Role of preoperative carbohydrate loading: a systematic review

INTRODUCTION

Surgical stress in the presence of fasting worsens the catabolic state, causes insulin resistance and may delay recovery. Carbohydrate rich drinks given preoperatively may ameliorate these deleterious effects. A systematic review was undertaken to analyse the effect of preoperative carbohydrate loading on insulin resistance, gastric emptying, gastric acidity, patient wellbeing, immunity and nutrition following surgery.

METHODS

All studies identified through PubMed until September 2011 were included. References were cross-checked to ensure capture of cited pertinent articles.

RESULTS

Overall, 17 randomised controlled trials with a total of 1,445 patients who met the inclusion criteria were identified. Preoperative carbohydrate drinks significantly improved insulin resistance and indices of patient comfort following surgery, especially hunger, thirst, malaise, anxiety and nausea. No definite conclusions could be made regarding preservation of muscle mass. Following ingestion of carbohydrate drinks, no adverse events such as apparent or proven aspiration during or after surgery were reported.

CONCLUSIONS

Administration of oral carbohydrate drinks before surgery is probably safe and may have a positive influence on a wide range of perioperative markers of clinical outcome. Further studies are required to determine its cost effectiveness.     

Serology and ultrasound for diagnosis of choledocholithiasis

Introduction

Magnetic resonance cholangiopancreatography (MRCP) is not a routine investigation to exclude choledocholithiasis unless there is clinical or biochemical suspicion of common bile duct (CBD) stones. This study attempted to determine which radiological or serological parameters best predicted CBD stones.

Methods

All patients undergoing MRCP from 2005 to 2011 were selected. Patients with pancreatitis were excluded. Liver function tests (LFTs) at admission and prior to MRCP were recorded, as was abdominal ultrasonography and MRCP results. Parameters measured routinely on LFTs included alkaline phosphatase (ALP), alanine transaminase (ALT) and bilirubin. Receiver operating characteristic curve area analysis (area under the curve [AUC]) and chi-squared analysis were undertaken.

Results

Overall, 195 patients were identified, 71 of whom had CBD stones on MRCP. Raised ALP levels on admission demonstrated a correlation with CBD stones (AUC: 0.619, odds ratio [OR]: 3.16, p=0.06). At ultrasonography, a dilated CBD (OR: 3.76, p<0.001) and intrahepatic duct dilation (OR: 5.56, p<0.001) were highly significant predictors. However, only 37% of patients had a dilated CBD on ultrasonography. Ongoing elevation of LFT parameters, particularly ALP (AUC: 0.707, OR: 4.64, p<0.001) and ALT (AUC: 0.646, OR: 5.40, p<0.001), displayed a significant correlation with CBD stones.

Conclusions

Ongoing (even if minor) elevations of liver function test parameters should prompt the need to exclude CBD stones even in the presence of a normal CBD diameter on ultrasonography.     

Thrombin causes subsecond changes in protein phosphorylation of platelets

We have developed a general quenched-flow approach to study platelet function as early as 0.3 seconds after stimulation. Phosphorylation of 20- and 40-kd proteins has been analyzed during the first five seconds of platelet response to thrombin from 0.1 to 5.0 U/mL and compared with the progress of aggregation and serotonin secretion. The onset time for aggregation and phosphorylation of both proteins was less than one second, although with lowest (less than 0.5 U/mL) thrombin levels, a lag of up to 0.6 seconds occurred before 40K phosphorylation increased. The thrombin sensitivity of aggregation and 20K phosphorylation was approximately twice that of 40K phosphorylation, with Ka values of 0.51 and 0.53 v 1.10 U/mL, respectively. External calcium was necessary for maximal 20K phosphorylation, since EDTA inhibited this by 30%. The 40K phosphorylation was not affected by EDTA. Platelet activation by thrombin thus induced biochemical changes well before one second. The quenched-flow approach may help to reveal relationships between phospholipase activation, calcium fluxes, and protein phosphorylation during these early periods of platelet function.     

Circulating T-Cell Subsets,Monocytes, and Natural Killer Cells in Peripartum Cardiomyopathy: Results From the Multicenter IPAC Study

Objective

The aim of this work was to evaluate the hypothesis that the distribution of circulating immune cell subsets, or their activation state, is significantly different between peripartum cardiomyopathy (PPCM) and healthy postpartum (HP) women.

Prediction of heart transplant rejection with a breath test for markers of oxidative stress

The Heart Allograft Rejection: Detection with Breath Alkanes in Low Levels study evaluated a breath test for oxidative stress in heart transplant recipients, and we report here a mathematical model predicting the probability of grade 3 rejection. The breath test divided the heart transplant recipients into 3 groups: positive for grade 3 rejection, negative for grade 3 rejection, and intermediate. The test was 100% sensitive for grade 3 heart transplant rejection when the p value was >/=0.98, and 100% specific when the p value was 相似文献   

Superoxide mediates sympathoexcitation in heart failure: roles of angiotensin II and NAD(P)H oxidase

