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At least 19 recordsLinked to original sources
PubMedDate not supplied

[Do the severity and duration of rheumatoid arthritis influence pulmonary ventilation?].

Pulmonary ventilation was studied in 100 patients with rheumatoid arthritis of an outpatient clinic, using whole-body plethysmography, spirography, and pneumometry. The patients with more or less severe joint involvement, as well as the patients with shorter or longer duration of their disease, did not show any significant difference in their dynamic and static pulmonary fuction. Patients with serious joint destructions showed a bronchial obstruction in 29%. 36 patients who were treated with thioglucose gold had a significantly better expiration capacity. A causal connection with the underlying disease is discussed. Further examinations should take therapeutic procedures and longitudinal studies into consideration. It is doubtful that significant restriction of ventilation is present in rheumatoid-arthritis. Methodically there was a good argreement between whole body plethysmography and pneumometry.

Adult↗
PubMed2000

Comparison of intratracheal pulmonary ventilation and hybrid intratracheal pulmonary ventilation with conventional mechanical ventilation in a rabbit model of acute respiratory distress syndrome by saline lavage.

OBJECTIVES: To study changes in PaCO2 and PaO2 during intratracheal pulmonary ventilation (ITPV) and hybrid intratracheal pulmonary ventilation (h-ITPV) compared with conventional mechanical ventilation (CMV) in a rabbit model of respiratory failure, and to define the technique of h-ITPV that combines conventional mechanical ventilation and ITPV. DESIGN: Prospective, interventional study. SUBJECTS: Twelve adult New Zealand White rabbits. INTERVENTIONS: Surfactant deficiency was induced by saline lavage, and rabbits were randomized to either ITPV or h-ITPV. The study consisted of four phases: phase 0, CMV after saline lavage, ventilator rate 30 breaths/min; phase I, ITPV or h-ITPV initiated at the same pressure and rate as in phase 0; phase II, ITPV or 1.0 L/min h-ITPV bias flow, with peak inspiratory pressure (PIP) decreased and ventilator rate increased to achieve the lowest tidal volume while maintaining adequate gas exchange; and phase III, animals returned to CMV. MEASUREMENTS AND MAIN RESULTS: In phase I, no difference in PaCO2 was observed between ITPV, h-ITPV, or CMV. There was a decrease in PaO2 when switching from CMV to ITPV but not to h-ITPV. In phase II, it was possible to decrease PIP (average of 37% for ITPV and 36% for h-ITPV) and tidal volume (average of 64% for ITPV and 53% for h-ITPV) without compromising gas exchange (p < .05). Oxygenation tended to improve from phase 0 to the end of phase II. In phase III, PaCO2 increased (average of 71% for ITPV and 79% for h-ITPV) and pH decreased (p < .05). Normocapnia was achieved using significantly higher PIP and tidal volume, compared with phase 0 (p < .05). CONCLUSIONS: ITPV and h-ITPV can effectively ventilate and oxygenate rabbits with surfactant-deficient lungs at tidal volumes and therefore pressures lower than required with CMV. Maximum benefit appears to occur at high ventilator rates. These findings suggest that both modes of ventilation may represent powerful new tools in the management of patients with acute respiratory failure. (Crit Care Med 2000; 28:774-781)

Acute Disease↗
PubMed1996

[Attempt of helical CT densitometry for assessing regional pulmonary ventilation].

Pulmonary dynamic CT densitometry during steady-state breathing was recorded and analyzed using helical CT scan in 14 patients with obstructive disorders involving small and large airways, and 2 with restrictive lung disease. The data set of 7-second, continuous helical scan at constant table position were reconstructed as 35 one-second temporarily overlapping images at 0.2- second intervals over 2-3 respiratory cycles, and regional CT densitometry was displayed. Normal lungs (5 volunteers) showed a regular sinusoidal curve, and maximal lung density change (LDC) was greater independent lungs than in independent lungs, with an average difference of 29.5 HU, indicating the gravitational effect In contrast, a regular sinusoidal curve was not shown in obstructive disorders, and a significant reduction in maximal LDC (33.7 +/- 22.6 HU) compared with the normal lungs (60.8 +/- 25.9 HU) (P < 0.001) was indicated. In contrast, no marked reduction in maximal LDC (53.7 +/- 28.6 HU) was shown in restrictive disorders. This method is fast and easy, and appears useful for the detection of ventilation abnormalities in obstructive lung disorders.

Absorptiometry, Photon↗
PubMedDate not supplied

Comparison of intratracheal pulmonary ventilation with hybrid intratracheal pulmonary ventilation in a rabbit model of acute respiratory distress syndrome by saline lavage.

