Sensory-mechanical relationships during high-intensity, constant-work-rate exercise in COPD.

During constant-work-rate exercise in chronic obstructive pulmonary disease, dyspnea increases steeply once inspiratory reserve volume (IRV) falls to a critical level that prevents further expansion of tidal volume (Vt). We studied the effects of this mechanical restriction on the quality and intensity of exertional dyspnea and examined the impact of an anticholinergic bronchodilator. In a randomized, double-blind, crossover study, 18 patients with chronic obstructive pulmonary disease (forced expiratory volume in 1 s = 40 +/- 3%predicted; mean +/- SE) inhaled tiotropium 18 mug or placebo once daily for 7-10 days each. Pulmonary function tests and symptom-limited cycle exercise at 75% of each patient's maximal work capacity were performed 2 h after dosing. Dyspnea intensity (Borg scale), operating lung volumes, breathing pattern, and esophageal pressure (n = 11) were measured during exercise. Dynamic hyperinflation reached its maximal value early in exercise and was associated with only mild increases in dyspnea intensity and the effort-displacement ratio, which is defined as the ratio between tidal swings of esophageal pressure (expressed relative to maximum inspiratory pressure) and Vt (expressed relative to predicted vital capacity). After a minimal IRV of 0.5 +/- 0.1 liter was reached, both dyspnea and the effort-displacement ratio rose steeply until an intolerable level was reached. Tiotropium did not alter dyspnea-IRV relationships, but the increase in resting and exercise inspiratory capacity was associated with an improved effort-displacement ratio throughout exercise. Once a critically low IRV was reached during exercise, dyspnea rose with the disparity between respiratory effort and the Vt response. Changes in dyspnea intensity after tiotropium were positively correlated with changes in this index of neuromechanical coupling.     

Effect of obesity on respiratory mechanics during rest and exercise in COPD

The presence of obesity in COPD appears not to be a disadvantage with respect to dyspnea and weight-supported cycle exercise performance. We hypothesized that one explanation for this might be that the volume-reducing effects of obesity convey mechanical and respiratory muscle function advantages. Twelve obese chronic obstructive pulmonary disease (COPD) (OB) [forced expiratory volume in 1 s (FEV(1)) = 60%predicted; body mass index (BMI) = 32 ± 1 kg/m(2); mean ± SD] and 12 age-matched, normal-weight COPD (NW) (FEV(1) = 59%predicted; BMI = 23 ± 2 kg/m(2)) subjects were compared at rest and during symptom-limited constant-work-rate exercise at 75% of their maximum. Measurements included pulmonary function tests, operating lung volumes, esophageal pressure, and gastric pressure. OB vs. NW had a reduced total lung capacity (109 vs. 124%predicted; P < 0.05) and resting end-expiratory lung volume (130 vs. 158%predicted; P < 0.05). At rest, there was no difference in respiratory muscle strength but OB had greater (P < 0.05) static recoil and intra-abdominal pressures than NW. Peak ventilation, oxygen consumption, and exercise endurance times were similar in OB and NW. Pulmonary resistance fell (P < 0.05) at the onset of exercise in OB but not in NW. Resting inspiratory capacity, dyspnea/ventilation plots, and the ratio of respiratory muscle effort to tidal volume displacement were similar, as was the dynamic performance of the respiratory muscles including the diaphragm. In conclusion, the lack of increase in dyspnea and exercise intolerance in OB vs. NW could not be attributed to improvement in respiratory muscle function. Potential contributory factors included alterations in the elastic properties of the lungs, raised intra-abdominal pressures, reduced lung hyperinflation, and preserved inspiratory capacity.     

Pulmonary function in men after oxygen breathing at 3.0 ATA for 3.5 h.

