Behaviorally segmented audiences for managing sunscreen chemical pollution risk in protected coastal natural resource areas

This audience segmentation of visitors at coastal parks in Hawaii and North Carolina addresses an emergent natural resource management concern and risk to aquatic ecosystems: sunscreen chemical pollution. Four audiences were identified that correspond to different behavioral profiles: sunscreen protection tourists, multimodal sun protection tourists, in-state frequent park visitors, and frequent beachgoers who skip sunscreen. The second-largest audience, sunscreen protection tourists, represents 29% of visitors at Cape Lookout National Seashore and 25% at Kaloko-Honokōhau National Historical Park. This group ranks of most concern for chemical pollution because they use sunscreen, but not typically mineral formulations or other methods such as protective clothing, and they have lower levels of sunscreen chemical issue awareness. The identification of similar audience segments across regions with differing cultural characteristics and sunscreen regulation status suggests the robustness of the model and its indicator variables, with implications for both environmental protection and public health. Further, coastal visitors' interest in enacting pro-environmental sun protection behaviors during their next park or beach visit indicates the potential for natural resource managers to holistically address risks in both domains through targeted interventions with audiences of most concern.

An Experimental Cold Gas Cannon for the Study of Porcine Lung Contusion and Behind Armor Blunt Trauma

Behind armor blunt trauma (BABT) is a non-penetrating injury caused by the rapid deformation of body armor, by a projectile, which may in extreme circumstances cause death. The understanding of the mechanisms is still low, in relation to what is needed for safety threshold levels. Few models of graded kinetic energy transfer to the body exist. We established an experimental model for graded BABT. The cold gas cannon was air-driven, consisted of a pressure vessel, a barrel, and a pressure actuator. It required short training to operate and was constructed by standard components. It produced standardized expulsion of plastic projectiles with 65 mm and weight 58 g. Velocity correlated linearly to pressure (R 0.9602, p < 0.0001), equation Y = 6.558*X + 46.50. Maximum tested pressure was 10 bar, velocity 110 m/s and kinetic energy (Ek) 351 J. Crossbred male swine (n = 10) mean weight (SD) 56 ± 3 kg, were subjected to BABT, mean Ek (SD) 318 (61) J, to a fix point on the right lateral thorax. Pulmonary contusion was confirmed by physiological parameters pO2 (p < 0.05), SaO2 (p < 0.01), pCO2 (p < 0.01), etCO2 (p < 0.01), MPAP (p < 0.01), Cstat (p < 0.01), intrapulmonary shunt (Q's/Q't) (p < 0.05), and qualified trans-thoracic ultrasound (p < 0.0001). The consistent injury profile enabled for the addition of future experimental interventions.

Heat strain of Japanese firefighters wearing personal protective equipment: a review for developing a test method

The aim of this review was to develop a test method for the evaluation of heat strain for structural firefighters wearing personal protective equipment (PPE) in Japan. We analysed a series of our laboratory's questionnaires and experimental studies and reviewed international standards on test methods. We investigated the actual average working conditions (total firefighting time on one incidence, working time with full PPE, maximum temperature and humidity during firefighting) at structural firefighting site in Japan by conducting a large-scale questionnaire survey of Japanese firefighters. We discussed test subjects (firefighters vs. non-firefighters; body size; physical fitness), exercise intensity (absolutes vs. relative; light vs. heavy) and duration, experimental temperature and relative humidity, experimental clothing items including station uniforms (shorts vs. long), and measurement variables (physiological and subjective responses), and suggested a standard test method to evaluate the heat strain of firefighters in hot and humid environments.Practitioner summary: We reviewed studies on human wear trials of firefighting personal protective equipment (PPE) in hot environments and suggested a standard test method to evaluate the heat strain of firefighters. The test method can be internationally utilised to examine the comfort functions and heat stress of PPE in hot, humid environments.

