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Introduction: Performance of routine Chest X-rays (CXRs) in asymptomatic individuals to assess hyperbaric exposure risk is controversial. The radiation risk may overshadow the low yield in many settings. However, the yield may be higher in certain settings, such as tuberculosis-endemic countries. We evaluated the utility of routine CXR in diving and submarine medical examinations in South Africa., Methods: Records of 2,777 CXRs during 3,568 fitness examinations of 894 divers and submariners spanning 31 years were reviewed to determine the incidence of CXR abnormality. Associated factors were evaluated using odds ratios and a binomial logistic regression model, with a Kaplan-Meier plot to describe the duration of service until first abnormal CXR., Results: An abnormal CXR was reported in 1.1% per person year of service, yielding a cumulative incidence of 6.5% (58/894) of the study participants. Only four individuals had a clinical indication for the CXR in their medical history. A range of potential pathologies were seen, of which 15.5% were declared disqualifying and the rest (84.5%) were treated, or further investigation showed that the person could be declared fit., Conclusions: In South Africa, a routine CXR has a role to play in detecting abnormalities that are incompatible with pressure exposures. The highest number of abnormalities were found during the initial examinations and in individuals with long service records. Only four individuals had a clinical indication for their CXR during the 31-year span of our study. Similar studies should be performed to make recommendations in other countries and settings., (Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in electronic and other forms.)

Introduction: The current practice in Hong Kong is to have potential recreational divers complete a Recreational Scuba Training Council self-declared medical statement (RSTC form) prior to participation in diving. There are no reports in the literature on the usefulness of the Chinese version of the form., Methods: The Professional Association of Diving Instructors (PADI) RSTC form (Chinese version) was completed by 117 research participants who were then individually interviewed (without examination) to establish whether relevant information was not captured by the form. Any discrepancies or problems identified were recorded for further analysis., Results: Among participants, 15.4% expressed difficulty in completing the RSTC form. Less than one-third (28.2%) replied 'all negative' to the questions. Some health conditions that could impose diving risks were not elicited by the questionnaire alone. Nevertheless, there was good sensitivity, specificity, positive predictive value and negative predictive value with the exception of a few questions. However, significant discrepancies were identified when comparing the English and Chinese versions. There was also uncertainty with aspects of implementation, including attitudes of the user and provider, reliability of self-declaration answers and the handling of completed questionnaires., Conclusions: Health screening with a questionnaire for recreational divers remains practical and acceptable. Full revision of the RSTC form in Chinese is recommended in view of problems with the construct validity and translation. People should be informed about the non-prescriptive approach of health assessment for recreational divers. Further research on the implementation of the form may help to improve the screening strategy in the future., (Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in electronic and other forms.)

The aim of the study was to determine the effect of attending a faith-based education program (FBEP) on self-assessed physical, mental and spiritual health parameters. The study was designed as a prospective, observational, cohort study of individuals attending a 5-day FBEP. Out of 2650 sequential online registrants, those previously unexposed to the FBEP received automated invitations to complete 5 sequential Self-Assessment Questionnaire's (SAQ's) containing: (1) Duke University Religion Index (DUREL); (2) Negative Religious Coping (N-RCOPE); (3) Perceived Stress Scale (PSS); (4) Center for Epidemiology and Statistics-Depression Scale (CES-D); (5) Brief Illness Perception Questionnaire (BIPQ); and the (6) State Trait Anxiety Inventory (STAI). Pre-attendance SAQ (S1) was repeated immediately post-FBEP (S2), at 30 days (S3), 90 days (S4) and after 1 year (S5). Of 655 invited, 274 (42 %) succeeded, 242 (37 %) failed and 139 (21 %) declined to complete S1. Of the 274, 37 (14 %) were excluded at on-site interview; 26 (9 %) never attended the FBEP (i.e., controls: 5♂; 21♀; 27-76 years); and 211 (77 %) participated (i.e., cases: 105♂; 106♀; 18-84 years) and were analyzed over time: 211 (S1); 192 (S2); 99 (S3); 52 (S4); 51 (S5). IRB approval was via the Human Research Ethics Committee of Stellenbosch University. DUREL showed significant, sustained changes in Intrinsic Religiosity. N-RCOPE showed significant, lasting improvement. In others, median values dropped significantly immediately after the FBEP (S1:S2) for STAI-State p < 0.0001; PSS p < 0.0001; BIPQ p < 0.0001; and CES-D p < 0.0001; and at 1 month (S1:S3) for STAI-Trait p < 0.001; all changes were sustained (S3 through S5). This FBEP produced statistically and clinically significant changes; these lasted in those followed up >1 year.

