No abstract available.
Humans ; Lung Compliance* ; Lung Diseases* ; Lung*

We had previously reported the purification of bovine lung natural surfactant-phospholoipd (PNSL)and the assessment of it's surface physical properties in vitro. To observe the clinical effectiveness of PNS-L in vivo, the degree of improvement of thoracic pressure-volume, compliance and histological changes following PNS-L instilation in premature rabbits with respiratory distress syndrome(RDS)were investigated. Rabbits, delivered prematurely by cesarean section at 27 days, treated with PNS-L via tracheostomy, were enrolled the study group. Two control groups were premature RDS rabbits (no treatment with PNS-L)and mature rabbits. We compared the results of thoracic pressure-volume changes during deflation phase and lung compliance changes among PNS-L treated study group and two control groups, and compared the results of aefated lung area ratio (%) on histologic samples among PNS-L treated study group and two control groups by the methods of IBSA-2000. There were significant improvements of thoracic pressure-volume during duflation phase(p<0.001), lung compliance (p<0.01, p<0.005, p<0.001) and increased acrated area histologically (p<0.005)in PNS-L treated study group compared with premature control group. It was suspected that PNS-L had contained the effective survace physical properties as a function of pulmonary surfactant. And improvement of pulmonary ventilatory functions and histological characteristics, were observed in PNS-L treated RDS model in vivo study.
Cesarean Section ; Compliance ; Female ; Humans ; Infant, Newborn* ; Lung ; Lung Compliance ; Pregnancy ; Pulmonary Surfactants ; Rabbits ; Tracheostomy

Oxygen therapy is clear benefit in the treatment of tissue hypoxia, but high concentrations and long term exposures of oxygen carry the risks of detrimental physiologic changes and tissue damages. Tissue damages involve decreased surfactant production,alveolar edema, and alveolar hemorrhage. In spite of these damage, diagnosis of oxygen toxicity is difficult in many clinical settings. In this study, we measured lung compliance to evaluate the oxygen toxicity in 60 white rat of 100-150 g body weight Rats were divided into 6 groups. Group I was control graup, exposed to room air, group II -group V were exposed to 100% oxygen, group II for 24 hours, group IlI for 48 hous, group IV for 72 hours, and group V for 96 hours. Group VI was exposed to oxygen in serial as 30% oxygen for 24 hours, 60% oxygen for 24 hours and then 100% oxygen for 96 hours. After oxygen exposure we obseved changes of lung compliance and pathologic findings, compliance of group V was 15.94 mL/cmH2O significantly lower than that of eontrol group (p<0.05) and lung weight of group V was 2.16 g/100 g heavier than the other groups (p<0.05). Although we found oxygen tolerance was developed in group V, we could not differentiate the degree of pathologic damage cauesd from oxygen toxicity by pathologic findings. We concluded that the measurement of lung compliance is valuable in diagnosis of oxygen toxicity and thus in reducing lung damages.
Animals ; Anoxia ; Body Weight ; Compliance ; Diagnosis ; Edema ; Hemorrhage ; Lung Compliance* ; Lung* ; Oxygen* ; Rats*

Oxygen therapy is clear benefit in the treatment of tissue hypoxia, but high concentrations and long term exposures of oxygen carry the risks of detrimental physiologic changes and tissue damages. Tissue damages involve decreased surfactant production,alveolar edema, and alveolar hemorrhage. In spite of these damage, diagnosis of oxygen toxicity is difficult in many clinical settings. In this study, we measured lung compliance to evaluate the oxygen toxicity in 60 white rat of 100-150 g body weight Rats were divided into 6 groups. Group I was control graup, exposed to room air, group II -group V were exposed to 100% oxygen, group II for 24 hours, group IlI for 48 hous, group IV for 72 hours, and group V for 96 hours. Group VI was exposed to oxygen in serial as 30% oxygen for 24 hours, 60% oxygen for 24 hours and then 100% oxygen for 96 hours. After oxygen exposure we obseved changes of lung compliance and pathologic findings, compliance of group V was 15.94 mL/cmH2O significantly lower than that of eontrol group (p<0.05) and lung weight of group V was 2.16 g/100 g heavier than the other groups (p<0.05). Although we found oxygen tolerance was developed in group V, we could not differentiate the degree of pathologic damage cauesd from oxygen toxicity by pathologic findings. We concluded that the measurement of lung compliance is valuable in diagnosis of oxygen toxicity and thus in reducing lung damages.
Animals ; Anoxia ; Body Weight ; Compliance ; Diagnosis ; Edema ; Hemorrhage ; Lung Compliance* ; Lung* ; Oxygen* ; Rats*

