Accuracy of dispersing tramadol capsules for oral administration in young children

Tramadol is used in children aged <12 years for analgesia, particularly for those at risk of obstructive sleep apnoea undergoing adenotonsillectomy. The Australian Therapeutic Goods Administration have strongly recommended that oral tramadol drops (100 mg/ml) not be used in children <12 years because of the risk of inadvertent overdose. The total mass of drug in a 10 ml bottle is 1000 mg. The only alternative preparation available is a 50 mg capsule that requires dispersion of a capsule's contents should smaller doses be required. The accuracy of this preparation has not been assessed. Twenty surgical ward nurses were asked to prepare a 15 mg dose of tramadol from a 50 mg capsule. The dose was within ±5% of 15 mg in 13 cases (65%) and within ±10% in 19 cases (95%) (range 13.9-17.1 mg). Despite the dose variability of this method of preparing tramadol, we consider it sufficiently accurate for clinical use. We also consider it safe, as even at the highest dose prepared, the variability would be unlikely to contribute to clinically significant side-effects or toxicity. Moreover, the maximal dose that could be administered is limited to the size of the capsule (50 mg).

Predictors of persistent pain after total knee arthroplasty: a systematic review and meta-analysis

BACKGROUND

Several studies have identified clinical, psychosocial, patient characteristic, and perioperative variables that are associated with persistent postsurgical pain; however, the relative effect of these variables has yet to be quantified. The aim of the study was to provide a systematic review and meta-analysis of predictor variables associated with persistent pain after total knee arthroplasty (TKA).

METHODS

Included studies were required to measure predictor variables prior to or at the time of surgery, include a pain outcome measure at least 3 months post-TKA, and include a statistical analysis of the effect of the predictor variable(s) on the outcome measure. Counts were undertaken of the number of times each predictor was analysed and the number of times it was found to have a significant relationship with persistent pain. Separate meta-analyses were performed to determine the effect size of each predictor on persistent pain. Outcomes from studies implementing uni- and multivariable statistical models were analysed separately.

RESULTS

Thirty-two studies involving almost 30 000 patients were included in the review. Preoperative pain was the predictor that most commonly demonstrated a significant relationship with persistent pain across uni- and multivariable analyses. In the meta-analyses of data from univariate models, the largest effect sizes were found for: other pain sites, catastrophizing, and depression. For data from multivariate models, significant effects were evident for: catastrophizing, preoperative pain, mental health, and comorbidities.

CONCLUSIONS

Catastrophizing, mental health, preoperative knee pain, and pain at other sites are the strongest independent predictors of persistent pain after TKA.

Randomized controlled trial of the effect of depth of anaesthesia on postoperative pain

BACKGROUND

Our hypothesis was that deep anaesthesia, as estimated by a low target bispectral index (BIS) of 30-40, would result in less postoperative pain than that achieved at a conventional depth of anaesthesia.

METHODS

We undertook a randomized double-blind controlled study at two tertiary teaching hospitals in New Zealand (2010-1) recruiting 135 adult patients ASA I-II presenting for non-emergent surgery under general anaesthesia requiring tracheal intubation. Anaesthesia was maintained with desflurane and a multimodal analgesia regimen comprising fentanyl infusion, i.v. paracetamol, and parecoxib. Patients were randomly assigned to either a low BIS (30-40) group or a high BIS (45-60) group. Desflurane concentrations were titrated to achieve these targets. Postoperative pain was assessed by: the pain on awakening (0-10, verbal rating scale, VRS(awake)) in the post-anaesthetic care unit; pain on activity at 20-24 h after operation (VRS(d1A)); and the rate of morphine patient-controlled analgesia (PCA) usage over the first 24 h.

RESULTS

There was no statistically significant difference between the two groups for any of the pain scores. The median [inter-quartile range (IQR)] VRS(awake) was 4.0 (0-8) for the low and 4.0 (0-8) for the high BIS groups (P=0.56). The median (IQR) VRS(d1A) was 3.0 (1-5) for the low and 3.0 (1.5-4.5) for the high BIS groups (P=0.83). The median PCA morphine consumption in the low BIS group was 0.61 mg h(-1) (0.04-1.5) vs 0.43 mg h(-1) (0-1.59) in the high BIS group (P=0.98).

CONCLUSIONS

We conclude that there is no clinically useful analgesic effect of a deep anaesthesia regimen.