Background: This paper considers the relationship between measures of personality and mood states, and susceptibility to inert gas narcosis. It briefly reviews the topics of inert gas narcosis affecting personality, and personality affecting the susceptibility to inert gas narcosis. There appears to be is a theoretical argument for a possible relationship between measures of personality, mood states, and susceptibility to narcosis. Practically, such a relationship may speak to issues in selection, training and preparation, risk assessments, and even accident investigation in the diving and/or hyperbaric environment., Materials and Methods: Twenty one divers completed measures of personality and mood states, and were then compressed to 709 kPa (equivalent to 60 msw) in a dry compression chamber, where they completed a task measuring speed of information processing, and a scale measuring subjective narcosis., Results and Conclusions: The main finding was the absence of any significant correlations between measures of personality traits and mood, and susceptibility to inert gas narcosis. Although the study found no evidence of any major relationship, it is presented as a case study to highlight some of the issues and pitfalls involved in such research. The lessons learned - including the careful defining and describing of concepts, and choosing of samples and measurements - are used to discuss some of the methodological and conceptual issues and future directions for researchers to consider.

Background: Hospital-associated infections (HAIs) are more frequently encountered in low- than in high-resource settings. There is a need to identify and implement feasible and sustainable approaches to strengthen HAI prevention in low-resource settings., Aim: To evaluate the biological contamination of routinely cleaned mattresses in both high- and low-resource settings., Methods: In this two-stage observational study, routine manual bed cleaning was evaluated at two university hospitals using adenosine triphosphate (ATP). Standardized training of cleaning personnel was achieved in both high- and low-resource settings. Qualitative analysis of the cleaning process was performed to identify predictors of cleaning outcome in low-resource settings., Findings: Mattresses in low-resource settings were highly contaminated prior to cleaning. Cleaning significantly reduced biological contamination of mattresses in low-resource settings (P < 0.0001). After training, the contamination observed after cleaning in both the high- and low-resource settings seemed comparable. Cleaning with appropriate type of cleaning materials reduced the contamination of mattresses adequately. Predictors for mattresses that remained contaminated in a low-resource setting included: type of product used, type of ward, training, and the level of contamination prior to cleaning., Conclusion: In low-resource settings mattresses were highly contaminated as noted by ATP levels. Routine manual cleaning by trained staff can be as effective in a low-resource setting as in a high-resource setting. We recommend a multi-modal cleaning strategy that consists of training of domestic services staff, availability of adequate time to clean beds between patients, and application of the correct type of cleaning products., (Copyright © 2015 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.)

Background: Human immunodeficiency virus (HIV) infection is a worldwide problem, with 68% of infected people residing in sub-Saharan Africa. Antiretroviral therapy is used as post-exposure prophylaxis (PEP) to prevent infection in cases of occupational exposure, and use has recently been expanded to nonoccupational exposure. Studies have demonstrated a lack of awareness of non-occupational PEP (NOPEP) in the general population., Aim: The aim of this study was to evaluate knowledge and attitudes towards availability of, access to and use of NO-PEP amongst first- and second-year medical students., Setting: Participants were medical undergraduates of Stellenbosch University in the Western Cape of South Africa who were registered in 2013., Methods: A descriptive cross-sectional study of 169 students was performed. Data were collected using self-administered questionnaires handed out in a classroom in August 2013. Self-reported knowledge and attitudes towards NO-PEP and barriers to access to and use of NO-PEP were analysed using frequency tables. Associations between self-reported and objective knowledge of NO-PEP were analysed by odds ratios., Results: Over 90% of students had good knowledge on HIV transmission, and about 75% knew how it can be prevented. Twenty eight per cent (n = 47) of students reported knowledge of NO-PEP; 67% reported hearing about it from lecturers, whilst 1% reported hearing about it from their partner. Studentswho knew the correct procedure to take when a dose is forgotten were 2.4 times more likely to report knowledge of NO-PEP than those who did not know what to do when a dose is forgotten (p = 0.029). No other associations were statistically signifiant., Conclusion: Students had positive attitudes towards the use of NO-PEP and also identifid barriers to its use. Despite good knowledge of HIV prevention and transmission, knowledge on NO-PEP was poor.

Background: The interaction of subjective experiences and objective measures of neuropsychological performance during hyperbaric exposure has received less attention in the literature, in part due to the shortage of available and appropriately standardized measures., Objective: This study aimed to describe the psychometric properties of a modified version of the Subjective High Assessment Scale when used in the hyperbaric context, by exploring internal reliability, factor structure, associations with psychological variables and simple cognitive delayed recall, and the effect of task focus on the recall of subjective experience., Method: Seventy qualified divers completed dry hyperbaric chamber dives to 607.95 kPa, and completed ratings of their subjective experiences. Some also completed a delayed recall task and psychological measures prior to their dives., Results: The scale displayed good internal consistency, with four meaningful factors emerging. It showed some significant but small associations with trait anxiety and transient mood states, and a small to moderate correlation with recall performance. There was no significant effect of task focus on self-report of subjective experiences., Conclusion: The modified scale, renamed the Subjective Narcosis Assessment Scale here, has useful psychometric properties, and promising potential for future use.

