Protein and energy supplementation in elderly people at risk from malnutrition.

BACKGROUND: Evidence for the effectiveness of nutritional supplements containing protein and energy, which are often prescribed for older people, is limited. Furthermore malnutrition is more common in this age group and deterioration of nutritional status can occur during illness. It is important to establish whether supplementing the diet is an effective way of improving outcomes for older people at risk from malnutrition. OBJECTIVES: This review examined the evidence from trials for improvement in nutritional status and clinical outcomes when extra protein and energy were provided, usually in the form of commercial 'sip-feeds'. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, Healthstar, CINAHL, BIOSIS, CAB abstracts. We also hand searched nutrition journals and reference lists and contacted 'sip-feed' manufacturers. Date of most recent search: March 2004. SELECTION CRITERIA: Randomised controlled trials and quasi-randomised controlled trials of oral protein and energy supplementation in older people with the exception of groups recovering from cancer treatment or in critical care. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed trials prior to inclusion and independently extracted data and assessed trial quality. Authors of trials were contacted for further information as necessary. MAIN RESULTS: Forty-nine trials with 4790 randomised participants have been included in the review. Most included trials had poor study quality. The pooled weighted mean difference [WMD] for percentage weight change showed a benefit of supplementation of 2.3% (95% confidence interval (CI) 1.9 to 2.7) from 34 trials. There was a reduced mortality in the supplemented compared with control groups (relative risk (RR) 0.74, CI 0.59 to 0.92) from 32 trials. The risk of complications from 14 trials showed no significant difference (RR 0.95, 95% CI 0.81 to 1.11). Few trials were able to suggest any functional benefit from supplementation. The pooled weighted mean difference (WMD) for length of stay from 10 trials also showed no statistically significant effect (WMD -1.98 days, 95% CI -5.20 to 1.24). AUTHORS' CONCLUSIONS: Supplementation produces a small but consistent weight gain in older people. There may also be a beneficial effect on mortality. However, there was no evidence of improvement in clinical outcome, functional benefit or reduction in length of hospital stay with supplements. Additional data from large-scale multi-centre trials are still required.

Protein and energy supplementation in elderly people at risk from malnutrition.

BACKGROUND: This review was carried out because evidence for the effectiveness of nutritional supplements containing protein and energy which are often prescribed for elderly people is limited. Furthermore malnutrition is more common in this age group and deterioration of nutritional status can occur during a stay in hospital. It is important to establish whether supplementing the diet with protein and energy is an effective way of improving outcomes for older people at risk from malnutrition. OBJECTIVES: This review examines the evidence from trials for improvement in nutritional status and clinical outcomes when extra protein and energy food were provided, usually in the form of commercial 'sip-feeds'. SEARCH STRATEGY: We searched The Cochrane Library (issue 1, 2001), MEDLINE (1966 to February 2001), EMBASE (1980 to March 2001), Health star (1975 to March 2001), CINAHL (1982 to Jan 2001), BIOSIS (1985 to March 2001) and CAB abstracts (1973 to March 2001). We also hand searched nutrition journals and reference lists and contacted 'sip-feed' manufacturers. Date of most recent search: March 2001. SELECTION CRITERIA: Randomised controlled trials and quasi-randomised controlled trials of oral protein and energy supplementation in older people with the exception of groups recovering from cancer treatment or in critical care. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed trials prior to inclusion and independently extracted data and assessed trial quality; any differences were resolved by reaching consensus. Authors of trials were contacted for further information as necessary. MAIN RESULTS: Thirty-one trials with 2464 randomised participants have been included in the review. Most included trials had poor study quality. Mortality data were combined for meta-analysis from twenty-two trials (1755 participants). The Relative Risk (RR) indicated a lower mortality in the supplemented group compared with the control group (0.67; 95% confidence interval (CI) 0.52 to 0.87). The risk of complications (total complications if available, otherwise for example the number of infections by the end of follow-up) from nine trials (608 participants) showed no significant difference (RR 0.93, 95% CI 0.77 to 1.13). We were unable to combine trials for meta-analyses of functional outcome, for example grip strength, walking distance and Barthel Index, however there was little evidence of benefit to functional outcomes from individual studies. Data describing length of stay were available from seven trials (658 participants). There was some indication that mean length of stay was shorter for the supplemented groups (-3.4 days, 95% CI -6.12 to -0.69). REVIEWER'S CONCLUSIONS: Supplementation appears to produce a small but consistent weight gain. There was a statistically significant beneficial effect on mortality and a shorter length of hospital stay. Additional data from large-scale multi-centre trials are still required to provide clear evidence of benefit from protein and energy supplements on mortality and length of hospital stay. Too few data were reported and the time scale of most studies was too short to have a realistic chance of detecting differences in morbidity, functional status and quality of life. Furthermore, most trials do not address the organisational and practical challenges faced by practitioners trying to meet the individual needs and preferences of those at risk from malnutrition.

