A randomized trial of protocol-directed sedation management for mechanical ventilation in an Australian intensive care unit

Objective: To compare protocol-directed sedation management with traditional non-protocol-directed practice in mechanically ventilated patients. Design: Randomized, controlled trial. Setting: General intensive care unit (24 beds) in an Australian metropolitan teaching hospital. Patients: Adult, mechanically ventilated patients (n = 312). Interventions: Patients were randomly assigned to receive sedation directed by formal guidelines (protocol group, n = 153) or usual local clinical practice (control, n = 159). Measurements and Main Results: The median (95% confidence interval) duration of ventilation was 79 hrs (56-93 hrs) for patients in the protocol group compared with 58 hrs (44-78 hrs) for patients who received control care (p = .20). Lengths of stay (median [range]) in the intensive care unit (94 [2-1106] hrs vs. 88 (14-962) hrs, p = .58) and hospital (13 [1-113] days vs. 13 (1-365) days, p = .97) were similar, as were the proportions of subjects receiving a tracheostomy (17% vs. 15%, p = .64) or undergoing unplanned self-extubation (1.3% vs. 0.6%, p = .61). Death in the intensive care unit occurred in 32 (21%) patients in the protocol group and 32 (20%) control subjects (p = .89), with a similar overall proportion of deaths in hospital (25% vs. 22%, p = .51). A Cox proportional hazards model, after adjustment for age, gender, Acute Physiology and Chronic Health Evaluation II score, diagnostic category, and doses of commonly used drugs, estimated that protocol sedation management was associated with a 22% decrease (95% confidence interval 40% decrease to 2% increase, p = .07) in the occurrence of successful weaning from mechanical ventilation. Conclusions: This randomized trial provided no evidence of a substantial reduction in the duration of mechanical ventilation or length of stay, in either the intensive care unit or the hospital, with the use of protocol-directed sedation compared with usual local management. Qualified high-intensity nurse staffing and routine Australian intensive care unit nursing responsibility for many aspects of ventilatory practice may explain the contrast between these findings and some recent North American studies. (C) 2008 Lippincott Williams & Wilkins, Inc.

Does an evidence-based sedation protocol improve practice and patient outcomes in critical care?

Learning Objective 1: compare protocol-directed sedation management with traditional non-protocol-directed practice in mechanically ventilated patients in an Australian critical care.

Learning Objective 2: explain the contrasting international research findings on sedation protocol implementation.
Minimization of sedation in critical care patients has recently received widespread support. Professional organizations internationally have published sedation management guidelines for critically ill patients to improve the use of research in practice, decrease practice variability and shorten mechanical ventilation duration. Innovations in practice have included the introduction of decision making protocols, daily sedation interruptions and new drugs and monitoring technologies. The aim of this study was to compare protocol-directed sedation management with traditional non-protocol-directed practice in mechanically ventilated patients in an Australian critical care setting.

A randomized, controlled trial design was used to study 312 mechanically ventilated adult patients in a general critical care unit at an Australian metropolitan teaching hospital. Patients were randomly assigned to receive protocol directed sedation management developed from evidence based guidelines (n=153) or usual clinical practice (n=159).

The median (95% CI) duration of ventilation was 58 hrs (44–78 hrs) for patients in the non-protocol group and 79 hrs (56–93) for those patients in the protocol group (p=0.20). Results were not significant for length of stay in critical care or hospital, the frequency of tracheostomies, and unplanned extubations. A Cox proportional hazards model estimated that protocol directed sedation management was associated with a 22% decrease (95% CI: 40% decrease to 2% increase, p=0.07) in the occurrence of successful weaning from mechanical ventilation.

Few randomized controlled trials have evaluated the effectiveness of protocol-directed sedation outside of North America. This study highlights the lack of transferability between different settings and different models of care. Qualified, high intensity nursing in the Australian critical care setting facilitates rapid, responsive decisions for sedation management and an increased success rate for weaning from mechanical ventilation.

Low back pain and disability in community-based women : prevalence and association factors

Objective: Although low back pain is characterized by both pain and disability, there is a paucity of studies that have concurrently examined risk factors for these features in community-dwelling women. We aimed to investigate the prevalence and identify factors associated with both back pain and disability.

Design: A questionnaire was mailed to 542 women from a community-based research database. Detailed demographic data were collected, including participants' menopause, relationship, and employment status. Point and period prevalence estimates for back pain were derived. Participants were classified based on pain intensity and disability scores calculated from the Chronic Pain Grade Questionnaire, and factors associated with high levels of pain and disability were examined.

