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At least 937 records · Page 52Linked to original sources
PubMed1985

[Special artificial respiration procedures and intracranial pressure. Animal experiment studies, development and use of a new pressure measuring technic, clinical aspects].

We investigated the influence of Forced Diffusion Ventilation (FDV), a special form of High Frequency Ventilation (HFV), on elevated intracranial pressure (ICP) in 5 dogs. Elevation of ICP was standardized by inflation of an epidural balloon. A typical finding with FDV is a reduced intrapleural pressure and therefore one could expect a better cerebrovenous drainage influencing ICP. Nevertheless, we found no changes in mean ICP under conditions of FDV compared with IPPV. Respirator-synchronous fluctuations of ICP, cisternal cerebrospinal fluid pressure and intrapleural pressure were drastically reduced with FDV. This phenomenon has been already reported by other groups as a typical effect of HFV with rates of 100/min. One can speculate, that this immediate impact of HFV on ICP-curves might be of some advantage in patients with critically reduced intracranial compliance requiring long-term artificial ventilation, because peaks and amplitudes of ICP are reduced. Our clinical experience with High Frequency Pulsation (HFP) includes 11 patients with severe brain trauma. In clinical routine this method of HFV is more facile to applicate than FDV, because there is no need of a special endotracheal tube and sufficient CO2-elimination is not strongly dependent on precise position of the tube. But HFP, as FDV, includes all advantages of respiratory systems, that are open against atmosphere (coughing and simultaneous breathing, without drastically increasing airway pressure, suction during respiration, etc.). However, we could find no special advantages or disadvantages in ICP-course during long-term application of HFP (up to 10 days). Because application of HFV is dependent on special technical equipment, we investigated in 6 patients the influence of respiratory frequency, tidal volume and inspiratory flow on ICP-fluctuations using conventional ventilators. ICP was recorded by a new, self constructed pneumatic epidural pressure sensor. Ventilator-related ICP-fluctuations were found to be markedly reduced at frequencies of 20/min and usually eliminated at 30/min. We found an exponential correlation between ICP-fluctuations and respiratory frequency and there was no correlation between tidal volume and ICP. Central venous pressure amplitudes were found to be in linear correlation with respiratory frequency and tidal volumes as well. The amplitude of respiratory ICP-fluctuations seems to be more dependent on duration of expiratory time. As our findings demonstrate, artificial ventilation without entilator-related fluctuations in ICP ("brain-protective" ventilation) may be performed by conventional volume-constant, time-cycled ventilators.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1985

[Indirect calorimetry in artificially respirated children. 2. A measuring procedure and its evaluation in a newly developed metabolism-lung model].

A new device for continuous measuring oxygen uptake (VO2) and carbondioxide elimination (VCO2) in artificially ventilated or CPAP-system breathing children has been developed. A dual-channel analyzer system based on zirconiumoxyd cells measures oxygen fractions. This allows not only single measurements but also continuous determination of fraction differences for oxygen (delta FO2) (accuracy +/- 0.003 Vol%). Carbondioxide is measured by infrared absorption. A mixing device for inspiratory gas was designed to smooth fluctuations of inspired oxygen fractions almost completely. The reliable sampling system for expiratory gases has already been described [19]. The breathing-e.g. ventilating-system was modified in such a way that the total gas flow is independent of mode and breathing volume (equally 15 l/min). For which purpose we use a self aspirating, time-cycled, volume limited respirator or a high-flow-CPAP-system. The prototype described ran test performances on a specially developed pneumatic metabolic-lung-model. This new lung model enables free choice of respiratory quotient (R) by independent setting of O2-uptake and CO2-elimination. Under these controlled laboratory conditions gasvolume-balances correspond to expected values in children really as shown during simulated trials. In the metabolic-lung-model accuracy and reproduction averaged +/- 1% for VCO2. Both were independent of the mode of ventilatory support, FIO2, and R. Determinations of VO2 were more dependent on FIO2 and R. After computing primary data according to a special formula which equalizes differences between VI and VE the maximal error was +/- 7%. Maximum difference between preset and measured R-values ranging from 0.769 to 1.429 was -4.6%, determined at R = 1.429. By means of this independent test series insights into clinically expected measurement errors and dimensions of limits of accuracy could be demonstrated. It seems to be justified that our newly developed device for accurate measuring O2-uptake and CO2-elimination is highly recommendable for use in extremely difficult conditions as in ventilated children.

