The diagnosis of anaerobic bone and joint infections (BJI) were underestimated before the advent of molecular identification and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). We report 61 cases of anaerobic infections based on our 4-year experience with the management of BJI. A total of 75% of cases were post-surgical infections, associated with osteosynthesis devices (65%). Early infections occurred in 27% of cases, delayed infections in 17.5% of cases, and late infections in 55% of cases. We recorded 36 species of 93 anaerobic strains using MALDI-TOF MS (91) and molecular methods (2). We identified 20 strains of Propionibacterium acnes, 13 of Finegoldia magna, six of Peptoniphilus asaccharolyticus, and six of P. harei. Polymicrobial infections occurred in 50 cases. Surgical treatment was performed in 93.5% of cases. The antibiotic treatments included amoxicillin (30%), amoxicillin-clavulanic acid (16%), metronidazole (30%), and clindamycin (26%). Hyperbaric oxygen therapy was used in 17 cases (28%). The relapse rate (27%) was associated with lower limbs localization (p = 0.001). P. acnes BJI was associated with shoulder (p = 0.019), vertebra (p = 0.021), and head flap localization (p = 0.011), and none of these cases relapsed (p = 0.007). F. magna BJI was associated with ankle localization (p = 0.014). Anaerobic BJI is typically considered as a post-surgical polymicrobial infection, and the management of this infection combines surgical and medical treatments. MALDI-TOF MS and molecular identification have improved diagnosis. Thus, physicians should be aware of the polymicrobial nature of anaerobic BJI to establish immediate broad-spectrum antibiotic treatment during the post-surgical period until accurate microbiological results have been obtained.

Clinical symptoms of spinal cord DCS and their initial course before admission to the hyperbaric center should be considered as major prognostic factors in recovery. A new severity score is proposed to optimize the initial clinical evaluation for spinal cord DCS.

Hyperoxia causes hemodynamic alterations. We hypothesized that cardiovascular and autonomic control changes last beyond the end of hyperoxic period into normoxia. Ten healthy volunteers were randomized to breathe either medical air or 100% oxygen for 45 min in a double-blind study design. Measurements were performed before (baseline) and during gas exposure, and then 10, 30, 60, and 90 min after gas exposure. Hemodynamic changes were studied by Doppler echocardiography. Changes in cardiac and vasomotor autonomic control were evaluated through changes in spectral power of heart rate variability and blood pressure variability. Cardiac baroreflex sensitivity was assessed by the sequence method. Hyperoxia significantly decreased heart rate and increased the high frequency power of heart rate variability, suggesting a chemoreflex increase in vagal activity since the slope of cardiac baroreflex was significantly decreased during hyperoxia. Hyperoxia increased significantly the systemic vascular resistances and decreased the low frequency power of blood pressure variability, suggesting that hyperoxic vasoconstriction was not supported by an increase in vascular sympathetic stimulation. These changes lasted for 10 min after hyperoxia (p < 0.05). After the end of hyperoxic exposure, the shift of the power spectral distribution of heart rate variability toward a pattern of increased cardiac sympathetic activity lasted for 30 min (p < 0.05), reflecting a resuming of baseline autonomic balance. Cardiac output and stroke volume were significantly decreased during hyperoxia and returned to baseline values (10 min) later than heart rate. In conclusion, hyperoxia effects continue during return to normoxic breathing, but cardiac and vascular parameters followed different time courses of recovery.

Immersion, body cooling, hyperoxia, increased hydrostatic pressure and strenuous exercise likely combine to induce pulmonary oedema in patients without cardiac disease. This study underlines new physiopathological tracks related to the frequent occurrence of symptoms noticed in the last part of the ascent and a higher incidence in women.

