Dissociation of neurological deficits in spinal decompression illness.

Functional differentiation is found in the spinal cord. A unique set of neurological deficits follows a multi-focal injury. Clinically, sensory and motor disturbance present independently, often resulting in sensory and motor deficit dissociation. This study examined 103 spinal decompression illness (DCI) cases. The neurological deficit dissociation was classified as follows: 1) Cases with sensory impairment only, or motor dysfunction alone, were tagged as having "dissociation" (44 cases); when a case was with both sensory and motor dysfunction, the spinal level of the sensory impairment was determined and was matched with the spinal segments responsible for the motor dysfunction; 2) If the two spinal areas did not match (i.e. with no regional overlap), they were tagged as having "dissociation" for each motor dysfunction (32 cases). In total, dissociation was present in 76 out of 103 cases. We concluded that clinical neurological deficit dissociation is frequently observed in spinal DCI.

The validity of the mangled extremity severity score in the assessment of upper limb injuries.

The Mangled Extremity Severity Score (MESS) may be used to decide whether to perform amputation in patients with injuries involving a limb. A score of 7 points or higher indicates the need for amputation. We have treated three patients with a MESS of 7 points or higher, in two of which the injured limb was salvaged. This scoring system was originally devised to assess injuries to the lower limb. However, a MESS of 7 points as a justification for amputation does not appear appropriate when assessing injuries to the major vessels in the upper limb.

Evaluation of HBO2 therapy in pneumatosis cystoides intestinalis.

Pneumatosis cystoides intestinalis (PCI) is a disease characterized by retention of gas in the intestinal wall. Retention of gas can be caused by three mechanisms; gas entry through the intestinal mucosa, gas dissection from the pulmonary alveoli and bronchi, and gas generation in the mucous membrane. Since gas in cysts is composed almost entirely of nitrogen, hyperbaric oxygen therapy (HBO2) is effective for treating PCI due to the oxygen windows effect. However, PCI, caused by a mechanism involving pulmonary alveoli or branches, can become aggravated by HBO2. Therefore, we propose modifying HBO2 protocols for cases that do not require an invasive treatment. This study describes favorable results obtained in 2 PCI cases after HBO2 therapy according to our protocol.

Decompression sickness and recreational scuba divers.

OBJECTIVES: The aim of this study is to clear the status of recreational scuba divers in Japan for promoting safety in recreational diving. METHODS: A five year (from 1996 to 2001) questionnaire survey was performed of Japanese divers at the Osezaki area in Japan. The subjects of this survey included diving instructors as well as recreational divers. Based on the obtained data, the study investigated the theory predicted incidence of decompression sickness (DCS) among Japanese recreational divers. RESULTS: The average (SD) of the maximum depth for diving was 37.4 (13.1) metres, which was deeper than the recommended depth of recreational diving. The incident rate of nitrogen narcosis (12%) was the most frequent, followed by barotraumas of the ear (11%) and barotraumas of the paranasal sinus (5.6%). The rate of DCS was 1.9 % (60 divers) during investigated period, and that DCS occurred once per 19 011 dives in calculation. CONCLUSIONS: This investigation showed that the status of leisure diving in Japan is still serious, because DCS would be expected to occur once a weekend in Japan. It is speculated that many divers may develop DCS while moving through high altitudes after diving, particularly at the Osezaki diving spot in Japan. Based on the results of this study, it is emphasised that every Japanese leisure diver should take an increasing interest in the safety of diving activity.

[Effects of closed-circuit breathing apparatus on respiration and metabolism].

The purpose of the study was to evaluate the influence of hyperoxia and hypercapnia on respiration and metabolism during a steady-state exercise. Thirteen healthy subjects were examined during bicycle-ergometer rides at approximately 50% VO2max under four different breathing gas conditions: 1) room air (control); 2) 40% oxygen; 3) 3% carbon dioxide; 4) 40% oxygen and 3% carbon dioxide. Hyperoxia, with or without hypercapnia, decreased respiratory ventilation and carbon dioxide elimination significantly. On the other hand, oxygen uptake in hyperoxia was not significantly different from that of normoxia. Hypercapnia increased respiratory ventilation more than 30% compared to normocapnia, but it did not change oxygen uptake and carbon dioxide elimination significantly.

[Randomized prospective trial of gentian violet with dibutyryl cAMP and povidone-iodine with sugar as treatment for pressure sores infected with methicillin-resistant Staphylococcus aureus in elderly patients].

A randomized prospective study was done to evaluate the two treatments for pressure sores infected with methicillin-resistant Staphylococcus aureus in elderly patients: Gentian violet plus dibutyryl cAMP (GVcAMP, n = 8) and povidone-iodine plus sugar (IS, n = 11). Age, underlying diseases, and nutritional status did not differ between the two groups. Specimens were obtained biweekly from the pressure sores and were cultured. The percentage of culture dishes with no methicillin-resistant S. aureus was 93% for the patients given GVcAMP, but only 74% for those given IS (p < 0.01). By the 14th week after the start of treatment, the mean area of the pressure sores in the GVcAMP group had decreased to 45% of the area at the start of treatment. In the IS group, the decrease was smaller to 56% of the area before treatment. No local or systemic adverse effects occurred in either group. GVcAMP is useful to treat pressure sores infected with methicillin-resistant S. aureus.

