Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “VENTILATION”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 775 records · Page 43Linked to original sources
PubMed2000

["Fuldaer ventilation surgery"--a surgical concept in severe ventilation disorders of the middle ear].

BACKGROUND: This report presents the long-term results of a special surgical technique in cases of persistent severe dysfunction of the Eustachian tube. PATIENTS AND METHODS: We performed this operation on 16 patients (18 ears) between 1982 and 1997. Almost all patients had undergone previous surgery. This included myringotomies and tube insertions, adenoidectomies, tonsillectomies, myringoplasties and mastoidectomies, sinus surgeries, and an operation on a cleft palate. The concept developed by one coauthor (Draf) combines different methods to improve ventilation of the middle ear and protect the eardrum against partial vacuum. The concept combines mastoidectomy, posterior tympanotomy, and removal of the incus and the head of the malleus with an interposition of the incus. The tympanic membrane is then stabilized with a cartilage-perichondrium graft, and a tube is placed leading from the tympanic cavity to the nose (Wright-tube). A T tube may also be used. The procedure was varied slightly on occasion depending on intraoperative findings. RESULTS: Thirteen patients (15 ears) were available for audiometry at a minimum of 5 months after surgery until 14 years (mean duration of 6.2 years). We compared preoperative and postoperative air-bone gaps. They were measured for the three speech frequencies (500, 1000, and 2000 Hz) at 5 dB intervals. The average preoperative air-bone gap was 25.7 dB versus 18.2 dB postoperatively. This represents an improvement of 7.5 dB. Seven of fifteen ears required revision. Six ears required one revision procedure each (three for cholesteatoma, one for myringitis, one for discharge due to a narrow external auditory meatus, and one for mastoiditis). Another patient required three revision procedures (one for mastoiditis and the other two for cholesteatoma). CONCLUSION: This concept can help prevent cholesteatoma and improve hearing in more than 50 per cent of severe cases of dysfunction of the Eustachian tube.

Adolescent↗
PubMed2000

Elective, non-therapeutic ventilation: a reply to Browne et al., "The ethics of elective (non-therapeutic) ventilation.

Browne, Gillett and Tweeddale propose that the use of non-therapeutic elective ventilation (EV) to secure transplantable organs is ethically indefensible. Their argument centres around several propositions: that explicit patient consent for EV is essential, but since it is not included in the consent process for donation from the patient, using it constitutes assault; that inferring consent for EV from the consent to donate itself is ethically and logically indefensible; and that explicit consent from next-of-kin should neither be sought nor honoured in view of the stress EV may cause to staff and families. This article examines their reasoning and suggests that it is fatally flawed. It argues further that in most cases of donation, not using EV may itself be unethical.

Disclosure↗
PubMed1993

Use of capnography for assessment of the adequacy of alveolar ventilation during weaning from mechanical ventilation.

A prospective study was conducted to determine the reliability of noninvasive end-tidal CO2 (PETCO2) monitoring as a reflection of arterial CO2 tension (PaCO2) during weaning from mechanical ventilation (MV). Simultaneous PaCO2 and PETCO2 determinations were compared during MV and again during a spontaneous breathing trial just before returning the patient to MV. Three groups of patients recovering from acute respiratory failure were evaluated. Group 1 consisted of 16 patients (28 observations) without parenchymal lung disease. Group 2 consisted of 22 patients (31 observations) with alveolar filling diseases. Group 3 was composed of 13 patients (22 observations) with emphysema. Significant Pearson correlation coefficients were demonstrated between PaCO2 and PETCO2 during both MV and spontaneous breathing in all three groups. Significant correlation was also demonstrated between the change in PaCO2 and the change in PETCO2 associated with weaning for each group; however, the degree of correlation varied between groups. Our data suggest that capnography offers a reasonable estimate of PaCO2 and changes in PaCO2 during weaning in patients without parenchymal lung disease. However, PETCO2 is less sensitive to changes in PaCO2 for patients with parenchymal lung disease, particularly patients with emphysema. Interpretation of capnographic data requires a full understanding of its limitations. An approach to capnographic monitoring during weaning is discussed.

Aged↗
PubMedDate not supplied

Advantages of infant ventilators over adapted adult ventilators in pediatrics.

A lung simulator with variable compliance and resistance components was used to evaluate the dynamic compliance of the Bournes, Babybird, and Pediatric Emerson postoperative ventilators. With increase in airway pressure from combined changes in compliance and resistance, the internal compliance of the Bournes was lowest and the internal compliance of the Emerson was highest. With low constant airway resistance (50 cm/L/sec), the Babybird exhibited tidal volume losses similar to those of the Bournes in the face of decreased lung compliance. With constant lung compliance (10 ml/cm H2O) and increasing airway resistance, the Babybird had marked volume losses at higher volumes. Under all simulated conditions, internal compliance of the Emerson, although large, was relatively constant and the Bournes had the smallest internal compliance.

