SEARCH · Search PubMed
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Toxic hepatitis due to anaesthetic gas inhalation has been well documented, but hepatitis caused by inhalation of non-halogenated hydrocarbons has not been reported. We present an acute case of occupational hepatitis due to chronic inhalation of propane and butane gases.
Neurobehavioral studies on operating room personnel exposed to anaesthetic gases in hospitals of the Region Lombardia have confirmed findings already reported in the literature. There was high subjective symptomatology and reduced efficiency at psychologic testing among exposed people with protracted exposure. In this group, reaction time was worse at the end of the workshift with respect to the beginning. These changes were reversible after removal from exposure. It was impossible to establish a clear dose/response relationship due to the difficulty to control an important confounding factor, such as stress, in field studies.
The Authors observed, in a group of 15 subjects working in operating theatres and occupationally exposed to anesthetic gases, an increase of simple reaction average times and an increase of the latency of the wave V of the brainstem auditory evoked potentials. The small number of subjects doesn't allow to draw conclusions. Nevertheless the findings agree with first analogous studies. The Authors, therefore, think opportune to continue the research to acquire further evidence and to ascertain the validity of the current TLV.
In 40 young males aged 18-20 years operated on for inguinal hernioplasty acute respiratory alkalosis was obtained in the 45th minute of general anaesthesia. The values of basic acid-base balance parameters, blood gases, pyruvate and lactate levels and "lactate excess" were determined before and after hyperventilation. Shifts in the concentrations of hydrogen and bicarbonate ions were found which are both typical of acute respiratory alkalosis. No changes were observed in the oxygenation of capillary blood and the values of "lactate excess" were normal which rules out tissue hypoxia during acute respiratory alkalosis. Passive hyperventilation being a less dangerous alternative of hypoventilation is a frequent occurrence during general anaesthesia and it causes transient respiratory alkalosis.
The effects of oxygen inhalation, nitroglycerin (NTG) and prostaglandin E1 (PGE1) on pulmonary hemodynamics and blood gases were studied in 15 patients with chronic lung disease (CLD). Cardiac catheterization was performed with Swan-Ganz catheter, and pulmonary hemodynamics and cardiac output were measured. After baseline hemodynamics and blood gas measurements were made, 15 patients inhaled oxygen for 15 minutes and the same measurements were repeated. Twenty minutes later, oxygen inhalation was stopped. Then the 15 patients were divided into two groups; one group was administered sublingual NTG (7 patients) and the other was administered PGE1 by continuous intravenous infusion (8 patients). Pulmonary hemodynamics and blood gas measurements were then performed. Oxygen inhalation significantly reduced mean pulmonary artery pressure (from 22.2 +/- 8.8 to 20.0 +/- 6.4 mmHg; p < 0.01) and heart rate (from 78.1 +/- 12.0 to 75.5 +/- 12.5 beats/min; p < 0.05). With respect to oxygenation, oxygen inhalation significantly increased PaO2 (from 68.6 +/- 10.7 to 113.4 +/- 31.4 mmHg; p < 0.01), PvO2 (from 35.1 +/- 3.7 to 38.0 +/- 3.3 mmHg; p < 0.01). Therefore, oxygen inhalation was thought to be useful in patients with chronic lung disease with pulmonary hypertension. Sublingual administration of NTG significantly reduced mean pulmonary artery pressure (from 24.1 +/- 0.2 to 17.6 +/- 6.8 mmHg; p < 0.01), C.I. (from 2.9 +/- 0.2 to 2.3 +/- 0.2 ml/min/m; p < 0.01), O2-transport (from 589.1 +/- 168.4 to 457.0 +/- 105.8 ml/min; p < 0.01), and had a tendency to decrease PvO2 (from 34.3 +/- 3.0 to 32.1 +/- 1.8 mmHg; p < 0.1).(ABSTRACT TRUNCATED AT 250 WORDS)
