Biomedical subjects

P Haidl

Publications and source records attributed to P Haidl.

25 records · Page 2Linked to original sources

PubMed1997

[Pressure versus volume constant ventilation in chronic ventilatory insufficiency].

BACKGROUND: Volume controlled intermittent ventilation (IPPV) via face mask is a treatment of proven efficacy for chronic respiratory failure (CRF). Pressure support ventilation has recently been introduced in the treatment of CRF. In this study we investigated whether pressure constant ventilation (PCV) via face mask could be an adequate long term alternative to IPPV. PATIENTS AND METHODS: We studied 30 (24 male, age: 52.2 +/- 15.9 years) patients with CRF. We measured the following parameters at baseline, after 1, 2 and 6 months, respectively: blood gas analysis, oxygen saturation, vital capacity, forced exspiratory volume, breathing frequency, tidal volume, inspiratory mouth occlusion pressure, maximal inspiratory pressure, subjective symptom scores and ventilator acceptance scores. In all patients, we attempted to treat with IPPV over 1 month, followed by 1 month's trial of PCV. If PCV, compared to IPPV, was adequate, PCV was continued for a follow-up period of 4 months' duration. If patients deteriorated after PCV they were treated the following 4 months with IPPV. RESULTS: In 28 out of 30 patients CRF improved concerning subjective and objective parameters. After IPPV 18 out of 28 patients changed to PCV, with an equal quality of treatment (PCV-responder). Ten patients were PCV-nonresponders since compared to IPPV the subjective scores deteriorated and the PaCO2 increased again. In all patients of either therapy group, subjective and objective parameters remained constant for another 4 months period. At baseline the PCV-nonresponders had significantly higher degree of hypercapnia and oxygen desaturation; no other parameters were found to be of predictive value concerning the efficacy of PCV. CONCLUSIONS: PCV proved to be an alternative to IPPV in the treatment of chronic respiratory insufficiency in approximately 60% of the patients with CRF. However there is a subgroup with more severe CRF at baseline in whom PCV is inadequate.

Adult↗

PubMed1997

Comparison of two different modes for noninvasive mechanical ventilation in chronic respiratory failure: volume versus pressure controlled device.

The most commonly used mode of noninvasive mechanical ventilation (NMV) is volume-controlled intermittent positive pressure ventilation (IPPV). Pressure support ventilation has recently become increasingly popular, but its merits have not been clearly defined. In an open, nonrandomized follow-up study, we evaluated two modes of NMV, volume-controlled (IPPV) and pressure-controlled ventilation (PCV) over 6 months in 30 consecutive patients (24 males and 6 females, aged 49 +/- 19 yrs) with chronic respiratory failure (CRF). The baseline assessments comprised both physiological and subjective data. In all cases, nasal IPPV was initially administered for 1 month, followed by a second month of nasal PCV. Thereafter, responders or nonresponders to PCV were defined according to the patients' subjective symptom score and/or the recurrence of hypercapnia. During the IPPV phase, in all but two patients the subjective and objective parameters improved significantly. During the following 1 month PCV phase, stabilization was maintained in 18 patients ("responders"), while 10 patients were defined as "nonresponders". In nonresponders, hypercapnia increased (arterial carbon dioxide tension (Pa,CO2): 5.7 +/- 0.4 to 6.6 +/- 0.5 kPa; p < 0.05) and symptom scores decreased. Compared with responders, nonresponders had a lower mean nocturnal arterial oxygen saturation (Sa,O2) (p < 0.05) and a higher daytime Pa,CO2 (p < 0.05) at baseline. We con clude that the majority of patients suffering from chronic respiratory failure who are initially satisfactorily ventilated with intermittent positive pressure ventilation may also be adequately maintained with pressure-controlled ventilation. However, there is a subgroup with more severe chronic respiratory failure at baseline, in whom pressure-controlled ventilation is inadequate. After 4 weeks of treatment with pressure-controlled ventilation, the subjective scores and the arterial carbon dioxide tension values reliably distinguished between long-term responders and nonresponders to pressure-controlled ventilation.