Thermal response of human body with immersion suit in cold environment

Hypothermia caused by cold water immersion is one of the main causes of death in marine accidents. Immersion suit is a kind of protective clothing when implementing flying tasks over the sea in cold seasons, with the main function to slow down the loss of human heat in water and prolong the survival time. In this study, the thermal properties and wearing types of immersion suit and underwear were analyzed. The subjects with internal- and external-wear immersion suit exposed to the experimental environments for 2 h in five working conditions. The core temperature, weighted average skin temperature, and average body temperature were measured and calculated. Both internal- and external-wear immersion suits could fulfil the cold protection requirements under the experimental conditions. The results of clothing parameter tests and physiological experiments both exhibit that the external-wear immersion suit has better thermal insulation effect. And the tolerance time in low-temperature water was predicted, which is crucial for effective and efficient rescue during shipwreck in adverse thermal scenarios. In future research, a comprehensive evaluation and analysis of the thermal insulation performance of immersion suit could be completed in combination with the water ingress of the clothing, the subjects' thermal comfort, and flexibility of the clothing.

Are there sex differences in physiological parameters and reaction time responses to overload in firefighters?

Male and female firefighters work side-by-side in the same in strenuous and risky conditions. Anthropometrics, physiological, and reaction time (mean of reaction time -MRT-, and errors made -E) parameters of 12 Female and 13 Male firefighters were compared. Effect of overload (step test with and without equipment) on the MRT and E were analyzed on 3 trials (T1 = 1-1s, T2 = 0.5-1s, T3 = 0.5–0.5s), compared with a pre-test condition (basal). T-test between males and females was applied to assess differences (p<0.05) in all parameters. ANOVA with repeated measures and Bonferroni on 3 conditions of step test between males and females was applied in reaction time variables. Between MRT and E, in T1, T2 and T3 trials and the 3 test conditions, ANCOVA models with interactions were used. Differences (p<0.05) in anthropometric, physiological and reaction time data emerged across groups, and on the 3rd trials (T3 vs T1 and T2) in reaction time parameters of each group. ANCOVA showed differences (p<0.001) in E among trials. Post hoc showed significant differences in T1vsT3 and T1vsT2. MRT x trial interaction was extremely significant (P<0.001). Implementing fitness and reaction time exercise programs is important to decrease the injury risk and increase work capacity in firefighters with reference to female workers.

Influence of age, geographical region, and work unit on heat strain symptoms: a cross-sectional survey of electrical utility workers

This study assessed self-reported heat strain symptoms in workers of a state wide electrical utility distributor to determine risk differences between age groups, geographical work regions and work units. Out of a total 3,250 workers, 918 (∼28%) outdoor staff completed an online survey, which assessed the frequency of self-reported heat strain symptoms in the work and post-work settings, factors contributing to symptoms and symptom management. Heat strain symptoms were grouped into chronic low-grade cases and isolated high-grade cases based on the severity and frequency of symptoms. The risk (likelihood) of an employee being classified as either a chronic low-grade or isolated high-grade case was calculated and compared to the mean risk of all categories to determine risk difference, expressed as -1.00 to 1.00. For chronic low-grade cases, the 41-50 years age group had significantly increased risk (+0.08, p < 0.05) while the over 60 years age group had significantly decreased risk (-0.14, p < 0.05). Two of the three regions (p < 0.01) and three of the nine work units also demonstrated risk differences (p < 0.01) for chronic low-grade cases. Work units were the sole grouping to demonstrate risk difference for isolated high-risk cases. Work units with greater exposure to heat and higher requirement for protective clothing, such as Underground (+0.19, p < 0.05), Overhead - Predominantly Live Line (+0.18, p < 0.01), and Overhead - Distribution and Transmission (+0.11, p < 0.05) were at greater risk of reporting heat stress symptoms. This study demonstrates that the pattern of self-reported chronic low-grade heat strain cases differs to isolated high-grade cases within the electrical utility industry. Age, geographical location, and work unit independently alter the risk of chronic low-grade heat strain, while the risk of isolated high-grade heat strain was only related to work unit. These outcomes support implementation of a flexible and targeted approach to heat stress management in large and diverse organizations in which employees are routinely exposed to heat.

