Ministry of health clinical practice guidelines: clinical blood transfusion.

The Health Sciences Authority (HSA) and the Ministry of Health (MOH) publish clinical practice guidelines on Clinical Blood Transfusion to provide doctors and patients in Singapore with evidence-based guidance for blood transfusion. This article reproduces the introduction and executive summary (with recommendations from the guidelines) from the HSA-MOH clinical practice guidelines on Clinical Blood Transfusion, for the information of readers of the Singapore Medical Journal. Chapters and page numbers mentioned in the reproduced extract refer to the full text of the guidelines, which are available from the Ministry of Health website (http://www.moh.gov.sg/mohcorp/publications.aspx?id=25700). The recommendations should be used with reference to the full text of the guidelines. Following this article are multiple choice questions based on the full text of the guidelines.

Signal-averaged electrocardiography in healthy children: relationship with age, sex, and anthropometry.

Signal-averaged electrocardiograms (SAECGs) have been found to be influenced by sex and anthropometry in adults. The purpose of this study was to evaluate this relationship in children. Total filtered QRS duration (TQRS), duration of high-frequency, low-amplitude signals in the terminal portion of the QRS complex that were less than 40 microV (HFLA) root-mean-square voltage in the last 40 ms of the filtered QRS (RMS40) were determined by high-resolution electrocardiographic (ECG) recording (MAC 15 ECG System, Marquette Electronics, Milwaukee, WI). These parameters were correlated with age, sex, body weight, height, relative weight, body mass index, and body surface area. As HFLA and RMS40 were not normally distributed, they were logarithmically transformed for regression analysis. The best subset multiple regression procedure was used to evaluate the variables that would optimally influence SAECG measurements and to obtain regression equations for the prediction of each SAECG parameter. Although univariate analysis shows that almost all the body characteristics and age are significantly correlated with SAECGs, multiple regression analysis reveals that TQRS is significantly influenced by height (P < .0001), relative weight (P = .012), and body mass index (P = .041); HFLA is influenced by weight (P = .001), height (P = .004), and body mass index (P = .001); and RMS40 is influenced by height (P < .0001) and relative weight (P = .001). Sex is noted to significantly influence both TQRS and RMS40 (P < .0001, P = .002, respectively), while HFLA is found to be significantly related to age (P = .001). In summary, SAECGs in Chinese children are shown to be influenced by height, weight, and relative weight or body mass index, but not body surface area, while age and sex also significantly contribute to the variation of some SAECG parameters.

Predictive factors for synchronous common bile duct stones in patients with cholelithiasis.

BACKGROUND: To determine the predictive factors of synchronous common bile duct (CBD) stones, data from 878 consecutive patients who underwent cholecystectomy in a university clinic from June 1991 to June 1996 were retrospectively analyzed. METHODS: Based on clinical, biochemical, and ultrasonographic criteria, 194 patients were selected for ERCP, 180 preoperative and 14 postoperative. RESULTS: Cannulation of CBD was successful in 192 (99%) patients. Stones were identified in 62 (32%) patients and sphincterotomy was performed in 56 (90%). Duct clearance was achieved in 43 (77%) cases. There was a high predictive value for the presence of CBD stones in patients with cholangitis, present jaundice, and dilated CBD with evidence of stones on ultrasound (75%, 72%, and 67% respectively). A dilated CBD without stone on ultrasound and elevated liver enzymes had less than 40% positive predictive value. History of previous jaundice, pancreatitis, previously raised liver enzymes, and present pancreatitis was predictive in less than 20% of the cases. Univariate analyses revealed that clinical findings of cholangitis and obstructive jaundice, elevated liver enzymes (previous and present), and ultrasonographic findings of stones in a dilated CBD were significant positive predictors. Subanalysis of each elevated liver enzyme revealed that alanine transaminase, aspartate transaminase, alkaline phosphatase, and gamma glutamyl transpeptidase were significant predictors. Both elevated conjugated and total bilirubins were also significant predictors for CBD stones. CONCLUSION: Multivariate logistic regression analysis on these significant predictors showed that cholangitis (odds ratio [OR]: 10.5), dilated CBD with evidence of stones on ultrasound (OR: 7.4), elevated aspartate transaminase (OR: 2.9), and conjugated bilirubin (OR: 5.3) were jointly significant. The likelihood of having stones in the duct without any of these predictors was 7%, but 99% when all the predictors were positive.

Predictive factors for conversion of laparoscopic cholecystectomy.

Reliable predictive factors for conversion of laparoscopic cholecystectomy (LC) would be extremely useful in the preparation and planning of admission for patients with symptomatic cholelithiasis. Data from 783 patients in whom LC was attempted in a university clinic from June 1990 to December 1995 were retrospectively analyzed. The aim of this study was to determine preoperative indicators that can be useful for predicting conversion to open cholecystectomy (OC). Conversion was required in 58 (7.4%) patients, of which 48 (83%) were elective and 10 (17%) emergency. Factors evaluated were age, sex, obesity, duration of gallstone disease, co-morbid factors, indication for surgery, previous abdominal surgery, fever, physical examination findings, white blood cell (WBC) count, liver function tests, ultrasound findings, and the experience of the surgeon. Acute cholecystitis, rigidity in the right upper abdomen, fever, thickened gallbladder wall on ultrasonography, elevated alkaline phosphatase (ALP), liver transaminases and the WBC count were significant predictors of conversion in the univariate analysis. Multivariate logistic regression analysis on these significant predictors showed that acute cholecystitis [odds ratio (OR) = 3.12], thickened gallbladder wall on ultrasonography (OR = 3.75), elevated ALP (OR = 2.23), and WBC count (OR = 3.69) were jointly significant.

Transcutaneous bilirubinometry in Chinese, Malay and Indian infants.

The objective of this study was to investigate the correlation of transcutaneous bilirubinometry (TcB) and plasma bilirubin concentrations in full-term Chinese, Malay and Indian infants. TcB was performed with the Minolta Airshields bilirubinometer on Chinese, Malay and Indian fullterm infants. The readings were taken on the chest (sternum) and forehead (glabella) when capillary blood was sampled for bilirubin determination. Five hundred and forty TcB indices in 253 Chinese infants, 282 in 169 Malay infants, and 182 in 120 Indian infants were obtained over the sternum and forehead. A good correlation between the TcB indices and the bilirubin concentrations was observed in Chinese, Malay and Indian infants: r = 0.78 (chest), r = 0.73 (forehead); r = 0.86 (chest), r = 0.84 (forehead); and r = 0.84 (chest), r = 0.82 (forehead). The correlation was just as good when the combined values were evaluated together: r = 0.80 (chest) r = 0.75 (forehead). In Chinese infants, correlation at values below 250 mumol l-1 was significantly better than that at values over 250 mumol l-1 r = 0.80 versus r = -0.20, p < 0.00001 (chest), and r = 0.74 versus r = 0.07, p < 0.00001 (forehead). However, a safer cut-off point clinically would be 200 mumol l-1, since only relatively few higher bilirubin values were encountered when TcB indices were below 200 mumol l-1. The same pattern was noticed with the other two groups, and the combined group. Thus, TcB provides a non-invasive, cost-effective screening method for significant neonatal jaundice, sparing infants and parents physical and emotional stress, and medical and nursing personnel extra work and inconvenience.