We compared different hybrid mode ITPV (h-ITPV) flow rates, and h-ITPV with intratracheal pulmonary ventilation (ITPV) with respect to CO2 clearance and oxygenation. Surfactant deficiency was induced in six adult rabbits with saline lavage. The study consisted of three phases. Phase 0: Stabilization on conventional mechanical ventilation (CMV). Phase I: Bias flow initiated at same pressure and respiratory rate as Phase 0. Flow rates of 25%, 50%, 75% h-ITPV, and ITPV were initiated. Animals were transitioned from CMV to 25% h-ITPV proceeding sequentially to ITPV or vice versa. Phase II: Animals were returned to CMV. Statistical analysis included the two-way analysis of variance (ANOVA) and repeated measures ANOVA with Tuckey's test. No difference in PaCO2 was observed among all h-ITPV flow rates or between h-ITPV and ITPV. After bias flow was introduced (transition from Phase 0 to Phase I), PaCO2 decreased by 37%. PaCO2 increased by 119% during Phase II. Oxygenation improved in all animals, particularly in those transitioned to 25% h-ITPV and proceeding to ITPV. No difference in CO2 clearance between ITPV and h-ITPV was observed. Even at low bias flows, excellent CO2 clearance was achieved. Oxygenation was superior when animals were transitioned from CMV to h-ITPV. Hybrid-ITPV offers some advantages over ITPV and may represent a powerful tool in the management of acute respiratory distress syndrome (ARDS).

Animals↗
PubMed1979

Influence of an end inspiratory pause on pulmonary ventilation, gas distribution, and lung perfusion during artificial ventilation.

Using a constant tidal volume and ventilatory frequency, anesthetized piglets were ventilated with a new tidal volume ventilator. A short inspiratory time without a pause (10% of breathing cycle) was compared with a longer inspiratory time with a pause (33%) both with and without bronchial obstruction. Mechanics of ventilation, pulmonary ventilation, gas exchange, gas distribution, and lung perfusion were measured. The longer inspiratory time with a pause resulted in lower peak airway and end inspiratory pressures and a higher total compliance. Dead space/tidal volume ratio was reduced and the RQ was increased. While the cranial pulmonary fields were less well ventilated, the right caudal field was better ventilated. In the presence of bronchial obstruction, better alveolar ventilation was achieved when an end inspiratory pause was added. The results emphasize the importance of static end inspiratory tracheal conditions although the tidal volumes were kept unchanged.

Animals↗
PubMed1979

Influence of ventilatory frequencies and ventilator volume/pressure quotients on pulmonary ventilation using a tidal volume ventilator.

The influence of ventilatory frequency and the ventilator's "internal state of gas compression" (Cvent) on mechanics of ventilation, pulmonary ventilation, gas distribution, gas exchange and lung perfusion was studied with free airway and experimental regional airway obstruction in 10 piglets (7-12 kg b. w. ), using a tidal volume ventilator. The VDphy/VTexp ratio was greater at f = 30 than at f = 10.3 cycles/min. This could be related to a significant increase in the VDanat/VTexp ratio at f = 30, while VDc/VTexp and VDlav/VTexp were unchanged at both frequencies. With regional ventilation and perfusion within the obstructed pulmonary field were reduced, compared to the values at f = 10.3 cycles/min. With Cvent 20 ml/kPa, the tidal volumes were insufflated in a shorter time and with a higher initial tracheal peak pressure than with Cvent 80 ml/kPa. Following bronchial obstruction, VA, RQ and Pao2 were greater with Cvent 20 than with Cvent 80 ml/kPa. With Cvent 20, the ventilation of the lung bases was reduced, which was compensated for by a large increase in ventilation within the apical areas of the lungs, while gas distribution within the unobstructed areas was more evenly distributed with Cvent 80. Ventilation at Cvent 20 showed no essential advantage over Cvent 80. Only in lungs extremely difficult to ventilate and with ventilatory frequencies over 50 cycles/min could possible indications for Cvent 20 be seen.

Animals↗
PubMed1997

Clearance of mucus from endotracheal tubes during intratracheal pulmonary ventilation.