In dealing with chlorinated organic compounds in waste gases, traditional treatment techniques show some severe shortcomings. Thermal oxidation may lead to the formation of dioxins, active carbon adsorption does not degrade the pollutants and biotechnological treatment is difficult since microorganisms do not always possess efficient degradation pathways for these compounds. These drawbacks explain the growing interest of the waste gas treatment sector for Advanced Oxidation Processes (AOPs) which were initially developed as water treatment techniques. AOPs generate highly reactive hydroxyl radicals that efficiently oxidise organic pollutants. In the peroxone process, this is done by a combination of ozone and hydrogen peroxide. In this work, the peroxone process is applied in an oxidative scrubber for the removal of trichloroethylene (TCE). Rapid oxidation of absorbed TCE in the liquid phase enhances TCE absorption Practically, a gas stream contaminated with TCE is mixed with an ozone loaded gas stream. The mixture is led through a bubble column that is fed with a buffered hydrogen peroxide solution. The effect of different process parameters (flow rates, buffer concentration, pH, hydrogen peroxide/ozone dosage ratio, TCE dosage) on TCE removal was investigated. Depending on the operating conditions, removal efficiencies up to 98% could be attained.
Blood oxygen transport, pH, acid-base status, urinary ketone level and urobilinogen were studied in 52 pregnant women in whom pregnancy ran a normal course and in 56 ones with a history of habitual abortions, treated for metabolic disorders. Signs of metabolic acidosis in the presence of respiratory alkalosis at the expense of pulmonary hyperventilation were detected in women with normal pregnancy. Follow-up of acid-base status and gases of blood, aciduria and ketonuria in pregnant women with a history of habitual abortions has revealed in them respiratory alkalosis signs presenting in hypoxemia and reduced oxygen saturation and ketonuria. Metabolic therapy included in combined therapeutic schemes for such patients actively influenced the processes of metabolic acidosis and ketonuria compensation, probably at the expense of its normalizing effect on intracellular metabolism. Metabolic therapy of pregnant women liable to spontaneous abortions, due to ovarian hypofunction had a marked antihypoxic effect, normalized the bicarbonate system status and was therefore conducive to improvement of oxygen transport to maternal tissues and the fetus.
Forty adult patients with acute severe asthma were assessed for arterial blood gases and acid-base changes at presentation at the Casualty Unit, Kenyatta National Hospital, Nairobi, Kenya. Marked degrees of hypoxaemia (mean P(a)O2 of 8.02 kP(a)), hypocapnia (mean P(a)CO2 of 4.62kP(a)) with apparently normal pH (mean 7.384) were documented in the majority of these patients. Based on these findings, a significant number of the patients (68.5%) were either candidates (5.3%) or potential candidates (63.2%) for artificial ventilation. Records at this hospital suggest an increasing trend in asthma admissions and mortality. Additionally, Intensive Care Unit (ICU) admissions for asthma are associated with high mortality (54.4%). Pulsus paradoxicus emerged as the most significant (p = 0.002) clinical correlate to asthma severity. Central cyanosis was detected in none of the study patients suggesting that it is an unusual finding in the common presentation of acute severe asthma at this hospital. Its clinical detection would therefore imply an ominous clinical state. It is recommended that clinicians should take every opportunity to adequately assess their asthma patients before prescribing medications. They are also encouraged to more frequently request for blood gas studies in acute asthma. Those in charge of clinical teaching should direct appropriate efforts towards improved understanding of the pathophysiology and interpretation of acid-base disorders.
The article presents results of studies covering changes in porphyrin and heme synthesis in lymphocytes of miners exposed to exhaust gases of diesel engines.