The adverse skin reactions of health care workers using personal protective equipment for COVID-19

In December 2019, a new coronavirus was found in Wuhan, Hubei Province, China, and spread rapidly throughout the country, attracting global attention. On February 11, the World Health Organization (WHO) officially named the disease caused by 2019-nCoV coronavirus disease 2019 (COVID-19). With the increasing number of cases, health care workers (HCWs) from all over China volunteered to work in Hubei Province. Because of the strong infectivity of COVID-19, HCWs need to wear personal protective equipment (PPE), such as N95 masks, latex gloves, and protective clothing. Due to the long-term use of PPE, many adverse skin reactions may occur. Therefore, the purpose of this study is to explore the adverse skin reactions among HCWs using PPE.Questionnaires were used for the research; a quantitative study was carried out to determine the incidence of adverse skin reactions among HCWs using PPE.A total of 61 valid questionnaires were collected. The most common adverse skin reactions among HCWs wearing N95 masks were nasal bridge scarring (68.9%) and facial itching (27.9%). The most common adverse skin reactions among HCWs wearing latex gloves were dry skin (55.7%), itching (31.2%), and rash (23.0%). The most common adverse skin reactions among HCWs wearing protective clothing were dry skin (36.1%) and itching (34.4%).When most HCWs wear PPE for a long period of time, they will experience adverse skin reactions. The incidence of adverse skin reactions to the N95 mask was 95.1%, that to latex gloves was 88.5%, and that to protective clothing was 60.7%.

Effectiveness of a field-type liquid cooling vest for reducing heat strain while wearing protective clothing

This study examined the effectiveness of a field-type liquid cooling vest (LCV) worn underneath an impermeable protective suit on heat strain during walking. Eight men walked for 60 min at a moderate speed (3.0 km/h) wearing the suit in a warm environment (33°C, 60% relative humidity) without (control, CON) or with the LCV. A smaller increase in rectal temperature was recorded in participants in the LCV than in the CON condition (37.6 ± 0.1°C vs. 37.9 ± 0.1°C, p<0.05). Walking while wearing the LCV reduced the level of physiological heat strain, as measured by the mean skin temperature (35.5 ± 0.1°C vs. 36.3 ± 0.1°C), chest sweat rate (13.5 ± 3.0 mg/cm²/h vs. 16.6 ± 3.8 mg/cm²/h), chest cutaneous vascular conductance (349 ± 88% vs. 463 ± 122%), body weight loss (0.72 ± 0.05% vs. 0.93 ± 0.06%), and heart rate (101 ± 6 beats/min vs. 111 ± 7 beats/min) (p<0.05, for all comparisons). These changes were accompanied by a decrease in thermal sensation and discomfort. These results suggest that a field-type LCV attenuates exertional heat strain while wearing impermeable protective clothing.

Wearing body armour and backpack loads increase the likelihood of expiratory flow limitation and respiratory muscle fatigue during marching

The effect of load carriage on pulmonary function was investigated during a treadmill march of increasing intensity. 24 male infantry soldiers marched on six occasions wearing either: no load, 15 kg, 30 kg, 40 kg or 50 kg. Each loaded configuration included body armour which was worn as battle-fit or loose-fit (40 kg only). FVC and FEV₁ were reduced by 6 to 15% with load. Maximal mouth pressures were reduced post load carriage by up to 11% (inspiratory) and 17% (expiratory). Increased ventilatory demands associated with carrying increased mass were met by increases in breathing frequency (from 3 to 26 breaths·min^-1) with minimal changes to tidal volume. 72% of participants experienced expiratory flow limitation whilst wearing the heaviest load. Loosening the armour had minimal effects on pulmonary function. It was concluded that as mass and exercise intensity are increased, the degree of expiratory flow limitation also increases. Practitioner Summary: This study investigated the effect of soldier load carriage on pulmonary function, to inform the trade-off between protection and burden. Load carriage caused an inefficient breathing pattern, respiratory muscle fatigue and expiratory flow limitation during marching. These effects were exacerbated by increases in mass carried and march intensity.