Directional specificity for head rotation in the pigeons posterior cerebellum.

Neurons in the posterior cerebellum, including the vestibulocerebellum, which respond to rotation in the plane of the horizontal semicircular canal exhibit considerably greater plane specificity than is known for primary afferents. This is shown by a response amplitude decline with tilt out of the canal plane which exceeds the decline predicted to a cosine function. Of 96 horizontal canal cells, 41 also responded to yaw movements about neck joints with only three of these cells exhibiting responses to roll movements as well. Other neurons responding to head rotation in roll very commonly responded to neck movements about the roll and/or pitch axes. Cells with converging vestibulo-cerevical input were found throughtout lobules VI to X, most of these cells being located in the uvula and only very few in the nodulus.

Labyrinthine and somatosensory convergence upon vestibulospinal neurons.

In awake cats cells forming the lateral (LVST) and medial (MVST) vestibulospinal tracts were identified by employing antidromic stimulation of the spinal cord. Neuronal responses to bilateral vestibular, forelimb, hindlimb, and neck electrical nerve stimulation were analysed. Extracellular recording in the vestibular nuclei was performed via a glass micropipette saturated with Fast Green, to aid in later histological tract identification. The number of cells projecting to cervical and lumbar regions in the dorsal and ventral division of Deiters' nucleus did not differ significantly. An unexpectedly large number of MVST units was found in the descending nucleus. Some MVST units projected to the lumbar cord but in both the medial and descending nuclei, projections to the cervical cord were in majority. Almost all spinal projecting vestibular neurons received labyrinthine input and more than half received somatosensory input. The units could be separated into several populations on basis of excitatory and inhibitory labyrinthine response latencies indicating multiple pathways. As regards labyrinthine-somatosensory integration the two tracts were found to be quite similar. The extent and complexity of labyrinthine-somatosensory convergence indicate the importance of feed-back mechanisms upon postural controls also at the level of the vestibular nuclei.

Labyrinthine input to the vestibular nuclei of the awake cat.

The labyrinthine input to the vestibular nuclei was investigated in 24 awake cats. Stimulus consisted of electrical shocks given through bipolar silver wire electrodes, implanted in the utricular and lateral ampullar nerves. Throughout the vestibular nuclei, single units were recorded extracellularly with glass micropipettes filled with Fast Green. The tracts of the penetrating electrodes were identified histologically. In all four nuclei units responding to both labyrinths outnumbered unilaterally responding neurones with certain differences between the individual nuclei. Excitatory as well as inhibitory responses were observed, polysynaptic being more common than mono- or disynaptic ones. No monosynaptic contralateral responses were seen. The latency distribution of contralateral responses closely mirrored that of ipsilateral responses within each nucleus. Both excitatory and inhibitory responses fell into relatively segregated populations, based upon latency distribution. This implies separate pathways for labyrinthine input to the vestibular nuclei.

Labyrinthine and somatosensory convergence upon vestibulo-ocular units.