Adult↗

PubMed1997

Daytime mechanical ventilation in chronic respiratory insufficiency.

Chronic respiratory insufficiency (CRI) is associated with nocturnal hypoventilation. Treatment with noninvasive mechanical ventilation (NIMV) performed overnight relieves symptoms of hypoventilation and improves daytime blood gases in CRI. In order to test whether the efficacy of NIMV depends on it being applied during sleep, we conducted a prospective case-controlled study comparing daytime mechanical ventilation (dMV) in awake patients with nocturnal mechanical ventilation (nMV) given in equal quantities. We enrolled 34 clinically stable patients (age 56.1+/-12.1 yrs, 20 females, 14 males) with CRI due to restrictive lung and chest wall disorders and neuromuscular disease. Using a prospective case-control design, matched subjects were allocated alternately to dMV and nMV. After 1 month of NIMV there was considerable symptomatic improvement in both dMV and nMV patients. There were no significant differences between groups in the improvement in daytime arterial carbon dioxide tension (Pa,CO2) (dMV from 7.5+/-0.6 to 5.7+/-0.6 kPa; nMV from 7.2+/-0.5 to 5.8+/-0.5 kPa, p<0.0001) and during the unassisted spontaneous night-time ventilation in terms of transcutaneous Pa,CO2 (dMV from 8.4+/-1.2 to 6.6+/-0.7 kPa; nMV from 8.2+/-1.2 to 6.8+/-0.5 kPa, p<0.0001). We conclude that in many respects, when compared to nocturnal mechanical ventilation, daytime mechanical ventilation in awake patients is equally effective at reversing chronic respiratory insufficiency. Since long-term safety issues were not addressed in this study, we recommend that nocturnal mechanical ventilation should remain the modality of choice for noninvasive mechanical ventilation.

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PubMed1996

[Intermittent self-ventilation in torsion scoliosis. Possibilities and limits].

BACKGROUND: In patients with hypercapnic respiratory failure due to restrictive lung diseases home mechanical ventilation leads to improvement of daytime blood gases and symptoms. In this paper we regard the possible pitfalls and complications associated with intermittent mechanical ventilation in patients with kyphoscoliosis. PATIENTS AND METHODS: From 1990 to 1994 we treated 30 patients suffering from severe kyphoscoliosis with home mechanical ventilation. RESULTS AND CONCLUSIONS: 1. As our cases show in the prehospital phase before initiating home mechanical ventilation there is still room for the outpatient pneumologists to improve their knowledge and awareness of symptoms and treatment of chronic respiratory failure. 2. In the subsequent inpatient phase and specialised center must be aware and experienced in regarding possible problems inherent with home mechanical ventilation. 3. After discharge during chronic home mechanical ventilation a good cooperation between the center, patient, relatives, general services and general pulmolgists is necessary. The centers should offer training courses for the caring persons and general pneumologists.

Adult↗

PubMed1996

[Intermittent self-ventilation after respirator weaning].

BACKGROUND: Weaning from the mechanical ventilator often proves to be difficult after prolonged ventilation due to excessive load or decreased capacity of the respiratory muscles. In the present retrospective study we examined the impact of the nocturnal mechanical ventilation during the "post-weaning-period" of long-term ventilated patients. PATIENTS AND METHODS: We studied 43 patients (23 men, 59.1 +/- 14.6 years) with chronic respiratory failure who were transmitted from external ICUs after a mechanical ventilation period of 57.5 +/- 60.3 days. The weaning regime consisted of an individually adapted volume-cycled ventilation. If the patients were hypercapnic (pCO2 > 48 mm Hg) after the first 24-hour-period of spontaneous breathing without supplemental oxygen nocturnal mechanical ventilation was initiated. RESULTS AND CONCLUSIONS: In a retrospective study we could show that the decision to initiate invasive or noninvasive nocturnal mechanical ventilation after successful weaning primarily depends on the question whether a chronic hypercapnic respiratory failure persisted also after weaning from long-term mechanical ventilation. In about 40% of unselected patients nocturnal mechanical ventilation stabilized the weaning success whereas 60% of the patients did not need any further nocturnal mechanical ventilation.

