Barriers to physical activity promotion by general practitioners and practice nurses

OBJECTIVE

To examine the promotion of physical activity by general practitioners (GPs) and practice nurses (PNs).

METHODS

A questionnaire that examined the types of barriers and the levels of their influence as well as stage of change for activity promotion and for personal behaviour was mailed to 846 subjects.

RESULTS

The return rate exceeded 70% in each group with a high proportion (69%) of GPs and PNs reporting that they regularly promote physical activity with their patients. GPs were less likely to regularly promote physical activity with their patients if they indicated lack of time as a barrier (odds ratio (OR) = 0.73, 95% confidence interval (CI) 0.58 to 0.93) or lack of incentives (OR = 0.74, 95% CI 0.59 to 0.94), and more likely to promote exercise if they themselves were regular exercisers (OR = 3.19, 95% CI 1.96 to 5.18). However, for PNs longer consultation times (by 1.5 to 2 minutes) had a higher likelihood of producing regular promotion of activity (OR = 1.61, 95% CI 1.02 to 1.62). For PNs personal physical activity stage was the strongest significant predictor of promotion level, but with a stronger effect (OR = 4.77, 95% CI 1.48 to 15.35) than in the GPs.

CONCLUSION

The main finding is that GPs in the action or maintenance stage of changing their own physical activity are three times more likely to regularly promote the same behaviour in their patients than those in the other stages; for PNs the same difference quadruples the likelihood of them promoting physical activity. Professional readiness to change is influenced by known system barriers in GPs, and not in PNs, but is more strongly predicted by personal physical activity behaviour in both groups.

Factors that influence practice nurses to promote physical activity

OBJECTIVE

To investigate what factors may influence practice nurses to promote physical activity.

METHODS

Postal questionnaires were sent to all practice nurses in the county of Avon, UK in 1994. Specifically, the questionnaire survey explored whether patient, provider, and practice factors influenced practice nurses promotion behaviour. In addition, the stages of change model was used to measure current levels of promoting behaviour.

RESULTS

A response rate of 80.9% was achieved. Over 80% of the sample reported currently promoting physical activity to some degree. "Promoting" nurses more frequently followed up all (new, established or targeted) patients' activity progress when compared with "restricted promoting" nurses (P < 0.05). Nurses who engaged in regular exercise were more likely to encourage physical activity as a treatment than "irregularly active" nurses (P < 0.05) for five of six clinical groups with the single exception of people with diabetes.

CONCLUSIONS

This study shows that the two stage measures (activity promotion and personal behaviour) of the health care professional are associated with important differences in patient and practice factors for physical activity promotion. Further investigations into the content and quality of delivery are required before planning strategies to develop physical activity in the general practice.

Infant arousals during mother-infant bed sharing: implications for infant sleep and sudden infant death syndrome research

OBJECTIVE

Normative values for infant sleep architecture have been established exclusively in the solitary sleeping environment. However, most of the world's cultures practice some form of parent-infant cosleeping. In addition, no previous polysomnographic studies in infants examined the frequency of electroencephalogram (EEG) arousals. This is the first study to assess (a) EEG arousals in infants and their relationship to sleep stages; (b) the impact on arousals of mother-infant bed sharing; and (c) the temporal overlap of infant with maternal arousals during bed sharing.

METHODOLOGY

Three nights of polysomnography were performed in 35 breastfeeding mother-infant pairs when the infants were 11 to 15 weeks old. An adaptation night was followed by one bed sharing night and one solitary sleeping night. Twenty infants had been bed sharing since birth and 15 were routine solitary sleepers. Both epochal awakenings (EWs), based on 30-second epoch scoring of sleep-wake stages, and more transient arousals (TAs) >/=3 seconds were quantified.

RESULTS

Stage 3-4 sleep was associated with a striking paucity of EWs and TAs compared with stages 1-2 or rapid eye movement sleep. Bed sharing facilitated EWs and TAs selectively during stage 3-4 sleep. EWs from stage 3-4 sleep were more frequent on the bed sharing night than on the solitary night in both infant groups. Routinely bed sharing infants also exhibited more frequent TAs in stage 3-4 than the routine solitary sleepers in both conditions. In both groups, the number of infant arousals (EWs + TAs) that overlapped the mother's was doubled during bed sharing, with infant arousals leading most often.