Results: A total of 506 (93.4%) women completed the questionnaire. More than 90% of participants had experienced low back pain, with 75.1% and 22.5% reporting pain in the past 12 months and currently, respectively. Seven percent of women reported a high level of disability and 16% reported high-intensity pain. Women with higher levels of disability were more likely to have a higher body mass index and to have pain currently, whereas those with greater pain intensity were more likely to be younger, have a higher body mass index, not be employed outside the home, drink alcohol, and have current pain.

Conclusions: Low back pain is a common problem for community-based women. A high body mass index and current pain were factors independently associated with both high pain intensity and disability. Longitudinal investigation is required to determine the predictive nature of these factors and their potential role in preventing pain and disability.

Acute signalling responses to intense endurance training commenced with low or normal muscle glycogen

We have previously demonstrated that well-trained subjects who completed a 3 week training programme in which selected high-intensity interval training (HIT) sessions were commenced with low muscle glycogen content increased the maximal activities of several oxidative enzymes that promote endurance adaptations to a greater extent than subjects who began all training sessions with normal glycogen levels. The aim of the present study was to investigate acute skeletal muscle signalling responses to a single bout of HIT commenced with low or normal muscle glycogen stores in an attempt to elucidate potential mechanism(s) that might underlie our previous observations. Six endurance-trained cyclists/triathletes performed a 100 min ride at ∼70% peak O₂ uptake (AT) on day 1 and HIT (8 × 5 min work bouts at maximal self-selected effort with 1 min rest) 24 h later (HIGH). Another six subjects, matched for fitness and training history, performed AT on day 1 then 1–2 h later, HIT (LOW). Muscle biopsies were taken before and after HIT. Muscle glycogen concentration was higher in HIGH versus LOW before the HIT (390 ± 28 versus 256 ± 67 μmol (g dry wt)⁻¹). After HIT, glycogen levels were reduced in both groups (P < 0.05) but HIGH was elevated compared with LOW (229 ± 29 versus 124 ± 41 μmol (g dry wt)−1; P < 0.05). Phosphorylation of 5'AMP-activated protein kinase (AMPK) increased after HIT, but the magnitude of increase was greater in LOW (P < 0.05). Despite the augmented AMPK response in LOW after HIT, selected downstream AMPK substrates were similar between groups. Phosphorylation of p38 mitogen-activated protein kinase (p38 MAPK) was unchanged for both groups before and after the HIT training sessions. We conclude that despite a greater activation AMPK phosphorylation when HIT was commenced with low compared with normal muscle glycogen availability, the localization and phosphorylation state of selected downstream targets of AMPK were similar in response to the two interventions.

Intramuscular determinants of the VO₂ slow component in trained cyclists

Fifteen trained male cyclists had muscle biopsies and performed cycling tests to determine if relationships exist between the oxygen uptake response and various intramuscular variables. It was found that muscle oxidative capacity is better able to explain the oxygen uptake response during high intensity cycling than muscle fiber distribution.

Effects of starting strategy on 5-min cycling time-trial performance

The importance of pacing for middle-distance performance is well recognized, yet previous research has produced equivocal results. Twenty-six trained male cyclists ( V O_2peak 62.8+5.9 ml ·kg^-1 · min^-1· maximal aerobic power output 340+43 W; mean+s) performed three cycling time-trials where the total external work (102.7+13.7 kJ) for each trial was identical to the best of two 5-min habituation trials. Markers of aerobic and anaerobic metabolism were assessed in 12 participants. Power output during the first quarter of the time-trials was fixed to control external mechanical work done (25.7+3.4 kJ) and induce fast-, even-, and slow-starting strategies (60, 75, and 90 s, respectively). Finishing times for the fast-start time-trial (4:53+0:11 min:s) were shorter than for the even-start (5:04+0:11 min:s; 95% CI=5 to 18 s, effect size=0.65, P 50.001) and slow-start time-trial (5:09+0:11 min:s; 95% CI=7 to 24 s, effect size=1.00, P 50.001). Mean VO₂ during the fast-start trials (4.31+0.51 litres · min^-1) was 0.18+0.19 litres · min^-1 (95% CI=0.07 to 0.30 litres · min^-1, effect size=0.94, P =0.003) higher than the even- and 0.18+0.20 litres · min^-1 (95% CI=0.5 to 0.30 litres · min^-1, effect size=0.86, P =0.007) higher than the slow-start time-trial. Oxygen deficit was greatest during the first quarter of the fast-start trial but was lower than the even- and slow-start trials during the second quarter of the trial. Blood lactate and pH were similar between the three trials. In conclusion, performance during a 5-min cycling time-trial was improved with the adoption of a fast- rather than an even- or slow-starting strategy.