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PubMed1995

[Effectiveness of intermittent self-ventilation after ventilator weaning].

The essential cause for long-term mechanical ventilation with unweanability from respirator is chronic failure of the inspiratory muscles. Principally two different causes exist for chronic respiratory failure: Primary pulmonary diseases with overload or load imbalance of primarily uncompromised respiratory muscles, and neuromuscular diseases with a significant decrease in respiratory muscle capacity. Intermittent nocturnal ventilation (INV) leads to recovery by unloading the respiratory pump. In the present retrospective study we examined the value of INV in the "post-weaning-phase" for previously unweanable, long term ventilated patients. In two years (1993 and 1994) 43 patients who had been ventilated for 57.5 +/- 60.3 days in outward intensive care units (ICU) in a predominantly assisted mode we could wean from the respirator within 8.4 +/- 5.5 days by means of consequently applying an individually adapted, volume cycled weaning regime. In all patients, on admission to our ICU and before discharge blood gases, P0.1, Pimax, breathing frequency and tidal volume were measured during spontaneous breathing. After weaning in about 40% of our patients we decided to initiate INV with intermittent positive pressure ventilation (IPPV). The indication for INV after weaning depended on whether a chronic hypercapnic respiratory failure continued to be demonstrable. In this group of patients, INV was the essential stabilizing factor for continuous weaning success, as the respiratory muscles recovered during the ensuing inpatient phase and the daytime PaCO2 normalised. In most of our patients (14 out of 18) INV could be performed non-invasively via breathing masks. Only 4 out of 18 patients continued to be long-term ventilated invasively via tracheostomy. The remaining patients (25 out of 43) showed normoventilation at daytime during the ensuing inpatient phase so they did not need INV. At the time of the patients' referral to our ICU, there was no predictive value regarding the ultimate indication for INV after weaning from respirator.

Adult↗

PubMedDate not supplied

Long-term oxygen therapy stops the natural decline of endurance in COPD patients with reversible hypercapnia.

BACKGROUND: Respiratory muscle weakness is one of the most important causes of hypercapnia in patients with COPD. There is evidence that stable hypercapnic patients will benefit from long-term oxygen therapy (LTOT). OBJECTIVES: The prognostic role of reversible hypercapnia in COPD is still unclear. Early implementation of LTOT in these patients may influence endurance time and mortality. METHODS: In this pilot study, we investigated 28 patients (26 males, 49-74 years) with COPD, advanced airflow limitation [forced expiratory volume in 1 s (percentage of predicted value) 40.8 +/- 10.2] and mild hypoxaemia (pO(2) 66.5 +/- 6.3 mm Hg). All patients had developed a moderate reversible hypercapnia during an acute exacerbation or during exercise testing (peak pCO(2) 48.0 +/- 2.5 mm Hg). Patients were allocated randomly to a control group (n = 14) or an LTOT group (n = 14). The two groups were well matched in terms of physiological data. Lung function, endurance time (cycle ergometer), dyspnoea score, blood gases and LTOT compliance were measured at baseline and every 6 months over a period of 3 years. RESULTS: Endurance time increased from 6.4 +/- 2.7 min at baseline to 7.1 +/- 2.7 min after 1 year in the LTOT group and decreased from 6.1 +/- 3.0 to 4.9 +/- 3.8 min in the controls (p < 0.05). After 1 year, the end-exercise dyspnoea score was significantly lower in the LTOT group (4.5 +/- 1.5) than in the controls (5.7 +/- 1.9). CONCLUSION: COPD patients with reversible hypercapnia and mild hypoxaemia benefit from LTOT in terms of endurance time and a reduction of exertional dyspnoea after 1 year.

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