Alterations of fibrinolytic activity in human during and after hyperbaric oxygen exposure.

To clarify the stage of fibrinolytic activation by hyperbaric oxygen (HBO) exposure, we examined its alterations in human during and after the HBO exposure. Eight healthy female volunteers breathed oxygen at 284 kPa (2.8 atmospheres absolute). Blood samples were collected before compression, shortly after compression to the pressure 284 kPa, shortly before the start of decompression, shortly after decompression, and then again 3 hours after decompression. We estimated the euglobulin fibrinolytic activity (EFA) and, the activities and antigens of both tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1). The PAI-1 activity and PAI-1 antigen showed significant decrease after compression to a pressure 284 kPa, before the start of decompression, and after decompression. The EFA level and t-PA activity rose significantly shortly after decompression, and 3 hours later returned on baseline. These findings suggest that fibrinolytic activity is elicited after HBO rather than during HBO.

[Safety evaluation of self-contained-self-rescures--carbon dioxide absorption of SCSRs under heavy work load].

The purpose of this study was to evaluate the safety of Self-Contained-Self-Rescuers (SCSRs) under a heavy work load. Three units, two chemical-oxygen (KO2) types and one compressed-oxygen type, were evaluated by a breathing and metabolic simulator and by a human subject. The metabolic rate in the simulator tests was equivalent to light work; the human subject tests were at a heavy work load. With regard to the main physiological stressors imposed by SCSRs, it was found that the inhalation temperature under heavy work conditions was able to be estimated from the data of the light work condition; the breathing resistance had roughly the same relationship under both light and heavy work conditions. On the other hand, for the inhaled carbon dioxide, there was no correlation between the two conditions. It was found that some SCSRs experienced a rapid increase in inhaled carbon dioxide when the metabolic rate of the user exceeded the absorbent capacity of the units. In those cases, the user could not continue walking nor breathing through the unit. To ensure the safety of the user, we propose that the certification standards be changed to include evaluation of carbon dioxide absorbent capacity under heavy work load.

[Health check on divers and compressed air workers].

We have conducted the health check of 3,554 compressed air workers and 1,821 divers, and also examined the incidence and severity of aseptic bone necrosis by using Roentgen pictures. We could classify 4,859 of 5,375 persons into four groups (A-D), based on our classification. We could also classify 4,205 of 5,375 persons that had had a bone X ray examination on the basis of the criteria described by Ota and Matsunaga (A-C). 4,859 persons belonged to four groups: class A (persons who can work, no limitations): 4,099 (84.4%), class B (persons who can work under conditions below 1.0 kg/cm2): 357 (7.3%), class C (persons who had better quit work under hyperbaric conditions, though they are not prohibited by regulations): 183 (3.8%), class D (persons who must be prohibited from working in a hyperbaric environment by laws of the Ministry of Labor): 88 (1.8%). About 90% of compressed air workers and divers (classes A and B) were permitted to work under hyperbaric conditions. Most of those belonging to classes C and D suffered from hypertension, cardiovascular disease and liver dysfunction. The incidence of aseptic bone necrosis was 11.1% (465 out of 4,205 persons). Eight persons (2.2%) belonged to criteria A which means poor prognosis. They were classified into class D. There is no differences between compressed air workers and divers in the incidence of aseptic bone necrosis.

[Saturation diving system at high altitude].

Practical saturation diving was firstly performed at high altitude in Japan in 1987. Its work was to change the screen which had covered the pipeline of a hydroelectric dam located 850 meters above sea level, the same operation had been conducted in 1992 and in 1993, 2 times each year (Total = 5 operations) after the work. The saturation dives have lasted from six to eight days on 4 occasions and 13 days (Total duration = 4075 minutes) on 1 occasion, since the initial pressurization until the end of the last decompression. In each operation, there had always been involved 3 divers. They have been compressed to an equivalent depth of 45-73m in the deck decompression chamber (DDC), briefed for work and transferred to the submersible decompression chamber (SDC), which was then submersed to 53-78m of depth. Wearing heated suit and breathing Heliox (both at the same temperature as the inside of the SDC), the divers have been locked out to perform their tasks, all monitored and supervised by the use of a remotely operated vehicle (ROV). The works have run uneventful and successfully until the end. The water temperature had been higher than the expected, i.e. 9-13 degrees C in all occasions. The inside conditions of the chamber had been the following: partial pressure of nitrogen was from 0.78 ATA; partial pressure of oxygen was from 0.35 to 0.40 ATA; partial pressure of carbon dioxide was less than 0.005 ATA; the inside temperature of the SDC was from 26 to 30 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)