Assessing physical activity during recess using accelerometry

Background : Physical activity guidelines recommend children should engage in 60 min of moderate-to-vigorous physical activity (MVPA) a day. School recess presents an opportunity for children to be physically active during the school day. Limited research has investigated children's activity levels during recess and its contribution to physical activity recommendations. Moreover, no target for physical activity during recess has been set.

Methods : One hundred sixteen boys and 112 girls (aged 5–10 years) from 23 schools had their physical activity during recess quantified using a uniaxial accelerometer during three recess breaks on one school day. The percentage of time spent engaged in moderate, high, and very high intensity activity was calculated using existing thresholds.

Results : Boys engaged in more moderate, high, and very high intensity activity than girls. On average, boys and girls spent 32.9% and 23% of recess engaged in physical activity, respectively.

Conclusions : Boys engaged in higher intensity activities than girls. The results suggest that recess can contribute 28 min for boys and 21.5 min for girls toward the accumulation of recommended daily physical activity. However, the physical activity intensities that children engaged in were low during recess. On average, children in this study did not achieve 50% of recess time in physical activity. Interventions for increasing the physical activity of children in the playground are warranted.

Substituted naphthoquinones as novel amino acid sensitive reagents for the detection of latent fingermarks on paper surfaces

In this paper, we present our preliminary studies into naphthoquinones as novel reagents for the detection of latent fingermarks on paper. Latent fingermarks deposited on paper substrates were treated with solutions of selected naphthoquinones in ethyl acetate/HFE-7100, with subsequent heating. The selected compounds were 1,4-dihydroxy-2-naphthoic acid, 1,2-naphthoquinone-4-sulfonate, 2-methoxy-1,4-naphthoquinone and 2-methyl-1,4-naphthoquinone. All of the tested compounds yielded purple-brown visible fingermarks, which also exhibited photoluminescence when illuminated with a high intensity filtered light source at 555nm and viewed through red goggles. Indirect heat using an oven at 150 ◦C for 1 h was found to be superior to direct heat with an iron, which while providing faster development lead to increased levels of background colouration. Luminescence spectrophotometry revealed differences in photoluminescence characteristics for fingermarks developed with the different naphthoquinones, with excitation over the range 530–590 nm. Luminescence spectrophotometry of developed lysine, glycine and serine spots on paper was used to confirm that the naphthoquinones were reacting with amino acids in the latent fingermark.

Seasonal reduction in physical activity and flow-mediated dilation in children

Purpose: Cardiovascular disease is a process that has its origins in childhood. Endothelial dysfunction is the earliest detectable manifestation of cardiovascular disease. This study aimed to assess the impact of seasonal changes in physical activity (PA) and body composition on conduit artery endothelial function in children.

Method: We studied 116 children (70 girls aged 10.7 ± 0.3 yr and 46 boys aged 10.7 ± 0.3 yr) on two occasions; in the northern summer (June) and late autumn (November). We assessed flow-mediated dilation (FMD) using high-resolution Doppler ultrasound. Body composition was measured by dual-energy x-ray absorptiometry. PA was assessed using accelerometry.

Results: FMD (10.0% ± 4.3% to 7.9% ± 3.9%, P < 0.001) and PA (94.1 ± 34.8 to 77.8 ± 33.7 min·d-1, P < 0.01) decreased, while percentage body fat increased (27.6% ± 6.8% to 28.0% ± 6.6%, P < 0.001) between summer and autumn. Decreases in FMD correlated with decreases in high-intensity PA (r = 0.23, P = 0.04), and change in high-intensity PA was the only predictor of change in FMD. No relationships were evident between changes in body composition and FMD.

Conclusions: Vascular function decreased between summer and autumn in this cohort. There were no relationships between change in FMD and changes in body composition or low/moderate-intensity PA. The associations between FMD and high-intensity PA suggests that future interventions should encourage this form of behavior, particularly at the times of year associated with lower PA.