CONCLUSIONS

Mother-infant bed sharing promotes infant arousals. Together with a previous report that bed sharing reduces stage 3-4 sleep, this suggests that normative values for infant sleep must be interpreted within the context of the sleeping environment in which they were established. Given that arousability is diminished in stage 3-4, we speculate that, under otherwise safe conditions, the observed changes in stage 3-4 sleep and arousals associated with bed sharing might be protective to infants at risk for SIDS because of a hypothesized arousal deficit. The responsivity of the mother to infant arousals during bed sharing might also be protective.

Maternal proximity and infant CO2 environment during bedsharing and possible implications for SIDS research

Sudden infant death syndrome (SIDS) is the leading cause of human infant mortality after the neonatal period in Western countries. Recently, child care practices have been shown to be important in determining infant vulnerability to SIDS. However, very little is known about the impact of parent-infant cosleeping on infant sleep physiology and behavior and SIDS risk. This reflects the failure of Western societal research paradigms to appreciate the human infant's evolutionary history of cosleeping, the recency of the emergence of solitary infant sleeping as a practice and the fact that parent-infant cosleeping is still the preferred sleeping arrangement for the majority of contemporary societies. Incorporating current hypotheses on the mechanisms of SIDS, we have hypothesized that the comparatively sensory-rich cosleeping environment might be protective against SIDS in some contexts. As a first step to characterize cosleeping environments, this investigation is aimed at assessing, in routinely bedsharing mothers and infants, their relative sleeping positions and the potential for sleeping in close face-to face proximity and for infant exposure to increased environmental CO2 produced by maternal respiration. The latter is important in that breathing elevated levels of CO2 can have diverse effects, ranging from respiratory stimulation at low levels to suffocation at very high levels. Two related laboratory studies were performed. In the first, all-night videotapes of 12 healthy, routinely bedsharing mother-infant pairs were analyzed for sleeping positions and time spent in face-to-face orientation and distances separating their faces. Infants were 11-15 wk old. Mothers predominantly positioned themselves on their sides facing their infants, with the infants placed either supine or on their sides. Mothers and infants slept oriented face-to-face for 64 +/- 27% (S.D.) of non-movement time, with distance less than 20 cm commonly separating their faces. In the second study, concentrations of CO2 in air were measured in six young women at distances of up to 21 cm from their nares. Peak expiratory CO2 concentrations remained above 1.0% at distances up to 9 cm and above 0.5% at 18 cm. Both baseline and peak CO2 levels were further increased at all distances when measured within a partial air pocket created to simulate a bedding environment sometimes seen during bedsharing. We conclude that during bedsharing there is potential for 1) a high degree of face-to-face orientation and close proximity and consequently 2) increased environmental CO2, as a result of maternal respiration, to non-lethal levels that might stimulate infant respiration. The close proximity would also maximize the sensory impact of the mother on the infant through other modalities. We also suggest that bedsharing may minimize prone infant positioning, a known risk factor for SIDS.

An improved valve rotator

A device to rotate valve prostheses is described. By using a polythene tubing universal joint the valve may be turned by twisting the handle of the valve rotator without altering its spatial orientation. This modification was designed to facilitate what can be a frustrating manoeuvre and should be applicable to any rotatable valve.