As a pulmonary component of Predictive Studies V, designed to determine O2 tolerance of multiple organs and systems in humans at 3.0-1.5 ATA, pulmonary function was evaluated at 1.0 ATA in 13 healthy men before and after O2 exposure at 3.0 ATA for 3.5 h. Measurements included flow-volume loops, spirometry, and airway resistance (Raw) (n = 12); CO diffusing capacity (n = 11); closing volumes (n = 6); and air vs. HeO2 forced vital capacity maneuvers (n = 5). Chest discomfort, cough, and dyspnea were experienced during exposure in mild degree by most subjects. Mean forced expiratory volume in 1 s (FEV1) and forced expiratory flow at 25-75% of vital capacity (FEF25-75) were significantly reduced postexposure by 5.9 and 11.8%, respectively, whereas forced vital capacity was not significantly changed. The average difference in maximum midexpiratory flow rates at 50% vital capacity on air and HeO2 was significantly reduced postexposure by 18%. Raw and CO diffusing capacity were not changed postexposure. The relatively large change in FEF25-75 compared with FEV1, the reduction in density dependence of flow, and the normal Raw postexposure are all consistent with flow limitation in peripheral airways as a major cause of the observed reduction in expiratory flow. Postexposure pulmonary function changes in one subject who convulsed at 3.0 h of exposure are compared with corresponding average changes in 12 subjects who did not convulse.     

重度脊柱侧凸后路一期小切口矫形对肺功能的影响

目的:探讨采用脊柱后路分期矫形策略治疗重度脊柱侧后凸,一期小切口矫形术对患者肺功能的影响。方法:自2007年05月-2010年12月采用脊柱后路分期矫形策略中一期小切口矫形术治疗重度脊柱侧凸患者32例,其中男12例,女20例,年龄5～25(13.5±6.12)岁。一期小切口矫形术前侧凸主弯冠状面Cobb’s角为108°～150°(128.75°±13.51°),胸腰段矢状位后凸角60°～140°(97.78°±27.88°)。测量一期矫形术前及术后2周、3月、6月肺功能,包括肺活量(VC)、用力肺活量(FVC)、第一秒时间肺活量(FEV1)、最大呼气中段流速(MMEF)、最大通气量(MVV),计算其占预计值的百分比[VC%、FVC%、FEV1%、MMEF%、MVV%]。观察患者术前与术后不同时期肺功能的变化。结果:术后3月时肺功能较术前有明显提高(P<0.05),术后6月较术后3个月无显著提高(P>0.05)。结论:对于严重的脊柱侧凸患者,后路一期小切口矫形术后3月肺功能即可获得明显改善,可行二期手术治疗。     

Disturbances of Pulmonary Function in Mitral Valve Disease

To study the sequence of changes in respiratory function that occur in the natural history of mitral stenosis, and the physiological basis of “cardiac dyspnea”, 30 patients with chronic mitral valve disease were subjected to detailed pulmonary function tests. There was no significant change in vital capacity and functional residual capacity. The reduction in maximal mid-expiratory flow rate showed excellent correlation with the respiratory symptoms. The pulmonary capillary blood volume was increased in moderately advanced cases but was consistently reduced in the severest cases. Hyperventilation was due to an increased respiratory rate. Dyspnea was associated with increased respiratory work owing to the interrelation between the reduction in diffusion capacity, compliance, cardiac output, the increase in airway resistance, and the uneven ventilation and perfusion of the lungs. The amount of “effort” required to breathe is incommensurate with the external load in these patients.     

Relationship between respiratory muscle function and age, sex, and other factors

To investigate the effects of gender and age on respiratory muscle function, 160 healthy volunteers (80 males, 80 females) were divided into four age groups. Twenty-eight of the male subjects were smokers. After the subjects were familiarized with the experimental procedure, respiratory muscle strength, inspiratory muscle endurance, and spirometric function, including forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), FEV1/FVC, tidal volume, breathing rate, and duty cycle, were measured. The respiratory muscle strength was indicated by the maximal static inspiratory and expiratory pressures (PImmax and PEmmax). Inspiratory muscle endurance was determined by the time the subject was able to sustain breathing against an inspiratory pressure load on a modified Nickerson-Keens device. The results showed that 1) except for inspiratory muscle endurance and FEV1/FVC, men had greater respiratory muscle and pulmonary functions than women, 2) respiratory muscle function and pulmonary function decreased with age, 3) smoking tended to lower duty cycle and FEV1/FVC and to enhance PE,mmax, and 4) inspiratory muscle endurance was greater in men who were physically active than in those who were sedentary. Therefore we conclude that there are sexual and age differences in respiratory muscle strength and pulmonary function and that smoking or physical activity may affect respiratory muscle function.     