The effect of firefighter personal protective equipment on static and dynamic balance

Firefighters work in unpredictable conditions, necessitating the use of personal protective equipment (PPE). However, the additional weight from the PPE and self-contained breathing apparatus (SCBA) alters their centre of mass (COM), restricts movement and limits vision (face mask) contributing to a firefighters' challenge of maintaining balance. Thus, the purpose of this study was to quantify the effects of firefighter PPE on static and dynamic balance. Participants performed two sets of three functional balance tests: (1) Static Single Leg (SSL); (2) Dynamic Single Leg (DSL); (3) Limits of Stability (LOS). The balance tests were performed under one control and three randomised PPE conditions: (1) athletic clothing; (2) turnouts; (3) turnouts + SCBA; (4) turnouts + SCBA + face mask. Our study found turnouts + SCBA both with and without the face mask negatively affected dynamic balance. These findings identify factors in fall-related injuries and strategies to reduce occupational risk. Practitioner summary: Slips, trips and falls are the most common cause of injury in firefighters. Our study investigated the effects of firefighter personal protective equipment (PPE) on static and dynamic balance utilising a computerised balance instrument. We found that turnouts with a self-contained breathing apparatus (SCBA) with or without face mask negatively affected balance.

Could wearing motorcycle protective clothing compromise rider safety in hot weather?

Motorcycle protective clothing (PPE) effectively reduces the risk of injury in crashes, however in hot conditions many motorcyclists ride unprotected. Recent work found available motorcycle PPE to be thermally inefficient in hot weather with potential to cause significant thermal strain under average Australian summer conditions. The current study investigated the potential for the cognitive and psychophysical concomitants of thermal strain to compromise reaction times, mood and fatigue with potential consequences for motorcyclists' safety.

METHOD

Volunteers wearing motorcycle PPE participated in a 90 min trial (cycling 30 W) in 35 °C, 40%RH with overhead radiant heaters and a fan to simulate wind speed. Heart rate, core and skin temperature were recorded continuously. Reaction time and subjective ratings of thermal sensation and comfort, workload and mood were recorded at baseline, during rest breaks at 25 min intervals and on completion of the trail. Repeated measures analysis assessed each participant's performance against their own baseline.

RESULTS

Core temperatures increased by 2 °C (p < .0001), skin temperatures (3 °C, (p < .0001) and heart rates (66bpm, p < .0001). Reaction times fluctuated 36 ms 8% (p < .0001) over the trial. Subjective workload increased 68% (p = 0.001) and mood deteriorated 33 points (p < .0001) including feeling less alert (p = <.0001), contented (p = 0.001) and calm (p = 0.0004). Multivariate repeated measures analysis found significant associations between core temperature and workload (p = 0.01), mood (p = 0.001) and reaction time (<.0001). Skin temperature and workload (p = 0.02), mood (p = 0.01) and reaction time (<.0001). Subjective ratings of temperature sensation and wetness discomfort were associated respectively with increased workload (p = 0.0001, p = 0.004), mood change (p < .0001, p = 0.04) and reaction time (p < .0001, p < .0001).

CONCLUSIONS

The physiological impact of wearing thermally inefficient motorcycle PPE in hot conditions could impair motorcyclists cognitive and psychophysical functioning and, potentially, their riding performance and safety. These outcomes indicate an urgent need for manufacturers to develop motorcycle PPE that is effective and suitable for use, in hot conditions.

