Undersea and Hyperbaric Medicine最新文献

Objective: To investigate the effect of 6 ATA air/ oxygen treatment scheme and 2.8 ATA oxygen inhalation scheme on cerebral gas embolism.

Methods: 29 patients with cerebral gas embolism admitted from January 2014 to June 2022 were retrospectively included. The patients were divided into 6 ATA air/ oxygen treatment scheme group (14 cases) and 2.8 ATA oxygen inhalation therapy scheme group (15 cases). Glasgow Coma Scale (GCS) was used to evaluate the therapeutic effect before and after treatment. The effective standard of treatment: recovery of consciousness (GCS scores>8).

Results: There was no significant difference between two groups in terms of gender, age, cause of disease, time of onset and GCS score before treatment (P>0.05). There was not significant difference between two groups in terms of GCS score after 1 day and 1 week of treatment (P>0.05). After 1 week of treatment, 78.6% (11/14) of patients in the 6 ATA group and 80.0% (12/15) in the 2.8 ATA group improved.

Conclusion: The 2.8 ATA oxygen inhalation scheme can effectively treat cerebral gas embolism, and effect is similar to the 6 ATA air/ oxygen treatment scheme.

The assessment of rectal temperature and behavior is an important parameter in all patients for whom hyperbaric oxygen (HBO₂) therapy is used. The study aims to verify if there is less reduction in body temperature after HBO₂ therapy in restless patients and their behavior during the therapeutic session. Clinical data from 217 HBO₂ therapy sessions with 2 to 2,5 atmospheres absolute (ATA) were reviewed under therapy protocols of 30 (P1) or 45 (P2) minutes, covering 29 canines and 13 felines. Behavioral data, initial rectal temperature (iRT), final (fRT), and variation between them (RTv) of each patient were recorded. Parameters of oxygen concentration, humidity, temperature, and chamber flow rate were also recorded. Three of 217 patients experienced major adverse effects (seizure and auto-trauma). 144/217 HBO₂ therapy session records were selected for statistical analysis. In P1 sessions, 33.3% of the canine and 33.3% of the feline patients were restless. In P2 sessions, 40.7% of the canine and 28.1% of the feline patients were restless. The study did not observe a correlation between vRT and patients' behavior (p> 0.089) or differences in vRT between quiet and restless patients. There was a difference between iRT and fRT only in canines submitted to P1 (p<0.001) and felines submitted to P2 (p<0.001). Older canine patients were more restless than young canine patients at P1 (p= 0.02). We conclude that there may be a reduction in the fRT of dogs and cats submitted to 2 ATA for 30 minutes and 2.5 ATA for 45 minutes, respectively.

Introduction: Submersion results in blood redistribution into the pulmonary circulation, causing changes in pulmonary compliance and increased cardiac preload. Few studies have compared incremental exercise to exhaustion (VO₂ max testing) in a dry environment with exercise underwater. We hypothesized that the physiological effects of submersion would result in lower heart rate (HR), minute ventilation (V_E), and peak oxygen uptake (VO₂ peak) compared with dry conditions.

Methods: Fourteen male and four female volunteers completed two VO₂ peak testing sessions with approximately two hours between trials: first in the dry laboratory on a cycle ergometer and second while fully submersed in a prone position with zero static lung load. HR was monitored via ECG, and inspiratory and expiratory gas compositions were recorded using a metabolic cart. The tests were terminated once the subject reached exhaustion.

Results: Absolute VO₂ peak was lower in the submersed VO₂ max trial (37.1 ± 7.0 mL•kg^-1•min^-1) compared with dry exercise (45.8 ± 8.9 mL•kg^-1•min^-1) p < 0.001. HR and V_E were also lower in the submersed trial.

Conclusions: VO₂ peak while submersed is reduced relative to dry VO₂ peak, which may be partly due to a decrease in heart rate and a reduction in V_E.

