Search Results
Results 501 - 550 of 1377
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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 ...
Naszlady A - - 1998
An analogue computer model has been constructed to simulate the dynamic behaviour of the human cardiorespiratory system for studying the effect of changes in different system-variables--as alveolar ventilation, functional residual capacity (FRC) of the human lung and the cardiac output--on the partial pressure of carbon dioxide in the arterial and ...
Lum L - - 1998
OBJECTIVE: To evaluate the accuracy of physiologic deadspace (VD/VT) measurement, using a metabolic monitor. DESIGN: Prospective collection of data. SETTING: University-affiliated children's hospital with a 51-bed critical care area. PATIENTS: Infants and children who were sedated and paralyzed and were receiving mechanical ventilation through a cuffed endotracheal tube. INTERVENTIONS: None. ...
Fontes N - - 1998
We studied the effect of pressure up to 300 bar on the catalytic efficiency of subtilisin Carlsberg suspended in compressed propane, near-critical ethane, near-critical carbon dioxide and tert-amyl alcohol, at constant temperature and fixed enzyme hydration. Increasing pressure lowered the catalytic efficiency of the enzyme in all the solvents, resulting ...
Nishino T - - 1998
We investigated the effects of increasing CO2 ventilatory drive on the coordination of respiration and reflex swallowing elicited by continuous infusion of distilled water into the pharynx (2.5 ml/min) in 11 normal subjects. Ventilation was monitored using a pneumotachograph and swallowing was recorded by submental electromyogram. The CO2 ventilatory drive ...
Schlünzen L - - 1998
The effect of modified ultrafiltration (MUF) after cardiopulmonary bypass for paediatric cardiac surgery was evaluated in 138 children with moderate to severe congenital heart disease. The median age was 0.4 years (0 days to 6.5 years), and the weight 5.3 kg (2.2-20 kg). The operation was discontinued in six cases, ...
Donaldson L L - - 1998
The use of laparoscopy for the diagnosis or therapeutic management of abdominal disease in the horse has distinct advantages when it allows the horse to remain standing. However, distending the abdomen by insufflation of a biologically active gas in an anaesthetised horse may add to the physiological challenge of general ...
Branche P E - - 1998
The intraperitoneal insufflation of carbon dioxide during laparoscopic procedures is associated with an increase in mean arterial pressure and systemic vascular resistance. To evaluate the time course of the circulatory changes related to intraabdominal pressure variation, we used transesophageal echocardiography in 10 patients anesthetized for laparoscopic cholecystectomy. Left ventricular dimensions, ...
Pizov R - - 1998
OBJECTIVE: To evaluate and compare the effect of tracheal gas insufflation using two gases with different physical properties, helium and oxygen, as an adjunct to conventional mechanical ventilation in patients with respiratory failure. DESIGN: Prospective, intervention study. SETTING: General intensive care unit in a tertiary university medical center. PATIENTS: Seven ...
Horvath K D - - 1998
BACKGROUND: This study investigated three factors postulated to be sources of physiological stress in laparoscopic surgery: hypercarbia, elevated intraabdominal pressure, and the steep Trendelenburg position. Our research was designed to define the effects of each of these potential stressors on hemodynamic responses observed during laparoscopic colectomy in pigs. METHODS: Twenty-four ...
Gehring H - - 1998
BACKGROUND: Respiratory function and pulmonary gas exchange are affected in laparoscopic procedures where a pneumoperitoneum is introduced using CO2. Previous studies have shown differing results concerning pulmonary gas exchange during laparoscopic procedures: Whereas in patients undergoing isoflurane anaesthesia decreases in PaO2 are demonstrated, this factor remains unchanged in patients undergoing ...
Volpino P - - 1998
BACKGROUND: The cardiopulmonary changes experienced by patients who undergo laparoscopic cholecystectomy (LC) and the prognostic value of patient characteristics are not well understood. METHODS: Cardiorespiratory changes were investigated in 120 patients undergoing LC or open cholecystectomy (OC). The results and their relation to patient variables were statistically evaluated. RESULTS: The ...
Blumenthal S R - - 1998
Hounds undergoing prolonged or complicated surgical procedures are often underventilated, as indicated by blood gas and end-tidal CO2 (CO2) values when using published ventilatory guidelines. We investigated the relationship between body weight, tidal volume, and inspiratory pressure delivered by the ventilator (lung inflation pressure) in 59 anesthetized hounds (19 to ...
