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Results for “Intermittent Positive-Pressure Ventilation”

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At least 37 records · Page 2Linked to original sources
PubMed1977

[Two-phase respiration of apnoeic newborn, basic research and clinical value (author's transl)].

Studies on fetal human and calf lungs proved an 1: 2,5 increase rate of the transpulmonary blood-flow after inflation of the alveolar spaces. The extent of the inflation depends on the function pressure X time. Based on the rupture rate of the pulmonary tissue, the factor pressure is limited to 20-30 ch H2O. Consequently the inflation only can be obtained by increasing the factor time. Conditional on the flow resistance in the variably calibrated branches of the pulmonary system, the maximal pressure of 30 cm H2O has to act repeated continuously at least 10 seconds over an endotracheal tubus. Only then even the periphere alveoles will fully be inflated (phase I equals monotone inflation phase). An intermittend pressure breathing of maximal plus 30 cm H2O respectively-30 cm H2O will be supporting. After the total inflation short pressure waves of plus 30 cm H2O in physiological frequency (equals 30/minute) will do for further ventilation of the alveoles (phase II equals rhythmical ventilation phase).

Asphyxia Neonatorum↗
PubMed1978

[Comparative study of venous contamination with low FiO2 and with pure oxygen in disease-induced pulmonary edema].

A comparative study of the venous contamination (Qs/Qt = (Cc'O2 - CaO2) / (Cc'O2 - C-vO2) under FIO2 = 0.45 - 0.6 and under FIO2 = 1, was realised in 9 patients with lesions of pulmonary oedema. Increasing the FIO2 lead to an increase in the venous contamination three times (average increase was 36 p. 100 of the initial value), to no change two times and a decrease four times (average decrease of 34 p. 100). The values of the venous contamination under average FIO2 are statistically lower in the group where it rises on increasing the FIO2 than in that in which it falls or remains unchanged (p is less than 0.005).

Humans↗
PubMed1976

[Note on the care of tracheotomized patients].

After considering the indications for tracheotomy on his intensive care unit, the author describes the risks of this operation and the means of avoiding them. Out of 1940 patients admitted over a period of 5 years on the intensive care unit of the Royal Victoria Infirmary, Newcastle-on-Tyne, 175 were tracheotomised, inclusing 133 who were submitted to intermittent positive pressure ventilation. Only three patients had complications linked to the tracheotomy, complications which were the cause of the death of two of them.

Hemorrhage↗
PubMed1977

Malarial lung: report of a case from Africa successfully treated with intermittent positive pressure ventilation.

We describe the first recorded case from Africa of malarial lung, acute pulmonary insufficiency in Plasmodium falciparum malaria. The patient was successfully treated with intermittent positive pressure ventilation (IPPV). There was heavy parasitemia, preceding cerebral complications and rapid onset of pulmonary edema in the absence of fluid overload or cardiac failure. A further complication of polyuria from tubular dysfunction developed whilst the patient was being ventilated. IPPV may have an important place in the management of this rare and usually fatal complication of falciparum malaria.

Adult↗
PubMed1976

Pulmonary function in premature lambs during the first few hours of life.

This study establishes the mean values, variations, and trend of pulmonary function during the first few hours of life in premature lambs. Measurements of intraesophaheal and tracheal pressure, air flow, tidal volume, and functional residual capacity enabled calculations of lung compliance, specific lung compliance, and inspiratory and expiratory resistance of the lungs. Arterial carbon dioxide tension and pH were maintained within a physiologic range. Mean arterial oxygen tension (PO2) at elevated inspired oxygen tension, varied in the individual animals from 51 to 185 mm Hg at an inspired oxygen concentration of 46 to 71%. It was found that the lungs of premature lambs delivered by cesarean section were mechanically unstable; the lambs were all ineffectual at breathing and required some form of mechanical ventilation. During the first 6 hours of postnatal life the lungs of premature lambs are characterized by a wide range of mechanical values and blood gas tensions.

Animals↗
PubMed1977

Air embolism with positive-pressure ventilation of rats.

