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At least 1,099 records · Page 61Linked to original sources
PubMed1997

Laparoscopy. Gasless vs. CO2 pneumoperitoneum.

OBJECTIVE: To compare gasless laparoscopy with conventional laparoscopy using CO2 pneumoperitoneum. STUDY DESIGN: Women undergoing bilateral laparoscopic tubal coagulation (LTC) were randomly assigned to one of two laparoscopy procedures: (1) a gasless laparoscopy system consisting of an intraabdominal fan retractor and electrically powered mechanical arm, and (2) standard CO2 pneumoperitoneum laparoscopy. The two laparoscopic procedures were compared on the basis of intraoperative visualization, operation duration, procedural difficulty, ventilatory parameters, hemodynamic stability, and postoperative pain and nausea. RESULTS: Significant disadvantages for the surgeon (increased technical difficulty, poorer visualization, longer operative times) and patient (greater postoperative pain and nausea) were seen with the gasless system. Because of these findings, the study was prematurely terminated after only 18 patients had participated. Intraoperative ventilatory and hemodynamic parameters were more stable in the gasless laparoscopy groups; however, the differences were not clinically significant in this population of healthy patients. CONCLUSION: The markedly increased technical difficulty and absence of clear clinical benefits for the healthy patient led to the conclusion that laparoscopy with CO2 pneumoperitoneum is preferable for routine LTC and most laparoscopic procedures in the pelvis. Gasless laparoscopy may be of benefit for the fragile patient with a compromised cardiovascular system who may suffer complications from hypercarbenemia.

Adult↗
PubMed1997

Fluticasone propionate nasal spray is more effective and has a faster onset of action than placebo in treatment of rhinitis medicamentosa.

BACKGROUND: Controversy still exists about the treatment of rhinitis medicamentosa and treatment has never been objectively evaluated. OBJECTIVE: To study the effect of fluticasone propionate aqueous nasal spray compared to placebo nasal spray in the treatment of rhinitis medicamentosa. METHODS: A parallel randomized, double-blind study was conducted to evaluate the treatment of rhinitis medicamentosa. Two groups containing 10 patients with rhinitis medicamentosa in each group stopped their overuse of nasal vasoconstrictor spray immediately and were treated with either fluticasone propionate nasal spray once daily 200 micrograms, or placebo nasal spray for 14 days. The nasal mucosal swelling was recorded with rhinostereometry, acoustic rhinometry and a peak inspiratory flow meter. Nasal stuffiness was estimated on a visual analogue scale in the morning and in the evening of each day. RESULTS: The mucosal swelling decreased after 7 and 14 days of treatment with fluticasone propionate as well as placebo, but the reduction was significantly greater after treatment with fluticasone propionate. The symptom scores for nasal stuffiness showed a marked reduction during the treatment period in both groups, but there was a faster onset of symptom reduction after treatment with fluticasone propionate. CONCLUSION: Fluticasone propionate is more effective and has a faster onset of action than placebo in the treatment of rhinitis medicamentosa. An adequate treatment of these patients consists of a combination of vasoconstrictor withdrawal and a topical corticosteroid to alleviate the withdrawal process.

Administration, Intranasal↗
PubMed1997

Hemodialysis treatment may improve inspiratory muscle strength and endurance.