Gueugniaud P Y PY Department of Anesthesiology, Edouard Herriot Hospital, CHU of Lyon, - - 1998
Cardiovascular changes due to pneumoperitoneum during laparoscopic surgery are established in adult patients, but not known in infants. We investigated the hemodynamic effects of laparoscopy during general anesthesia in 12 ASA physical status I infants by using noninvasive continuous esophageal aortic blood flow (ABF) echo-Doppler monitoring. During the laparoscopic procedure, ...
Martinez J M - - 1998
This study compares the hemodynamic response to panic disorder subjects with that of normal controls during respiratory challenges. Panic patients meeting DSM-IIIR criteria for panic disorder and normal controls were challenged with room air hyperventilation, 5% CO2 breathing, and 7% CO2 breathing. Measurements of pulse and blood pressure were taken ...
Manner T - - 1998
Insufflation of CO2 and positioning of patients induces changes in cardiovascular and respiratory function during laparoscopic procedures. This study was initiated to assess respiratory mechanics such as lung compliance and peak airway pressure (PIP) during laparoscopic surgery in paediatric patients. Ten consecutive patients (age 1-15 years) scheduled for laparoscopic procedure ...
Peters J W - - 1998
The purpose of this clinical trial was to investigate the safety and efficacy of semi-closed circle ventilation of the Dräger anaesthesia ventilators (Cicero, Cato), using a fresh gas flow (FGF) of 600 ml.min-1. Twenty infants, weighing less than 6000 g, without cardiorespiratory abnormalities who required general anaesthesia of at least ...
Byrne A J - - 1998
We have measured the performance of 10 trainee anaesthetists during a single simulated anaesthetic during which there was a complex critical incident. Errors in the recording on the anaesthetic charts of the "patient's" oxygen saturation, heart rate, systolic and diastolic arterial pressures and end-tidal carbon dioxide concentrations were used as ...
Novak-Janković V - - 1998
Tracheal and arterial CO2 partial pressures were measured simultaneously in 27 laryngectomized patients both while they were awake and during high-frequency jet ventilation. Tracheal gas was sampled during brief interruptions of high-frequency jet ventilation. Agreement between tracheal and arterial CO2 partial pressures was assessed using the Bland-Altman method. The tracheal-arterial ...
Mikami O - - 1998
BACKGROUND: Laparoscopic procedures are associated with several complications, such as hemodynamic, respiratory, and endocrine complications. In our previous clinical study, plasma epinephrine and norepinephrine concentrations remained unchanged after the insertion of a Veress needle, but increased significantly immediately after insufflation with carbon dioxide into the peritoneum. The mechanisms for this ...
Koivusalo A M AM Department of Anaesthesia, University of Helsinki, - - 1998
Carbon dioxide (CO2) insufflation with increased intraabdominal pressure (IAP) has adverse hemodynamic, pulmonary, and renal effects. To avoid these problems, an abdominal wall lift method with a retractor was used to provide the surgical view without CO2 insufflation. Twenty-six patients undergoing elective laparoscopic cholecystectomy were randomly allocated to either the ...
Willms J R - - 1997
An instrument for measuring low rates of biological O2 exchange using an open-flow gas analysis system is described. A novel differential O2 sensor that is capable of measuring as little as 0.4 Pa O2 against a back-ground of ambient air (20,900 Pa O2), yet has a dynamic range of +/- ...
Brunston R L RL - - 1997
BACKGROUND: To reduce the complexity, complications, and cost of conventional extracorporeal membrane oxygenation, we have developed a technique of simplified arteriovenous extracorporeal CO2 removal (AVCO2R) with a low-resistance membrane gas exchanger for total CO2 removal to provide lung rest in the setting of severe respiratory failure. METHODS: We initially used ...
Brunston R L RL - - 1997
OBJECTIVE: The effects of prolonged arteriovenous carbon dioxide removal on hemodynamics during severe respiratory failure were evaluated in adult sheep with severe smoke inhalation injury. METHODS: Adult female sheep (n = 6,33.8 +/- 5.2 kg) were subjected to intratracheal cotton severe smoke insufflation to a mean carboxyhemoglobin level of 83% ...