Despite established exposure limits and safety standards, and the availability of carbon monoxide (CO) alarms, each year an estimated 50,000 people in the United States visit emergency departments for CO poisoning. Carbon monoxide poisoning can occur from brief exposures to high levels of CO or from longer exposures to lower levels. If the CO exposure is sufficiently high, unconsciousness and death occur quickly, and without symptoms. With non-lethal exposures to CO, common symptoms include headaches, nausea and vomiting, dizziness, general malaise, and altered mental status. Some patients may have chest pain, shortness of breath, and myocardial ischemia, and may require mechanical ventilation and treatment of shock. Individuals poisoned by CO often develop brain injury. As with brain injury from non- CO causes such as traumatic brain injury, the clinical expression of brain injury caused by CO poisoning includes the domains of cognition, affect, neurological, and somatic. Common problems are neurological: imbalance, motor weakness, neuropathies, hearing loss, tinnitus, Parkinson's-like syndrome, vestibular, gaze, auditory processing, cognitive, anxiety and depression, posttraumatic stress, personality change, persistent headaches, dizziness, sleep problems, and others. In addition, some will have cardiac or other problems. While breathing oxygen hastens the removal of carboxyhemoglobin (COHb), hyperbaric oxygen (HBO₂) hastens COHb elimination and favorably modulates inflammatory processes instigated by CO poisoning, an effect not observed with breathing normobaric oxygen. Hyperbaric oxygen improves mitochondrial function, inhibits lipid peroxidation transiently, impairs leukocyte adhesion to injured microvasculature, and reduces brain inflammation caused by CO-induced adduct formation of myelin basic protein. Based upon supportive randomized clinical trials in humans and considerable evidence from animal studies, HBO₂ should be considered for all cases of acute symptomatic CO poisoning. Hyperbaric oxygen is indicated for CO poisoning complicated by cyanide poisoning, often concomitantly with smoke inhalation.

Introduction: Preterm birth may significantly impair the functional and anatomical development of the respiratory system and could be a background for various life-long medical sequelae. Prematurity has been recently connected to changes in hypercapnic reactions at adult age. Altered reactions to pCO₂ in premature-born subjects may impact breath-hold underwater exercises (freediving) results.

Methods: AIDA International provided the list of top-100 rankings freediving athletes for the years 2016- 2021 with their personal best results. Data was collected using a subject questionnaire developed for the study (subject-reporting outcomes).

Period of data collection: March 2022 to June 2022.

Results: Within the sample of divers (n=146), 17.1% (n=25) were born prematurely. 13.7% (n=20) were moderate to late preterm, and 3.4% (n=6) were very preterm. The proportion of the athletes whose birth was premature was 18.1% for females and 16.2% for males. These figures are higher than the standardized estimated mean of the preterm birth rate of 8.5% calculated based on the geographical distribution of our sample. There was no difference in best personal results in freediving between the preterm and full-term elite freedivers.

Conclusions: The proportion of preterm within the elite freedivers is higher than could be estimated for the general population. There is no difference in best personal results between preterm and full-term elite freedivers.

The hip is the most common location for avascular necrosis of the femoral head (AVN), with an estimated incidence in the United States of 10,000 to 20,000 new cases per year. The current standard of care for early disease is core decompression, with bone marrow injections becoming more commonplace. Hyperbaric oxygen enhances oxygen delivery to tissue, promotes an anti-inflammatory and pro-healing environment, and helps initiate angiogenesis. We believe that these properties of HBO₂ make it a unique tool for AVN and applied it in conjunction with the standard of care for our patient.