Chronic renal failure can result in a variety of conditions leading to muscle weakness. However, little is known about inspiratory muscle performance and the acute effects of hemodialysis on the muscles. We investigated the inspiratory muscle performance in chronic renal failure patients undergoing maintenance dialysis. Static inspiratory pressures and inspiratory muscle endurance were determined in 21 patients (13 men and 8 women), before and after dialysis. Inspiratory muscle strength before dialysis was significantly reduced in all subjects but one (mean +/- SEM, PImax = 52.9% of predicted). Following dialysis, the static inspiratory pressure was increased in 18 patients, decreased in 1 patient and remained unchanged in 2. Inspiratory muscle endurance was almost normal before dialysis (mean +/- SEM, PmPeak/PImax = 66.1%). Following dialysis, the inspiratory muscle endurance increased in 13 patients, decreased in 5 patients and remained unchanged in 3. There was no significant correlation between inspiratory muscle strength and the time on chronic hemodialysis. We conclude that in patients with chronic renal failure receiving maintenance hemodialysis there is predialysis reduction in inspiratory muscle strength and less significant reduction in the endurance. Both the inspiratory muscle strength and endurance significantly increased following hemodialysis in most but not all of the subjects. The dialysis-induced changes in biochemical parameters may exert opposing effects on inspiratory muscle performance. This might explain the diversity of the results obtained in this study and studies performed by others.

Adult↗
PubMed1997

[Monitoring of FiO2 mask under nebulized oxygen therapy for post-heart surgery patients].

Using Oxygen-Meter measure FiO2 directly inside the patient's mask in different oxygen flow. The purpose was to realize the actual FiO2 that patient inspirated. So oxygen therapy can be carried on correctly and scientifically and provide basis for respiratory monitoring and management post heart surgery. When patient breathe in oxygen in mask nebulize way, a porbe of oxygen meter was put in through a side hole 10 minutes later, the result was recorded. It demonstrated that when oxygen flow was 5L/min FiO2 inside mask was 56% approximately 58%. That means it's not correct to determine FiO2 according to the oxygen flow meter. The oxygen-meter should be used to monitor in order to avoid complications caused by incorrect adjustment and ensure the post heart surgery patient to recovery quickly.

Adolescent↗
PubMed1997

Holding chambers for pMDI use.

Spacer devices for pressurized metered-dose inhalers (pMDI) are needed to slow down the aerosol jet and hence to reduce oropharyngeal deposition as well as to overcome coordination problems. A new spacer, JET (Chiesi, Italy), which is less cumbersome to carry, was tested on five healthy volunteers. They inhaled with a slow inspiratory vital capacity maneuver 2 x 100 micrograms doses of the beta 2-agonist salbutamol, labelled with 99mTc, via a pMDI (Butovent, Chiesi) with and without the new JET spacer. The percentage of total delivered activity to the lungs increased with the JET from 14.3 +/- 4.5% to 22.3 +/- 4.1%, while the extrapulmonary deposition (oropharynx and stomach) was reduced from 39.8 +/- 12.2% to 11.0 +/- 3.4%. These results show that the optimal application of the JET can improve therapeutic efficacy by reducing extrapulmonary drug deposition while increasing the drug delivery to the lungs. Use of holding chambers as reservoirs should be avoided as well as frequent cleaning of the spacer.

Administration, Inhalation↗
PubMed1976

Automated rodent respiratory monitor and histogram computer--a preliminary report.

The system described in this paper was designed to monitor total inhaled volume (V), tidal volume (VT), and respiratory frequency (f) of Fisher rats before, during, and after exposure to cigarette smoke. The systems consists of three major subsystems: plethysmograph, analog signal conditioner, and histogram computer. The volume type whole body plethysmograph incorporates a rubber nose seal. Tidal flow rate (V) from the tube, measured by a pneumotachometer, is integrated by the signal conditioning system to obtain VT and V. Both V and V are displayed on a strip chart recorder. A rat will often exhibit considerable sniffing, especially in the presence of cigarette smoke. Consequently, average tidal volume (VT) and average respiratory frequency (f) are not accurate measurements of typical VT and f. Sensitivity of the system to changes in typical VT and f is important snce the system will be used to evaluate the effects of subtle differences in types of experimental cigarettes. A microprocessor was used in conjunction with a cathode ray tube to compute and display both the VT and respiratory period (T = 1/f) as histograms. From the histograms the most common (typical) VT (mode of the histogram) and the most common T can be easily observed and recorded. The histogram computer also calculates and digitally displays VT and f.