Adult↗
PubMed1989

Superimposed high frequency ventilation with conventional mechanical ventilation.

A 73-year-old man with ARDS-multiple organ failure due to Chlamydia psittaci, was successively supported with conventional respiratory techniques. After 48 hours of no clinical improvement, HFV was superimposed to CMV in order to combine the advantages of each one. Since improvement has been seen in all ventilatory parameters, this method is suggested as another mode of ventilation for patients with refractory hypoxia and hypercarbia who do not respond to conventional respiratory care.

Aged↗
PubMed1993

[Invention of an air forced ventilated micro-isolation cage and rack system--environment within the cages: ventilation, air flow].

A forced air ventilation system for small laboratory animals was developed. The system consists of an air handling unit with air supply and exhaust fans, a rack, hard cage covers with a large diameter air inlet and an outlet, and shoe box cages. Air flow from the supply duct, to the exhaust duct and within the cage were observed. Variations in air flow among cages was minimal. The optimal air exchange rate of the cages in this system was determined to be 60 times per hour based on the results obtained in the present study. At this air exchange rate, air flow at the base of the cages had a velocity of less than 0.09m/sec, which was within the range of recommended values for humans. The observed results show that the system developed is capable of sustaining a laboratory animal microenvironment well in terms of air flow, without too much energy cost.

Air Movements↗
PubMed1979

[H.R.P.-J.M.V.-200. A device for the simple adoption of modern ventilation techniques with various, even old, mechanical ventilators (author's transl)].

A new constructed device (H.R.P.-I.M.V.-2000) is presented. New techniques of artificial respiration such as E.S.-I.M.V., I.D.V., I.P.P.B. + P.E.E.P. compl., C.P.A.P. ect. can now be used with different types of respirators (pressure-, pressure-flow- and volume-time cycled) even older models. No constructional modifications, are necessary. To perform these techniques manipulation of only two control elements are necessary. Additionally hand ventilation is possible without any further device by the use of the H.R.P.-Respiration-Sets. The significance of E.S.-I.M.V. compared with I.M.V. and I.D.V. has between demonstrated. E.S.-I.M.V. has proved very valuable, because a basic mandatory respiratory is combined with the possibility of a patient-triggered expiration phase. Therefore fighting against the respirator is avoided. In addition the I.M.V.-device is the universal adapter for a new developed respiratory system (H.R.P.-System 2000) for different types of respirators. These sets (including a heated humidifier) are available as disposables or reusables and guarantee optimum hygiene during artificial respiration.

Humans↗
PubMed1988

[Bacterial contamination of the inspiratory circuit of artificial ventilation apparatus: influence of the frequency of circuit renewal and the duration of ventilation].

In a study concerning contamination of artificial ventilators (Drager model UV1), the influence of 2 parameters was assessed: the frequency of changing the circuit (2 and 4 days) and the interval between admission of the patient into the intensive care unit and obtaining the sample. As a function of these variables, 4 groups of 15 patients each were constituted. The levels of contamination noted at 4 sites in the inspiratory phase tubing (cascade humidifier, condensate collector, tubing nearest to the patient and tubing nearest to the humidifier) and in the gas flow showed no significant difference between the groups, regardless of whether the circuit was changed after 2 or 4 days, or whether the patient had been recently admitted to the department or had been there for at least 6 days. Quantitative and qualitative study of bacteria showed that the one(s) contaminating the inspiratory phase tubing were the same as the one(s) colonizing the tracheal secretions of the patient, and that the most contaminated areas were those nearest to the patient (proximal tubing, collector), which confirms the retrograde contamination of the circuit.

Bacterial Infections↗
PubMedDate not supplied

High frequency ventilation--the relationship between ventilator design and clinical strategy in the treatment of hyaline membrane disease and its complications: a brief review.

Progress in the application of techniques of HFV to clinical settings has been hampered by a lack of comparative data. Ventilator design and/or strategy place clear limitations on the effective and safe use of these devices. There is a definite need to develop clear therapeutic goals for HFV, to define the operating characteristics and limitations of each device, and to develop effective and safe strategies for their use in various clinical settings. Only then can adequate controlled clinical trials be performed and the role of these techniques be firmly established.

Cardiac Output↗
PubMed1994

[High frequency oscillation ventilation after surfactant use in hyaline membrane disease. Outcome of ventilation parameters].