Schoffelen P F - - 1997
This study characterizes respiration chambers with fully automated calibration. The system consists of two 14-m3 pull-type chambers. Care was taken to provide a friendly environment for the subjects, with the possibility of social contact during the experiment. Gas analysis was automated to correct for analyzer drift and barometric pressure variations ...
Mann C C Department of Anesthesia, Hopital Saint-Eloi, Montpellier, - - 1997
We investigated the possibility of using argon, an inert gas, as a replacement for carbon dioxide (CO2). The tolerance of argon pneumoperitoneum was compared with that of CO2 pneumoperitoneum. Twenty pigs were anesthetized with enflurane 1.5%. Argon (n = 11) or CO2 (n = 9) pneumoperitoneum was created at 15 ...
Breen P H PH Department of Anesthesiology, University of California-Irvine Medical Center, Orange 92868, USA. - - 1997
Expiratory valve incompetence in the circle circuit is diagnosed by using capnography (PCO2 versus time) when significant CO2 is present throughout inspiration. However, inspiratory valve incompetence will allow CO2-containing expirate to reverse flow into the inspiratory limb. CO2 rebreathing occurs early during the next inspiration, generating a short extension of ...
Ikeda T - - 1997
We investigated effects of tissue-type plasminogen activator (tPA) on regional pulmonary arterial hemodynamics in pulmonary thromboembolism (PTE) in a canine model of unilobar PTE. Ten beagle dogs were divided into two groups-tPA (n = 5) and control group (n = 5). In each dog an artificial blood circuit (ABC) consisting ...
Imanaka H - - 1997
Video-assisted thoracoscopic surgery (VATS) is replacing thoracotomy, but no study has addressed the extent or duration of VATS-induced diaphragmatic alteration. We hypothesized that VATS would impair diaphragmatic function less and return diaphragmatic function faster than thoracotomy. In eight sheep, sonomicrometers were randomly implanted on the right costal diaphragm via VATS ...
Gannedahl P - - 1997
BACKGROUND: Laparoscopic surgery involves the use of intra-abdominal carbon dioxide insufflation (pneumoperitoneum). The increased intra-abdominal pressure causes marked haemodynamic changes, which may influence electrocardiographic monitoring. The aim of the present study was to elucidate the influence of pneumoperitoneum on vectorcardiographic recordings. METHODS: Vectorcardiographic changes (QRS vector difference = QRS-VD, QRS ...
Prause G - - 1997
Satisfactory artificial ventilation is defined as sufficient oxygenation and normo- or slight arterial hypocarbia. Monitoring end tidal CO2 values with non-invasive capnometry is a routine procedure in anaesthesia, emergency medicine and intensive care. In anaesthesia the ventilation volume is adjusted to the capnometric end tidal CO2 (ETCO2), taking into account ...
Rudston-Brown B - - 1997
PURPOSE: The use of helium for insufflation during laparoscopic surgery avoids hypercarbia and acidosis associated with absorbed CO2, but the effects of helium gas embolism are unknown. We compared the effects of CO2 with He gas embolism on survival, haemodynamic variables, oxygenation, and ventilation in pigs. METHODS: Anaesthetized juvenile pigs ...
Smith W - - 1997
Our results showed more rapid falls in pulse rate and blood pressure in rats euthanized in a chamber precharged with carbon dioxide (CO2), when compared with rats euthanized more slowly, but death still took over 5 min in the former group. There was no behavioural evidence of pain or distress ...
Koivusalo A M AM Department of Anaesthesia, Helsinki University Hospital, - - 1997
Carbon dioxide (CO2) pneumoperitoneum together with an increased intraabdominal pressure (IAP) induces a hemodynamic stress response, diminishes urine output, and may compromise splanchnic perfusion. A new retractor method may be less traumatic. Accordingly, 30 ASA physical status I or II patients undergoing laparoscopic cholecystectomy were randomly allocated to a CO2 ...
Rentero N - - 1997
A catechol signal recorded with in vivo voltammetry within the rat rostral ventrolateral medulla (RVLM) was taken as an index of the activity of RVLM adrenergic neurons and related to the level of arterial PCO2, under halothane anesthesia. Reversible increases in catechol signal were observed during reversible increases in arterial ...