Neuromuscular control and running economy is preserved in elite international triathletes after cycling

Running is the most important discipline for Olympic triathlon success. However, cycling impairs running muscle recruitment and performance in some highly trained triathletes; though it is not known if this occurs in elite international triathletes. The purpose of this study was to investigate the effect of cycling in two different protocols on running economy and neuromuscular control in elite international triathletes. Muscle recruitment and sagittal plane joint angles of the left lower extremity and running economy were compared between control (no preceding cycle) and transition (preceded by cycling) runs for two different cycle protocols (20-minute low-intensity and 50-minute high-intensity cycles) in seven elite international triathletes. Muscle recruitment and joint angles were not different between control and transition runs for either cycle protocols. Running economy was also not different between control and transition runs for the ow-intensity (62.4 ^ 4.5 vs. 62.1 ^ 4.0 ml/min/kg, p . 0.05) and high-intensity (63.4 ^ 3.5 vs. 63.3 ^ 4.3 ml/min/kg, p . 0.05) cycle protocols. The results of this study demonstrate that both low- and high-intensity cycles do not adversely influence neuromuscular control and running economy in elite international triathletes.

Change in running kinematics after cycling are related to alterations in running economy in triathletes

Emerging evidence suggests that cycling may influence neuromuscular control during subsequent running but the relationship between altered neuromuscular control and run performance in triathletes is not well understood. The aim of this study was to determine if a 45 min high-intensity cycle influences lower limb movement and muscle recruitment during running and whether changes in limb movement or muscle recruitment are associated with changes in running economy (RE) after cycling. RE, muscle activity (surface electromyography) and limb movement (sagittal plane kinematics) were compared between a control run (no preceding cycle) and a run performed after a 45 min high-intensity cycle in 15 moderately trained triathletes. Muscle recruitment and kinematics during running after cycling were altered in 7 of 15 (46%) triathletes. Changes in kinematics at the knee and ankle were significantly associated with the change in VO₂ after cycling (p < 0.05). The change in ankle angle at foot contact alone explained 67.1% of the variance in VO₂. These findings suggest that cycling does influence limb movement and muscle recruitment in some triathletes and that changes in kinematics, especially at the ankle, are closely related to alterations in running economy after cycling.

Profile of position movement demands in elite junior Australian rules footballers

This study investigated the positional movement patterns in elite junior Australian Football (AF). Thirty players (17.1 ± 0.9 years) participating in this study were tracked over seven home games of the regular 2006 Victorian junior (Under 18) league season. Using lapsed-time video analysis, each position for an entire match was videotaped on three separate occasions over the course of the season. Data analysed included the number of individual efforts, duration and frequency of efforts; distance and percentage time for the classifications of standing, walking jogging, running and sprinting. Results showed that the midfield position travelled the greatest distance (4173 ± 238 m per quarter; p < 0.05; ES = .94) whilst the full forward/full back travelled the least (2605 ± 348 m per quarter, p < 0.05, ES = 1.21). For all positions, walking or jogging accounted for the greatest number of efforts (45-55%), conversely running and sprinting accounted for 5-13% of match efforts. The majority of efforts across all classifications were between 0-3.99 s. The data from this study provides further evidence that AF is an intermittent sport characterised by high intensity movements separated by low intensity movements at a ratio of one high intensity effort every 12-40 s. However, careful interpretation of the data is required when training junior AF players for specific positions, given the specific group studied.

The Yo-Yo Intermittent Recovery Test (Level 1) to discriminate elite junior Australian football players

The Yo-Yo Intermittent Recovery (IR) Test is currently used to assess endurance performance in team sport athletes. However, to date, no data has been presented on its application to an elite junior Australian football (AF) playing group. Therefore, the aim of this study was to evaluate the Yo-Yo Intermittent Recovery Test Level 1 (IR1) ability to discriminate between junior AF players at two different playing standards and a group of non-athletic healthy males. Sixty age matched participants (16.6 ± 0.5 years) spread over three groups (20 per group): elite junior footballers; sub-elite junior footballers; and non-athletic healthy males participated in this study. Participants undertook a single Yo-Yo test performance on an indoor basketball court for each group. A one-way ANOVA with Scheffe's post hoc analysis revealed the elite junior footballers covered a significantly greater total distance (p < 0.001) and completed a significantly greater number of high-intensity efforts (p < 0.001) in comparison to their sub-elite counterparts, whilst both AF groups performed significantly better (p < 0.001) than the non-athletic healthy males. This study demonstrates the ability of the Yo-Yo IR1 to discriminate endurance performance between elite and sub-elite AF players, whilst further distinguishing AF players from a non-athletic healthy control group.