Objective: Commercial diving often occurs in low visibility, where divers are reliant on their tactile senses. This study examined the effect of nitrogen narcosis on tactile memory for shapes as well as the influence of psychological and biographical factors on this relationship., Method: This crossover study tested 139 commercial divers in a dry hyperbaric chamber at 101.325 and 607.95 kPa (1 and 6 atmospheres absolute/atm abs). Divers memorized shapes while blindfolded, using their tactile senses only. Delayed recall was measured at the surface after each dive. Psychological and biographical data were also collected., Results: A significant effect of hyperbaric pressure on tactile memory was demonstrated, and a further effect of sequence of testing found. Thus, divers' delayed shape recall deteriorated by 8% after learning material at depth, compared to learning on the surface. There were also significant but small effects of psychological and biographical markers on tactile memory performance, with lower trait anxiety associated with better recall, and lower education associated with poorer recall., Conclusion: The findings emphasize the importance of utilizing other forms of recording of events or objects at depth, particularly in conditions of low visibility during deeper diving, to aid memory encoding and subsequent recall at the surface.

Background: In a task-environment where visibility has deteriorated, individuals rely heavily on tactile performance (perception and manipulation) to complete complex tasks. When this happens under hyperbaric conditions, factors like nitrogen narcosis could influence a person's ability to successfully complete such tasks., Objective: To examine the effect of nitrogen narcosis on a complex neuropsychological task measuring tactile performance at a pressure of 608 kPa (6 atm abs), in the absence of visual access to the task., Methods: In a prospective cross-over study, 139 commercial divers were tested in a dry chamber at 101.3 kPa and 608 kPa. They completed the Tupperware Neuropsychological Task (TNT) of tactile performance without visual access to the task, and completed questionnaires to provide psychological and biographical data, which included trait anxiety and transient mood states, as well as formal qualifications and technical proficiency., Results: A significant decrement (9.5%, P < 0.001) in performance on the TNT at depth was found, irrespective of the sequence of testing. Generally, neither the psychological nor biographical variables showed any significant effect on tactile performance. Tactile performance on the surface was a good indicator of performance at depth., Conclusion: These findings have practical implications for professional diving where conditions of low visibility during deeper diving occur. Recommendations are made towards managing potential impairments in tactile performance, such as pre-dive practical learning ('rehearsal') as an aid to successful completion of tasks.

Unlabelled: Recreational divers are introducing "deep stops" at half the depth (HD-DS) to reduce the risk of spinal DCS with only Doppler evidence to support it. Therefore this research was designed to show the effect of an HD-DS on spinal DCS manifestations by evaluating whether: (1) air diving-induced spinal DCS could be produced in awake, freely moving rats at 3.5-6.0 atm abs (350-600 kPa); and (2) whether the introduction of an HD-DS reduced spinal DCS in such a model. Fifty-one female, Wistar rats (221 to 450 g) underwent one-hour compression at 350 to 600 kPa with seven minutes of decompression with/without a five-minute DS (HD-DS / No-DS). Animals were observed for three hours. Outcomes were classified as: (1) asymptomatic; (2) breathing difficulties; (3) paralysis/weakness; (4) immobility; or (5) death. Eight animals, exposed to 385 kPa air breathing for 60 minutes followed by a three-staged decompression of 7.5 minutes, remained asymptomatic. The profile is known to produce spinal DCS in anesthetized rats. Eleven animals were then used to determine the threshold for DCS: 500 kPa. A total of 14 animals were compressed to 550 kPa (Group 1). Group 1-A (n = 8) No-DS; Group 1-B (n = 6) HD-DS; 18 were compressed to 600 kPa (Group 2). Group 2-A (n = 8) No-DS; Group 2-B (n = 10) HD-DS., Results: (1) 385 kPa protocol did not produce visible DCS manifestations in awake rats. The binomial probability of no DCS in this sample size is 0.002818 for the proportion expected from a published report. The binomial probability of no fatalities is 0.005346). (2) No animals developed spinal DCS when assessed by visible paralysis/weakness or immobility, so no difference could be shown. Group 1-A: two deaths; two breathing abnormalities; four asymptomatic. Group 1-B: all asymptomatic. Difference recorded for breathing difficulties (p = 0.0483); none for fatalities (p = 0.2024). Group 2 mortality was 55% (n = 10). Group 2-A and 2-B: no difference for death (p = 0.6063) or breathing problems (p = 0.2084)., Conclusions: This model could not evaluate HD-DS for the prevention of spinal DCS in rats.

A diving fatality at the extreme depth of 264 m fresh water is described. The diver was equipped with an underwater video camera which recorded events leading to his death. These events corroborated predictions about respiratory complications at extreme pressure made by early researchers. Review of the video and relevant literature resulted in the following physiological interpretation: an increase in respired gas density during descent caused a progressive increase in resistance to flow in both the airways and the breathing circuit. Initially, this was associated with a shift to ventilation at higher lung volumes, a relative degree of hypoventilation, and mild permissive hypercapnia. The promotion of turbulent airway flow by increasing gas density resulted in effort-independent expiratory flow at lower flow rates than usual. The consequent inability to match ventilation to the demands of physical work at the bottom precipitated a spiraling crisis of dyspnea, increasing PaCO2, and wasted respiratory effort, thus producing more CO2. Extreme hypercapnia eventually led to unconsciousness. This tragic case provides a timely and salient lesson to a growing population of deep "technical" divers that there are physiological limitations that must be understood and considered when planning extreme dives.