Search Results
Results 451 - 500 of 1372
< 5 6 7 8 9 10 11 12 13 14 15 >
Nishiyama T - - 1999
PURPOSE: Gas embolism during hysteroscopy is rare but sometimes fatal. A fatal case of gas embolism during diagnostic hysteroscopy using carbon dioxide (CO2) is presented. CLINICAL FEATURES: A 68 yr old woman was admitted for treatment of myoma and cancer of the uterus. Hysteroscopy using CO2 was performed without monitoring ...
Dahan A - - 1999
BACKGROUND: Inhalational anesthetics depress breathing dose dependently. The authors studied the dynamics of ventilation on changes in end-tidal sevoflurane partial pressure. To learn more about the mechanisms of sevoflurane-induced respiratory depression, the authors also studied its influence on the dynamic ventilatory response to carbon dioxide. METHODS: Experiments were performed in ...
Nagao K - - 1999
Carbon dioxide embolism is a rare but potentially devastating complication of laparoscopy. To determine the effects of insufflation pressure on the mortality from carbon dioxide embolism, six swine had intravascular insufflation with carbon dioxide for 30 seconds using a Karl Storz insufflator at a flow rate of 35 mL/kg/min. The ...
Bernardin G - - 1999
OBJECTIVE: To evaluate the influence of changes in alveolar ventilation on the following tonometry-derived variables: gastric intramucosal CO2 tension (PtCO2), gastric arterial CO2 tension difference (PgapCO2), gastric intramucosal pH (pHi) and arterial pH-pHi difference (pHgap). DESIGN: Clinical prospective study. SETTING: A medical intensive care unit in a university hospital. PATIENTS: ...
De Robertis E - - 1999
Alveolar ventilation and CO2 elimination during mechanical ventilation can be enhanced by reducing dead-space ventilation. Aspiration of gas from the dead space (ASPIDS) is a new principle, according to which gas rich in CO2 during late expiration is aspirated through a channel ending at the distal end of the tracheal ...
Hansen D - - 1999
Moderate hypothermia (32-33 degrees C) occurs in anesthetic practice. However, intrapulmonary gas exchange and the effect of temperature correction of blood gases on oxygen and carbon dioxide exchange have not been investigated in these patients. We investigated alveolar-arterial difference in oxygen tension (AaDO2) and arterial to end-tidal difference in carbon ...
Fahy B G - - 1999
We used transesophageal echocardiography (TEE) to monitor venous gas embolism, cardiac performance, and the hemodynamic effects of positioning and pneumoperitoneum in 16 healthy kidney donors undergoing laparoscopic nephrectomy. A four-chamber view was used continuously, except at predetermined intervals, when a complete TEE examination for cardiac function was performed. Other clinical ...
Itoh Y - - 1999
The effects of hypercapnia, which has been reported to impair consciousness, on the long-term potentiation of the population spike in the CA1 pyramidal cell of the hippocampus in anesthetized rats were studied. Experimental hypercapnemia was induced by inspired 13% CO2 with 21% O2. Arterial blood gas analysis after 80 min ...
Bebout D E - - 1999
Avian intrapulmonary chemoreceptors (IPC) are vagal sensory neurons that participate in the control of breathing. IPC action potential frequency is inversely proportional to PCO2, but it is unclear whether low PCO2 or high pH is the immediate stimulus for signal transduction in IPC. To address this question, comparisons were made ...
Hetzel A - - 1999
BACKGROUND AND PURPOSE: Responsiveness to CO2 is an established test of cerebrovascular reserve capacity. Arterial partial pressure of CO2 (PCO2) and arterial blood pressure (BP) are key parameters for cerebral blood flow. To investigate the interaction between PCO2 and BP, we performed a study with simultaneous measurement of CO2 and ...
Baird J E - - 1999
BACKGROUND: Laparoscopic techniques are being increasingly used for retroperitoneal surgery. However, hemodynamic and ventilatory efforts of retroperitoneal carbon dioxide (CO2) insufflation have not been studied. We hypothesized that differences in absorptive surface, anatomy, and compartment compliance could result in different hemodynamic and ventilatory effects between retroperitoneal and intraperitoneal insufflation. METHODS: ...
Suzuki T - - 1999
The objective of this study was to develop a simple and portable CO2 incubator using effervescent granules (EG) and to examine the effect of negative and positive air pressure for in vitro maturation (IVM), fertilization (IVF) and culture (IVC) of bovine oocytes. In experiment 1, cumulus-oocyte complexes (COCs) were matured ...