Chronic heart failure (CHF) is often associated with excitation of the sympathetic nervous system. This event is thought to be a negative predictor of survival in CHF. Sympathoexcitation and central angiotensin II (Ang II) have been causally linked. Recent studies have shown that NAD(P)H oxidase-derived reactive oxidant species (ROS) are important mediators of Ang II signaling. In the present study, we tested the hypothesis that central Ang II activates sympathetic outflow by stimulation of NAD(P)H oxidase and ROS in the CHF state. CHF was induced in male New Zealand White rabbits by chronic ventricular tachycardia. Using radio telemetry of arterial pressure and intracerebroventricular infusions, experiments were performed in the conscious state. Renal sympathetic nerve activity (RSNA) was recorded as a direct measure of sympathetic outflow. Intracerebroventricular Ang II significantly increased RSNA in sham (131.5+/-13.3% of control) and CHF (193.6+/-11.9% of control) rabbits. The increase in CHF rabbits was significantly greater than in sham rabbits (P<0.01). These responses were abolished by intracerebroventricular losartan, tempol, or apocynin. Resting RSNA was significantly reduced by intracerebroventricular losartan, tempol, or apocynin in CHF rabbits but not in sham rabbits. Intracerebroventricular administration of the superoxide dismutase inhibitor diethyldithio-carbamic acid increased RSNA significantly more in sham compared with CHF rabbits. NADPH-dependent superoxide anion production in the rostral ventrolateral medulla (RVLM) was increased by 2.9-fold in CHF rabbits compared with sham rabbits. Finally, increases in the RVLM mRNA and protein expression of Ang II type 1 (AT1) receptor and subunits of NAD(P)H oxidase (p40phox, p47phox, and gp91phox) were demonstrated in CHF rabbits. These data demonstrate intense radical stress in autonomic areas of the brain in experimental CHF and provide evidence for a tight relationship between Ang II and ROS as contributors to sympathoexcitation in CHF.     

Diagnostic role of an immunoassay-detected polymorphism of factor IX for potential carriers of hemophilia B

In hemophilia B, assays based on a monoclonal antifactor IX specific for the Thr-148 variant of an exonic polymorphism have diagnosed carriers in selected families by either establishing linkage or by indicating the presence or absence of a given normal factor IX. The sensitivity of the immunoassays for detecting heterozygous women was explored by comparing results from immunoassays with solid-phase polyclonal v the monoclonal antifactor IXs. Factor IX with the normal Ala-148 variant gave a flat dilution curve, qualitatively distinct from factor IX with the Thr-148 variant in the monoclonal assay. The two were indistinguishable in the polyclonal assay. Mixtures of equal amounts of the two types gave an intermediate result, about half as reactive in the monoclonal as compared with the polyclonal assay system. Whereas mixtures with 10% Ala-148 and 90% Thr-148 factor IXs could not readily be distinguished from Thr-148 factor IX plasma, as little as 1% of the Thr-148 protein was detected in Ala-148 factor IX plasma. The frequency of the Ala-148 variant varied in individuals with different ethnic backgrounds; it was found in 29% of white, 12% of black, and none of Asian blood donors' factor IX genes in Seattle. Only 4% of samples from South African black men were nonreactive (ie, Ala- 148). The Thr/Ala-148 dimorphism is in strong linkage disequilibrium with Taql restriction fragment length polymorphisms (RFLPs). Three recombinations were noted in normal white genes and one in a normal black factor IX gene (less than 2% of those examined). In 34 white families with at least one woman being a possible carrier, genetically, the immunoassay results were informative in 18. RFLP analyses were informative in eight of the 15 families tested. In five families each, assignment of carrier status was made to a woman by only DNA or only immunoassay results, whereas the other approach was noninformative. The immunoassays provide a rapid, inexpensive screening test and complement DNA analysis in white women who are potential carriers of hemophilia B.     

Bringing prevost's sign into the third dimension: Artificial intelligence estimation of conjugate gaze adjusted length (CGAL) and correlation with acute ischemic stroke

Conjugate gaze deviation is associated with acute ischemic stroke (AIS), although previously only measured on a 2D plane. The current study evaluates 3D imaging efficacy to assess conjugate gaze deviation and correlate direction and strength of deviation to neuro-clinical findings.A retrospective analysis of 519 patients who had CT scans for suspected AIS at our institution. Direction and angle of eye deviation were calculated based on 2D axial images. Volumetric reconstruction of CT scans allowed for calculation of 3D conjugate gaze adjusted length (CGAL). Angle, direction, and vector strength of both 2D and 3D scans were calculated by an artificial intelligence algorithm and tested for agreement with hemispheric ischemia location. CGAL measurements were correlated to NIHSS scores. Follow up MRI data was used to evaluate the sensitivity and specificity of CGAL in the identification of AIS.The final analysis included 122 patients. A strong agreement was found between 3D gaze direction and hemispheric ischemia location. CGAL measurements were highly correlated with NIHSS score (r = .72, P = .01). A CGAL >0.25, >0.28, and >0.35 exhibited a sensitivity of 91%, 86%, and 82% and specificity of 66%, 89%, and 89%, respectively, in AIS identification. A CGAL >0.28 has the best sensitivity-specificity balance in the identification of AIS. A CGAL >0.25 has the highest sensitivity.Given CED''s correlation with NIHSS score a 1/4 deviation in the ipsilateral direction is a sensitive ancillary radiographic sign to assist radiologists in making a correct diagnosis even when not presented with full clinical data.     

