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.     

Temporary replacement of missing maxillary lateral incisors with orthodontic miniscrew implants in growing patients: rationale,clinical technique,and long-term results

Abstract

The missing maxillary lateral incisor in adolescent patients presents an orthodontic challenge. Historically, there have been three treatment options to address this clinical problem: (1) canine substitution, (2) tooth auto-transplantation, and (3) dental restoration. Unfortunately, these methods are not without limitation. A novel treatment concept, originating in 2003 and utilizing orthodontic miniscrew implants, is presented along with the rationale, clinical technique and 8 years of follow-up.     

Abnormalities of the cervical spine in Down's syndrome: diagnosis, risks, and review of the literature, with particular reference to the Special Olympics

Over a four-month period, we did roentgenographic examinations of the cervical spine on 35 individuals with Down's syndrome, most of whom planned to participate in the Special Olympics. There were abnormalities in 40%, the most frequent being atlantoaxial subluxation. The presentations, risks, and recognition of this abnormality are discussed, as well as the pathomechanics. Many parents and some physicians may still be unaware of the possible hazards involving these spinal abnormalities, and of the recommendations and screening procedures that should be followed before individuals with Down's syndrome engage in strenuous activities.     

Structuring a safer donor-replacement program

BACKGROUND: Replacement donors are more likely than volunteer donors to have positive or abnormal tests for transfusion-transmissible disease. In an effort to increase the donor pool, workers sought to identify a safer replacement-donor subgroup that may be acceptable for routine donations. STUDY DESIGN AND METHODS: In a retrospective review and cohort study, the replacement-donor effect was separated from the new- donor effect. The relative effect the replacement donor has on the risk of transfusion-transmissible diseases, donor retention, and frequency of returning donations was then quantified by comparison against the effect of repeat volunteer donors. RESULTS: The replacement donor had 3.1 times the risk and 0.72 times the donor retention rate and made 0.81 times as many returning donations as the repeat volunteer donor. The figures for the new-donor effect were similar. The two risks were additive, making a new replacement donor particularly hazardous. If replacement donations only from repeat replacement donors were considered, the donor risk and the number of donations per returning donor were made comparable to those for the general (combined) volunteer donor. CONCLUSION: The negative effect of the replacement donor is similar in magnitude to that of the new volunteer donor. A replacement-donation program targeting repeat replacement donors has an acceptable risk profile and may be a valuable adjunct to the collection of blood from general volunteer donors.     

The effect of endotoxin and dexamethasone on enrofloxacin pharmacokinetic parameters in swine

The impact of Escherichia coli-derived lipopolysaccharide (LPS) on the pharmacokinetic parameters of enrofloxacin in swine was assessed to determine whether this model would substitute for a pleuropneumonia infection model for pharmacokinetic evaluation of drugs. All animals received a single i.v. dose of enrofloxacin (5 mg/kg). Half the animals also received dexamethasone (0.5 mg/kg) to determine the impact of inflammation on any changes in enrofloxacin pharmacokinetics, as most of the effects of LPS are due to elaboration of inflammatory mediators. Administration of LPS alone (2.0 microg/kg) was associated with a decrease in clearance of enrofloxacin. Volume of distribution at steady state was increased in the dexamethasone-treated animals. The terminal elimination half-life of enrofloxacin was significantly increased in the LPS group. Dexamethasone administration, either alone or in combination with LPS challenge, increased the volume of distribution both at steady state and during the elimination phase. Lipopolysaccharide challenge did not affect the volume of distribution. Lipopolysaccharide challenge did not affect urinary excretion of enrofloxacin but did increase the urinary excretion of its principal metabolite, ciprofloxacin. However, the increased excretion did not begin until 24 h after administration of enrofloxacin. Because these pharamcokinetic results are different from those obtained with the pleuropneumonia model using the bacteria Actinobacillus pleuropneumoniae, the results of this study demonstrate that LPS is not a generic substitute for infection for the pharmacokinetic evaluation of drugs.     

Student reflective groups at a Scottish College of Nursing

In this paper student views on reflective groups, set up as an important element of the new Project 2000 course in a Scottish College of Nursing, are reported. A random sample of 19 students were interviewed. While the reflective groups were very popular with students because they provided support, there was little evidence of a linkage between theory and practice. It was clear that the ambitious objective of stimulating reflection-on-action was not attained. Practice certainly was discussed, but it tended to be dominated by dramatic and emotionally charged aspects of care rather than the more frequent routine concerns. There were, however, indications that the original aim of the reflective groups could be achieved if tutors could establish a common understanding of the purpose of the groups and of reflection, and if the practices on which students reflected consisted less of single day visits where the students saw themselves as non-participant outsiders.     

Chronic Tumor Necrosis Factor Alters T Cell Responses by Attenuating T Cell Receptor Signaling

Repeated injections of adult mice with recombinant murine TNF prolong the survival of NZB/W F1 mice, and suppress type I insulin-dependent diabetes mellitus (IDDM) in nonobese diabetic (NOD) mice. To determine whether repeated TNF injections suppress T cell function in adult mice, we studied the responses of influenza hemagglutinin-specific T cells derived from T cell receptor (HNT-TCR) transgenic mice. Treatment of adult mice with murine TNF for 3 wk suppressed a broad range of T cell responses, including proliferation and cytokine production. Furthermore, T cell responses of HNT-TCR transgenic mice also expressing the human TNF-globin transgene were markedly reduced compared to HNT-TCR single transgenic littermates, indicating that sustained p55 TNF-R signaling is sufficient to suppress T cell function in vivo. Using a model of chronic TNF exposure in vitro, we demonstrate that (a) chronic TNF effects are dose and time dependent, (b) TNF suppresses the responses of both Th1 and Th2 T helper subsets, (c) the suppressive effects of endogenous TNF produced in T cell cultures could be reversed with neutralizing monoclonal antibodies to TNF, and (d) prolonged TNF exposure attenuates T cell receptor signaling. The finding that anti-TNF treatment in vivo enhances T cell proliferative responses and cytokine production provides evidence for a novel regulatory effect of TNF on T cells in healthy laboratory mice. These effects are more pronounced in chronic inflammatory disease. In addition, our data provide a mechanism through which prolonged TNF exposure suppresses disease in animal models of autoimmunity.