Maternal sleep and arousals during bedsharing with infants

Contrary to popular perception, studies show that parent-infant bedsharing is not uncommon in American society. A belief that bedsharing with infants negatively impacts the quality of adult sleep also appears wide-spread. This has not been substantiated, however, because the few studies that have measured the impact of bedsharing on adult sleep examined only bedsharing with another adult. In the present study, laboratory polysomnography was performed in 20 routinely bedsharing and 15 routinely solitary-sleeping, breastfeeding, Latino mother-infant pairs comparing the mothers' sleep when bedsharing to solitary-sleeping nights. Infants were 11-15 weeks old at the time. Irrespective of routine sleeping arrangement, mothers' total sleep time was not decreased on the bedsharing night compared to the solitary night. Across the two groups, percent Stage 3-4 sleep (of total sleep time) was significantly reduced on the bedsharing night but only by 3.9%, while Stage 1-2 sleep was increased 3.7%. Episodes of both Stages 3-4 and 1-2 were significantly shorter. The amount of rapid eye movement (REM) sleep was unaffected. Overall, arousal frequency was significantly increased by 3.6 hour-1. As the increase in arousal frequency was stage specific, it could account for the pattern of stage changes. Nocturnal wakefulness was not increased, however, because awakenings were of shorter duration. these effects of bedsharing did not habituate with routine bedsharing because they were not diminished in the routinely bedsharing mothers compared to the routinely solitary-sleeping mothers. We find that the impact of bedsharing on maternal sleep is modest and somewhat different from the reported impact of sleeping with another adult. From the infant's standpoint, the effects on maternal sleep are adaptive to the extent that opportunities to monitor the infant's status are enhanced. The mother's caregiver role is likely germane to differential effects on sleep of bedsharing with an infant versus another adult.

Sleeping position, orientation, and proximity in bedsharing infants and mothers

The impact of mother-infant bedsharing on infant sleeping position, orientation, and proximity to the mother was assessed in 12 breast-feeding Latino mother-infant pairs. Six routinely bedsharing and six routinely solitary-sleeping pairs slept 3 nights in the sleep laboratory. The first night matched the routine home condition, followed by 1 bedsharing night and 1 solitary-sleeping night in random order. During bedsharing infants were never placed prone, regardless of their routine sleeping condition. On the bedsharing night, mothers and infants spent most of the night oriented toward each other; seven of 12 infants remained oriented toward their mothers the entire night. While sleeping in a face-to-face orientation, most pairs slept most of the time less than 30 cm apart with appreciable amounts of time at less than 20 cm. This orientation and proximity should facilitate sensory exchanges between mother and infant which, we hypothesize, influence the infant's sleep physiology and nocturnal behavior. We conclude that bedsharing minimizes the use of the prone infant sleeping position, probably in part to facilitate breast feeding. By promoting nonprone positions, bedsharing may protect some infants from sudden infant death syndrome (SIDS), since prone sleeping is a known risk factor for SIDS. The large percentage of the night that mothers spent oriented toward their infants suggests that a higher degree of maternal vigilance may also result from bedsharing.

Infant sleep architecture during bedsharing and possible implications for SIDS

Arousal is an important protective response during sleep, and arousal deficit is hypothesized to play a role in the etiology of sudden infant death syndrome (SIDS). Because environmental or caretaking factors have been shown to exert powerful effects on susceptibility to SIDS, manipulations that facilitate arousability might be protective against SIDS. All-night laboratory polysomnographic recordings were performed in 20 routinely bedsharing and 15 routinely solitary sleeping healthy breast-feeding Latino infants within the peak age range for SIDS, in both bedsharing (with mother) and solitary sleeping environments. The most important findings revealed by repeated measures analyses of variance were a significant reduction in stage 3/4 sleep and an inverse increase in stage 1/2 sleep on the bedsharing night compared to the solitary night, irrespective of routine sleeping arrangement. Shorter mean duration episodes of stage 3/4 sleep and longer mean stage 1/2 sleep episodes accounted for these differences. Because the arousal threshold is high in the electroencephalographic delta range, by limiting the amount of stage 3/4 sleep, bedsharing should promote infant arousability and might be protective against SIDS. The results also suggest that accepted normative values for infant sleep established in solitary sleeping infants may not be representative of infants raised in social sleeping environments.

A double-blind comparison of ropivacaine 0.5%, 0.75%, 1.0% and bupivacaine 0.5%, injected epidurally, in patients undergoing abdominal hysterectomy

PURPOSE

Ropivacaine is a new long-acting, injectable local anaesthetic currently undergoing clinical investigation world wide. It is structurally very similar to bupivacaine, but with less potential for central nervous system or cardiac toxicity. The purpose of this double-blind study was: to investigate the dose-response relationship of increasing doses of ropivacaine on the quality of anaesthesia and the duration of both motor and sensory blockade, and to compare these results with an established local anaesthetic, bupivacaine.