We studied the standard values and normal limits for arterial blood gases in healthy elderly Japanese subjects. The criteria for inclusion were; 1) older than 60 years and able to walk independently, 2) non-smoker, 3) no respiratory symptoms, 4) no thoracic deformity, 5) no clinical signs of chest disease, 6) no abnormal findings in chest X ray, and 7) no cardiac disease or obesity. The number of subjects was 78. The oldest subject was a 96-year-old female. Arterial punctures were performed with the subjects in a recumbent position. PaO2 ranged from 79 to 106 Torr, with a mean value of 89.8 Torr. PaCO2 ranged from 32 to 48 Torr with a mean value of 39.6 Torr. Maximum values of alveolar-arterial O2 tension difference and arterial-alveolar N2 tension difference were 20.2 Torr and 11.6 Torr, respectively. The regression equation for PaO2 with respect to age was; PaO2 = 99.32-0.126 x (age), and its residual standard deviation was 6.06 Torr. These values were not different from those obtained in healthy young Japanese subjects.
We studied the effects of the combination of nitroglycerin and vasopressin on portohepatic hemodynamics, hepatic function, and blood gases in nine patients with cirrhosis and portal hypertension. Vasopressin infusion at a dose of 0.4 U/min caused a significant fall in portal pressure, which is evaluated by portal venous pressure gradient (-34%, p less than 0.01), associated with a decrease in hepatic perfusion (-33%, p less than 0.01) and intrinsic clearance (-20%, p less than 0.01) after 30 min. The arterial oxygenation, however, was not modified (paO2; from 73 +/- 8 to 72 +/- 7 mm Hg, NS). Nitroglycerin infusion at a dose of 100 micrograms/min was then administered for 20 min. The addition of nitroglycerin produced a further reduction in free portal venous pressure (-12%, p less than 0.01), but this was not associated with a significant improvement in both hepatic perfusion (+16%, NS) and intrinsic clearance (-7%, NS). In addition, there was a significant fall in arterial oxygenation (paO2; from 72 +/- 7 to 59 +/- 5 mm Hg, p less than 0.01). We conclude that the addition of nitroglycerin to vasopressin has a beneficial effect on free portal venous pressure, but does not have hepatic benefit. Moreover, sufficient care must be taken, when treating portal hypertension with this combination, to avoid arterial hypoxemia.
The influence of interfering substances on breath-alcohol measurements is handled by the OIML by giving a list of test gases and prescribing the maximum permissible cross-sensitivity of a measuring system. The expertise of the Federal Health Office for evidential breath analysers prefers an other way to detect interfering substances in expired air. By the use of two measuring systems with different analytical specificity interfering substances as e.g. methanol, isopropanol, aceton, ethylacetat, and toluene cause measured values with a difference which exceeds the limits permitted in the OIML recommendations. The same happens with interfering substances in expired air which are most commonly used by sniffers as e.g. Pattex, Uhu adhesive, or petrol.
The debate as to whether carbon dioxide, methane, nitrous oxide and other greenhouse gas emissions will become subject to increasing regulation, increased restrictions, and probably to some form of carbon tax, has moved from a simple "yes" or "no" to "when". Wastewater treatment plants will be significantly impacted by increased energy costs and by specific regulations and/or penalties associated with emissions of methane and nitrous oxide. In this paper, the greenhouse gases emissions of different wastewater process options are estimated. The paper outlines the increasing need for wastewater treatment plants to factor greenhouse gas mitigation issues into their medium- as and long-term strategies, and identifies anaerobic enhouse as processes as being at the core of such strategies. Further, the paper identifies a number of key research challenges to be addressed if such strategies are to play a larger role in attenuating the likely impacts of GHG mitigation requirements on wastewater treatment plant design and operation.
Pulmonary artery and pulmonary wedge pressures were measured at rest and during exercise in 25 young patients with moderate to severe scoliosis. Simultaneous determinations of arterial blood gases and pH were performed. The results of the vascular pressure measurements were compared with those obtained in 15 healthy young subjects. In all patients the pulmonary artery and pulmonary wedge pressure were normal at rest. During mild ergometer exercise, however, an abnormal rise in pulmonary artery pressure occurred in 9 patients. Moreover, an increased diastolic pressure gradient across the pulmonary vascular bed was found in some scoliotic patients indicating an elevated pulmonary vascular resistance. It is supposed that this haemodynamic abnormality is primarily due to a restriction of the pulmonary vascular bed. Relationships between pulmonary artery pressure and arterial oxygen tension and blood pH, respectively, could be found. The possible significance of these results is discussed.