CARDIORESPIRATORY FUNCTION

Accurate evaluation of the degree of impairment of pulmonary function in persons with fibrosis and emphysema requires: (1) ventilatory measurements from rapid spirogram tracings (vital capacity, maximal breathing capacity and the time required to blow the air from the lungs); (2) determination of the degree of bronchospasm present; (3) determination of the degree of pulmonary emphysema (residual air expressed quantitatively as percent of total lung volume); (4) determination of the arterial blood oxygen saturation at rest and immediately after step-up exercise; (5) measurement of the oxygen extraction from inspired air (per cent of oxygen removed) during rest and exercise; (6) determination of the oxygen up-take during exercise; and (7) observation of the duration of dyspnea after step-up exercise.No single physiologic test is adequate in evaluating impairment of pulmonary function, and roentgenograms of the chest are unreliable as a sole basis for appraisal of disability.In industrial medicine, pulmonary function studies make possible (a) more accurate diagnosis and evaluation of pulmonary disability; and (b) earlier detection and thus prevention of prolonged exposure by susceptible individuals to environmental hazards.     

Effect of normobaric hyperoxia on airways of normal subjects

Airway responsiveness to inhaled cholinergic agonist during the early stage of pulmonary O2 toxicity was examined to determine whether normobaric hyperoxia alters airway function. Eight healthy nonsmoking males with moderate base-line methacholine responsiveness breathed normobaric O2 (greater than or equal to 95%) over 12 h and on another occasion breathed air in an identical protocol. Vital capacity, expiratory flow, airway responsiveness to methacholine, and respiratory symptoms were measured at 0, 4, 8, and 12 h while subjects breathed O2 and 12 h afterwards. After 12 h, forced vital capacity was significantly decreased with O2 breathing but not with air breathing. At 4, 8, or 12 h of exposure and 12 h after exposure, there was no difference in methacholine sensitivity or reactivity between O2 and air-exposure trials. The earliest manifestations of pulmonary normobaric O2 toxicity in normal adults include diminished vital capacity and the onset of respiratory symptoms, but early O2 toxicity does not produce altered responsiveness to inhaled methacholine.     

Dyspnoea,disability, and distance walked: comparison of estimates of exercise performance in respiratory disease.

Forty-four patients with airway obstruction and 18 with pulmonary infiltration were studied in an attempt to correlate exercise tolerance, as assessed by a simple walking test, with basic respiratory function values and differing subjective assessments of exercise performance. The distance walked in 12 minutes was significantly correlated with the response to a structured questionnaire and with the patients'' assessment of performance using an oxygen-cost diagram. The distance walked did not agree well with simple subjective estimates obtained in the clinical history. It was better correlated with forced vital capacity than with forced expiratory volume in one second in both groups of patients, and was well correlated with carbon monoxide transfer factor in those with pulmonary infiltration. The scatter of results, however, was such that exercise performance could not usefully be predicted from the respiratory function values or from subjective assessments. Simple exercise tests are an essential part of assessing disability and response to treatment in patients with respiratory impairment.     

Abnormal Pulmonary Function and Respiratory Muscle Strength Findings in Chinese Patients with Parkinson’s Disease and Multiple System Atrophy–Comparison with Normal Elderly

Background

There have been limited comparative data regarding the investigations on pulmonary and respiratory muscle function in the patients with different parkinsonism disorders such as Parkinson’s disease (PD) and multiple system atrophy (MSA) versus normal elderly. The present study is aiming to characterize the performance of pulmonary function and respiratory muscle strength in PD and MSA, and to investigate the association with severity of motor symptoms and disease duration.

Methods

Pulmonary function and respiratory muscle strength tests were performed in 30 patients with PD, 27 with MSA as well as in 20 age-, sex-, height-, weight-matched normal elderly controls. All the patients underwent United Parkinson’s disease rating scale (UPDRS) or united multiple system atrophy rating scale (UMSARS) separately as diagnosed.