METHODS

One hundred and twenty five patients were randomly assigned to one of four treatment groups and 116 completed the study. Epidural anaesthesia was established using 25 ml test solution, injected over three minutes following a satisfactory test dose. Sensory onset, spread and duration, using the pin prick method, and motor scores using a modified Bromage scoring system were compared.

RESULTS

A dose/response relationship was observed with increasing doses of ropivacaine for all variables tested except analgesia and muscle relaxation (P < 0.01). There were differences in: (i) motor onset (Levels 1 and 2), when ropivacaine 1.0% was compared with ropivacaine 0.75% and 0.5% (P < 0.05); (ii) in sensory duration at all levels except T6 when ropivacaine was compared with ropivacaine 0.5% (P < 0.05); (iii) differences in sensory duration at T12 and S1 when ropivacaine 1.0% was compared with bupivacaine 0.5% (P < 0.05); (iv) differences in motor duration at all levels when ropivacaine 1.0% was compared with ropivacaine 0.5% (P < 0.05). No serious adverse events were reported in this study.

CONCLUSION

Increasing doses of ropivacaine were associated with an increased clinical effect. The most consistent differences occurred when ropivacaine 1.0% was compared with 0.5% and the least consistent between ropivacaine 0.5%, 0.75% and bupivacaine 0.5%. The main difference between ropivacaine 1.0% and bupivacaine was in sensory duration. No serious adverse events were reported.

Continuous epidural infusion of ropivacaine for the prevention of postoperative pain after major orthopaedic surgery: a dose-finding study

PURPOSE

A dose-finding study to investigate the use of epidural infusions of ropivacaine for postoperative analgesia following orthopaedic surgery.

METHODS

This was a randomized, double-blind study. Surgery was performed using a combination of a lumbar epidural block utilizing ropivacaine 0.5% and a standardized general anaesthetic. Postoperatively, an epidural infusion of the study solution (saline, ropivacaine 0.1%, 0.2% or 0.3%) was started at the rate of 10 ml.hr-1 and continued for 21 hr after arrival in the PACU. Analgesia was supplemented with PCA morphine (dose = 1.0 mg, lock-out = 5 min).

RESULTS

Forty-four patients completed the study. The ropivacaine 0.1%, 0.2%, 0.3% groups required less morphine over the 21 hr than the saline group (P < 0.01). The VAS pain scores were also lower in the three ropivacaine groups (P < 0.001). The ropivacaine groups maintained sensory anaesthesia to pinprick when compared with saline (P < 0.05). The motor block in the 0.3% group was significantly higher than the saline group at all times (P < 0.05), and higher than the 0.1% group at eight hours (P < 0.01), while the 0.2% group had higher Bromage scores than saline at 4 and 21 hr (P < 0.05).

CONCLUSIONS

The use of continuous epidural infusions of ropivacaine 0.1%, 0.2% and 0.3% at 10 ml.hr-1 improved postoperative pain relief and decreased PCA morphine requirements in patients undergoing major orthopaedic surgery. The 0.1% and 0.2% concentrations produced similar sensory anaesthesia with less motor blockade than the 0.3% concentration.

Experimental studies of infant-parent co-sleeping: mutual physiological and behavioral influences and their relevance to SIDS (sudden infant death syndrome)

We hypothesize that maternal sensory exchanges, likely involving a combination of heat, sound, gas, smells, movement, and touch, induce important physiological changes, especially in the healthy infant's arousal patterns, body temperature, and sleep architecture as defined by standard physiological measures. We summarize the results of two preliminary physiological studies, and some early data from a third, in which mothers and infants are monitored using standard polysomnographic techniques as they sleep in the same bed, and then in adjacent rooms. Our data suggest that infant-parent co-sleeping alters the infant's sleep experience as, for example, the characteristics of arousals, the frequency and duration of nursing, infant sleep position and the number of maternal inspections. For example, while sleeping in the same bed, mothers nurse their infants three times more frequently than they do while their infants sleep in an adjacent room. These preliminary data demonstrate significant differences between routine co-sleeping and solitary sleeping environments. This work underscores the importance of studying infant sleep as it unfolds in the co-sleeping environment, the environment within which it evolved over at least 5 million years of human evolution. Should our preliminary findings be confirmed in future studies they will provide a beginning point for considering additional, possibly unconventional ways of helping to reduce SIDS risks.