Calorimetry↗
PubMed1989

[Nightly home artificial respiration in juvenile Pompe's disease with pulmonary hypertension and right cardiac insufficiency].

A 17-year-old girl with type II glycogen storage disease (Pompe's) developed severe right-heart failure as a result of pulmonary hypertension due to, predominantly nocturnal, hypoventilation. At night the partial pressure of oxygen was only 30-50 mmHg, pCO2 70-100 mmHg. After persistent nightly intermittent positive pressure ventilation blood gases as well as electrocardiographic and echocardiographic findings have now--after 12 months--become normal and the patient has been completely restored to a normal life. This case demonstrates that life expectancy and quality of patients with chronic forms of Pompe's disease (and probably also with other chronic neuromuscular diseases) can be markedly improved by nightly artificial ventilation which reduces nocturnal hypoventilation and resulting pulmonary hypertension.

Adolescent↗
PubMed1984

[Treatment results in 951 newborn infants with IRDS (idiopathic respiratory distress syndrome), especially in relation to artificial respiration from 1967 through 1981].

UNLABELLED: Evaluation of intermittent positive pressure ventilation (IPPV) in newborn children is presented by analysis of the data of all 951 children with hyaline membrane disease (HMD) treated in the Wilhelmina Gasthuis during the years 1967-1981. Gestational age varied from 24 to 39 weeks. Birthweight varied from 600-4660 grams. RESULTS: Overall survival was 64.9%. The incidence of pneumothorax, intracranial hemorrhage and bronchopulmonary dysplasia (BPD) was 11.5%, 18.2% and 11.3% respectively, related to the total number of patients. The overall survival did not change. The mean gestational age decreased from 31.6 in the first 5 years to 30.7 in the last 5 years. The mean birthweight decreased from 1873 to 1588 grams. The incidence of IPPV rose from 32.8 to 57.3%. For a separated group artificially ventilated children with gestational ages of greater than or equal to 28 weeks and less than or equal to 33 weeks and with birthweight greater than or equal to 1000 grams and less than or equal to 2499 grams survival increased from 36 to 50% and mean birthweight decreased from 1636 to 1489 grams. Introduction of continuous positive airway pressure (CPAP) did not change either incidence of IPPV or incidence of BPD. The most important determinants of a poor prognosis are low gestational age, low birthweight and necessity of IPPV. The prognosis of the individual patient is improved. The continuously bad prognosis for children with very low birthweight (less than 1000 grams) with HMD makes the search for other ventilation techniques worthwhile.

Birth Weight↗
PubMed1994

[Indications for the use of closed endotracheal suction. Artificial respiration with high positive end-expiratory pressure].

UNLABELLED: A new closed tracheo-bronchial suction system was evaluated. With this device the patient need not be disconnected from the ventilator during suctioning, and can thus have a continuous supply of oxygen. The closed suction system is attached to the patient's endotracheal tube and ventilator Y-piece. The catheter, which is enveloped by a plastic sheet, can remain connected to the patient for as long as 24 h (Fig. 1). MATERIALS AND METHODS. In the medical and surgical intensive care unit of Alt/Neuötting General District Hospital, 39 trials on 16 mechanically ventilated patients receiving more than 8 cm H2O positive end-expiratory pressure (PEEP) and/or more than 60% FiO2 were performed. Each subject was suctioned using the open and closed methods. Arterial blood gases were obtained through an indwelling catheter before suctioning and then 1, 5, and 15 min after suctioning. Open suctioning: After 2 min preoxygenation with 100% oxygen the patient was disconnected from the ventilator, the suction catheter was inserted and the subject suctioned for a maximum of 15 s, then manually ventilated four times and reconnected. Closed suctioning: After preoxygenation the patient was suctioned without disconnection by means of the closed suction system. Statistical analysis was done by the two-tailed t-test on individual paired differences or by Student's t-test. P values of less than 0.05 were accepted as significant. RESULTS: Patients were subdivided according to the PEEP level used (less or more than 8 cm H2O) and analysed separately. One minute after suctioning (T1) arterial pO2 was found to increase significantly for the open-system method when PEEP ventilation was < or = 8 cm H2O (Table 1) and for the closed system method when PEEP ventilation was both < or = 8 cm H2O (Table 1) and > 8 cm H2O (Table 2). Five (T5) and 15 (T15) min after suctioning, pO2 dropped significantly compared to baseline values in the open-system method when PEEP was > 8 cm H2O (Table 2). PO2 values 15 min after closed suctioning with PEEP > 8 cm H2O were significantly higher than those after open suctioning (Table 2). After the pO2 differences were formed between baseline and values 1, 5, and 15 min after suctioning, significant differences between open- and closed-system suctioning were found for PEEP > 8 cm H2O at T1, T5, and T15 (Table 2, Fig. 3). DISCUSSION. The increase in pO2 as a positive effect of preoxygenation with 100% oxygen before suctioning was less marked for open-system suctioning with PEEP > 8 cm H2O because FiO2, measured at the ventilator Y-piece, was abruptly reduced after disconnection and simultaneously PEEP was lost. As a consequence, pO2 values fell significantly 5 and 15 min after suctioning in this situation, whereas for all the other conditions pO2 reached baseline as well as slightly higher values. Patients with severe respiratory insufficiency need continuous positive airway pressure to keep unstable alveoli patent. Every maneuver that reduces intra-alveolar pressure may precipitate alveolar collapse. However, in the diseased lung closed alveoli may not re-expand at once when pressure is re-established. Therefore, closed-system suctioning may help to prevent prolonged deterioration of oxygenation in patients with severe respiratory failure.

