The development of hospital-based palliative care services in public hospitals in the Western Cape, South Africa.

With the recent approval of a South African (SA) National Policy Framework and Strategy for Palliative Care by the National Health Council, it is pertinent to reflect on initiatives to develop palliative care services in public hospitals. This article reviews the development of hospital-based palliative care services in the Western Cape, SA. Palliative care services in SA started in the non-governmental sector in the 1980s. The first SA hospital-based palliative care team was established in Charlotte Maxeke Johannesburg Academic Hospital in 2001. The awareness of the benefit of palliative care in the hospital setting led to the development of isolated pockets of excellence providing palliative care in the public health sector in SA. This article describes models for palliative care at tertiary, provincial and district hospital level, which could inform development of hospital-based palliative care as the national policy for palliative care is implemented in SA.

Canadian Guidelines for Controlled Pediatric Donation After Circulatory Determination of Death-Summary Report

OBJECTIVES: Create trustworthy, rigorous, national clinical practice guidelines for the practice of pediatric donation after circulatory determination of death in Canada. METHODS: We followed a process of clinical practice guideline development based on World Health Organization and Canadian Medical Association methods. This included application of Grading of Recommendations Assessment, Development, and Evaluation methodology. Questions requiring recommendations were generated based on 1) 2006 Canadian donation after circulatory determination of death guidelines (not pediatric specific), 2) a multidisciplinary symposium of national and international pediatric donation after circulatory determination of death leaders, and 3) a scoping review of the pediatric donation after circulatory determination of death literature. Input from these sources drove drafting of actionable questions and Good Practice Statements, as defined by the Grading of Recommendations Assessment, Development, and Evaluation group. We performed additional literature reviews for all actionable questions. Evidence was assessed for quality using Grading of Recommendations Assessment, Development, and Evaluation and then formulated into evidence profiles that informed recommendations through the evidence-to-decision framework. Recommendations were revised through consensus among members of seven topic-specific working groups and finalized during meetings of working group leads and the planning committee. External review was provided by pediatric, critical care, and critical care nursing professional societies and patient partners. RESULTS: We generated 63 Good Practice Statements and seven Grading of Recommendations Assessment, Development, and Evaluation recommendations covering 1) ethics, consent, and withdrawal of life-sustaining therapy, 2) eligibility, 3) withdrawal of life-sustaining therapy practices, 4) ante and postmortem interventions, 5) death determination, 6) neonatal pediatric donation after circulatory determination of death, 7) cardiac and innovative pediatric donation after circulatory determination of death, and 8) implementation. For brevity, 48 Good Practice Statement and truncated justification are included in this summary report. The remaining recommendations, detailed methodology, full Grading of Recommendations Assessment, Development, and Evaluation tables, and expanded justifications are available in the full text report. CONCLUSIONS: This process showed that rigorous, transparent clinical practice guideline development is possible in the domain of pediatric deceased donation. Application of these recommendations will increase access to pediatric donation after circulatory determination of death across Canada and may serve as a model for future clinical practice guideline development in deceased donation

Impact of transthoracic echocardiography at district hospital level.

BACKGROUND: The use of and demand for echocardiography (ECHO) has increased worldwide. In developed countries, this has not translated into improved access outside tertiary centres. Previous studies have favoured the appropriate use of ECHO over its clinical impact, limiting generalisability to resource-constrained settings. OBJECTIVES: To assess the impact of an ECHO service at district hospital level in Cape Town, South Africa. METHODS: A prospective, cross-sectional study was performed. A total of 210 consecutive patients, referred to the ECHO clinic over a 5-month period, were recruited. Transthoracic ECHO was evaluated in terms of its indication, new information provided, correlation with the referring doctor's diagnosis and subsequent management plan. Impact included the escalation and de-escalation of treatment, as well as usefulness without a change in management. RESULTS: The results show that 83.8% of the patients' management was impacted on by echocardiography. Valvular lesions were the main indication. The most frequent contribution was information provided towards the diagnosis of heart failure and assessment after myocardial infarction. Of the echocardiograms, 56.2% confirmed the referring doctor's diagnosis, yet were still associated with a significant impact. The rational prescription of medication had the major impetus, followed by de-escalation of therapy and screening patients to determine referral to a tertiary facility. CONCLUSION: ECHO has a positive impact on patient management outside tertiary settings, where the definition of impact appears to be different. The value of a normal study, screening prior to upstream referral and usefulness irrespective of change have been established. This should alert policy makers against restriction of access to ECHO and promote training of personnel in its use.

The unsuspected killer: Liquefied petroleum gas overexposure in South Africa.