The consequences of a prolonged total body immersion in cold water on the muscle function have not been documented yet, and they are the object of this French Navy research program. Ten elite divers were totally immerged and stayed immobile during 6 h in cold (18 and 10 degrees C) water. We measured the maximal voluntary leg extension (maximal voluntary contraction, MVC) and evoked compound muscle potential (M wave) in vastus lateralis and soleus muscles at rest, after a submaximal (60% MVC) isometric extension allowing the measurement of the endurance time (Tlim). The power spectrum of surface electromyograms (EMG) was computed during 60% MVCs. MVCs and 60% MVC maneuvers were repeated four times during the immersion. Data were compared with those obtained in a control group studied in dry air condition during a 6-h session. Total body cooling did not affect MVC nor Tlim. The M wave duration increased in the coolest muscle (soleus), but only at 10 degrees C at rest. There were no further fatigue-induced M wave alterations in both muscles. During 60% the MVCs, a time-dependant increase in the leftward shift of the EMG spectrum occurred at the two temperatures. These EMG changes were absent in the control group of subjects studied in dry air. The plasma lactate concentration was elevated throughout the 18 and mostly the 10 degrees C immersion conditions. Throughout the 18 degrees C immersion study, the resting potassium level did not significantly vary, whereas at 10 degrees C, a significant potassium increase occurred soon and persisted throughout the study. Thus, total body immersion in cold water did not affect the global contractile properties of leg muscles during static efforts but elicited significant alterations in electromyographic events which may be related to the variations of interstitial fluid composition.

This study investigated the sources of physiological stress in diving by comparing SCUBA dives (stressors: hydrostatic pressure, cold, and hyperoxia), apneic dives (hydrostatic pressure, cold, physical activity, hypoxia), and dry static apnea (hypoxia only). We hypothesized that despite the hypoxia induces by a long static apnea, it would be less stressful than SCUBA dive or apneic dives since the latter combined high pressure, physical activity, and cold exposure. Blood samples were collected from 12 SCUBA and 12 apnea divers before and after dives. On a different occasion, samples were collected from the apneic group before and after a maximal static dry apnea. We measured changes in levels of the stress hormones cortisol and copeptin in each situation. To identify localized effects of the stress, we measured levels of the cardiac injury markers troponin ( cTnI ) and brain natriuretic peptide ( BNP ), the muscular stress markers myoglobin and lactate), and the hypoxemia marker ischemia‐modified albumin ( IMA ). Copeptin, cortisol, and IMA levels increased for the apneic dive and the static dry apnea, whereas they decreased for the SCUBA dive. Troponin, BNP , and myoglobin levels increased for the apneic dive, but were unchanged for the SCUBA dive and the static dry apnea. We conclude that hypoxia induced by apnea is the dominant trigger for the release of stress hormones and cardiac injury markers, whereas cold or and hyperbaric exposures play a minor role. These results indicate that subjects should be screened carefully for pre‐existing cardiac diseases before undertaking significant apneic maneuvers.

Drowning in fresh water was associated with deeper hypoxemia in the initial assessment. Despite this initial difference, latter respiratory and biological parameters or outcome were similar in both groups.

Pulmonary edema has been reported in breath-hold divers during fish-catching diving activity. The present study was designed to detect possible increases in extravascular lung water (EVLW) in underwater fishermen after a competition. Thirty healthy subjects were studied. They participated in two different 5-h fish-catching diving competitions: one organized in the winter (10 subjects) and one organized in the autumn (20 subjects). A questionnaire was used to record underwater activity and note respiratory problems. An increase in EVLW was investigated from the detection of ultrasound lung comets (ULC) by chest ultrasonography. Complementary investigations included echocardiography and pulmonary function testing. An increase in EVLW was detected in three out of 30 underwater fishermen after the competition. No signs of cardiovascular dysfunction were found in the entire population and in divers with an increase in the ULC score. Two divers with raised ULC presented respiratory disorders such as cough or shortness of breath. Impairment in spirometric parameters was recorded in these subjects. An increase in EVLW could be observed after a fish-catching diving competition in three out of 30 underwater fishermen. In two subjects, it was related to respiratory disorders and impairment in pulmonary flow.