Adult↗
PubMed2001

[Survival with artificial respiration at home. An open, prospective study on home ventilation for neuromuscular diseases, in particular, the situation of ALS patients].

A growing number of patients with neuromuscular disease have been treated with home mechanical ventilation during the past 15 years. We prospectively examined the long-term effects and complications of this method, particularly with regard to noninvasive positive pressure ventilation (NPPV). Thirty-one patients with amyotrophic lateral sclerosis (ALS, n = 20) or other slowly progressive neuromuscular diseases (NMD, n = 11) were observed for 17,517 home ventilation days (almost 48 ventilation years). The mean observed ventilation time was 565 days (min/max: 30/2930). Twenty-five patients were ventilated noninvasively with different masks. The calculated mean survival with NPPV ventilation (criteria: death, tracheostomy, or patient deciding to break off) was 2052 (SE: +/- 317.8) days in the NMD group, 248 days (+/- 35.7) for ALS patients without bulbar symptoms, and 82 days (+/- 27.4) with bulbar paralysis. Complications with the need for intervention were observed six times more frequently with ALS than with NMD. NPPV is effective for years in patients with slowly progressing NMD. Those ALS patients without bulbar symptoms can profit for up to a year from NPPV, while those with bulbar paralysis can have some symptom relief. Complications of every kind are much more frequent in ALS patients.

Adult↗
PubMed1989

[Weaning from artificial respiration: value of continuous monitoring of mixed venous oxygen saturation].

Weaning from mechanical ventilation is particularly difficult in patients with combined cardiac and respiratory failure. Continuous monitoring of mixed venous blood oxygen saturation (SvO2) redefines weaning in terms of tissue oxygenation. A stable SvO2 greater than 60% during weaning is a reliable index of weanability. However, further studies are required to establish a tolerance threshold for SvO2 during weaning. In the limited experience reported here, an immediate and abrupt fall in SvO2, when the patient started to breathe spontaneously was invariably associated with difficulties in weaning. In some patients, other signs of left ventricular dysfunction rapidly ensued, with a fall in cardiac index. Weaning remained possible if the treatment was capable of increasing cardiac output and normalizing SvO2. If, during spontaneous breathing, SvO2 remained stable in the 50-55% range, with no significant decrease in cardiac output, abrupt and unpredictable drops of SvO2 under 40% range occurred. Such falls always preceded signs of tissue hypoxia, leading to a resumption of controlled mechanical ventilation. However, further studies are required to fully delineate the role of SvO2 in the fine tuning of inotropic support and ventilatory assistance in the difficult weaning of patients recovering from cardio-respiratory failure.

Cardiac Output↗
PubMed1991

[Physical characteristics of devices for artificial respiration].

Expired air resuscitation forms an essential part of First Aid in patients with respiratory insufficiency. The use of devices should encourage the rescuer to start the measure, make it easier to perform and protect him from a possible transmission of infectious material. 17 devices (mask, tube instruments) were examined in respect of their physical properties (resistance, leakage). None of them fulfilled all the criteria relevant for their use. In most of them changes and modifications seem to be necessary. Mask and tube instruments have definitive disadvantages compared to foil-like adjuncts which are being developed at present.

Humans↗