Analog-Digital Conversion↗
PubMed1998

Oral and inhaled corticosteroids in the treatment of pulmonary sarcoidosis--a critical reappraisal.

Oral corticosteroids are widely used in patients with pulmonary sarcoidosis, but no consensus has yet been reached on their place in the management of the disease. Over the short term, oral corticosteroids can improve respiratory symptoms, chest X-ray, lung function and biochemical markers of disease activity. However, over the long term, there is no conclusive evidence of an effect on the development of irreversible pulmonary damage. In many patients the lung is the only organ displaying clinically significant impairment of function, and prognosis is closely associated with pulmonary status. The localization of the inflammation in the lungs is predominantly "bronchocentric", and the disease is accompanied by a lymphocytic alveolitis. Due to these features, and a low frequency of side effects, it should be evaluated as to whether inhaled corticosteroids may influence the outcome of the disease. Two double-blind, placebo-controlled studies have examined the effect of inhaled budesonide 1.2 to 2.0 mg/day given for 6 to 12 months to patients with pulmonary sarcoidosis stage I, II or III. In one study there was no effect on any of the recorded parameters (symptoms, chest X-ray, lung function, 67Gallium scan, biochemistry). In the other study there was a favourable effect only on inspiratory vital capacity but not on any of the other parameters. The number of patients who had to be switched to oral corticosteroids was similar in the budesonide and placebo groups. Due to spontaneous recovery from the disease, an improvement was seen in symptoms and biochemical measures in both the budesonide and placebo groups. At present it has not been clarified as whether there is a place for inhaled corticosteroids in the treatment of pulmonary sarcoidosis. Until convincing evidence in favour of inhaled corticosteroids has been presented, these drugs should not be recommended as a routine treatment for pulmonary sarcoidosis.

Administration, Inhalation↗
PubMed1990

Lung volumes and maximal respiratory pressures in collegiate swimmers and runners.

To determine whether respiratory muscle strength is related to pulmonary volume differences in athletes and nonathletes, 11 intercollegiate female swimmers, 11 female cross-country runners, and two nonathletic control groups, matched to the athletes in height and age, were evaluated for pulmonary parameters including maximal inspiratory pressure (PImax) and maximal expiratory pressure (PEmax). Swimmers exhibited larger (p less than .05) vital capacities (VC), residual lung volumes (RV), inspiratory capacities (IC), and functional residual capacities (FRC) than both the runners or the controls but no difference (p greater than .05) in either PImax or inspiratory flow (FIV 25%-75%). Timed expiratory volumes (FEV 0.5 and FEV 1.0) were significantly (p less than .05) lower in the swimmers than in the controls. These data suggest that an adaptational growth may be responsible, in part, for the augmented static lung volumes demonstrated in swimmers.

Adolescent↗
PubMed1989

Mechanism of action of ozone on the human lung.

Fourteen healthy normal volunteers were randomly exposed to air and 0.5 ppm of ozone (O3) in a controlled exposure chamber for a 2-h period during which 15 min of treadmill exercise sufficient to produce a ventilation of approximately 40 l/min was alternated with 15-min rest periods. Before testing an esophageal balloon was inserted, and lung volumes, flow rates, maximal inspiratory (at residual volume and functional residual capacity) and expiratory (at total lung capacity and functional residual capacity) mouth pressures, and pulmonary mechanics (static and dynamic compliance and airway resistance) were measured before and immediately after the exposure period. After the postexposure measurements had been completed, the subjects inhaled an aerosol of 20% lidocaine until response to citric acid aerosol inhalation was abolished. All of the measurements were immediately repeated. We found that the O3 exposure 1) induced a significant mean decrement of 17.8% in vital capacity (this change was the result of a marked fall in inspiratory capacity without significant increase in residual volume), 2) significantly increased mean airway resistance and specific airway resistance but did not change dynamic or static pulmonary compliance or viscous or elastic work, 3) significantly reduced maximal transpulmonary pressure (by 19%) but produced no changes in inspiratory or expiratory maximal mouth pressures, and 4) significantly increased respiratory rate (in 5 subjects by more than 6 breaths/min) and decreased tidal volume.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1999

In normal subjects bracing impairs the function of the inspiratory muscles.