Using trunk posture to monitor heat strain at work

This study aimed to determine if trunk posture during walking is related to increases in rectal temperature (T_re). 24 males treadmill walked in one of four conditions (1): 30 min at 3.0 mph and 0% grade, 20 °C and 50% relative humidity (RH), wearing healthcare worker (HCW) PPE; (2): 30 min at 3.0 mph and 0% grade, 27.5 °C and 60% RH, HCW PPE; (3): 30 min at 3.0 mph and 0% grade, 32.5 °C and 70% RH, HCW PPE; and (4): 40 min at 40% VO₂max, 30 °C and 70% RH, wearing firefighter PPE. Trunk posture (Zephyr BioHarness 3) and T_re were measured continuously. T_re was positively related to trunk posture, controlling for covariates (B = 3.49, p < .001). BMI and age moderated this relationship (T_re×age, B = 0.76, p < .001; T_re*BMI, B = -1.85, p < .001). Trunk posture measurement may be useful in monitoring fall potential and magnitude of heat stress of workers in hot environments. Practitioner Summary: Occupational hyperthermia increases worker risk for heat illness and injury but is difficult to monitor in the field. This investigation shows that trunk posture is independently and positively related to core temperature. Non-invasive measurement or visual inspection of trunk posture could provide novel insight on individual heat strain level.

The maximum evaporative potential of constant wear immersion suits influences the risk of excessive heat strain for helicopter aircrew

The heat exchange properties of aircrew clothing including a Constant Wear Immersion Suit (CWIS), and the environmental conditions in which heat strain would impair operational performance, were investigated. The maximum evaporative potential (im/clo) of six clothing ensembles (three with a flight suit (FLY) and three with a CWIS) of varying undergarment layers were measured with a heated sweating manikin. Biophysical modelling estimated the environmental conditions in which body core temperature would elevate above 38.0°C during routine flight. The im/clo was reduced with additional undergarment layers, and was more restricted in CWIS compared to FLY ensembles. A significant linear relationship (r2 = 0.98, P<0.001) was observed between im/clo and the highest wet-bulb globe temperature in which the flight scenario could be completed without body core temperature exceeding 38.0°C. These findings provide a valuable tool for clothing manufacturers and mission planners for the development and selection of CWIS's for aircrew.

Influence of work clothing on physiological responses and performance during treadmill exercise and the Wildland Firefighter Pack Test

This study investigated physiological responses and performance during three separate exercise challenges (Parts I, II, and III) with wildland firefighting work clothing ensemble (boots and coveralls) and a 20.4 kg backpack in four conditions: U-EX (no pack, exercise clothing); L-EX (pack, exercise clothing); U-W (no pack, work clothing); and, L-W (pack and work clothing). Part I consisted of randomly-ordered graded exercise tests, on separate days, in U-EX, L-EX and L-W conditions. Part II consisted of randomly-ordered bouts of sub-maximal treadmill exercise in the four conditions. In Part III, subjects completed, in random-order on separate days, 4.83 km Pack Tests in L-EX or L-W conditions. In Part I, peak oxygen uptake was reduced (p < .05) in L-W. In Part II, mass-specific oxygen uptake was significantly higher in both work clothing conditions. In Part III, Pack Test time was slower (p < .05) in L-W. These results demonstrate the negative impact of work clothing and load carriage on physiological responses to exercise and performance.

Investigation of the thermal hazardous effect of protective clothing caused by stored energy discharge

In addition to direct thermal energy from a heating source, a large amount of thermal energy stored in clothing will continuously discharge to skin after exposure. Investigating the thermal hazardous effect of clothing caused by stored energy discharge is crucial for the reliability of thermal protective clothing. In this study several indices were proposed and applied to evaluate the impact of thermal energy discharge on human skin. The heat discharge from different layers of fabric systems was investigated, and the influences of air gaps and applied compression were examined. Heat fluxes at the boundaries of fabric layers and the distribution of heat discharge were determined. Additionally, the correlation between heat storage during exposure and heat discharge after exposure was identified. The results demonstrated that heat discharge to the skin could be correlated with heat storage within the fabric, however, it highly depended on the air gap under clothing, the applied compression, and the insulation provided by the fabric layers. Results from this study could contribute to thoroughly understanding the thermal hazardous effect of clothing and enhance the technical basis for developing new fabric combinations to minimize energy discharge after exposure.