Although air embolism is known to occur in humans and animals when the lung is overdistended, very few cases have been reported to be associated with positive-pressure ventilation. We have observed that air embolism occurs in rats ventilated with high inspiratory pressures (70 cmH2O) associated with high end-expiratory pressures (10 cmH2O). However, it does not occur in normal rats if the end-expiratory pressure is less than 5 cmH2O or the peak inspiratory pressure is below 60 cmH2O when the frequency of ventilation is 30. Hemorrhagic shock predisposes to air embolism, whereas conditions with pulmonary edema (fluid overloading, lung injury from ventilation with high inspiratory and low expiratory pressures, or oxygen toxicity) decrease the probability of its occurrence.

Animals↗
PubMedDate not supplied

[Immediate effects and conditions of effectiveness of a session of mechanical assisted ventilation (M.A.V.) in severe respiratory insufficiency (PaCO2 greater than 50 mmHg) out of intensive care conditions (author's transl)].

Effectiveness and haemodynamic tolerance of M.A.V. in conscious patients with a severe respiratory insufficiency is mainly due to the proper adaptation to ventilator with low frequency and adequate V.T. Thus M.A.V. is an eventual complement to directed ventilation exercises which in addition reduce the "rebound" of hypoxia and hypercapnia after a M.A.V. session. A proper adaptation ensures haemodynamic tolerance. Expiratory time should be sufficient in such obstructive patients. A post inspiratory pause can improve V.C.O2. Nevertheless, it should not shorten inspiratory time to less than one second and for each patient the best ventilatory profile should be properly established taking into account blood gases, circulatory, expired CO2 and clinical monitoring.

Carbon Dioxide↗
PubMed1977

Myocardial changes in immature infants requiring prolonged ventilation.

Fourteen infants who had required prolonged ventilation with high concentrations of oxygen for 14 days or more, were studied at necropsy. 11 infants of immature gestation at birth had gross cardiac hypertrophy, defined as a heart weight greater than 2 SD above the mean for their age. No congenital malformation of valves or septum was found, and in the 7 youngest infants with hypertrophy, the ductus arteriosus was anatomically patent. 3 of these 7 infants had an accompanying nurmur. All 11 infants had severe bronchopulmonary dysplasia. The cardiac hypertrophy affected both ventricles and septum in an irregular fashion and was associated with areas of necrosis, progressing to coarse fibroelastotic scars. The intramural vessels showed marked intimal thickening but the main coronary vessels were normal. The 2 youngest infants with cardiac hypertrophy showed the presence of intravascular and endocardial platelet thrombi. In the 3 infants without cardiac hypertrophy less severe zones of necrosis and scarring were present, and only occasional bundles of hypertrophied muscle fibres were seen. In an attempt to understand these hitherto undescribed lesions, a group of 50 fresh stillbirths and 50 first-week neonatal deaths of comparable gestational age were studied. In 19 of these infants foci of myocardial fibre necrosis were present. It is suggested that the lesions in the older infants represent a more advanced and continuing stage of that seen in the younger infants, and that the foci of necrosis are the result of continuing hypoxia and related problems to a failing coronary circulation. The possibility of myocardial damage represents a serious hazard to the successful therapy of the immature asphyxiated infants.

Cardiomegaly↗
PubMed1975

Pulmonary oxygen transfer during IPPV in man.

The efficiency of pulmonary oxygen transfer, measured as the difference between pulmonary end-capillary and arterial oxygen content, was assessed at several different inspired oxygen concentrations in 20 patients during intermittent positive pressure ventilation (IPPV) with oxygen/nitrogen mixtures. In only three of the patients did the patterns of response correspond with those predicted from iso-shunt and ventilation/perfusion mismatch models of lung function, in which it is assumed that oxygen exerts only a passive physical effect within the lungs. It is suggested that the pattern of response obtained during IPPV in the remaining 17 patients is explicable on the basis of an active physiological effect of oxygen such that an increasing alveolar oxygen partial pressure is associated with a progressive increase in the proportion of the pulmonary blood flow which bypasses ventilated alveoli. This "hyperoxic shunt", which is readily reversible, may be the result of redistribution of either ventilation or blood flow within the lung.