Normal subjects can increase their capacity to sustain hyperpnoea by bracing their arms on fixed objects, a procedure which is also known to reduce dyspnoea in patients with chronic obstructive pulmonary disease (COPD). In the present study, it was tested whether bracing per se could improve the function of the diaphragm. The effect of bracing on diaphragm function was studied in six normal subjects by recording changes in oesophageal (delta Poes) and transdiaphragmatic (delta Pdi) pressure during inspiratory capacity (IC) manoeuvres in the seated and upright postures, and in the seated posture, also during bilateral phrenic nerve stimulation (BPNS) at functional residual capacity (FRC). The pattern of ribcage motion and deformation associated with bracing and with diaphragm contraction was also evaluated using inductance plethysmography and magnetometers. Bracing increased FRC by >300 mL and reduced IC by approximately 200 mL, in both postures. Delta Pdi during BPNS decreased on average by 15% indicating an impaired diaphragmatic function. The ribcage was deformed with bracing and was more distortable during BPNS. In conclusion, in normal subjects, bracing impairs the function of the inspiratory muscles and reduces ribcage stability. These negative effects cannot explain the improved capacity to sustain hyperpnoea when the arms are braced.

Adult↗
PubMed2005

Shape and tension distribution of the active canine diaphragm.

Both diaphragm shape and tension contribute to transdiaphragmatic pressure, but of the three variables, tension is most difficult to measure. We measured transdiaphragmatic pressure and the global shape of the in vivo canine diaphragm and used principles of mechanics to compute the tension distribution. Our hypotheses were that 1) tension in the active diaphragm is nonuniform with greater tension in the central tendon than in the muscular regions; 2) maximum tension is essentially oriented in the muscle fiber direction, whereas minimum tension is orthogonal to the fiber direction; and 3) during submaximal activation change in the in vivo global shape is small. Metallic markers, each 2 mm in length, were implanted surgically on the peritoneal surface of the diaphragm at 1.5- to 2.0-cm intervals along the muscle bundles at the midline, ventral, middle, and dorsal regions of the left costal diaphragm and along a muscle bundle of the crural diaphragm. Postsurgery, a biplane videofluoroscopic system was used to determine the in vivo three-dimensional coordinates of the markers at end expiration and end inspiration during quiet breathing as well as at end-inspiratory efforts against an occluded airway at lung volumes of functional residual capacity and at one-third maximum inspiratory capacity increments in volume to total lung capacity. A surface was fit to the marker locations using a two-dimensional spline algorithm. Diaphragm surface was modeled as a pressurized membrane, and tension distribution in the active diaphragm was computed using the ANSYS finite element program. We showed that the peak of the diaphragm dome was closer to the ventral surface than to the dorsal surface and that there was a depression or valley in the crural region. In the supine position, during inspiratory efforts, the caudal displacement of the dorsal region of the diaphragm was greater than that of the dome, and the valley along the crural diaphragm was accentuated. In contrast, at lower lung volumes in the prone posture, the caudal displacement of the dome was greater than that of the crural region. At end of inspiration, transdiaphragmatic pressure was approximately 6.5 cmH2O, and tensions were nonuniform in the diaphragm. Maximum principal stress sigma(1) of central tendon was found to be greater than sigma(1) of the costal region, and that was greater than sigma(1) of the crural region, with values of 14-34, 14-29, and 4-14 g/cm, respectively. The corresponding data of the minimum principal stress sigma(2) were 9-18, 3-9, and 0-1.5 g/cm, respectively. Maximum principal tension was approximately parallel to the muscle fibers, whereas minimum tension was essentially orthogonal to the longitudinal direction of the muscle fibers. In the muscular region, sigma(1) was approximately 3-fold sigma(2), whereas in the central tendon, sigma(1) was only approximately 1.5-fold sigma(2.).