A 21-year-old woman with no past medical history of note was found unconscious together with five of her family members after prolonged exposure to liquefied petroleum gas. She was admitted to the intensive care unit at Victoria Hospital, Wynberg, Cape Town, South Africa, following resuscitation for pulseless electrical activity. On examination the following was found: coma without focal neurology; shock requiring fluid resuscitation and adrenaline; probable pneumonitis or aspiration pneumonia; acute rhabdomyolysis with severe metabolic acidosis; and raised serum K+. A carboxyhaemoglobin test was unable to confirm or exclude carbon monoxide poisoning.

Maternal high fat diet during critical windows of development alters adrenal cortical and medullary enzyme expression in adult male rat offspring.

We previously reported that a maternal high fat (HF) diet resulted in adult offspring with increased adiposity and hyperleptinemia. As leptin has an inhibitory effect on adrenal steroidogenesis and a stimulatory effect on epinephrine synthesis, we hypothesized that key adrenal steroidogenic and catecholaminergic enzymes would be altered in these offspring. Wistar rats were randomized into three groups at weaning: (1) control dams fed a standard control chow diet from weaning and throughout pregnancy and lactation (CON), (2) dams fed a HF diet from weaning and throughout pregnancy and lactation (MHF) and (3) dams fed standard control chow diet throughout life until conception, then fed a HF diet in pregnancy and lactation (PLHF). Dams were mated at day 100 (P100). After birth at P22 (weaning), male offspring were fed a standard control chow (con) or high fat (hf) diet. At P160, plasma samples and adrenal tissues were collected. Postweaning hf diet significantly elevated plasma corticosterone concentrations in PLHF-hf offspring compared to PLHF-con. MHF nutrition increased adrenal adrenocorticotrophic hormone receptor (ACTH-R) mRNA levels compared to CON-con. 3ß-hydroxysteroid dehydrogenase (3ßHSD) mRNA levels were decreased in MHF compared to PLHF offspring. Phenylethanolamine N-methyltransferase (PNMT) mRNA levels were increased in MHF-hf offspring compared to MHF-con. Plasma homocysteine (HCY) concentrations were significantly elevated in CON-hf and MHF-hf offspring compared to chow-fed offspring, associated with elevated intakes of methionine and reduced intakes of pyridoxine. Immunoreactive leptin receptor (ObRb) and PNMT were colocalized in medullary chromaffin cells. This study suggests that a postweaning HF diet in offspring induced changes in adrenal gene expression levels that are dependent upon the level of maternal nutrition.

The auditory startle response in post-traumatic stress disorder.

Post-traumatic stress disorder (PTSD) patients are considered to have excessive EMG responses in the orbicularis oculi (OO) muscle and excessive autonomic responses to startling stimuli. The aim of the present study was to gain more insight into the pattern of the generalized auditory startle reflex (ASR). Reflex EMG responses to auditory startling stimuli in seven muscles rather than the EMG response of the OO alone as well as the psychogalvanic reflex (PGR) were studied in PTSD patients and healthy controls. Ten subjects with chronic PTSD (>3 months) and a history of excessive startling and 11 healthy controls were included. Latency, amplitude and duration of the EMG responses and the amplitude of the PGR to 10 auditory stimuli of 110 dB SPL were investigated in seven left-sided muscles. The size of the startle reflex, defined by the number of muscles activated by the acoustic stimulus and by the amplitude of the EMG response of the OO muscle as well, did not differ significantly between patients and controls. Median latencies of activity in the sternocleidomastoid (SC) (patients 80 ms; controls 54 ms) and the deltoid (DE) muscles (patients 113 ms; controls 69 ms) were prolonged significantly in PTSD compared to controls (P < 0.05). In the OO muscle, a late response (median latency in patients 308 ms; in controls 522 ms), probably the orienting reflex, was more frequently present in patients (56%) than in controls (12%). In patients, the mean PGR was enlarged compared to controls (P < 0.05). The size of the ASR response is not enlarged in PTSD patients. EMG latencies in the PTSD patients are prolonged in SC and DE muscles. The presence of a late response in the OO muscle discriminates between groups of PTSD patients with a history of startling and healthy controls. In addition, the autonomic response, i.e. the enlarged amplitude of the PGR can discriminate between these groups.

Caffeine potentiates low frequency skeletal muscle force in habitual and nonhabitual caffeine consumers.