Surfactant therapy in hyaline membrane disease (HMD) does not suppress all risks of subsequent broncho-pulmonary dysplasia. This study aimed to estimate the efficacy of Surfexo followed by high frequency ventilation (HFV) on respiratory parameters and long term outcome. 47 neonates (44 premature) with HMD received first Surfexo then HFV whenever hypercarbia (pH < 7.25, PaCO2 > 7 kPa) and/or hypoxaemia (PaO2 < 7kPa, FiO2 = 0.5) continued. Surfactant was given at 3 hours of life (mean), HFV was started at 5 h (mean) and continued for 36 h (mean). FiO2 was lowered after a HFV of 3 h (p < 0.01) and mean broncho-tracheal pressure decreased after 12 h (p < 0.001). Six children deceased (1 from massive pulmonary haemorrhage, 5 from neurological complications), 1 developed pneumothorax (this was the only barotraumatic complication in our series), 2 children had a mild broncho-pulmonary dysplasia. All the 38 remaining patients had a good uncomplicated outcome. Thus Surfexo -HFV association appears to be an excellent therapy of HMD in newborns.

Birth Weight↗
PubMed1993

[The effect of the ventilation rate on the air particle and air microbe concentration in operating rooms with conventional ventilation. 2. Measurement during surgical activity with respect to surgical personnel number and surgical activity phases].

For measurements with surgical activity, it was investigated if the air-exchange-rate has a significant influence on airborne particle and bacteria concentrations in two conventionally ventilated operating theatres. Next to that the influence of number of personnel in the operating theatre and the various operating phases were calculated (explanation of variance). Statistical differences were found for airborne particle concentrations and a few for airborne bacteria concentrations in supply and ambient air. From the hygienic point of view these differences must be considered to be irrelevant because of the little margin (less than one lg-step) between the values. The comparison of all air-exchange-rates as well as that between the two air-exchange-rates in the two operating theatres show that the number of personnel present in the operating theatre has the most influence on airborne particle concentrations variance. Concerning airborne bacteria concentrations explanation of variance by the treatment factors air-exchange-rate, personnel and operating phase is negligible. Summarizing the low (7.5 and 10/h) and high (15 and 20/h) air-exchange-rates did not increase the explanation of variance for airborne particle and bacteria concentrations although the differences were on a significant level.

Air Microbiology↗
PubMed1991

The effects of inversed ratio ventilation (IRV) on arterial oxygenation during mechanical ventilation in patients with acute respiratory failure.

We investigated the effects of inversed ratio ventilation by altering the inspiratory:expiratory (I:E) ratio and assessing the time course changes in the intrapulmonary shunting (Qs/Qt) in 14 patients with acute respiratory failure. Stepwise prolongation of the I:E ratio from 1:1.9 to 2:1 and then to 2.6 or 4:1 was applied when PEEP failed to raise the PaO2 above 80 mmHg while breathing oxygen. A significant decrease in Qs/Qt was observed following prolongation of the I:E ratio from 1:1.9 (Qs/Qt = 45 +/- 9%) to 2:1 (Qs/Qt = 29 +/- 9%) but not with further prolongation of the I:E ratio (Qs/Qt = 27 +/- 7%). Improvement of the pulmonary ventilation/perfusion imbalance became more marked with continued IRV and a significant increase in PaO2 was observed at 6 h after initiating prolongation of the inspiratory time (P less than 0.05). There were no significant changes in hemodynamics, PaCO2, or peak inspiratory pressure during IRV. This ventilatory pattern may be indicated when PEEP fails to improve PaO2, but prolongation of the inspiratory time above an I:E ratio of 2:1 did not produce a greater improvement in Qs/Qt and further increases in PaO2 did not occur after more than 10 h of IRV in our 14 patients.

Acute Disease↗
PubMed1980

Canopy ventilation monitor for quantitative measurement of ventilation during sleep.

A portable, easily assembled system that allows quantitative monitoring of ventilation in the sleeping human subject is described. It is a modification of the system used by Kinney et al. (Metab. Clin. Exp. 13: 205-211, 1964) and Spencer et al. (J. Appl. Physiol. 33: 523-528, 1972). The system directly measures gas flow without reliance on indirect CO2 or temperature sensors or on chest wall motion. It is comfortable and reflects the tidal volume with an accuracy of 92%. It also allows measurement of oxygen consumption and CO2 production. The gas breathed by the subject can be varied in composition. Two illustrative examples of the use of the system are given: 1) a case of obstructive apnea; and 2) a case in which a drop in arterial oxygen saturation is explained by quantified hypoventilation undetected by a nasal CO2 probe.