Apoprotein A-V: an important regulator of triglyceride metabolism

Apolipoprotein A-V (apoA-V) was discovered in 2001 both by comparative sequencing and as a liver regeneration protein. The gene is a located at the APOA1/C3/A4/A5 gene cluster on chromosome 11q23, a locus well known for playing a major role in regulating plasma cholesterol and triglyceride (TG) levels. ApoA-V is produced in the liver and has very low plasma concentrations (0.1-0.4 mug/ml). Mice lacking apoA-V have 4-fold increased TG levels, whereas apoA-V overexpression leads to 40% plasma TG reduction. Based on metabolic studies in vivo, apoA-V enhances the catabolism of TG rich lipoproteins rather than affecting their intestinal or hepatic production. By activating proteoglycans-bound lipoprotein lipase (LPL), apoA-V can accelerate TG hydrolysis from VLDL and chylomicrons independent from other apoproteins. Several variants at the APOA5 gene locus have been detected in humans. Some single nucleotide polymorphisms (SNPs) are associated with significantly higher plasma TG levels in patients (e.g., -1131T > C, S19W, G185C). In addition, these SNPs may affect fibrate response and obesity. However, data for a possible association of APOA5 variants with coronary heart disease are not consistent. Severe structural mutations (Q139X, Q148X, IVS3 + 3G > C) predispose to familial hypertriglyceridaemia and late-onset chylomicronaemia. Thus, despite its low plasma concentration, apoA-V is a major regulator of plasma TG metabolism in humans. However, the precise mechanism of its function is not yet clear.

BIS and Entropy in the elderly

The interaction of many poorly defined, physiological, pharmacological, and pathological factors make titration of general anaesthesia in the elderly difficult. There may be a potential clinical benefit using the processed electroencephalogram (EEG) to monitor hypnotic level in this population. We prospectively studied 16 patients aged over 65 years having hip fractures repaired under general anaesthesia by experienced anaesthetists blinded to Bispectral Index (BIS(XP)) and Entropy values. Pre-induction EEG indices did not correlate with age or mini-mental state examination (MMSE). During maintenance of anaesthesia, BIS(XP) and Response Entropy (RE) values were within the recommended range of 40-60, 45% and 32% of the total time, respectively. BIS(XP) and Response Entropy (RE) values were above 60 for 11% and 13% of the total time, respectively, and below 40 for 44% and 55% of the total time, respectively. BIS(XP) correlated well with RE in 12 patients, but in the other four patients there was a difference of more than 20 points between BIS(XP) and RE.

Propofol anaesthesia via target controlled infusion or manually controlled infusion: effects on the bispectral index as a measure of anaesthetic depth

Target controlled infusions (TCI) of propofol allow anaesthetists to target constant blood concentrations and respond promptly to signs of inappropriate anaesthetic depth. Studies comparing propofol TCI with manually controlled infusion (MCI) reported similar control of anaesthesia, but did not use an objective measure of anaesthetic depth. We therefore tested whether the Bispectral Index (BIS), an electroencephalographic (EEG) variable, is more stable during propofol TCI or MCI. Forty patients received midazolam and fentanyl before induction and were randomized to TCI or MCI. Target propofol concentrations in the TCI group were 3 to 8 microg/ml. The MCI group received propofol bolus (approximately 2 mg/kg) and infusion (3 to 10 mg/kg/h). Neuromuscular blockade was achieved with rocuronium. Following endotracheal intubation, nitrous oxide (66%) in oxygen was delivered and propofol infusion and fentanyl boluses were titrated against clinical signs. Blood pressure, heart rate and EEG were recorded, although the anaesthetist was blind to BIS values. The ideal BIS for general anaesthesia was defined as 50. Performance error, absolute performance error, wobble and divergence of BIS, and maximum changes in blood pressure and heart rate were compared using two-sample t-tests or rank-sum tests where appropriate. There was no difference in absolute performance errors during maintenance of anaesthesia with propofol TCI or MCI (23 +/- 11% vs 23 +/- 9%; P=0.97). The two groups did not differ significantly in performance error, wobble, divergence on haemodynamic changes. We conclude that TCI and MCI result in similar depth of anaesthesia and haemodynamic stability when titrated against traditional clinical signs.

Clinical and cellular effects of cytochrome P-450 modulators

Stress stimulates the hypothalamic-pituitary-adrenal axis and leads to elevated glucocorticoid hormones (GCs). GCs reduce inflammation and suppress responses mediated by cytokines, including fever and pulmonary inflammation. Besides cyclooxygenases and lipoxygenases, cytochrome P-450 enzymes (CYP), referred to as epoxygenases, are also involved in the metabolism of arachidonic acid, implicating epoxygenases in regulating inflammation and the generation of fever. Intraperitoneal injection of lipopolysaccharide (LPS) triggers fever in rats and mice, and administration of compounds known to induce CYP reduces LPS-induced fever, while inhibitors of CYP suppress fever. Consistent with these findings, inhibitors of CYP augment the elevation of LPS-induced prostaglandin E2 levels, an endogenous pyrogen, and administration of epoxygenase metabolites results in antipyresis. CYP inducers also reduce lung inflammation, the resulting mucous cell metaplasia, and the percentage of Bcl-2-positive mucous cells in rat airways after intratracheal instillation of LPS. Together, these observations indicate that CYP modulators may have therapeutic anti-inflammatory effects, and this pathway may be involved in stress-induced reduction of inflammation.

