated the model using published variant frequencies.Results:The model correctly calculates observed rates of incidental findings. Changing the model’s parameters shows that even minor changes in diagnostic criteria or sequencing accuracy cause large variation in rates of incidental findings.Conclusion:Our model correctly explains observed rates of incidental findings. Key drivers of rates include diagnostic criteria, variant frequency, disease penetrance, and sequencing and bioinformatics accuracy. Rates of incidental findings are relatively insensitive to even large increases in the number of conditions included.Genet Med 17 3, 197–204.

Improving the quality of information on pathology request forms

Background: We have investigated the causes of incomplete pathology request forms received at our clinical chemistry laboratory. Based on a request form audit we found that the data most frequently missing from a pathology request form was the doctors name, unique identification provider number, or signature. Methods: We examined the effect of issuing the requesting doctors with self-inking stamps personalized with their name and a unique provider number. Results: The intervention led to an immediate and sustained improvement in compliance, with the proportion of incomplete forms falling from 43% to 2%. In contrast, distribution of a memorandum alone made no significant change to the number of pathology request forms with incomplete data arriving at the laboratory. Conclusion: This study describes a simple and low-cost solution to one of the causes of incomplete pathology request forms. It also demonstrates the effectiveness of systems improvement in health care.

Making sense of a haemolysis monitoring and reporting system: a nationwide longitudinal multimethod study of 68 Australian laboratory participant organisations

Abstract Background: The key incident monitoring and management systems (KIMMS) quality assurance program monitors incidents in the pre- and postanalytical phases of testing in medical laboratories. Haemolysed specimens have been found to be the most frequent preanalytical error and have major implications for patient care. The aims of this study were to assess the suitability of KIMMS for quality reporting of haemolysis and to devise a meaningful method for reporting and monitoring haemolysis. Methods: A structured survey of 68 Australian KIMMS laboratory participant organisations was undertaken. Quarterly haemolysis reports (2011–2014) were analysed. Results: Among 110 million accessions reported, haemolysis rates varied according to the reporting methods that participants used for assigning accessions (16% of participants reported haemolysis by specimen and 83% reported by episode) and counting haemolysis rejections (61% by specimen, 35% by episode and 3% by test). More than half of the participants (56%) assigned accessions by episode and counted rejections by specimen. For this group, the average haemolysis rate per 100,000 episodes was 177 rejected specimens with the average rate varying from 100 to 233 over time. The majority of participants (91%) determined rejections using the haemolysis index. Two thirds of participants (66%) recorded the haemolysis manually in laboratory information systems. Conclusions: KIMMS maintains the largest longitudinal haemolysis database in the world. However, as a means of advancing improvements in the quality of the preanalytical laboratory process, there is a need to standardise reporting methods to enable robust comparison of haemolysis rejection rates across participant laboratories.

Key factors influencing the incidence of hemolysis: A critical appraisal of current evidence

Abstract Hemolysis is a leading cause of pre-analytical laboratory errors. The identification of contributing factors is an important step towards the development of effective practices to reduce and prevent hemolysis. We performed a review of PUBMED, Embase, Medline and CINAHL to identify articles published between January 2000 and August 2016 that identified factors influencing in vitro hemolysis rates. The 40 studies included in this review provide excellent evidence that hemolysis rates are higher in Emergency Departments (EDs), for non-antecubital draws, for specimens drawn using an intravenous catheter compared to venipuncture and for samples transported by pneumatic tube compared to by hand. There is also good evidence that hemolysis rates are higher when specimens are not collected by professional phlebotomists, larger volume specimen tubes are used, specimen tubes are filled less than halfway and tourniquet time is greater than one minute. The results of this review suggest that hospitals and clinical laboratories should consider deploying phlebotomists in EDs, drawing all blood through a venipuncture, using the antecubital region as the optimum blood collection site and transporting specimens by laboratory assistant/other personnel, or if this in not practical, ensuring that pneumatic transport systems are validated, maintained and monitored. Studies also recommend making hemolysis a hospital-wide issue and ensuring high-quality staff training and adherence to standard operating procedures to reduce hemolysis rates. Awareness of the factors that influence hemolysis rates, and adoption of strategies to mitigate these risk factors, is an important step towards creating quality practices to reduce hemolysis rates and improve the quality of patient care.

More on Lot-to-Lot Changes

To the Editor: Shifts in patient results due to reagent lot changes are a major issue for laboratories, and their investigation is both time-consuming and expensive. In a recent article, Algeciras-Schimnich et al. (1) point out the effect that reagent lot-to-lot changes over time can have on patient results and how these shifts, if large enough, could lead to misdiagnosis and inappropriate treatment. As was the case in this article, on insulin-like growth factor 1, it is often clinicians who alert the laboratory to changes in patient results. We have had similar experiences for a number of analytes, including creatinine. For this analyte, clinicians monitoring renal transplantation patients have asked whether changes as small as from 1.13 mg/dL (100 μmol/L) to 1.24 mg/dL (110 μmol/L) are real or due to shifts in the assay. In the laboratory, shifts in patient results can be caused by a number of assay system components, but the most likely are reagent …

Pneumatic tube transport of blood-stained cerebrospinal fluid specimens has no clinically relevant effect on rates of haemolysis compared to manual transport

Background Pneumatic tube transport of pathology specimens from the emergency department to the laboratory for analysis is a widely used practice. When compared to manual specimen transport, it results in savings in both time and labour. Sampling of cerebrospinal fluid still forms part of the workup of patients with suspected subarachnoid haemorrhage. There are claims in the literature that transport of cerebrospinal fluid samples by pneumatic tube results in excess haemolysis, which interferes with cerebrospinal fluid analysis for the presence of bilirubin. The aim of our study was to ascertain whether pneumatic tube transport of blood-stained cerebrospinal fluid to the laboratory, results in clinically significantly higher levels of haemolysis compared with manual transport of the same specimens. Methods Stored cerebrospinal fluid was spiked with varying amounts of red blood cells creating 72 specimens of varying red cell concentration. Half of these specimens were transported to the laboratory manually while the other half were sent by pneumatic tube transport. The rates of haemolysis were compared between the pneumatic tube and manual transport samples. Results There was no clinically significant difference in the rates of haemolysis between the samples transported to the laboratory by pneumatic tube compared with those moved manually. Conclusions Pneumatic tube transport of cerebrospinal fluid to the laboratory is not associated with clinically significantly higher rates of haemolysis when compared to manual transport.