Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020440 (hypercapnia)
 7,939 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The purpose of the present study was to investigate the effect of simulated joint effusion on pO2, pCO2, the regional blood flow and intraosseous bone marrow pressure in the subchondral bone of rabbit. Mass spectrometry was used for simultaneous and continuous registration of subchondral pO2 and pCO2, while the relative argon signal was used for qualitative estimation of regional bone blood flow. The bone marrow pressure was recorded continuously by pressure transducers. Isotonic sodium chloride infusion at a constant pressure of 75 mmHg into the knee joint cavity constituted the basis for joint effusion. An instant increase in the subchondral bone marrow pressure followed the joint effusion (P less than 0.001). This resulted in a significant (P less than 0.01) decrease in the qualitative bone blood flow, significant (P less than 0.01) hypoxia and significant (P less than 0.01) hypercapnia in the subchondral bone. Joint effusion always lasted 30 minutes. Following its release all changes were reversed to normal values within 15 minutes. Within the period of observation no nervous or humoral factors seem to be brought into action. It was concluded that regional venous stasis was responsible for all changes, and that joint effusion should not be left untreated for long periods.
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PMID:Effect of simulated joint effusion on subchondral haemodynamics and metabolism. 309 36

Sedation may be used in intensive care and emergency medicine to improve the oxygen demand/delivery ratio. The influence of sedation has most frequently been investigated in a dose-related manner. The aim of the present study was to determine the effect-related influence of different sedatives on oxygen uptake (VO2) in relation to defined resting conditions. METHODS. Forty ASA I patients who had to undergo a minor surgical procedure were investigated 1.5 h before surgery at basal energy-expenditure measurement conditions. One of the following substances was given with a preset bolus rate in a double-blind, randomised order until a defined level of sleep or side effects was encountered: propofol (n = 8), midazolam (n = 8), thiopentone (n = 8), sodium chloride (n = 8), and fentanyl (n = 8). The sleep level was defined as sluggish response to a loud voice or tapping on the forearm. The variables VO2, carbon dioxide elimination (VCO2), end tidal CO2 (p(et)CO2), oxygen saturation (SaO2), heart rate, systemic blood pressure, skin temperature, and skin resistance on the sole of the foot were documented on-line on a computer. All variables were compared using differences of averages from 10-min periods before and after sedation during which the VO2 was minimal. RESULTS. The mean VO2 before sedation was 264 +/- 60 ml/min, and the measured energy expenditure did differ by -0.2% (+/- 14%) from mean predicted values using the Harris-Benedict equation. The VO2 was reduced by 15 +/- 2% with propofol, by 12 +/- 8% with midazolam, and by 10 +/- 5% with thiopentone. This was statistically significant compared to placebo treatment, as was the difference between propofol and thiopentone effects. All patients in these groups reached the defined sleep level, which was not achieved by the placebo and fentanyl groups. Placebo treatment changed the VO2 by 0.1% (+/- 2%). Fentanyl increased the VO2 by 5% (+/- 8%), which did not reach significance. In the fentanyl group the bolus application had to be stopped at a p(et)CO2 of 50 mm Hg in all patients. In the propofol, midazolam, and thiopentone groups the phasic changes of skin resistance were reduced to zero and the skin temperature increased from 27 +/- 2 degrees C to 32 +/- 2 degrees C. The fentanyl group showed an increase in changes of skin resistance without changes in temperature. CONCLUSIONS. Sleep induced by propofol, midazolam, or thiopentone to a clinically maximal desirable level in spontaneously breathing patients reduced VO2 by 10% to 15%. This level of sedation did not induce a relevant change in P(et)CO2 or SaO2. The effect of propofol appeared to be the most pronounced and least variable. This may be attributable to a more pronounced reduction in single-organ VO2 or to an undetected difference in level of sedation. Fentanyl did, in contrast to most publications on opioid effects, seem to increase VO2. Underlying mechanisms may be sought in an increased rate-pressure product and sympathetic activity on the basis of hypercapnia and changes in muscle tension.
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PMID:[The effect of sedation on oxygen uptake during spontaneous breathing]. 834 51

Trigeminally innervated, mechanically sensitive chemoreceptors (M) were previously identified in rainbow trout, Oncorhynchus mykiss, but it is not known whether these receptors are responsive only to noxious, chemical irritants or have a general chemosensory function. This study aimed to characterise the stimulus-response properties of these receptors in comparison with polymodal nociceptors (P). Both P and M gave similar response profiles to acetic acid concentrations. The electrophysiological properties were similar between the two different afferent types. To determine whether the receptors have a nociceptive function, a range of chemical stimulants was applied to these receptors, including non-noxious stimuli such as ammonium chloride, bile, sodium bicarbonate and alarm pheromone, and potentially noxious chemical irritants such as acetic acid, carbon dioxide, low pH, citric acid, citric acid phosphate buffer and sodium chloride. Only irritant stimuli evoked a response, confirming their nociceptive function. All receptor afferents tested responded to carbon dioxide (CO(2)) in the form of mineral water or soda water. The majority responded to 1% acetic acid, 2% citric acid, citric acid phosphate buffer (pH 3) and 5.0 mol l(-1) NaCl. CO(2) receptors have been characterised in the orobranchial cavity and gill arches in fish; however, this is the first time that external CO(2) receptors have been identified on the head of a fish. Because the fish skin is in constant contact with the aqueous environment, contaminants with a low pH or hypercapnia may stimulate the nociceptive system in fish.
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PMID:Characterisation of chemosensory trigeminal receptors in the rainbow trout, Oncorhynchus mykiss: responses to chemical irritants and carbon dioxide. 2227 76