BACKGROUND: Intratracheal pulmonary ventilation (ITPV) is a form of tracheal gas insufflation in which all gas emerges in a cephalad direction from the tip of a reverse-thrust catheter positioned within an endotracheal tube. In vitro experiments have shown that this rapid gas flow, with 5 ml/h of normal saline added to the gas flow, continuously removes tracheal secretions from within the endotracheal tube. The authors evaluated its effectiveness to remove mucus in long-term studies in sheep. METHODS: Fourteen healthy sheep were tracheally intubated and ventilated for 3 days with ITPV or with volume-controlled ventilation. Measurements were made of the total amount of secretions within the endotracheal tubes (weight gain), the protein content within the endotracheal tubes, and the increase in resistance to constant air flow. The structure of the airways was examined grossly and histologically. Three additional sheep were ventilated for 24 h with ITPV, and Evans Blue dye was added to the saline to assess the distribution of the infused saline. RESULTS: There was significantly less mucus in endotracheal tubes of sheep ventilated with ITPV than with conventional ventilation, as shown by minimal weight gain (0.70 +/- 0.14 g vs. 2.44 +/- 0.81 g; P < 0.001), lower protein content (14.09 +/- 10.79 mg vs. 294.99 +/- 153.06 mg; P < 0.001), and lower resistance to constant air flow (6.15 +/- 0.54 cm H2O x 1(-1) x s(-1) vs. 15.34 +/- 5.28 cm H2O x 1(-1) x s(-1); P < 0.001). Results of gross and histological examinations of the tracheas of animals in both groups were similar, and the tracheas were well preserved. More than 95% of the instilled saline was recovered during ITPV. Only traces of Evans Blue dye were found near the tip of the endotracheal tubes. CONCLUSION: Intratracheal pulmonary ventilation makes it possible to keep the endotracheal tubes of sheep ventilated for 3 days free of mucus without suctioning.

Animals↗
PubMed1990

[Pulmonary ventilation and central hemodynamics in pulmonary tuberculosis patients].

Computerized devices were used for evaluation of the state of pulmonary ventilation and central hemodynamics in 32 patients with pulmonary tuberculosis depending on the spread of the specific process. Patients with limited changes in the lungs, showed disorders of bronchial patency and compensatory increase of organic ejection of the right ventricle. In the presence of spread changes in the lungs the above mentioned changes were supplemented by restrictive ventilation disorders with a reduction of the contractile myocardial capacity. These functional changes should be considered in the treatment of patients with pulmonary tuberculosis.

Adolescent↗
PubMedDate not supplied

[Biorhythmologic analysis of the dynamics of indices of pulmonary ventilation during orthostatic manipulations].

Pulmonary ventilation parameters (breathing depth, frequency and minute volume, and alveolar ventilation) of 5 healthy male test subjects who performed a 20-minute tilt test were analyzed. During tilt tests the above parameters showed oscillations in a range of about 1 minute. During the first 1-3 minutes of exposure the parameters exhibited an accentuated synchronization of the oscillations and the phenomenon of "general autonomic switch-over" with the negative phase (fall of the parameters under study below the baseline level after an initial increase above the baseline level). From the 4th minute till the 6.5th minute the function of individual components of the pulmonary ventilation system mismatched and the respiration efficacy fell. Thereafter this synchronization of the processes studied returned to the normal. Adequate adaptation of pulmonary ventilation to tilting developed not earlier than during the 13-14th minute.

Adult↗
PubMed1996

Intratracheal pulmonary ventilation provides effective ventilation in a near-drowning model.

Overdistension of the lungs from high inspiratory pressure is increasingly recognized as a major contributor to lung injury and worsening respiratory failure in the child who requires prolonged mechanical ventilation. Many modes of ventilation (such as high-frequency ventilation) have been introduced in an attempt to decrease this lung injury. Recently, a new mode of tracheal ventilation, intratracheal pulmonary ventilation (ITPV), has been described. By using a catheter positioned at the carina with continuous gas flow, it is possible to achieve effective ventilation at very low pressures. The purpose of this study was to evaluate the usefulness of ITPV in a near-drowning model. Ten domestic Yorkshire swine underwent arterial, venous, and pulmonary arterial catheter as well as tracheotomy placement. All animals received 13 mL/kg of fresh water intratracheally to induce a pulmonary injury. Six pigs were ventilated for 4 hours using ITPV; the other four pigs received conventional mechanical ventilation (CMV). Circulatory and ventilatory pressures, hemodynamic variables, arterial blood gases, and end-tidal CO2 were measured before lung injury and every 30 minutes thereafter. Both proximal and distal peak and mean airway pressures were measured. The animals were ventilated as needed to maintain the arterial blood gases in the normal range. The authors found the expected changes in pulmonary compliance, oxygen requirement, and airway pressure after inducement of lung injury. The six animals treated with ITPV had significantly lower airway pressures than those of controls. Peak inspiratory pressures with ITPV were 8.2 +/- 1.9 cm H2O versus 17.8 +/- 3.7 with CMV (P < .001). Distal mean airway pressures using ITPV were 2.3 +/- 0.1 cm H2O versus 9.0 +/- 3.2 with CMV (P < .01). With respect to hemodynamic variables, there were no differences between experimental and control animals. In conclusion, ITPV can afford effective ventilation in a near-drowning model of lung injury at airway pressures significantly lower than those required with CMV. ITPV could be a very valuable addition to the currently available methods of mechanical ventilation.

Animals↗