Evaluation of North Sea saturation procedures through divers monitoring.

BACKGROUND: Saturation diving is a standard method of intervention for commercial diving during offshore operations. Current saturation procedures achieve a high level of safety with regards to decompression sickness but still put the divers under multiple stressors: 1) Environmental stress (long confinement, heat/cold, dense gases, high oxygen levels), 2) Work stress (muscular fatigue, psychological pressure, breathing equipment, etc.), 3) venous gas emboli associated with decompression, 4) Inflammation related to oxidative stress and microparticles. We present the results of a saturation divers monitoring campaign performed in the North Sea Danish sector, on the Tyra field, during 2022. The study was supported by TotalEnergies, the field operator, and performed by Boskalis Subsea Services, the diving contractor, onboard the diving support vessel Boka Atlantis. The objective was twofold: document the level of diving stress during saturation operations in the Danish sector, and compare the performances of two saturation procedures, the Boskalis and the NORSOK procedures. MATERIALS AND METHODS: Fourteen divers volunteered for the study. The monitoring package include weight and temperature measurements, psychomotor tests (objective evaluation) and questionnaires (subjective evaluation), Doppler bubble detection and bioimpedance. The results were presented in a radar diagram that provides a general view of the situation. RESULTS: The data were analysed along 3 dimensions: work and environmental, desaturation bubbles, oxidative stress and inflammation. The results showed little or no variations from the reference values. No bubbles were detected after excursion dives and the final decompression, except for two divers with a grade 1 after arriving at surface. No statistical difference could be found between the Boskalis and the NORSOK saturation procedures. CONCLUSIONS: At a depth of 40-50 msw corresponding to the Danish sector, the two saturation procedures monitored induce no or little stress to the divers. The divers know how to manage their diet, equilibrate their hydration and pace their effort. Data available on divers' post saturation period show a recovery over the 24-48 hours following the end of the decompression. Further research should focus on diving deeper than 100 msw where a greater stress can be anticipated.

Hindsight bias critically impacts on clinicians' assessment of care quality in retrospective case note review.

Objective To determine whether hindsight bias impacts on retrospective case note review using a five point scoring system based on modern clinical governance toolkits. Design Survey. Setting Clinicians of varying grades invited to complete a short internet survey. Participants Ninety three clinicians were invited to complete an anonymous survey in which they reviewed three case vignettes for the purposes of a fictional clinical governance meeting. For each vignette, participants were randomised to an outcome in which the patient made a full recovery or alternatively died shortly after discharge. Main outcome measure. Participants submit scores from 1 to 5 to indicate the quality of care provided to patients prior to their discharge. These scores were compared to determine whether judgements about the quality of antecedent care were biased by the description of a patient death. Results In two out of three case vignettes clinicians exhibited marked hindsight bias. In a case of a patient with a swollen leg, identical antecedent care was scored as poor by participants when the patient died the next day, but good when the patient recovered (p<0.00001). In a case of headache, care was scored as poor when the patient died but adequate when the patient made a full recovery (p=0.0003). A third case of chest pain did not exhibit hindsight bias. Seniority of clinician had no impact on the tendency to exhibit hindsight bias when reviewing case notes. Conclusion In some cases, clinicians are markedly more critical of identical healthcare when a patient dies compared to when a patient survives. Hindsight bias while reviewing care when a patient survives might prevent identification of learning arising from errors. Additionally, we predict hindsight bias combined with a legal duty of candour will cause families to be informed that patients died because of healthcare error when this is not a fact.

An experimental model to measure the ability of headphones with active noise control to reduce patient's exposure to noise in an intensive care unit.

BACKGROUND: Defining the association between excessive noise in intensive care units, sleep disturbance and morbidity, including delirium, is confounded by the difficulty of implementing successful strategies to reduce patient's exposure to noise. Active noise control devices may prove to be useful adjuncts but there is currently little to quantify their ability to reduce noise in this complex environment. METHODS: Sound meters were embedded in the auditory meatus of three polystyrene model heads with no headphones (control), with headphones alone and with headphones using active noise control and placed in patient bays in a cardiac ICU. Ten days of recording sound levels at a frequency of 1 Hz were performed, and the noise levels in each group were compared using repeated measures MANOVA and subsequent pairwise testing. RESULTS: Multivariate testing demonstrated that there is a significant difference in the mean noise exposure levels between the three groups (p < 0.001). Subsequent pairwise testing between the three groups shows that the reduction in noise is greatest with headphones and active noise control. The mean reduction in noise exposure between the control and this group over 24 h is 6.8 (0.66) dB. The use of active noise control was also associated with a reduction in the exposure to high-intensity sound events over the course of the day. CONCLUSIONS: The use of active noise cancellation, as delivered by noise-cancelling headphones, is associated with a significant reduction in noise exposure in our model of noise exposure in a cardiac ICU. This is the first study to look at the potential effectiveness of active noise control in adult patients in an intensive care environment and shows that active noise control is a candidate technology to reduce noise exposure levels the patients experience during stays on intensive care.