BACKGROUND: Low values of lung compliance have been reported in patients with increased pulmonary blood flow due to intracardiac left to right(L-R) shunt. The compliance had returned to within normal limits 4 to 6 weeks after surgical correction of the shunt. We investigated whether lung compliance was improved immediately after surgical correction of the shunt. METHODS: Fifty four pediatric patients who were undergoing repair of intracardiac L-R shunt were evaluated. Lung compliance, arterial oxygen tension(PaO2) and arterial to end-tidal carbon dioxide tension difference(Pa-ETCO2) were measured after induction of anesthesia and at the completion of surgery. Left atrial pressure(LAP) was monitored. Lung compliance and end-tidal carbon dioxide tension were measured by monitoring system built in Cato anesthetic ventilator system. RESULTS: Lung compliance was significantly lower after surgery(6.57+/-6.46 ml/mbar) than after induction of anesthesia(7.71+/-7.18 ml/mbar). After surgery, PaO2 was significantly decreased and Pa-ETCO2 significantly increased than after induction of anesthesia. The decrease in lung compliance after surgery significantly correlated with a decrease in PaO2(r=0.43) and an increase in Pa-ETCO2 (r=0.47) but not correlated with LAP. CONCLUSIONS: Although surgical correction of intracardiac L-R shunt reduces pulmonary blood flow, the lung compliance decreases in immediate postoperative period. Therefore a deterioration of postoperative lung compliance may need judicious management for pulmonary and hemodynamic instability.
Anesthesia ; Carbon Dioxide ; Compliance ; Hemodynamics ; Humans ; Lung Compliance* ; Lung* ; Oxygen ; Postoperative Period ; Ventilators, Mechanical

BACKGROUND: The present study will focus on the rationale for the use of small tidal volume with 6 cmH2O positive end expiratory pressure (PEEP) with the changes of arterial oxygen tension, plateau airway pressure, and static lung compliance during one lung ventilation for endoscopic thoracic surgery. METHODS: Forty-three patients were intubated with a double-lumen endobronchial tube. After positioning the patients in the lateral decubitus, one-lung ventilation was started with 100% oxygen, tidal volume 10 ml/kg without PEEP; arterial oxygen tension, plateau airway pressure, and static compliance were checked as baseline values (T0). Fifteen minutes later, same parameters were measured (T15). The tidal volume had changed to 6 ml/kg with 6 cmH2O PEEP. Fifteen minutes later, the same parameters were measured (T30). RESULTS: Oxygen tension had decreased at T15 (282.1 +/- 83.4 mmHg) compared to T0 (477.2 +/- 82.4 mmHg) (P < 0.0001), but was maintained at T30 (270.4 +/- 81.9 mmHg). There was no difference in peak inspiratory pressure at T15 or T30 compared to T0, plateau airway pressure was increased at T15 and T30 (P < 0.05) and static lung compliance was decreased at T15 and T30 (P < 0.0001). CONCLUSIONS: In carrying out one-lung ventilation for thoracic surgery using an endoscope, the addition of a PEEP of 6 cmH2O in the dependent lung, while reducing the tidal volume of 6 ml/kg, both oxygen tension and lung compliance are maintained without increasing the plateau airway pressure. Protective lung ventilation is useful for one lung ventilation.
Compliance ; Endoscopes ; Humans ; Lung ; Lung Compliance ; One-Lung Ventilation* ; Oxygen ; Positive-Pressure Respiration* ; Thoracic Surgery* ; Thoracoscopy ; Tidal Volume* ; Ventilation*

OBJECTIVES: Although bronchoscopy is an important diagnostic tool for lung disease, patients compliance is low due to discomfort. Recently, midazolam which has a favorable anterograde amnesia effect and short action duration, has been used to relieve patients discomfort during bronchoscopy. Midazolam was investigated in order to see the beneficial effect and safety during bronchoscopy. METHODS: The study design was single blind, randomized, prospective. 102 patients were included, in whom bronchoscopy was performed between June, 19% and October, 1995 at Samsung Medical Center. They were categorized into midazolam group and control group. Patients were asked about the amnesic effect, discomfort of procedure and the willingness to repeat procedure. The consciousness level of patients during procedure, patient cooperation during procedure and ease of procedure were also reported by bronchoscopists. RESULTS: 1) The difference of oxygen saturation between two groups: There was no significant difference in oxygen saturation between midazolam group and control group before and after bronchoscopy. During procedure, however, mean oxygen saturations in midazolam group (90+/-6.4%) was significantly lower than in control group (93+/-4.7%)(p<0.05). 2) Evaluations by patients (1) Effect of amnesia: 41 patients (82%) in midazolam group could not recall the procedure but 52 patients (100%) recalled the entire procedure in control group. A favorable amnesic effects could be found in midazolam group(p<0.05). {2) The discomfort during the procedure: 43 patents(86%) did not experience discomfort from procedure in midazolam group but 25 patients(48%) complained of discomfort in control group (p<0.05). (3) Most patients except two(96%) were willing to repeat fiberoptic bronchoscopy in midazolam group but 13 patients (25%) answered that they would never repeat bronchoscapy. There was a statistically significant difference between two groups in the willingness to repeat bronchocopy (p<0.05). 3) The evaluations by bronchoscopists Cooperations of the patients and ease of procedure were not different between two groups. The patients in midazolam group except eight could not respond to verbal stimuli but most patients were awakened during procedure in control group(p<0.05). CONCLUSION: Midazolam is a good sedative agent for a patient to give a favorable amnesia, reduction of discomfort during bronchoscopy. We concluded that midazolam is a safe and useful sedative agent and midazolam may be used routinely during bronchoscopy. Monitoring of oxygen saturation, however, is essential to prevent severe hypoxia during procedure.
Amnesia ; Amnesia, Anterograde ; Anoxia ; Bronchoscopy* ; Compliance ; Consciousness ; Humans ; Lung Diseases ; Midazolam* ; Oxygen ; Patient Compliance ; Prospective Studies*