Animals↗
PubMed1975

Positive end-expiratory pressure in weaning patients from controlled ventilation. A prospective randomised trial.

Twenty-five patients in acute respiratory failure were randomised to receive either 5 cm of positive end-expiratory pressure (P.E.E.P.) or no-P.E.E.P. while weaning from controlled ventilation. The use of P.E.E.P. resulted in a significant reduction in the increase in alveolar-arterial oxygen tension gradient (AaDO21) which occurred in the group of patients who were converted from controlled ventilation to spontaneous ventilation without P.E.E.P. Patients who weaned without P.E.E.P. had a mean increase in AaDO21 of 102+/-35 mm Hg S.E. while those who weaned with P.E.E.P. had a mean increase of only 10+/-22 mm Hg (P less than 0-03). The use of P.E.E.P. was also associated with a significant improvement in the vital capacity and the maximum inspiratory force. Patients who weaned with P.E.E.P. had an increase in vital capacity of 258+/-108 ml (P less than 0-05) and an increase in inspiratory force of -15+/-5 cm H2O (P less than 0-01), while patients who weaned without P.E.E.P. did not have significant changes in these measurements. The use of P.E.E.P. during weaning may be helpful in patients who fail to wean because of the development of hypoxaemia due to rapid alveolar collapse, since P.E.E.P. appears to minimise the increase in intrapulmonary right-to-left shunt which normally occurs during weaning from controlled ventilation.

Acute Disease↗
PubMed2002

Inspiratory muscle training fails to improve endurance capacity in athletes.

PURPOSE: The purpose of this study was to examine the effects of specific inspiratory muscle training (IMT) on respiratory muscle strength and endurance and whole-body endurance exercise capacity in competitive endurance athletes. METHODS: Seven collegiate distance runners (5 male/2 female; VO2max = 59.9 +/- 11.7 mL.kg-1.min-1) were recruited to participate in this study. Initial testing included maximal oxygen consumption (VO2max), sustained maximal inspiratory mouth pressure (MIP), breathing endurance time (BET) at 60% MIP, and endurance run time (ERT) at 85% VO2max. Heart rate (HR), minute ventilation (VE), oxygen consumption (VO2), and ratings of perceived dyspnea (RPD) were recorded at 5-min intervals and during the last minute of the endurance run. Blood lactate concentration (BLC) was also obtained immediately before and at 2 min after the endurance run. All testing was repeated after 4 wk of IMT (50-65% MIP, approximately 25 min x d(-1), 4-5 sessions/week, 4 wk). RESULTS: After 4 wk of IMT, MIP and BET were significantly increased compared with pretraining values (P < 0.05). No significant differences between pre and post values were observed in VO2max or ERT at 85% VO2max after IMT. No significant differences between pre and post values were detected in HR, VE, VO2, or RPD during the endurance run as measured at steady state and end of the test after IMT. BLC was not significantly different before or at 2 min after the endurance run between pre and post IMT. CONCLUSION: These results suggest that IMT significantly improves respiratory muscle strength and endurance. However, these improvements in respiratory muscle function are not transferable to VO2max or endurance exercise capacity as assessed at 85% VO2max in competitive athletes.

Adult↗
PubMed1979

Fatigue of inspiratory muscles and their synergic behavior.

