Trimix instead of air, decreases the effect of short-term hyperbaric exposures on platelet and fibrinolysis activation.

PURPOSE: Short-term and saturated simulated dives followed by decompression with air, cause a decrease in platelet count and increased activation of fibrinolysis. The aim of this study was to determine whether short-term dives with trimix as a breathing mixture induce the activation of platelets, and/or fibrinolysis. MATERIAL AND METHODS: 30 male divers were subjected to short-term hyperbaric exposures to 0.7 MPa. Thirty divers used air and then the same divers used trimix as a breathing mixture. RESULTS: The mean platelet count dropped significantly after decompression only in the group breathing air. The number of CD62P positive platelets and the amount of platelet-derived micro particles were statistically significant higher after decompression in both exposures. The number of CD61 positive platelets increased significantly only in the group breathing air. We observed a significant decrease of factor XII and fibrinogen concentrations after decompression only in the group breathing air. A significant increase in the concentration of plasminantiplasmin complex in both groups was detected. CONCLUSIONS: Short-term hyperbaric exposure and decompression performed according to current safety standards activates platelets and the fibrinolytic system. Trimix protects divers from a reduction in the amount of platelets, fibrinogen and factor XII in the course of these exposures.

Decreased levels of PAI-1 and alpha 2-antiplasmin contribute to enhanced fibrinolytic activity in divers.

BACKGROUND: There are a number of reported cases of decompression sickness (DCS) with haemorrhages. These cases have not been sufficiently investigated and thus bleeding complications could not be directly correlated to the enhanced fibrinolysis. OBJECTIVES: The effect of hyperbaric exposition and decompression on the main components of fibrinolytic system has been measured. METHODS: Two groups of 25 male divers each were subjected to hyperbaric exposures to the pressure of either 400 kPa - group I - or 700 kPa - group II followed by a staged decompression. The divers were monitored for clinical symptoms of DCS and checked for Doppler-detected venous gas bubbles. Venous blood was drawn from divers before exposition and 15 min after decompression. The concentrations and activities of t-PA and PAI-1 as well as concentrations of PAP and alpha2-antiplasmin and activity of factor XIIa were measured. RESULTS: In all groups of divers no cases of DCS as well as detectable gas bubbles were noted. We observed elevated concentration of PAP, decreased concentration of alpha2-AP, decreased PAI-1 concentration and activity. There were no significant changes in factor XIIa activity as well as of t-PA concentration and activity. CONCLUSIONS: Hyperbaric exposition and decompression induce activation of fibrinolysis, even in the absence of detectable gas bubbles. Fibrinolytic activity increases mainly due to decrease of PAI-1 concentration and activity. Further clinical trials are necessary for the estimation of the importance of activation of fibrinolysis with decreased level of PAI-1 and alpha2-AP as a possible risk factor for bleeding in divers.

Changes in the extrinsic and intrinsic coagulation pathways in humans after decompression following saturation diving.

We have investigated the effect of simulated saturation diving on the activation of intrinsic and extrinsic coagulation pathways. Thirty-one male divers divided into two groups were tested in decompression habitat LSH-200. The first group of 16 divers was subjected to hyperbaric exposure at pressure of 180 kPa with air as a breathing mixture, and the second group of 15 divers, exposed to a pressure of 400 kPa with a heliox breathing mixture (helium-oxygen mixture: pO2, 40 kPa; pN2, 40 kPa; pHe, 420 kPa). The concentrations of tissue factor, tissue factor pathway inhibitor, factors XII, X, VII, and I, prothrombin fragment F1 + 2, and thrombin-antithrombin complex as well as platelet count, prothrombin time, activated partial thromboplastin time, plasmin-antiplasmin complex (PAP) and D-dimers were measured. We did not detect activation of the extrinsic coagulation pathway after decompression. There was a statistically significant decrease in platelet counts and factor I, XII and X concentrations after air-diving, and a potent and statistically significant increase of PAP concentration in both groups of divers. We suggest that saturated air or heliox diving followed by decompression have little if any effect on thrombin generation. Saturated air diving, however, may induce a decrease in platelet count and factor XII concentration. The observed elevation of PAP concentrations in both groups of divers suggests possible activation of fibrinolysis. The exact effect of diving and decompression on fibrinolytic system has to be further investigated.