The vestibular nuclei were investigated in 18 adult cats. Vestibulo-oculo-motor neurons were identified by antidromic stimulation of the ascending medial longitudinal fasciculus (MLF). The neurons were subjected to various stimuli: vestibular, neck, forelimb and hindlimb nerve stimulation on both sides. The recording was extracellular with micropipettes containing Fast Green. Only the medial and the superior vestibular nuclei were found to project to the MLF. All projecting units had input from the labyrinths. Excitatory response latencies to ipsilateral labyrinth stimulation never exceeded 3 msec. Both excitatory and inhibitory response latencies could be distributed into different categories. The majority of the neurons did not receive a somatosensory input, and surprisingly few convergent units could be seen. Peripheral somatosensory information apparently plays a minor role in vestibulo-ocular relations.

Factors influencing the participation of older people in clinical trials - data analysis from the MAVIS trial.

BACKGROUND: Older people are less likely to be included in clinical trials. Little is known about factors influencing older people's decisions about participating in clinical trials. OBJECTIVES: To examine the views of older people about participating in clinical trials. METHODS: Postal questionnaire to 801 participants who had completed the MAVIS nutrition trial, aged 65 yrs and older. Closed and open questions sought participants' views about factors important to them when deciding to take part in a trial, features of the MAVIS trial they liked and disliked and changes they would suggest. RESULTS: 540 (59% of MAVIS trial participants) returned the questionnaire. The most important reasons reported for taking part in the trial were helping the research team and medical knowledge, and helping other older people. Participants valued good communication with the trial staff and good organisation. Participants reported concerns about swallowing pills and taking a placebo. Participants reported that future participation in trials could be influenced by poor health status. LIMITATIONS: This questionnaire surveyed older participants who had taken part in a randomised controlled trial. It did not elicit the views of people who had withdrawn or never decided to take part in the trial. CONCLUSIONS: Older people report altruistic reasons for taking part in trials. Simple trial designs, which minimise demands on participants and maintain good communications should be preferred. Explaining the need for older people, despite poor health, to participate in trials may help the generalisability of clinical trials.

Repeatability and validity of a food frequency questionnaire in free-living older people in relation to cognitive function.

OBJECTIVES: To determine the repeatability and validity of a self-administered, 175-item food frequency questionnaire (FFQ) in free-living older people and to assess whether these are influenced by cognitive function. PARTICIPANTS AND SETTING: 189 free-living people aged 64-80 y were recruited from participants in a previous study. DESIGN: To assess repeatability, 102 (52 M, 50 F) participants completed the FFQ on two occasions three months apart. To assess validity, another 87 participants (44 M, 43 F) completed the FFQ and a four-day weighed diet record three months later. 25 nutrients were studied. RESULTS: For repeatability, Spearman rank correlation coefficients were above 0.35 (p<0.05) for all nutrients. Cohen's weighted Kappa was above 0.4 for all nutrients except starch, riboflavin, retinol, beta-carotene, and calcium. There were no substantial differences in correlation coefficients between sub-groups divided by short-term memory test score. There was no clear pattern for correlation coefficients in sub-groups divided by executive function test score. For validity, the Spearman rank correlation coefficients were above 0.2 (p<0.05) for all nutrients except fat, mono-unsaturated fatty acids, niacin equivalents and vitamin D, and Cohen's weighted kappa was above 0.4 for alcohol and was above 0.2 for 13 other nutrients. Participants in the lowest-score groups of short-term memory and executive function had the lowest median Spearman correlation coefficient. CONCLUSIONS: The FFQ had reasonable repeatability and validity in ranking nutrient intakes in this population though the results varied between nutrients. Poor short-term memory or executive function may affect FFQ validity in ranking nutrient intakes.

Oxygen therapy after thoracotomy.

Arterial blood samples were taken from patients before thoracotomy, and on the 1st day after operation, with the patient breathing first air, and then 24%, 28% and 35% oxygen from a venturi-type mask. PaO2 was reduced markedly by operation, the reduction being related to the value before operation. Oxygen therapy restored PaO2 to a value greater than the value before operation in nine of 11 patients and was not associated with significant increases in PaCO2. The effect of administration of oxygen on PaO2 could be predicted from the PaO2 when breathing air. The pattern of response to oxygen suggested that the hypoxaemia was caused by ventilation/perfusion mismatch in most of the patients.

Health services can be cool: partnership with adolescents in primary care.