Bams J L - - 1999
To compare how outcome can be predicted from global haemodynamic compared with regional perfusion-related variables (gastric intramucosal pH (pHi) and intramucosal-arterial PCO2 difference (delta PCO2)), we measured global haemodynamics, gastric pHi and delta PCO2 in 68 haemodynamically compromised patients after cardiac surgery on admission to the intensive care unit (ICU) ...
Mohan R M - - 1999
We compared the central-chemoreflex sensitivities estimated from steady-state tests with those estimated from rebreathing tests in five subjects. In one laboratory, each subject underwent nine dynamic end-tidal forcing experiments. Three repetitions of 3, 6 and 9 mmHg step changes in the end-tidal partial pressure of carbon dioxide, from a pre-step ...
Blaney M W - - 1999
Although considerable experimental and clinical knowledge exists on the physiology of pneumoperitoneum, insufflation of the preperitoneal space has not been extensively studied. The purpose of this study is to evaluate the physiology associated with preperitoneal carbon dioxide (CO2) insufflation in a porcine model. Eleven pigs weighing 35 to 45 kg ...
Niwa Y - - 1999
PURPOSE: To develop a new system for safely supplying carbon dioxide (CO2) to open-angle glaucoma patients. METHODS: The orbital hemodynamics of 7 glaucoma patients were determined by color Doppler imaging under baseline conditions and during CO2 supplementation sufficient to increase the end-tidal CO2 partial pressure by 10%. Systemic conditions, including ...
Puri G D - - 1999
BACKGROUND: Mechanical ventilation under anaesthesia needs to be controlled to maintain normal oxygen and carbon dioxide tensions in the blood and to economize on fresh gas flows. Various ventilation nomograms such as Radford's nomogram and Nunn's CO2 predictor are based on data from studies, some of which do not mimic ...
Grenier B - - 1999
In neurosurgery, estimation of PaCO2 from PETCO2 has been questioned. The aim of this study was to reevaluate the accuracy of PETCO2 in estimating PaCO2 during neurosurgical procedures lasting >3 h and to measure the effect of surgical positioning on arterial to end-tidal CO2 gradient (P[a-ET]CO2) over time. One hundred ...
Annane D - - 1999
The hypothesis that, in neuromuscular and chest wall diseases, improvement in central respiratory drive explains the effects of night-time ventilation on diurnal gas exchanges was tested. The effects at 6 months, 1, 2 and 3 yrs of intermittent positive pressure ventilation (IPPV) on arterial blood gas tension, pulmonary function, muscle ...
Kitajima T - - 1998
To clarify the influence of the head-up position on cerebral oxygen metabolism during laparoscopy with CO2 insufflation in 12 patients who underwent laparoscopic cholecystectomy, changes in the concentrations of cerebral oxyhemoglobin (HbO2), deoxyhemoglobin (Hb), total hemoglobin (total Hb) and oxidized cytochrome aa3 (Cyt aa3) were measured by use of near-infrared ...
Schlager A - - 1998
We investigated transcutaneous partial CO2 and O2 pressures and respiratory rate in unpremedicated elderly patients of ASA physical status 1 to 3 who underwent cataract surgery under retrobulbar anaesthesia. In group A no air suction was used. In group B suction was applied under the sterile drapes to avoid rebreathing ...
Walsh R M - - 1998
BACKGROUND: Early diagnosis and treatment of intra-abdominal pathology in critically ill intensive care unit (ICU) patients remains a clinical challenge. The objective of this study is to assess the feasibility of portable, bedside diagnostic laparoscopy (DL) in the ICU for patients suspected of intra-abdominal pathology, and to contrast its accuracy ...
Carry P Y - - 1998
The abdominal wall lift (AWL) has been proposed for laparoscopic cholecystectomy to reduce hemodynamic effects caused by carbon dioxide (CO2) and high intraabdominal pressures (IAP). Data concerning effects of AWL on respiratory mechanics are scant. We therefore used a noninvasive method to evaluate whether the AWL could offset these effects. ...
Wagenaar M - - 1998
Acetazolamide, a carbonic anhydrase inhibitor, is used in patients with chronic obstructive pulmonary diseases and central sleep apnoea syndrome and in the prevention and treatment of the symptoms of acute mountain sickness. In these patients, the drug increases minute ventilation (V'E), resulting in an improvement in arterial oxygen saturation. However, ...
Nattie E E - - 1998
Neurotoxin microinjected into the retrotrapezoid nucleus of anesthetized rats decreases phrenic activity and eliminates the response to CO2. In unanesthetized rats, such treatment has no effect on awake, resting breathing and decreases CO2 sensitivity by 40% (M. Akilesh, M. Kamper, A. Li, and E. E. Nattie. J. Appl. Physiol. 82: ...