Results

Vital capacity, forced expiratory volume in 1 second and forced vital capacity decreased, residual volume and ratio of residual volume to total lung capacity increased in both PD and MSA groups compared to controls (p<0.05). Diffusing capacity was decreased in the MSA group, compared with PD and normal elderly control groups (p<0.05). Respiratory muscle strength was lower in both PD and MSA groups than in controls (p<0.05). The values representing spirometry function and respiratory muscle strength were found to have a negative linear correlation with mean score of UPDRS-III in PD and mean score of UMSARS-I in MSA. Respiratory muscle strength showed a negative linear correlation with the mean score of UMSARS-II and disease duration in MSA patients.

Conclusions

These findings suggest that respiratory dysfunction is involved in PD and MSA. Respiratory muscle strength is remarkably reduced, and some of the parameters correlate with disease duration and illness severity. The compromised respiratory function in neurodegenerative disorders should be the focus of further researches.     

Systemic and discoid lupus erythematosus: analysis of pulmonary function

To determine the prevalence of pulmonary dysfunction in lupus erythematosus, 24 patients with systemic lupus erythematosus (SLE) and 5 patients with discoid lupus erythematosus (DLE) were studied. Diffusing capacity for carbon monoxide was abnormal in 17 (71 percent) SLE patients. A restrictive ventilatory defect was present in 6 (25 percent) and arterial hypoxemia in 4 of 23 (17 percent). The mean ratio of forced expiratory volume in one second to forced vital capacity (FVC) was 83 percent. To test for the presence of small airways disease, maximum expiratory flow rate at 50 percent of FVC was measured on air and on an 80 percent helium-20 percent oxygen mixture. Ten patients (5 smokers and 5 nonsmokers) with SLE were nonresponders to helium suggesting small airways disease. Pulmonary dysfunction was present in 90 percent (9/10) of SLE patients with a previous history of pleuritis and/or pneumonitis, and in 71 percent (10/14) without respiratory symptoms or history of lung disease and with a normal chest radiograph. Pulmonary function tests were normal in DLE patients except for an abnormal response to helium and/or mild arterial hypoxemia in two patients, all of whom were smokers. These data indicate that there is a high prevalence of pulmonary function abnormalities in SLE including patients without clinically evident pleuropulmonary disease.     

Effect of lung resection on blood lactate threshold in lung cancer patients

We studied the effect of a decrease in vital capacity (VC) on the blood lactate threshold detected during exercise in 16 preoperative (PRE) and 10 postoperative (POST) lung cancer patients who had undergone lobectomy or pneumonectomy. The PRE patients were selected on the basis of having normal preoperative pulmonary function. The POST patients were selected on the basis of having normal preoperative pulmonary function and a postoperative VC of less than 80%. The oxygen consumption/body surface area at a 2.2 m.mol.l-1 arterial lactate concentration (VO2/BSA at La-2.2) was adopted as the blood lactate threshold. VC/BSA in the POST group significantly correlated with VO2/BSA at La-2.2 (r = 0.85, P less than 0.01), but not in the PRE group. SaO2 at La-2.2 was 95.4 +/- 1.5% in the PRE group and 95.2 +/- 1.3% in the POST group. SaO2 at La-2.2 did not correlated with VC/BSA in either group. The hemoglobin concentration (Hb) in the arterial blood correlated significantly with VC/BSA in the POST group (r = 0.65, P less than 0.05) but not in the PRE group. These results indicate that VO2/BSA at La-2.2 was restricted by VC in patients with restrictive pulmonary function disorder. Of the three elements of oxygen delivery, Hb was a limiting factor for VO2/BSA at La-2.2 but SaO2 was not. Cardiac output, which was not measured in our study, was speculated to be another limiting factor for VO2/BSA at La-2.2.     

The three syndromes of fat embolism: pulmonary manifestations.