Creteur J - - 1997
BACKGROUND: Saline gastric tonometry of carbon dioxide has been proposed as a means to assess the adequacy of splanchnic perfusion. However, this technique has several disadvantages, including the long time interval needed for gases to reach equilibrium in saline milieu. Thus the authors evaluated a system that uses a gas-filled ...
Bannenberg J J - - 1997
BACKGROUND: Total extraperitoneal laparoscopic surgery is an alternative to the laparoscopic transperitoneal route; however, its effects on hemodynamics have not been adequately studied. This experimental study compared the effects of intraperitoneal insufflation and extraperitoneal insufflation on hemodynamics and oxygen transport. METHODS: Sixteen pigs were randomly assigned for intraperitoneal insufflation or ...
Kline J A - - 1997
OBJECTIVE: To evaluate the utility of a modified calculation of the alveolar dead space fraction (Vd/Vt), combined with plasma D-dimers, to aid in the exclusion of acute pulmonary embolism (PE). METHODS: A prospective comparison of screening modalities was performed in a metropolitan teaching ED. Ambulatory patients evaluated for PE underwent ...
Berguer R - - 1997
BACKGROUND: There is increasing interest in the rat model of laparoscopic surgery. This study evaluates the cardiorespiratory effects of increasing CO2 pneumoperitoneum (PP) in the rat. METHODS: Nine Sprague-Dawley rats were subjected to CO2 PP at pressures of 2, 5, 10, and 15 mmHg or control (no PP) under anesthesia. ...
Frank B R - - 1997
Percutaneous cannulas with low resistance are necessary for arteriovenous carbon dioxide removal (AVCO2R) to allow highest flow at lowest pressure to maximize CO2 removal. Commercially available arterial (A) and venous (V) percutaneous cannulas (8-18 Fr) were tested for pressure/flow characteristics under conditions that simulated percutaneous AVCO2R at clinically pertinent flow ...
Goldberg J M - - 1997
OBJECTIVE: To determine if the theoretic advantages of gasless laparoscopy are realized in direct comparison to laparoscopy with pneumoperitoneum. METHODS: Fifty-seven patients undergoing laparoscopic surgery chose to participate in this trial and were randomized after the induction of general anesthesia. Twenty-nine of the 57 patients were randomized to the pneumoperitoneum ...
Lin H C - - 1997
To study the combined effects of intra-abdominal CO2 insufflation with changes in body position during laparoscopy in xylazine-ketamine-halothane anesthetized llamas. Prospective, controlled study. Nine castrated, male llamas weighing 114 +/- 23 kg, 3 to 13 years old. Three llamas (preliminary study [PS] group) were used to study the effect of ...
Calder N A - - 1997
1. The maturation of carotid chemoreceptor steady-state and dynamic responses to CO2 in newborn lambs was measured. In total, sixteen fibres (13 lambs) were studied at 3-4 days, nineteen fibres (13 lambs) at 5-9 days and twenty-one fibres (17 lambs) at 10-24 days after birth. 2. Steady-state CO2 sensitivity was ...
Byrnes C A - - 1997
BACKGROUND: It is possible to measure nitric oxide (NO) levels in exhaled air. The absolute concentrations of exhaled NO obtained by separate workers in similar patient groups and normal subjects with apparently similar techniques have been very different. A study was undertaken to determine whether changes in measurement conditions alter ...
Talamini M A - - 1997
BACKGROUND: Laparoscopic Nissen fundoplication (LNF) is gaining popularity. Although the hemodynamic effects of the typical pneumoperitoneum have been studied, the additional consequences of the hiatal dissection necessary for LNF have not. METHODS: Seven female pigs were anesthetized, intubated, and ventilated with a volume ventilator and hemodynamic and mechanical pressure monitoring ...
Levine R L - - 1997
BACKGROUND: Survival after cardiac arrest occurring outside the hospital averages less than 3 percent. Unfortunately, the outcome of prolonged resuscitative attempts cannot be predicted. End-tidal carbon dioxide levels reflect cardiac output during cardiopulmonary resuscitation. We prospectively determined whether death could be predicted by monitoring end-tidal carbon dioxide during resuscitation after ...
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