Renal abscess (RA) is a collection of infective fluid in or around the renal parenchyma. It typically occurs in immunocompromised patients, including those with diabetes mellitus (DM), poor nutritional status, or steroid administration. We herein report a case of RA associated with DM in which hyperbaric oxygen (HBO₂) therapy greatly contributed to the resolution of this disease. The patient was an 85-year-old man with poorly controlled type 2 DM. Contrast-enhanced computed tomography for postoperative follow-up of appendiceal cancer showed a mass lesion with poor contrast enhancement extending from the upper pole of the left kidney to the dorsal side. Therefore, a diagnosis of RA was established. The lesion was percutaneously punctured, and a drainage tube was placed. Antibiotics following sensitivity testing were administered. The catheter was removed six days after its placement. However, pus discharge continued from the catheter removal site, with persistent redness around the wound. Therefore, a lumbotomy incision for abscess drainage was performed on the 49th day. However, the pus discharge persisted, and we decided to perform HBO₂ therapy, expecting decreases in bacterial proliferation, reduction in local edema, and improvement of host defense. HBO₂ therapy for 90 min at two atmospheres absolute was performed ten times. The amount of pus discharge decreased, and redness improved from the fifth day after HBO₂ therapy. One month after starting HBO₂ therapy, the wound was closed, and the pus discharge resolved completely. Four years have passed since the HBO₂ therapy, and there have been no symptomatic or imaging relapses of RA.

Studies suggest that COVID-19 infections may have longer-term and more significant complications, even with mild or absent symptoms. This may predispose divers to pulmonary barotrauma, arterial gas embolisms, and reduced exercise tolerance, and impact physical and cognitive performance during diving. Military diving is physically, physiologically, and psychologically taxing on the individual. This study aims to assess the incidence of complications after COVID-19 infections in a cohort of active military divers and the incidence of diving-related injuries such as decompression sickness and barotrauma following recovery from acute COVID-19 infections. A single-center, retrospective cohort study of complications after COVID-19 infections was done in a cohort of the Republic of Singapore Navy (RSN) Naval Diving Unit (NDU) Divers and involved the collection of retrospective data for 329 military divers who were diagnosed with COVID-19 infection from 25 Mar 2020 and 13 Feb 2023. We found no clinical or subclinical complications after COVID-19 infection in our fully vaccinated, low-risk population of NDU divers after asymptomatic or mild COVID-19 infection. There were also no incidences of diving-related injuries related to COVID-19 after recovery from the acute illness. Based on the study results, it is recommended that all military divers with asymptomatic or mild COVID-19 infections return to military diving activities immediately after recovery from acute COVID-19 infection with resolution of symptoms. As existing guidelines recommend, divers with moderate to critical COVID-19 infection should be reviewed by a diving physician and undergo necessary investigations before returning to military diving.

In clinical management of carbon monoxide (CO) poisoning, serum cardiac enzyme biomarkers and electrocardiogram (ECG) are both highly recommended emergency check-ups to evaluate myocardial injuries. Medical imaging - including head CT or MRI - are not routine for CO poisoning emergency management. We herein report on a comatose patient who was diagnosed with cerebral infarction secondary to 24 hours previous acute CO poisoning, warned by a typical cerebral-type T waves on ECG in advance, and confirmed by a head MRI. Fortunately, the patient made a full recovery based on a timely treatment with medications and hyperbaric oxygen (HBO₂) therapy. We would like to propose that a vital, stable, conscious CO poisoning patient who remains a higher risk for hemorrhagic or ischemic stroke should be closely monitored for potential neurological abnormalities, and a continuous ECG monitoring should be reinforced throughout the treatment. A head MRI or CT is a priority in evaluating the secondary cerebral stroke and should be arranged immediately in the event of an abnormal ECG or if unusual new symptoms are apparent.

World War II was approaching its end in Italy in 1944 when one of the worst train disasters in world history occurred near the small town of Balvano in the Apennine Mountains. The train did not derail or crash into something as in most major train disasters. Instead, it entered a mountainous railway tunnel, and when it emerged, over 500 passengers were dead from carbon monoxide poisoning. The event was not allowed to be publicized for almost two decades. This manuscript reconstructs the story of possibly the most significant incident of carbon monoxide mortality ever recorded.