[Cytoadherence in cerebral malaria as particular example of pathology in host--parasite system]. / Cytoadherencja w malarii mózgowej jako szczególny przyklad patologii w ukladzie gospodarz--pasozyt.

Cerebral malaria in man and in animals is the consequence of a cascade of events, involving the patological changes, leading to the amplification of the expression of the receptors for cytoadherence on brain capillary endothelial cells. Sequestration is the process by which erytrocytes infected with the mature forms of the malaria parasite Plasmodium falciparum disappear from circulation and accumulate within venules and capillaries of various organs and tissues. The molecular mechanism in sequestration is one of the most rapidly advancing fields in malaria research. The several specific aspects considered in this paper. Our electron micrographs show cytoadherence in own model of cerebral malaria in rats infected with Plasmodium berghei.

The effect of air and nitrox divings on platelet activation tested by flow cytometry.

BACKGROUND: Nitrogen (N2) microbubbles activate the blood platelets and coagulaltion system. HYPOTHESIS: Breathing nitrox rather than air may reduce the level of platelet activation associated with decompression. METHODS: We tested platelet counts and the expression of functional membrane molecules on platelets in 10 divers subjected to saturated compression in nitrox at 4 ATA and in 9 divers subjected to compression in air at 2.8 ATA. Blood samples were taken before and immediately after the test. We measured the percentages of microplatelets, platelet aggregates and platelets bearing the activation marker C-D62P, and bearing molecules forming receptors for fibrinogen (CD61) and for von Willebrand factor (CD42b) using flow cytometry and specific monoclonal antibodies. Symptoms for DCS were also evaluated. RESULTS: DCS symptoms were not noted in either the nitrox or air group. In both groups we observed a marked increase in the percentage of activated platelets bearing CD62P molecules and an enhanced number of microplatelets and a marked drop in the platelets count in the blood of (divers in the air group. CONCLUSION: In all divers we observed certain changes in the platelet system, nevertheless decompression in nitrox resulted in a lesser degree of platelet activation. Though this study cannot exclude platelet activation as an etiological factor in DCS, the findings suggest platelet activation can occur in the absence of observable sign of DCS. Thus, platelet activation may be too sensitive a marker to serve as a predictor of DCS.

Evaluation of heliox saturated diving on the basis of selected haemostatic parameters.

The present study was conducted to evaluate decompression, stress after heliox saturated dives on the basis of selected haemostatic parameters. Instantenously before and after each pressure exposure, the following examinations were performed: determination of blood platelets count, of aggregation and fibrinogen level, of several coagulation factors VII, XII and of hematocrit. After diving, a slight drop of blood platelet count and XII factor and fibrinogen was observed. Evaluation of haemostasis is a useful tool not only to verify decompression systems, but to correct them as well.

Effect of saturated air and nitrox diving on selected parameters of haemostasis.

The objective of the study was to evaluate decompression stress after air and nitrox saturated divings on the basis of the parameters of haemostasis. Before and after each diving the following examinations were performed: blood platelet count, aggregation, fibrinogen level and coagulation factors VII, X and XII. After the air saturated dives a slight reduction of factor X and XII and of fibrinogen was observed. Evaluation of haemostatis may be one of the basic elements in the assessment of decompression sickness risk.

[Diagnostic difficulties in the evaluation of diving accidents]. / Trudnosci diagnostyczne w ocenie wypadków nurkowych.

The aim of the paper was to present the difficulties in diagnostics of diver diseases and accidents and the leading role of the otolaryngologist in this aspect. These problems have been illustrated with two unusual diver accidents (the bilateral barotrauma of the inner ear and subcutaneous emphysema of the eye socket in the course of the osteoma of ethmoidal sinuses.