The clinical course and radiographs of 30 patients with fat embolism syndrome were reviewed. In all cases the classic triad of neurologic dysfunction, respiratory insufficiency, and petechiae were present. Three responses to embolized fat were noted. The hyperacute response was seen in two patients with paradoxical embolization of fat to the systemic circulation. A "classic response" was noted in 18 patients with transient respiratory compromise and variable radiographic findings. The two deaths in the group responding in the classical manner were attributed to massive pulmonary emboli. The third response, noted in ten patients, consisted of a chest radiograph compatible with pulmonary edema in the clinical setting of the adult respiratory distress syndrome. In this group the degree of respiratory dysfunction and pulmonary damage correlated with the development of disseminated intravascular coagulation. Pathologic correlations are presented and the mechanisms by which embolic fat produces tissue damage are discussed.     

Changes in the Pulmonary Function Test after Radioactive Iodine Treatment in Patients with Pulmonary Metastases of Differentiated Thyroid Cancer

ObjectivePulmonary function test (PFT) is a useful tool for an objective assessment of respiratory function. Impaired pulmonary function is critical for the survival and quality of life in patients with pulmonary metastases of solid cancers including thyroid cancer. This study aimed to evaluate clinical factors associated with severely impaired pulmonary function by serial assessment with PFT in patients with pulmonary metastasis of differentiated thyroid cancer (DTC) who received radioactive iodine treatment (RAIT).PatientsThis retrospective study enrolled 31 patients who underwent serial PFTs before and after RAIT for pulmonary metastasis of DTC. We evaluated the risk factors for severe impairment of pulmonary function.ResultsThe median age of the patients was 44.1 years and 18 of them were female patients. Severe impairment of pulmonary function was observed in five patients (16%) after a median of three RAITs (cumulative I-131 activity = 20.4 GBq). These patients were older and more frequently had mild impairment of baseline pulmonary function, respiratory symptoms, or progressive disease compared with patients with stable pulmonary function. Neither cumulative dose nor number of RAIT was associated with decreased pulmonary function. Coexisting pulmonary diseases, presence of respiratory symptoms, and metastatic disease progression were significantly associated with severe decrease in forced vital capacity during follow-up (p =.047, p =.011, and p =.021, respectively).ConclusionsPulmonary function was severely impaired during follow-up in some patients with pulmonary metastasis of DTC after a high-dose RAITs. Neither the number of RAIT nor the cumulative I-131 activity was associated with decreased pulmonary function. Serial PFT might be considered for some high-risk patients during follow-up.     

Pulmonary complications following abdominal lipectomy

Previous reports underestimate the morbidity of a lipectomy, having focused on mortality statistics. Alterations of respiratory kinetics leading to complications do not always correlate with the usual signs and symptoms of respiratory failure. Patients at increased risk, namely, those with obesity, a smoking history, or lung disease, deserve special attention, including appropriate pulmonary function studies in the preoperative and postoperative phase. The following studies are indicated in the preoperative assessment of the high-risk patient: (1) vital capacity, (2) arterial blood gases, and (3) chest radiograph.     

Animal model of acute respiratory insufficiency by HCl aspiration in Lewe mini-pigs

Acute respiratory insufficiency or adult respiratory distress syndrome is a common medical emergency in intensive medicine complicated by high mortality. To study the acute respiratory insufficiency under standardized conditions an animal model in Lewe-mini-pigs has been developed. This model is based on aspiration pneumonitis produced by intrabrochial atomisation of 0.2 N hydrochloric acid. General anesthesia was performed by neuroleptanalgesia. In all animals the profound changes in gas exchange, pulmonary mechanics and hemodynamics as well as quasi-static volume-pressure relationships after hydrochloric acid aspiration were described. The results suggest that this model is suitable to outline the profound changes in pulmonary function in this type of acute respiratory insufficiency.     