Fluid replacement advice during work in fully encapsulated impermeable chemical protective suits

A major concern for responders to hazardous materials (HazMat) incidents is the heat strain that is caused by fully encapsulated impermeable chemical protective suits. In a research project, funded by the US Department of Defense, the thermal strain experienced when wearing these suits was studied. One particular area of interest was the fluid loss of responders during work in these suits as dehydration may be an additional health concern to the heat strain. 17 City of Raleigh firemen and 24 students were tested at two different labs. Subjects between the ages of 25 and 51 were used for human subject trials in a protocol approved by the local ethical committee. Six different Level A HazMat suits were evaluated in three climates: moderate (24°C, 50% RH, 20°C WBGT), warm-wet (32°C, 60% RH, 30°C WBGT), and hot-dry (45°C, 20% RH, 37°C WBGT, 200 W/m² radiant load) and at three walking speeds: 2.5 km/hr, 4 km/hr, and 5.5 km/hr. 4 km/hr was tested in all three climates and the other two walking speeds were tested in the moderate climate. Weight loss data was collected to determine fluid loss during these experiments. Working time ranged from as low as 20 min in the hot-dry condition to 60 min (the maximum) in the moderate climate, especially common at the lowest walking speed. The overall results from all experiments showed that fluid loss ranged from 0.2-2.2 L during these exposures, with the average fluid loss being 0.8 L, with 56% of the data between 0.5 L and 1 L of fluid loss. Further analysis showed that a suggestion of drinking 0.7 Liter per hour would safely hydrate over 50% of responders after one work-rest cycle. Applying this fluid volume over three work-rest cycles only put 11% of responders at risk of hypohydration vs. the 57% at risk with no fluid intake.

Additional helmet and pack loading reduce situational awareness during the establishment of marksmanship posture

The pickup of visual information is critical for controlling movement and maintaining situational awareness in dangerous situations. Altered coordination while wearing protective equipment may impact the likelihood of injury or death. This investigation examined the consequences of load magnitude and distribution on situational awareness, segmental coordination and head gaze in several protective equipment ensembles. Twelve soldiers stepped down onto force plates and were instructed to quickly and accurately identify visual information while establishing marksmanship posture in protective equipment. Time to discriminate visual information was extended when additional pack and helmet loads were added, with the small increase in helmet load having the largest effect. Greater head-leading and in-phase trunk-head coordination were found with lighter pack loads, while trunk-leading coordination increased and head gaze dynamics were more disrupted in heavier pack loads. Additional armour load in the vest had no consequences for Time to discriminate, coordination or head dynamics. This suggests that the addition of head borne load be carefully considered when integrating new technology and that up-armouring does not necessarily have negative consequences for marksmanship performance. Practitioner Summary: Understanding the trade-space between protection and reductions in task performance continue to challenge those developing personal protective equipment. These methods provide an approach that can help optimise equipment design and loading techniques by quantifying changes in task performance and the emergent coordination dynamics that underlie that performance.

Cardiovascular and respiratory effects of the neoprene wetsuit in non-immersed divers