The mechanism of action underlying the ergogenic effect of caffeine is still unclear. Caffeine increases the force of muscular contraction during low-frequency stimulation by potentiating calcium release from the sarcoplasmic reticulum. Studies have also suggested an enhancement of lipid oxidation and glycogen sparing as potential mechanisms. Given that several studies have found an ergogenic effect of caffeine with no apparent metabolic effects, it is likely that a direct effect upon muscle is important. Twelve healthy male subjects were classified as habitual (n = 6) or nonhabitual (n = 6) caffeine consumers based on a 4-day diet record analysis, with a mean caffeine consumption of 771 and 14 mg/day for each group, respectively. Subjects were randomly allocated to receive caffeine (6 mg/kg) and placebo (citrate) in a double-blind, cross-over fashion approximately 100 min before a 2-min tetanic stimulation of the common peroneal nerve in a custom-made dynamometer (2 trials each of 20 and 40 Hz). Tetanic torque was measured every 30 s during and at 1, 5, and 15 min after the stimulation protocol. Maximal voluntary contraction strength and peak twitch torque were measured before and after the stimulation protocol. Caffeine potentiated the force of contraction during the final minute of the 20-Hz stimulation (P<0.05) with no effect of habituation. There was no effect of caffeine on 40-Hz stimulation strength nor was there an effect on maximal voluntary contraction or peak twitch torque. These data support the hypothesis that some of the ergogenic effect of caffeine in endurance exercise performance occurs directly at the skeletal muscle level.

Developmental apraxia arising from neonatal brachial plexus palsy.

OBJECTIVE: To determine whether motor unit activation is impaired in patients with persisting disability arising from neonatal brachial plexus palsy (NBPP). BACKGROUND: In NBPP patients, the authors previously found more extensive muscle reinnervation than might have been anticipated from the clinical examination. METHODS: Motor skills were tested in a group of nine boys and seven girls with prior NBPP, who then underwent physiologic investigation of proximal and distal muscles in their affected and unaffected arms. The latter tests comprised measurements of maximal evoked muscle compound action potential (M-wave) amplitude, maximal voluntary torque, twitch torque, and twitch interpolation. A group of 17 children of similar ages served as control subjects. RESULTS: In the NBPP group, motor skills were diminished and voluntary torque was reduced relative to M-wave amplitude and twitch torque. Moreover, interpolated twitches could be demonstrated in some NBPP patients but not in control subjects. CONCLUSION: Persisting disability in NBPP patients is due, at least in part, to impaired motor unit activation. The authors suggest that the impairment is a form of developmental apraxia caused by defective motor programming in early infancy.

The RULER model. Is this how the somatosensory cortex works?

Despite a wealth of information, it is still not known how neurones in the different neocortical layers interact to produce a conscious perception. We now put forward a model for the somatosensory cortex in which a touch is perceived whenever superficial cortical pyramidal cells (in layers II and III) are made to discharge by a recurrent input from deep pyramidal neurones (in layer V). The superficial cells act as biological amplifiers and the number discharging will depend both on the strength of the message from the thalamus and on the variable background depolarisation of their apical dendrites. The recurrent volley arises in the layer V neurones at the end of an IPSP (inhibitory postsynaptic potential), which itself follows an excitatory response induced by the incoming thalamic signal; the IPSP is generated by local basket cells. The duration of the initial excitation--IPSP--late excitation sequence corresponds to a time chunk, that is, the period over which neural activity is integrated to produce a perception. During the time chunk, the superficial cortical pyramids, unlike the deeper ones, can accumulate information as subthreshold excitatory postsynaptic potentials (EPSPs). The relative time at which the information arrived in the cortex is roughly coded by the gradient of EPSPs among cells in an axis perpendicular to the cortical surface. Although developed for the somatosensory cortex, the basic features of the model may well apply to other sensory receiving areas of the cortex.

Central venous catheter replacement strategies: a systematic review of the literature.