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)     

Predictors of velopharyngeal insufficiency in cleft palate orthognathic surgery

The purpose of this study was to appraise the value of preoperative speech assessments, nasopharyngoscopy, and surgical models as predictors of velopharyngeal deterioration after a Le Fort I maxillary advancement in cleft patients. This retrospective study involved a series of 26 cleft patients (16 unilateral complete and nine bilateral complete cleft lips and palates, and one isolated complete cleft palate) who had Le Fort I maxillary advancements between March 1, 1993, and February 7, 1996. The 13 male patients and 13 female patients ranged in age from 15.3 to 46 years (mean age, 19.5 years). Four of these patients had previously undergone pharyngeal flap surgery. Eleven patients had palatal fistulas and one had a bifid uvula that was repaired at the time of orthognathic surgery. Patients with perceived hypernasal speech preoperatively all had hypernasality after advancement (nine of nine). Velopharyngeal insufficiency was observed in two of the 16 whose resonance preoperatively was within normal limits. Speech assessment, therefore, predicted accurately the postoperative status in 23 of 26 patients. Twelve patients had preoperative nasopharyngoscopy that indicated a high risk for velopharyngeal insufficiency (borderline or inadequate closure). Nine of these patients had postoperative velopharyngeal insufficiency. Two of the 14 patients not judged at risk by nasopharyngoscopy developed velopharyngeal insufficiency. Therefore, 21 of the 26 patients were accurately predicted by nasopharyngoscopy. Scoping detected borderline velopharyngeal insufficiency in one patient who was not detected by speech alone. The combined predictive value of speech and scope identified all but one patient who would develop postoperative velopharyngeal insufficiency. The degree of anteroposterior movement determined from surgical models was not predictive of the outcome. Patients with hypernasal speech preoperatively continue to have hypernasal speech after Le Fort I advancement. Preoperative perceptual speech assessment by specially trained speech-language pathologists is an excellent test for predicting postoperative velopharyngeal insufficiency status. Nasopharyngoscopy is an invasive and resource-dependent test that should be assessed with respect to cost effectiveness. In this series, only one patient's risk was more accurately predicted using nasopharyngoscopy than by speech assessment alone.     

Nd-YAG Laser in Lung Cancer

We administered 45 Nd-YAG laser treatments in 29 patients (18 men) aged 39 to 82 years who had lung malignancy; 26 patients had primary non-oat cell lung cancer and three had metastatic airway malignancy. In all, 25 of the patients had been previously treated with combination(s) of surgical procedure, radiation therapy and chemotherapy. Indications for laser treatment included endobronchial airway obstruction with uncontrolled cough, hemoptysis, dyspnea or unresolved atelectasis-pneumonia. Of 15 patients with partially occluded tracheobronchial airway tumors, immediate palliative relief was achieved in 13 patients and lasted one to six months after a single treatment. In this group there was one postoperative death related to respiratory failure and two patients subsequently died of massive pulmonary hemorrhage. However, of 14 patients with totally obstructed airways, immediate palliative relief was achieved in only five patients and this lasted three weeks to three months after a single treatment. In this group there were two postoperative deaths related to progressive respiratory failure; in one case it was associated with endobronchial combustion of the fiberoptic bronchoscope. All three patients in both groups who died of respiratory failure were in acute respiratory distress and terminally ill before the procedure. These findings suggest that Nd-YAG laser therapy may be most beneficial in patients with partially rather than totally occluded airways due to lung malignancy.     

Role of echocardiography in surgery of pulmonary tuberculosis

Doppler echocardiography was used to examine 26 patients aged 18 to 65 years who had undergone different surgical interventions for disseminated and acutely progressive pulmonary tuberculosis. Nineteen patients were diagnosed as having fibrocavernous pulmonary tuberculosis; 6 and 1 patients had caseous pneumonia and disseminated pulmonary tuberculosis. Echocardiography was performed with a LSC-700 echotomograph (Piker International, USA) by the routine procedure. Analyzing central hemodynamic parameters in the patients identified 3 types of hemodynamics: hypokinetic, eukinetic, and hyperkinetic, which made it possible to perform a course of cardial therapy adequately in the preoperative period. Preoperatively, 21 (80.8%) patients were found to have elevated mean pulmonary pressures and 5 patients had pulmonary pressures in the normal ranges. In the uncomplicated postoperative period, pulmonary pressures gradually decreased and reached normal values in some patients.