Safety and efficacy of target controlled infusion (Diprifusor) vs manually controlled infusion of propofol for anaesthesia

In this multi-centre, randomized trial, we compared the safety and efficacy of Diprifusor TCI with manually controlled infusion (MCI) of propofol for anaesthesia. With approval, 123 adult male and female patients were studied. Firstly, each investigator anaesthetized five patients to familiarize themselves with Diprifusor TCI. In Stage 2, 98 patients were randomized to receive propofol-based anaesthesia via TCI or MCI. Adjuvant drugs, airway management and monitoring were managed at the discretion of the anaesthetist. Results are presented as mean (SD). Induction times were significantly longer [67 (32) vs 54 (17)s] and induction doses were significantly lower [14 (5) vs 16 (4) ml] in the TCI vs the MCI group. Recovery times and total doses were not significantly different. There were statistically but not clinically significant differences in mean arterial blood pressure and heart rate. Quality of anaesthesia and ease of control of anaesthesia were similar. We conclude that Diprifusor TCI and MCI are similar in terms of safety and efficacy.

Life-sustaining treatment decisions by spouses of patients with Alzheimer's disease

OBJECTIVE

To examine the anticipated decisions to consent to or to forgo life-sustaining treatment by spouses of patients with Alzheimer's disease and to describe the relationship of spouse and patient characteristics to predicted decisions.

DESIGN

Prospective quantitative study.

SETTING

The Aging and Dementia Research Center (ADRC), part of an Alzheimer's Disease Center Core Grant, at New York University Medical Center.

PARTICIPANTS

Fifty spouse caregivers of Alzheimer's disease patients, evaluated at the ADRC, who had a minimum Stage 4 on the Global Deterioration Scale.

MEASUREMENTS

Spouses were presented with two conditions (critical illness and irreversible coma) and rated their agreement with, certainty of, and comfort with four treatments (resuscitation, breathing machine, feeding tube, and antibiotics). Data were also obtained as to patients' current quality of life, spouses' standard of decision-making, and spouse burden.

RESULTS

Eighteen of 50 patients had a durable power of attorney for health care, 20 of 50 had a living will, and 26 of 50 had neither. In the face of critical illness, almost equal numbers of spouses would consent to or forgo CPR, 28 of 50 would forgo a breathing machine, 21 of 50 a would forgo a feeding tube, and 5 of 50 would forgo antibiotics. Five of 50 would forgo all four treatments, and 12 of 50 all but antibiotics. Spouses were significantly more likely to forgo treatment in the face of coma than for critical illness (P < .001). Spouses were more certain about decisions related to coma than to critical illness (P < .001), and there was a positive and significant correlation between certainty and comfort (P = .001). Those consenting to treatment were more comfortable than those forgoing treatment (for CPR and antibiotics P = .001). Spouses of patients with Stage 7 AD were more likely to forgo CPR than those with Stages 4 to 6 AD (P < .001). Only two of 50 spouses selected descriptors congruent with a purely substituted judgment standard of decision-making. An equal number of spouses rated patient quality of life as good, fair, or poor. For critical illness, the poorer the quality of life rating, the more likely the spouses were to forgo feeding tubes (P < .001). There was a trend for highly burdened spouses to consent to treatment.

CONCLUSIONS

The results provide evidence that spouses of patients with AD anticipate forgoing life-sustaining treatments in the face of coma but are less sure about choices for critical illness. Although preliminary in nature, findings suggest that doctors, nurses, and social workers need to provide additional support to spouses choosing to forgo rather than consent to treatment and need to inquire as to what spouses perceive as the factors that are important to them in making a decision.

Renovating? Take a look at the new short-term paths to financing

A hospital's renovation project can be financed through a diversity of financing techniques. Although the traditional vehicle for hospital capital financing is long-term, fixed-rate debt, there are a growing number of short-term financing alternatives that can provide greater flexibility and generate debt service savings. The author describes some of the new short-term financing techniques, as well as the advantages and disadvantages of short- versus long-term financing.