BACKGROUND: This study was designed to assess the effects of pneumoperitoneal pressure (PP) and positional changes on the respiratory mechanics during laparoscopy assisted colectomy. METHODS: Peak inspiratory pressure, plateau pressure, lung compliance, and airway resistance were recorded in PP of 10 mmHg and 15 mmHg, with the position change in 5 steps: head-down at 20degrees, head-down at 10degrees, neutral position, head-up at 10degrees and head-up at 20degrees. RESULTS: When the patient was placed head-down, the position change accentuated the effects of pneumoperitoneum on respiratory mechanics. However, when the patient was placed in a head-up position during pneumoperitoneum the results showed no pattern. In the 20degrees head-up position with the PP being 10 mmHg, the compliance increased from 30.6 to 32.6 ml/cmH2O compared with neutral position (P = 0.002). However with the PP being 15 mmHg, the compliance had not changed compared with neutral position (P = 0.989). In 20degrees head-down position with the PP of 10 mmHg, the compliance was measured as 24.2 ml/cmH2O. This was higher than that for patients in the 10degrees head-down position with a PP of 15 mmHg, which was recorded as 21.2 ml/cmH2O. Also in the airway resistance, the patient in the 20degrees head-down position with the PP of 10 mmHg showed 15.8 cmH2O/L/sec, while the patient in the 10degrees head-down position with the PP of 15 mmHg showed 16.2 cmH2O/L/sec of airway resistance. These results were not statistically significant but still suggested that the head-down position accentuated the effects of pneumoperitoneum on respiratory mechanics. CONCLUSIONS: Our results suggest that respiratory mechanics are affected by the patient position and the level of PP - the latter having greater effect.
Airway Resistance ; Colectomy ; Compliance ; Humans ; Laparoscopy ; Lung Compliance ; Pneumoperitoneum ; Respiratory Mechanics

OBJECTIVE: To analyze the factors influencing the capacity of cough, the relationships between maximal respiratory pressure, lung compliance, capacity of cough, and assisted cough techniques were evaluated in tetraplegics. METHOD: The vital capacity (VC) in seated and supine position, maximum insufflation capacity (MIC), maximum inspiratory (MIP) and expiratory (MEP) pressure in seated position were measured. Unassisted and assisted peak cough flow (PCF) at two different conditions (a volume assisted method by the mechanical insufflation [PCFmic] and the manual assistance by abdominal compression [MPCF]) were evaluated in 44 tetraplegic patients. RESULTS: The mean value of VC in supine was greater than that of seated position (p<0.01). The MICs of the subjects were significantly higher than VCs in a same position (<0.01). Both volume and manual assisted method showed significantly higher PCF than unassisted PCF (p<0.01). MIP (r=0.53) correlated with UPCF as well as MEP (r=0.68), although MEP was better correlated with UPCF. CONCLUSION: Generally the therapists apply manual pressure only to increase capacity of cough, which assist the expulsive phase. The results of this study showed that both inspiratory and expulsive phases should be assisted to enhance the effectiveness of cough.
Compliance* ; Cough* ; Humans ; Insufflation ; Lung Compliance ; Respiratory Muscles* ; Supine Position ; Vital Capacity

In 15 patients without cardiopulmonary disease, We studied the effects of positive end- expiratory pressure(PEEP) on the deadspace-tidal volume ratio (VD/VT ratio) and total static compliance after induction of anesthesia. PEEP of 0,37+/- and 15 cmH2O were sequentially applied. Mean VD/VT ratio and compliance were 0.34+/-7.11, 57+/-8 m17H70 at zero PEEP, 0.37 +/-0.06, 64+/-6ml/H2O at 10 cmH70 PEBP, 0.43+/-0.16, 59+/-8 ml/cmH2O at 10 cmH2O PEEP and 0.43+/-0.16, 59.8 ml/cmHaO at 15 cm/H20 PEEP At each level of PEEP, VD/VT retie and compliance had increased with elevation of PEEP. VD/VT ratio at 15 cmH20 was signica- ntlr differed from that of utero PEEP but not in compliance. We 77served in anesthetized patients with healthy lung that the ap1ication of PEEP up to 15 omHaO increased VD/VT ratio and compliance.
Adult* ; Anesthesia* ; Compliance* ; Humans ; Lung ; Positive-Pressure Respiration*