Young people's health is giving rise to increasing concern. However, despite recent government emphasis on patient involvement and partnership, little discussion has occurred concerning how this may be achieved with younger age groups in primary care. Here we outline issues relating to adolescents' health and characteristics of current provision. These are considered in the context of innovative services that have incorporated adolescents' views. Finally, we discuss the challenge of establishing a partnership with adolescents and propose strategies for achieving this.

Convulsive reaction following enflurane anaesthesia.

A case of convulsive muscle activity immediately after recovery from enflurane anaesthesia is reported. The implications for postoperative oxygen therapy and management are discussed.

Hematological status of male runners in relation to the extent of physical training.

Blood biochemical indices of iron status were measured in venous blood from 20 runners and 6 control subjects. All subjects were male, ages 20 to 40 years, and stable with regard to body weight and degree of physical activity. Dietary analysis was undertaken using a 7-day weighed food intake. There was no evidence of iron deficiency: hemoglobin concentrations and serum ferritin levels were within the normal population range for all individuals. However, serum ferritin was negatively correlated with the amount of training. Daily iron intake appeared to be adequate; iron intake was correlated with protein intake but not related to training or energy intake. Serum ferritin, an indicator of iron status, was significantly correlated with vitamin C intake but not iron intake. Serum transferrin concentration was higher in the group of athletes undertaking a high weekly training load compared with the control subjects, suggesting an alteration in iron metabolism although there was no evidence of increased erythropoiesis. The biological significance of this is unclear.

Representation of vestibular afferents in somatosensory thalamic nuclei of the squirrel monkey (Saimiri sciureus).

1. In awake squirrel monkeys the thalamus was investigated for neuronal responses to vestibular, auditory, visual, proprioceptive, and exteroceptive somatosensory stimulation. The vestibular representation in the thalamus was focused.2. Units responding to electrical vestibular stimulation were found to be scattered within thalamic nuclei receiving somatosensory afferents.3. Ventrobasal neurons have previously been considered place and modality specific. The present data suggest exceptions to this belief. Vestibular input converges with somatotopically organized proprioceptive afferents on neurons in the nucleus ventralis posterior lateralis, pars oralis (identical to nucleus ventralis intermedius), as well as in the posterior portion of the caudal part of the same nucleus. Convergence of both modalities was also found in other nuclei, mainly belonging to the posterior nuclear group, where auditory convergence was also demonstrated.4. Of the vestibular cells in the nucleus ventralis posterior lateralis, 23% projected to the sensorimotor cortex, some with collaterals to both pre- and postcentral gyri.

One lung anaesthesia. Cardiovascular and respiratory function compared during conventional ventilation and high frequency jet ventilation.

Ten patients about to undergo left-sided thoracotomy for carcinoma of the lung were entered into a crossover trial to compare cardiovascular and respiratory function during high frequency jet ventilation and conventional mechanical ventilation for one lung anaesthesia. All patients were anaesthetised with a standard technique using double lumen tubes and placed in the lateral position with the left chest open. The results showed no significant differences with regard to ventilation sequence but one lung high frequency jet ventilation gave higher values than one lung conventional ventilation for shunt (p less than 0.01) and positive end expiratory pressure (p less than 0.05) and lower peak inflation pressure values (p less than 0.01). There were no significant differences in cardiac output, pulmonary capillary wedge pressure, arterial carbon dioxide or available oxygen. Surgical conditions were satisfactory during both methods of ventilation and satisfactory gas exchange occurred. It was, however, more difficult to assess adequacy of ventilation during high frequency jet ventilation and the routine use of this method of ventilation is not recommended during one lung anaesthesia.

Studies on the integrative activity of the vestibular nuclei complex.

Central mechanisms currently used in clinical vestibular tests are far more complex than generally thought. The first synaptic station, the vestibular nuclei, represents a sensory-motor centre integrating vestibular impulses with proprioceptive afferents from muscles and joints. This convergence can be found on cells with long axons projecting to the oculo-motor system, to the spinal cord and to the thalamus as well as on cells without long projecting axons. There are also vestibulo-motor cells transmitting pure vestibular information.