A neoprene wetsuit is widely used to reduce thermal dispersion during diving. Recent observations have pointed out that elastic recoil of the wetsuit might have significant compressive effects, able to affect water and electrolyte homeostasis during both dry and immersed conditions. The aim of this study was to evaluate the possible cardiovascular and respiratory effects of the neoprene wetsuit in dry conditions in a sample of experienced divers. Twenty-four (24) healthy divers were evaluated by Doppler-echocardiography and by spirometry in basal conditions and while wearing a full neoprene wetsuit. During wetsuit conditions, we observed a significant decrease in heart rate (-5%; p ⟨ 0.05) and cardiac output (-12%; p ⟨ 0.05), and a significant increase in total peripheral resistances (15%; p ⟨ 0.05). Moreover, a significant reduction of right ventricular early diastolic filling was observed (-15%; p ⟨ 0.05). As concerns pulmonary function, a significant reduction of vital capacity (-2%; p ⟨ 0.001) and expiratory reserve volume (-25%; p ⟨ 0.001), and a significant increase of inspiratory capacity (9%; p ⟨ 0.001) and tidal volume (25%; p ⟨ 0.05) were observed. These data support the hypothesis that neoprene elastic recoil, possibly due to a compression exerted on chest, might affect systemic circulation (decreasing cardiac output and impairing right ventricular filling) and respiratory function.

Lead Aprons Are a Lead Exposure Hazard

PURPOSE

To determine whether lead-containing shields have lead dust on the external surface.

METHODS

Institutional review board approval was obtained for this descriptive study of a convenience sample of 172 shields. Each shield was tested for external lead dust via a qualitative rapid on-site test and a laboratory-based quantitative dust wipe analysis, flame atomic absorption spectrometry (FAAS). The χ² test was used to test the association with age, type of shield, lead sheet thickness, storage method, and visual and radiographic appearance.

RESULTS

Sixty-three percent (95% confidence interval [CI]: 56%-70%) of the shields had detectable surface lead by FAAS and 50% (95% CI: 43%-57%) by the qualitative method. Lead dust by FAAS ranged from undetectable to 998 μg/ft². The quantitative detection of lead was significantly associated with the following: (1) visual appearance of the shield (1 = best, 3 = worst): 88% of shields that scored 3 had detectable dust lead; (2) type of shield: a greater proportion of the pediatric patient, full-body, and thyroid shields were positive than vests and skirts; (3) use of a hanger for storage: 27% of shields on a hanger were positive versus 67% not on hangers. Radiographic determination of shield intactness, thickness of interior lead sheets, and age of shield were unrelated to presence of surface dust lead.

CONCLUSIONS

Sixty-three percent of shields had detectable surface lead that was associated with visual appearance, type of shield, and storage method. Lead-containing shields are a newly identified, potentially widespread source of lead exposure in the health industry.

Parafricta Bootees and Undergarments to Reduce Skin Breakdown in People with or at Risk of Pressure Ulcers: A NICE Medical Technologies Guidance

As part of the development of the National Institute for Health and Care Excellence (NICE) Medical Technologies Guidance on Parafricta Bootees and Undergarments to reduce skin breakdown in people with, or at risk of, pressure ulcers, the manufacturer (APA Parafricta Ltd) submitted clinical and economic evidence, which was critically appraised by an External Assessment Centre (EAC) and subsequently used by the Medical Technologies Advisory Committee (MTAC) to develop recommendations for further research. The University of Birmingham and Brunel University, acting as a consortium, were commissioned to act as the EAC, independently appraising the submission. This article is an overview of the original evidence submitted, the EAC's findings and the final NICE guidance. Very little comparative evidence was submitted to demonstrate the effectiveness of Parafricta Bootees or Undergarments. The sponsor submitted a simple cost analysis to estimate the costs of using Parafricta in addition to current practice-in comparison with current practice alone-in hospital and community settings separately. The analysis took a National Health Service (NHS) perspective. The basis of the analysis was a previously published comparative study, which showed no statistical difference in average lengths of stay between patients who wore Parafricta Undergarments and Bootees, and those who did not. The economic model incorporated the costs of Parafricta but assumed shorter lengths of stay with Parafricta. The sponsor concluded that Parafricta was cost saving relative to the comparators. The EAC made amendments to the sponsor's analysis to correct for errors and to reflect alternative assumptions. Parafricta remained cost saving in most analyses, and the savings per prevalent case ranged from £757 in the hospital model to £3455 in the community model. All analyses were severely limited by the available data on effectiveness-in particular, a lack of good-quality comparative studies.