Nodelman V - - 1998
An intravascular gas exchange device for the treatment of respiratory failure consisted of a multitude of blind-ended hollow fibers glued in a pine-needle arrangement to a central gas supply catheter. It has previously been shown that gas desorption rates can be significantly enhanced by cycling gas pressure between a hypobaric ...
Jacobi C A - - 1998
BACKGROUND: The influence of raised intraperitoneal pressure during laparoscopy on tumour growth and port site metastasis is still unknown. METHODS: Tumour growth of colonic adenocarcinoma DHD/K12/TRb was measured after laparoscopy with carbon dioxide at different pressures (0, 5, 10 and 15 mmHg) in a rat model. Cell kinetics were determined ...
Dassieu G - - 1998
OBJECTIVE: Instrumental dead space wash-out can be used to improve carbon dioxide clearance. The aim of this study was to define, using a bench test, an optimal protocol for long-term use, and to assess the efficacy of this technique in neonates. DESIGN: A bench test with an artificial lung model, ...
Garrigós M C - - 1998
A test method based on supercritical fluid extraction (SFE) and gas chromatography has been developed for some aromatic amines, such as 4-chloro-o-toluidine, beta-naphthylamine and 4-aminobiphenyl. A two-level factor design was used as the optimization procedure. Four main variables were considered: CO2 pressure, extraction temperature, static extraction time and volume of ...
Babenco H D - - 1998
BACKGROUND: Diphenhydramine is used as an antipruritic and antiemetic in patients receiving opioids. Whether it might exacerbate opioid-induced ventilatory depression has not been determined. METHODS: The ventilatory response to carbon dioxide during hyperoxia and the ventilatory response to hypoxia during hypercapnia (end-tidal pressure of carbon dioxide [PETCO2] is approximately equal ...
Montes de Oca M - - 1998
The resting mouth occlusion pressure 0.1 s after onset of inspiration (P0.1) and minute ventilation (V'E) and their response to CO2 in patients with chronic obstructive pulmonary disease (COPD) remain controversial. The ventilatory drive and the factors that predict resting arterial CO2 tension (Pa,CO2) were studied in 19 eucapnic and ...
Yoshizaki H - - 1998
To clarify the control mechanism of ventilation during posture change, ventilatory parameters, PETCO2, and ventilatory response to CO2 were examined in 11 healthy male subjects at supine (0 degrees) and 75 degrees head-up tilt positions. Minute expiratory ventilation (V.E), tidal volume (VT), respiratory frequency (f), end-tidal and transcutaneous PCO2 and ...
Mayer K L - - 1998
BACKGROUND: Although the low-flow CO2 insufflation rate used to initiate pneumoperitoneum may reduce the severity of potential venous embolism, its safety is not established. METHODS: Anesthetized pigs were ventilated with room air at a fixed minute ventilation. After 1 h of baseline, they were intravenously infused with CO2 at the ...
Blobner M - - 1998
BACKGROUND: Intraabdominally insufflated carbon dioxide (CO2) during laparoscopy may have a specific effect on splanchnic circulation that may be unrelated to the effects of increased intraabdominal pressure alone. Therefore, the influences of insufflation with CO2 versus air on splanchnic circulation were compared. METHODS: Pigs were chronically instrumented for continuous recording ...
Frappell P B - - 1998
The saccular lung in lizards is large and highly compliant compared with mammalian lungs, and these properties led us to question to what extent body movements could affect pulmonary gas exchange and the partial pressure of arterial blood gases. Specimens of two species of lizards, the frilled lizard (Chlamydosaurus kingii, ...
Vidal Melo M F - - 1998
We studied the effect of the interaction between diffusion limitation and alveolar ventilation to perfusion ratio (VA/Q) mismatch in the relation between blood gas partial pressures and cardiac output (Q). The analysis was based on a mathematical model of gas exchange involving two exchanging compartments and a right to left ...
Stone J - - 1998
Objective: The number and types of surgical procedures being preformed using laparoscopic technique is increasing due to technological advances. Recent studies suggest the carbon dioxide pneumoperitoneum and patient positioning causes hemodynamic alterations, respiratory acidosis, and a release of stress hormones. However, to date, no studies have investigated the physiological effect ...
Iscoe S - - 1998
We used a modified rebreathing technique to measure chemoreflex thresholds to CO2 in decerebrate, paralyzed and ventilated cats. Cats were hyperventilated to neural apnea (PaCO2 < 15 mmHg) with one ventilator and then switched to a rebreathing circuit consisting of a balloon inside a bottle connected to a second ventilator. ...