OBJECTIVE: To evaluate the effect of guidewire exchange and new-site replacement strategies on the frequency of catheter colonization and infection, catheter-related bacteremia, and mechanical complications in critically ill patients. DATA SOURCES: We searched for published and unpublished research by means of MEDLINE and Science Citation Index, manual searching of Index Medicus, citation review of relevant primary and review articles, review of personal files, and contact with primary investigators. STUDY SELECTION: From a pool of 151 randomized, controlled trials on central venous catheter management, we identified 12 relevant randomized trials of catheter replacement over a guidewire or at a new site. DATA EXTRACTION: In duplicate and independently, we abstracted data on the population, intervention, outcome, and methodologic quality. DATA SYNTHESIS: As compared with new-site replacement, guidewire exchange is associated with a trend toward a higher rate of catheter colonization (relative risk 1.26, 95% confidence interval 0.87 to 1.84), regardless of whether patients had a suspected infection. Guidewire exchange is also associated with trends toward a higher rate of catheter exit-site infection (relative risk 1.52, 95% confidence interval 0.34 to 6.73) and catheter-related bacteremia (relative risk 1.72, 95% confidence interval 0.89 to 3.33). However, guidewire exchange is associated with fewer mechanical complications (relative risk 0.48, 95% confidence interval 0.12 to 1.91) relative to new-site replacement. Exchanging catheters over guidewires or at new sites every 3 days is not beneficial in reducing infections, compared with catheter replacement on an as-needed basis. CONCLUSIONS: Guidewire exchange of central venous catheters may be associated with a greater risk of catheter-related infection but fewer mechanical complications than new-site replacement. More studies on scheduled vs. as-needed replacement strategies using both techniques are warranted. If guidewire exchange is used, meticulous aseptic technique is necessary.

Mixed carbohydrate supplementation increases carbohydrate oxidation and endurance exercise performance and attenuates potassium accumulation.

We studied the effects of different CHO supplements on exercise metabolism (1 hr at 75% VO2max) and performance (fatigue time at 85% VO2max) in 8 male endurance athletes (VO2max = 68.8 +/- 3.8 ml.kg-1.min-1. Four treatments were administered in a randomized, double-blind fashion: Trial A = 3-day pretest, postexercise supplementation (177 kcal [81% carbohydrate, 19% protein] consumed < 10 min after exercise) + 600 ml 8% glucose polymers/ fructose 1 hr pretesting + 600 ml 8% glucose polymers/glucose during testing; Trial B = placebo during 3-day pretest + remainder same as Trial A; Trial C = placebo at all time points; and Trial D = same as Trial B with 8% glucose 1 hr before the test as well as during the test. Time to fatigue at 85% VO2max (increases 24%) and total CHO oxidation were greater for A versus C (p < .05). Plasma glucose concentration was higher for A and B versus C, while increases in plasma potassium concentration were attenuated for A versus C (both p < .05). None of the supplements had differential effects upon hematocrit, plasma sodium [Na+] and lactate, VO2, or rating of perceived exertion during exercise. Three-day preexercise protein + carbohydrate supplements followed by 1-hr pre- and during-exercise mixed carbohydrate supplements increased time to fatigue and carbohydrate oxidation and attenuated rises in plasma [K+] compared to placebo.

Potentiation and depression of the M wave in human biceps brachii.

1. The effects of repeated excitation on the compound action potential, or M wave, of mammalian muscle fibres have been investigated in the human biceps brachii. 2. During continuous indirect stimulation at 10 and 20 Hz the mean voltage-time area of the M wave doubled within the first minute, while the mean peak-to-peak amplitude increased by approximately half. The enlargement of the M wave was sustained during stimulation at 10 Hz but not at 20 Hz. Stimulation at 3 Hz caused a small increase which was significant for M wave amplitude only. 3. When the 20 Hz stimulation was performed under ischaemic conditions, the M wave first enlarged and then gradually declined. After 20 Hz stimulation was discontinued, the M wave increased in size; in the ischaemic experiments the release of the cuff produced a further, rapid augmentation. In both the ischaemic and non-ischaemic experiments, the amplitudes and areas of the M waves during the recovery period became significantly larger than the resting values (range, 15-60% at the endplate zone). 4. The mean muscle fibre impulse conduction velocity decreased to less than half the resting value during 20 Hz stimulation, with or without ischaemia, and then increased above the resting value during recovery. 5. On the basis of previous experiments in animals, the augmentation of the M wave was attributed to enhanced electrogenic Na(+)-K+ pumping, and the biceps brachii appeared to be an excellent preparation for studying the time course of this enhancement.

Effect of selective and nonselective beta-blockade on skeletal muscle excitability and fatiguability.

The effects of beta-blockade on skeletal muscle excitability and fatiguability during exercise were examined. Ten healthy males (mean age 21.9 +/- 1.1 yr) performed a 4-min fatigue protocol consisting of intermittent isometric voluntary contractions of the knee extensors in one leg. Subjects performed the exercise after treatment with placebo, 100 mg metoprolol, or an equipotent dose of propranolol (60 mg, n = 1; 80 mg, n = 8; 100 mg, n = 1) twice a day for 76 h before testing according to a randomized double-blind design. The evoked twitch torque, maximal voluntary torque, and maximal M-wave amplitude were unaffected by the beta-blockade treatments before fatigue. During the placebo trial, there were significant reductions in the evoked and voluntary torques (77 +/- 15 and 55 +/- 11%, respectively) after the fatigue protocol; however, both the voluntary electromyogram and evoked M waves were well maintained throughout fatigue. The beta-blockade treatments had no significant effect on torque or electromyogram activity over the course of the exercise. Thus, despite evidence for an impairment of dynamic exercise performance with beta 1- and beta 1,2-blockade, there appears to be no effect of these agents on muscle excitability and fatiguability during isometric muscle activity.