Adolescent↗
PubMedDate not supplied

Intermittent mandatory ventilation in the neonate.

Intermittent Mandatory Ventilation (IMV) provides an alternative method of support to assisted and controlled mechanical ventilation in neonates with acute respiratory failure. Specific advantages include the use of only the level of mechanical support which is required on an individual basis. Because intrapleural pressure ventilation (IPPV), venous return and cardiac output are maintained at more nearly normal levels, with or without positive end-expiratory pressure (PEEP). Duration of mechanical ventilatory support is reduced, weaning enhanced, and the incidence of pulmonary barotrauma decreased with IMV. Physiological homeostasis in terms of acid-base changes is more readily maintained as a result of precise regulation of alveolar ventilation. Newer concepts in mechanical support, such as "reversed" inspiratory:expiratory ratio (I:E ratio) ventilation, are possible with IMV because of the lower ventilator rates employed compared to IPPV.

Adaptation, Physiological↗
PubMed1976

The haemodynamic effects of unsupplemented nitrous oxide-oxygen-relaxant anaesthesia in cardiac patients.

The effect on the systemic and pulmonary circulation of unsupplemented nitrous oxide in about 30% oxygen, with and without IPPV, was investigated in five cardiac patients and compared with control periods at rest with air breathing. The results of this investigation show that nitrous oxide in conventional oxygen concentration does not cause any great haemodynamic changes. During tracheal intubation, however, significant increases in both systemic and pulmonary blood pressures were registered. However, these pressures reverted to the control values immediately after the tracheal intubation. The results of this study support many earlier clinicaly good experiences obtained when using this conventional nitrous oxide-oxygen mixture in cardiac patients.

Adult↗
PubMed1975

Ventilation and cardiovascular studies during mechanical control of ventilation in horses.

Eleven out of 12 horses were underventilating while breathing spontaneously during halothane anaesthesia with high arterial carbon dioxide tensions. In addition, large alveolar to arterial oxygen tension gradients were found to be present. Mechanically, controlled ventilation with an intermittent positive pressure of 20-30 cm H2O reduced arterial carbon dioxide levels to normal. The alveolar to arterial oxygen gradients did not increase and in some cases decreased. These (A - a) Po2 gradients were due mainly to true shunt of the order of 30 per cent and not to ventilation perfusion inequality.

Anesthesia, Inhalation↗
PubMed1977

Pulmonary aerosol deposition in chronic bronchitis: intermittent positive pressure breathing versus quiet breathing.

Quiet breathing by mouth of a 3-mum aerosol was compared with intermittent positive pressure delivery of the same aerosol to the lung in a group of bronchitics. The pattern of lung deposition and the total dose delivered to the lung were measured. The differences between quiet breathing and intermittent positive pressure breathing were found not to be significant (P greater than 0.5). In addition, during similar or greater total ventilation, intermittent positive pressure breathing delivered a mean of 32% less aerosol to the lung than did quiet breathing. These findings suggest that intermittent positive pressure breathing as currently used for aerosol delivery cannot be expected to enhance peripheral deposition of inhaled aerosols in patients with airway obstruction.

Aerosols↗
PubMed1975

Elective postoperative I.P.P.V. for extensive head and neck skin grafting.

Patients with extensive skin-grafting of the head and neck are managed for the first 24-48 hours postoperatively in the Intensive Care Unit with muscle paralysis, controlled ventilation, timed parenteral analgesia and sedation. The aims are to provide full immobilization of the graft and to allow pressure dressings without embarrassment to the airway. The regime is suggested as an added indication for intensive care therapy.

Adenocarcinoma↗
PubMed1976

[General anesthesia and bronchoscopy].

High frequency, positive pressure ventilation during anesthesia for bronchoscopy, uses the intermittent delivery of oxygen and an anesthetic gas mixture thus avoiding the risks of hypoxia, retention of carbon dioxide and concomitant acidosis. This technique may be used with low pressures in the airways (8 to 10 cm of water during insufflation).

Anesthesia, Inhalation↗