Case of carbon monoxide poisoning treated with oxygen hyperbarism.

A case of heavy carbon monoxide poisoning is reported, with disorders in the central nervous system and circulatory disturbances (brain oedema), disfunction of the cardiac muscle and of platelet haemostasis). The level of carboxyhaemoglobin was over 45%. The patient was given hyperbaric treatment at 0.15 MPa (2.5 ATA). On the first day of treatment, the time of stay in the hyperbaric chamber was 90 minutes. During the session the patient regained consciousness. Hyperbaric treatment was continued for 4 days more. At completion of the treatment, the disturbances in both the central nervous system and blood circulation recessed.

Efficacy of hyperbaric oxygenation in atopic dermatitis.

Ten patients (5 with atopic dermatitis and 5 with asthma-prurigo) aged 8-38 years, were treated with hyperbarie oxygenation, at the Institute of Maritime and Tropical Medicine. Daily one exposure was applied at 0.1 MPa pure oxygen, during 15 days. Parallelly to the clinical evaluation also G, M, E immunoglobulins and the level of C3 and C4 complement were determined. All patients given this treatment improved clinically. In 9 of them, the level of IgE immunoglobulin decreased. The complement levels also decreased.

Effect of nitrox saturation diving upon platelet hemostasis.

Two nitrox saturation exposures (seven- and nine-days) at a pressure equivalent to 40 and 45 m (pO2 40-50 kPa) with three divers were carried out. During one exposure 6 excursions from the plateau to the depth of 70 m (one hour) and 60 m (four hours) were made. Before and after the exposures blood platelet count, aggregation and adhesion of blood cells were determined. After the first series of diving a slight increase of adhesion and aggregation was observed, after the other one, despite the larger depth and the excursions from the saturation plateau to 60 and 70 m, a slight decrease of adhesion occurred. This allows to conclude that the phenomenon is related to the decompression load degree as well as to the condition of the divers. Finding about the effect of decompression upon the processes of hemostasis may be useful for the evaluation of the verified system of saturation decompression.

Preliminary reports on hyperbaric oxygen therapy in multiple sclerosis.

Preliminary clinical examinations comprised 16 patients suffering from multiple sclerosis, the mean duration of the disease 9.33 years, of the manifestations at different stages of the development--evaluated on the basis of Kurtzke scale. The patients were subjected exclusively to the treatment with oxygen hyperbary--all in all 25-30 exposures, with the intervals of 24 hours, under the O2 pressure of 2 ata. The qualification for the purposes of treatment and the classification of the symptoms present were carried out according to Fisher, the results obtained were evaluated in conformity with standard version of the Disability Status Scale of Kurtzke. Apart from the routine clinical and laboratory tests the programme of the examinations included also a quantitative determination of immunoglobulins level, complement activity as well as the determination of T and B lymphocytes. An eminent change for the better was found in 14 afflicted persons, in one patient after 15 exposures a worsening was observed and the treatment was arrested. As to the immunological parameters investigated, a general decrease of IgG, IgM, IgA in serum, increase of the complement fraction and its 50% hemolysis determined activity were observed, whereas quantitatively investigated T and B lymphocytes did not show any typical changes. The authors discuss the results.

[Behavior of staphylococci of the nasal cavity in subjects exposed to hyperbaric oxygen]. / Comportamento degli stafilococchi delle cavità nasali di soggetti esposti ad ossigeno iperbarico.

A careful qualitative and quantitative study revealed a significant decrease in bacterial, and especially staphylococcal, cultures from nasal swabs 24 hr after exposure to oxygen at 2.5 atm for 30', followed by a gradual return to initial values after a further four days. It is felt that this picture was ascribable to the influence of hyperbaric O2 on the microorganisms and their metabolism, and on the body's defence mechanisms.