Muscle excitation in elderly adults: the effects of training.

Muscle membrane excitability is thought to decline with aging; the extent of this decline may be noninvasively assessed by measurement of the electrically evoked compound muscle action potential (M-wave). The intent of this study was two-fold: (1) to compare the M-wave in the brachioradialis (BR), tibialis anterior (TA), and thenar (TH) muscles of elderly (mean age = 66.3 +/- 3.7 years) and young (mean age = 31.2 +/- 4.9 years) adults, and (2) to determine the effects of 12 weeks of resistance training on M-wave characteristics in elderly adults. Prior to training, the elderly subjects had significantly smaller (P less than 0.05) resting M-waves than the young adults in the BR (4.8 mV vs. 8.7 mV), TA (8.8 mV vs. 11.0 mV), and TH (5.2 mV vs. 10.2 mV) muscles. During a 2-minute voluntary fatigue paradigm (3 seconds MVC per 2 seconds rest for 2 minutes), there was no evidence of excitability failure in either group. Following training, there was a significant increase (P less than 0.05) in the size of the M-wave of the TH (pretraining: 5.2 mV; posttraining: 8.96 mV) and BR (pretraining: 4.8 mV; posttraining: 6.1 mV), and a nonsignificant increase in the M-wave of the TA, but there was no change in the relative behavior of the M-wave during the 2-minute voluntary fatigue paradigm. It is suggested that the decline in muscle membrane excitation with aging may be due, at least in part, to the effects of a decreased membrane potential on the muscle fiber action potential.(ABSTRACT TRUNCATED AT 250 WORDS)

Neuromuscular fatigue during repetitive stimulation in elderly and young adults.

The purpose of this investigation was to examine the integrity of neuromuscular transmission and impulse propagation during fatigue by examining the muscle compound action potential (M wave) in elderly and young adults. The tibialis anterior muscle of nine elderly [mean = 67.7 (SE 1.7) years] and nine young [mean = 26.7 (SE 1.2) years] adults was maximally stimulated repetitively at frequencies of 20, 30 or 40 Hz for 60 s on separate occasions. There was a significantly smaller resting M wave amplitude [7.9 (SE 0.4) mV versus 9.9 (SE 0.6) mV] and M wave area [0.038 (SE 0.005) mV s versus 0.06 (SE 0.004) mV.s] in the elderly versus the young adults respectively. Measurement of the evoked muscle contractile properties revealed significantly (P < 0.05) longer twitch durations and a significantly (P < 0.05) greater peak twitch torque [4.6 (SE 0.4) Nm versus 3.2 (SE 0.5) Nm] in the elderly versus the young adults, respectively. The elderly adults had a significantly greater torque decline during the 20-Hz trial; however, the decline in torque during the 30-Hz and 40-Hz trials was similar in the elderly and the young adults (30 Hz: 40%; 40 Hz: 56%). Throughout each of the stimulation trials, the decline in torque was accompanied by a significant reduction in M wave amplitude (20 Hz: 14%; 30 Hz: 53%; 40 Hz: 67%); M wave area also declined significantly during the 30-Hz (31%) and 40-Hz (53%) trials. There was no significant difference between the elderly and the young adults in the reduction in the M wave amplitude or area during each trial.(ABSTRACT TRUNCATED AT 250 WORDS)

Twitch potentiation during fatiguing exercise in the elderly: the effects of training.

Twitch potentiation was studied during a fatigue paradigm involving intermittent maximum voluntary contractions (MVCs) of the tibialis anterior muscle in the elderly and in young adults. Resting twitch torques were similar between groups, but twitch potentiation was significantly greater (241% vs 166%) in the young; the recovery of the twitch after fatigue was similar between groups. Contraction time, time to peak torque and half-relaxation time were all significantly slower in the elderly. Following 12 weeks of resistance training in the elderly, there was no significant change in the twitch contractile properties at rest, but there was a significant main effect of training on the degree of twitch potentiation during the same fatigue protocol (peak potentiation 192% post-training vs 165% pretraining). These data suggest that the mechanism(s) responsible for twitch potentiation following MVCs may be influenced by both aging and training.