Influence of the diving wetsuit on standard spirometry

INTRODUCTION A well-fitting wetsuit exerts a pressure on the body that may influence spirometry. This pressure is expected to reduce the forced vital capacity (FVC) due to hampered inspiration. Since the shape of the spirometric flow curve should not be changed by the pressure effects of the wetsuits, FVC, the forced expiratory volume during the first second of expiration (FEV₁), the peak expiratory flow (PEF) and the flow between 25 and 75% of FVC (FEF25-75) should change to the same degree. This study investigates the influence of a wetsuit on spirometric variables using age, suit thickness and suit type as the parameters.

METHODS

Spirometry (dry) was performed in 28 volunteers (12 women), aged 27-69 years.

RESULTS

The wetsuit (3.8 mm, range 2-7 mm) resulted in a change in FVC of -4.0% (P = 2∙E-08 〈 0.001), in FEV₁ of -3.6% (P = 3∙E-05 〈 0.001) and in PEF of -2.4% (P = 0.03); the FEF25-75 may also diminish. The FEV₁/FVC ratio did not change. The decreases can be regarded as a quasi-ageing effect of about 3.5 years. No influence of age, suit thickness and suit type was found.

CONCLUSION

The wetsuit appears to impair ventilatory mechanics. Both the medical examiner and the diver should be aware that a too-thick or too-tight suit might be a potential pulmonary risk factor in diving.

Biophysical Assessment and Predicted Thermophysiologic Effects of Body Armor

INTRODUCTION

Military personnel are often required to wear ballistic protection in order to defend against enemies. However, this added protection increases mass carried and imposes additional thermal burden on the individual. Body armor (BA) is known to reduce combat casualties, but the effects of BA mass and insulation on the physical performance of soldiers are less well documented. Until recently, the emphasis has been increasing personal protection, with little consideration of the adverse impacts on human performance.

OBJECTIVE

The purpose of this work was to use sweating thermal manikin and mathematical modeling techniques to quantify the tradeoff between increased BA protection, the accompanying mass, and thermal effects on human performance.

METHODS

Using a sweating thermal manikin, total insulation (IT, clo) and vapor permeability indexes (im) were measured for a baseline clothing ensemble with and without one of seven increasingly protective U.S. Army BA configurations. Using mathematical modeling, predictions were made of thermal impact on humans wearing each configuration while working in hot/dry (desert), hot/humid (jungle), and temperate environmental conditions.

RESULTS

In nearly still air (0.4 m/s), IT ranged from 1.57 to 1.63 clo and im from 0.35 to 0.42 for the seven BA conditions, compared to IT and im values of 1.37 clo and 0.45 respectively, for the baseline condition (no BA).

CONCLUSION

Biophysical assessments and predictive modeling show a quantifiable relationship exists among increased protection and increased thermal burden and decreased work capacity. This approach enables quantitative analysis of the tradeoffs between ballistic protection, thermal-work strain, and physical work performance.

Effect of firefighters' personal protective equipment on gait

The biomechanical experiment with eight male and four female firefighters demonstrates that the effect of adding essential equipment: turnout ensemble, self-contained breathing apparatus, and boots (leather and rubber boots), significantly restricts foot pronation. This finding is supported by a decrease in anterior-posterior and medial-lateral excursion of center of plantar pressure (COP) trajectory during walking. The accumulation of this equipment decreases COP velocity and increases foot-ground contact time and stride time, indicating increased gait instability. An increase in the flexing resistance of the boots is the major contributor to restricted foot pronation and gait instability as evidenced by the greater decrease in excursion of COP in leather boots (greater flexing resistance) than in rubber boots (lower resistance). The leather boots also shows the greatest increase in foot contact time and stride time. These negative impacts can increase musculoskeletal injuries in unfavorable fire ground environments.