De Vito E L - - 1998
In order to elucidate if the inspiratory effort sensation (IES) associated with carbon dioxide (CO2) is independent of the concomitant increase in the ventilation, we studied 23 normal resting volunteers (mean age 34 +/- 11 yr) during CO2 rebreathing. Our main goal was to compare the IES at the same ...
Biro P - - 1998
For adequate and safe use of high-frequency jet ventilation (HFJV), reliable monitoring of the PCO2 status and course is necessary. Because of improved handling and performance, recently available transcutaneous PCO2 monitoring devices such as MicroGas 7650 (Kontron Instruments Medical Sensors, Basel, Switzerland) should enable more effective surveillance of CO2 elimination ...
Kohn R A - - 1998
We describe a model to calculate the buffering capacity of bicarbonate in the rumen. The addition of NaHCO3 results in the release of CO2 from solution and eventually from the rumen via eructation. This process directly neutralizes ruminal acidity. The degree to which the process continues depends on the partial ...
Laffon M - - 1998
PURPOSE: To assess the effect of pneumoperitoneum on P(a-ET)CO2 gradient in children. METHODS: Sixty one ASA I and II children (10.7 +/- 3.0 yr, 38.4 +/- 14.2 kg, mean +/- SD), scheduled for visceral or urological laparoscopic procedures, were studied. They were anaesthetized, intubated, paralysed and their lungs ventilated with ...
Henry R A - - 1998
We studied interactions between CO2 chemoreflexes and arterial baroreflexes in 10 supine healthy young men and women. We measured vagal carotid baroreceptor-cardiac reflexes and steady-state fast Fourier transform R-R interval and photoplethysmographic arterial pressure power spectra at three arterial pressure levels (nitroprusside, saline, and phenylephrine infusions) and three end-tidal CO2 ...
Hahn C E - - 1998
This tutorial review charts the development of electrochemical sensors for the analysis of blood-gases, gases and vapours in clinical medicine over the past four decades. The development of each sensor is set in its historical and clinical context, and the first part of the review concentrates on aqueous electrolyte electrochemistry ...
Koivusalo A M - - 1998
BACKGROUND: Carbon dioxide (CO2) pneumoperitoneum for laparoscopic surgery increases arterial pressures, systemic vascular resistance and heart rate and decreases urine output. METHODS: In this double-blind randomized study esmolol, an ultrashort-acting beta1-adrenoceptor antagonist was compared with physiological saline (control) in 28 patients undergoing laparoscopic surgery in standardized 1 MAC isoflurane anaesthesia. ...
Gentz B A - - 1998
STUDY OBJECTIVE: To compare the rate of increase of arterial carbon dioxide tension (PaCO2) during apneic oxygenation preceded by acute respiratory hypocapnia with that during apnea preceded by respiratory eucapnia. DESIGN: Randomized, prospective, single crossover study. SETTING: Operating room at a teaching hospital. PATIENTS: 19 ASA physical status I, II, ...
Sellers G J - - 1998
BACKGROUND: We investigated the ability of pressurized CO2 gas to aerosolize B16 melanoma (B16) tumor cells in an in vitro model. METHODS: The experimental apparatus consisted of an 18.9-L plastic cylindrical vessel and a compliant latex pouch was attached to the top. Two 5-mm ports penetrated the vessel; insufflation and ...
Sexton J - - 1998
The purpose of the study was to determine whether chamber exposure to low levels of CO2 results in functional alterations in gas mixing and closing volume in humans. Four healthy volunteer subjects were exposed to 0.7% CO2 and to 1.2% CO2. Spirometry, lung volumes, single breath nitrogen washout, diffusing capacity ...
O'Sullivan D C - - 1998
This study evaluated the incidence and factors involved in the occurrence of gas embolism after laparoscopic injuries. A 5-MHz transesophageal echocardiographic (TEE) probe was placed in 11 anesthetized pigs and used to examine the right cardiac chambers and pulmonary artery. A calibrated carbon dioxide analyzer continuously measured end-tidal carbon dioxide ...
Baraka A - - 1998
During laparoscopy, the increase of the carbon dioxide tension may increase the synthesis of hydrochloric acid in the parietal cells of the stomach; the source of the secreted hydrogen ions is carbonic acid derived from the hydration of carbon dioxide. The present report tests this hypothesis by correlating the changes ...
< 5 6 7 8 9 10 11 12 13 14 15 >