In order to determine the relationship between pulmonary function, performance on stair climbing, pre- and post-exercise arterial blood gases and post thoracotomy complications, we performed a prospective study on 19 patients. Sixteen of seventeen patients could accomplish a five flight stair climb. All of the seventeen patients survived and could be weaned off the respirator. Four developed postoperative complications. MMEFP (per cent mid maximum expiratory flow) showed statistically significant differences between patients with and without complications.
We experienced the leak of anesthetic gases inside the anesthesia machine in spite of performing the leak test before its use. After induction of anesthesia, a laryngeal mask airway was inserted and the patient was ventilated manually. At the beginning we could not find any signs of machine troubles. High airway pressure occurred immediately after switching to the mechanical ventilation. Because we could not detect the details of the machine trouble, tidal volume was set lower and the surgery was continued. After surgery, we found a crack in a fresh gas circuit valve. We have to check the anesthesia machine regularly and know its duration of use.
BACKGROUND: The practice of on-ice storage of arterial-blood samples in plastic syringes for delayed analysis continues, and the effects of storage time and temperature on the measurement of blood-oxygen-saturation values (S(aO2)) have not been adequately described. OBJECTIVE: To determine the effects of syringe material, storage time, and storage temperature on normal arterialized blood gas and S(aO2) values. METHODS: We used a temperature-controlled extracorporeal circuit to "arterialize" 500 mL of fresh, whole human blood at 37 degrees C, and we used certified calibration gases of 12% O2 and 5% CO2 to produce normal blood-gas values. From that arterialized blood we took 90 samples and randomly assigned them to 6 groups, until there were 15 samples in each group. The groups were (1) plastic syringe, analyzed immediately, (2) plastic syringe, stored 30 min at 0-4 degrees C, (3) plastic syringe, stored 30 min at 22 degrees C, (4) glass syringe, analyzed immediately, (5) glass syringe, stored 30 min at 0-4 degrees C, and (6) glass syringe, stored 30 min at 22 degrees C. RESULTS: Compared to the samples that were analyzed immediately, the P(O2) of the samples stored in plastic syringes for 30 min at 22 degrees C and at 0-4 degrees C was significantly higher, with a clinically important magnitude of 11.9-13.7 mm Hg. The P(CO2) of blood stored in glass for 30 min at 0-4 degrees C was significantly lower, although the magnitude of the difference (1.5 mm Hg) was not clinically important. There were no statistically significant differences in pH or oxygen saturation among the 6 groups. CONCLUSION: For accurate arterial-blood-gas results, samples drawn in plastic syringes should be analyzed immediately. If the analysis is going to be delayed, the samples should be drawn and stored in glass.
The removal of sulfur dioxide (SO2) from simulated flue gases streams (N2/O2/H2O/SO2) was experimentally investigated using microgap discharge. In the experiment, the thinner dielectric layers of aluminum oxide (Al2O3) were used to form the microgap discharge. With this physical method, a high concentration of hydroxyl (OH*) radicals were produced using the ionization of O2 and H2O to further the conversion of SO2 into sulfuric acid (H2SO4) at 120 degrees C in the absence of any catalysts and absorbents, which were captured with the electrostatic precipitator (ESP). As a result, the increase of discharge power and concentrations of O2 and H2O increased the production of OH. radicals resulting in enhanced removal of SO2 from gas streams. With the test and analysis, a number of H2SO4 droplets were produced in experiment. Therefore, a new method for removal of SO2 in semidry method without ammonia (NH3) additive was found.