The time (tlim) required to produce inspiratory muscle fatigue was measured in five normal subjects breathing at functional residual capacity (FRC) against a variety of high inspiratory resistive loads. In every breathing test the subjects generated with each inspiration a mouth pressure (Pm) that was a predetermined fraction of maximum Pm (Pmmax). They continued breathing until they were unable to generate this Pm. The Pm/Pmmax that could be generated indefinitely (Pmcrit) was around 60%. The inspiratory power output at that level of breathing was 6.6 kg.m/min (Wcrit). In three of those subjects the same experiment was conducted at an end-expiratory volume of FRC + one-half inspiratory capacity (1/2IC). The higher lung volume was actively maintained by the subjects watching end-expiratory transpulmonary pressure on an oscilloscope. For any fraction of the maximum mouth pressure at FRC + 1/2IC (Pm'max), tlim was shorter than FRC. Pmcrit decreased to 30% Pm'max and Wcrit to 2.6 kg.m/min. Monitoring the abdominal pressure revealed that the contribution of the diaphragm and intercostal accessory muscles alternated in time, possibly postponing the onset of fatigue.

Diaphragm↗
PubMed1985

Pulmonary deposition of aerosols by different mechanical devices.

With a new method for easy labeling of beta 2-agonists we measured intra- and extrapulmonary aerosol deposition after the administration of a bolus from a metered-dose inhaler at residual volume (RV) inhaling after a pause of 2 s and after immediate administration into the inspiratory flow at functional residual capacity (FRC). Immediate administration during a slow inspiratory vital capacity maneuver gives the highest intrapulmonary deposition (30-40%). Compressed air and ultrasonic nebulizers with a particle distribution pattern of 2-5 micron aerodynamic mass median diameter (AMMD) allow in normal subjects to achieve an intrapulmonary deposition of 30-60% during standardized tidal breathing at rest, the magnitude of the deposition depending mainly on each subject's larynx geometry. The outlet system leads to different deposition patterns in aerosol generators with the same AMMD. Many commercially available aerosol generators do not fulfill the criteria for any intrapulmonary aerosol deposition. For drug administration into the lungs, condensation aerosol generators ('steam boiler nebulizers') are useless as well as compressed-air, ultrasonic and steam driven nebulizers with a particle size of more than 10 micron AMMD.

Adrenergic beta-Agonists↗
PubMed1992

Normal maximal expiratory and inspiratory pressures in healthy teenagers.

Maximal expiratory pressure at total lung capacity and maximal inspiratory pressure at residual volume were measured in 364 male and 325 female healthy teenage subjects. Predictive equations have been drawn based on coefficients of age, height and weight. The pressures may be used to evaluate respiratory muscle strength and follow the progress in patients with neuromuscular disorders, dyspnoea and respiratory failure.

Adolescent↗
PubMed2005

Respiratory effects of combined truncal and abdominal support in patients with spinal cord injury.

OBJECTIVE: To determine whether a custom girdle, designed to provide truncal stability and abdominal support, will improve pulmonary function, enhance inspiratory muscle activity, and reduce the sensation of respiratory effort in patients with spinal cord injury (SCI). DESIGN: Pulmonary function, transdiaphragmatic pressure time product (PTP di ), twitch (Tw Pdi) and maximal transdiaphragmatic pressures (Pdi), and perception of respiratory effort (Borg Rating of Perceived Exertion score) were measured with and without an abdominal girdle in a seated position. SETTING: Rehabilitation hospital. PARTICIPANTS: Ten patients with posttrauma SCI (injury level, C5-T6). INTERVENTION: Application of the abdominal girdle. MAIN OUTCOME MEASURES: Borg score and measures of lung volumes, dynamic abdominal compliance, and Tw Pdi and maximal Pdi. RESULTS: Wearing of the girdle was associated with a lower Borg score (P = .002) and reduced functional residual capacity (P = .006) but increased inspiratory capacity (P = .02) and forced vital capacity (P = .02). Although there was a decrease in dynamic abdominal compliance (P < .001) and an increase in PTP di (P = .02), this was accompanied by an increase in both Tw Pdi (P = .02) and maximal Pdi (P = .03). CONCLUSIONS The custom girdle reduced the sensation of respiratory effort in patients with SCI by optimizing the operating lung volumes and decreasing abdominal compliance, which enhanced diaphragm performance.

Abdomen↗