Reaching Children Never Previously Vaccinated for Influenza Through a School-Located Vaccination Program

Objectives. We determined the success of the school-located vaccination (SLV) program, implemented in 2009 in New York City to deliver pandemic influenza A (H1N1) monovalent vaccine (pH1N1), versus provider offices in reaching children who had never previously received influenza vaccine.Methods. We compared the immunization history of children vaccinated in school versus provider offices. We included records in the Citywide Immunization Registry with pH1N1 administered between October 2009 and March 2010 to elementary school-aged children.Results. In total, 96 524 children received pH1N1 vaccine in schools, and 102 933 children received pH1N1 vaccine in provider offices. Of children vaccinated in schools, 34% had never received seasonal influenza vaccination in the past, compared with only 10% of children vaccinated at provider offices (P < .001). Children vaccinated in schools were more likely to have received a second dose of pH1N1 in 2009–2010 than those vaccinated in provider offices (80% vs 45%).Conclusions. The SLV program was more successful at reaching children who had never received influenza immunization in the past and should be considered as a strategy for delivering influenza vaccine in routine and emergency situations.Improving vaccination coverage in children may lead to decreased morbidity and mortality in the general population, including decreasing influenza deaths and illness in adults.1–4 In 2006, the Advisory Committee on Immunization Practices recommended influenza vaccine for healthy children aged 6 months to 4 years5 and expanded their recommendation in subsequent years to include children aged 5 to 18 years.6 The goal of vaccinating all children annually raises a significant operational question of how to target children most effectively.Pediatricians provide the majority of immunizations given to children. However, after the 4- to 6-year-old well child visits, children may not visit medical providers regularly. School-located vaccination (SLV) offers a convenient alternative because it reaches the majority of children regardless of their access to medical care,7 and schools have been successfully used for hepatitis B vaccination administration in the past.8,9 SLV also offers parents the convenience of not having to make a trip to the provider’s office or even be present. Jurisdictions such as Hawaii have routinely offered influenza vaccine through schools and have achieved vaccination rates as high as 46% in children aged 5 to 13 years.10Despite the potential advantages of SLV, to our knowledge, whether it successfully reaches children who otherwise would have gone unvaccinated is unknown. We examined this issue in New York City (NYC) in 2009 when the NYC Department of Health and Mental Hygiene offered pandemic influenza A (H1N1) monovalent vaccine (pH1N1) through an elementary school–located campaign. During this influenza season, because of a late-emerging strain of novel H1N1, pH1N1 vaccine was developed and offered separately from routine seasonal influenza vaccination. Using data on pH1N1 vaccination from the Citywide Immunization Registry (CIR), the NYC Department of Health and Mental Hygiene’s Immunization Information System, we compared the demographic characteristics and immunization history of children vaccinated through the SLV campaign with those of children vaccinated in medical provider offices. We examined the proportion of children in each setting for whom the pH1N1 vaccine was the first influenza vaccine ever received to determine the potential for SLV programs to effectively reach children who have not previously received an influenza vaccination and who therefore might be unlikely to get vaccinated in the current season as well. We also predicted the probability of being vaccinated at schools controlling for demographic characteristics and immunization history.     

Mumps vaccine effectiveness and risk factors for disease in households during an outbreak in New York City

Background and objectives

Mumps outbreaks have been reported among vaccinated populations, and declining mumps vaccine effectiveness (VE) has been suggested as one possible cause. During a large mumps outbreak in New York City, we assessed: (1) VE of measles-mumps-rubella vaccine (MMR) against mumps and (2) risk factors for acquiring mumps in households.

Methods

Cases of mumps were investigated using standard methods. Additional information on disease and vaccination status of household contacts was collected. Case households completed follow-up phone interviews 78–198 days after initial investigation to ascertain additional cases. Mumps cases meeting the study case definition were included in the analysis. Risk factors for mumps were assessed, and VE was calculated using secondary household attack rates.

Results

Three hundred and eleven households with 2176 residents were included in the analysis. The median age of residents was 13 years (range <1–85), and 462 (21.2%) residents met the study mumps case definition. Among 7–17 year olds, 89.7% received one or more doses of MMR vaccine, with 76.7% receiving two doses. Young adults aged 10–14 years (OR = 2.4, CI = 1.3–4.7) and 15–19 years (OR = 2.5, CI = 1.3–5.0) were at highest risk of mumps. The overall 2-dose VE for secondary contacts aged five and older was 86.3% (CI 63.3–94.9).

Conclusions

The two-dose effectiveness of MMR vaccine against mumps was 86.3%, consistent with other published mumps VE estimates. Many factors likely contributed to this outbreak. Suboptimal MMR coverage in the affected population combined with VE may not have conferred adequate immunity to prevent transmission and may have contributed to this outbreak. Achieving high MMR coverage remains the best available strategy for prevention of mumps outbreaks.