Carbon Dioxide↗
PubMed1999

Bacterial colonization patterns in mechanically ventilated patients with traumatic and medical head injury. Incidence, risk factors, and association with ventilator-associated pneumonia.

We prospectively evaluated the relation of upper airway, lower airway, and gastric colonization patterns with the development of pneumonia and its etiology in 48 patients with surgical (n = 25) and medical (n = 23) head injury. Initial colonization was assessed by cultures of nasal and pharyngeal swabs, tracheobronchial aspirates, gastric juice, and bronchoscopically retrieved protected specimen brush. Follow-up colonization was determined until the end points extubation, suspected ventilator-associated pneumonia (VAP), or death. The initial colonization rate at any site at ICU admission was 39/47 (83%). It mainly accounted for Group I pathogens (Streptococcus pneumoniae, Staphylococcus aureus, Hemophilus influenzae) of the upper and lower airways. At follow-up, colonization rates with Group II pathogens (Gram-negative enteric bacilli and Pseudomonas spp.) increased significantly. The high initial bacterial load with Group I pathogens of the upper airways and trachea decreased during Days 2 to 4, whereas that of Group II pathogens increased. Upper airway colonization was an independent predictor of follow-up tracheobronchial colonization (odds ratio [OR], 9.9; 95% confidence interval [CI], 1.8 to 56.3 for initial colonization with Group I pathogens; OR, 23.9; 95% CI, 3.8 to 153.3 for follow-up colonization with Group II pathogens). Previous (short-term) antibiotics had a protective effect against colonization with Group I pathogens of the lower respiratory tract (OR, 0.2; 95% CI, 0.05 to 0.86), but they were a risk factor for colonization with Group II pathogens (OR, 6.1; 95% CI, 1.3 to 29). Initial tracheobronchial colonization with Group I pathogens was associated with a higher probability of early onset pneumonia (OR, 4. 1; 95% CI, 0.7 to 23.3), whereas prolonged antibiotic treatment (> 24 h) independently predicted late-onset pneumonia (OR, 9.2; 95% CI, 1.7 to 51.3). We conclude that patients with head injury are colonized in the airways mainly by Group I pathogens early in the evolution of illness. The upper airways represent the main reservoir for subsequent lower airway colonization with Group I pathogens. Previous (short-term) antibiotic treatment is protective against initial tracheobronchial colonization with Group I pathogens, but it represents a risk factor for subsequent lower airway colonization by Group II pathogens.

Adult↗
PubMed2005

Pressure support ventilation versus continuous positive airway pressure ventilation with the ProSeal laryngeal mask airway: a randomized crossover study of anesthetized pediatric patients.

Continuous positive airway pressure (CPAP) and pressure support ventilation (PSV) improve gas exchange in adults, but there are little published data regarding children. We compared the efficacy of PSV with CPAP in anesthetized children managed with the ProSeal laryngeal mask airway. Patients were randomized into two equal-sized crossover groups and data were collected before surgery. In Group 1, patients underwent CPAP, PSV, and CPAP in sequence. In Group 2, patients underwent PSV, CPAP, and PSV in sequence. PSV comprised positive end-expiratory pressure set at 3 cm H(2)O and inspiratory pressure support set at 10 cm H(2)O above positive end-expiratory pressure. CPAP was set at 3 cm H(2)O. Each ventilatory mode was maintained for 5 min. The following data were recorded at each ventilatory mode: ETco(2), Spo(2), expired tidal volume, peak airway pressure, work of breathing patient (WOB), delta esophageal pressure, pressure time product, respiratory drive, inspiratory time fraction, respiratory rate, noninvasive mean arterial blood pressure, and heart rate. In Group 1, measurements for CPAP were similar before and after PSV. In Group 2, measurements for PSV were similar before and after CPAP. When compared with CPAP, PSV had lower ETco(2) (46 +/- 6 versus 52 +/- 7 mm Hg; P < 0.001), slower respiratory rate (24 +/- 6 versus 30 +/- 6 min(-1); P < 0.001), lower WOB (0.54 +/- 0.54 versus 0.95 +/- 0.72 JL(-1); P < 0.05), lower pressure time product (94 +/- 88 versus 150 +/- 90 cm H(2)O s(-1)min(-1); P < 0.001), lower delta esophageal pressure (10.6 +/- 7.4 versus 14.1 +/- 8.9 cm H(2)O; P < 0.05), lower inspiratory time fraction (29% +/- 3% versus 34% +/- 5%; P < 0.001), and higher expired tidal volume (179 +/- 50 versus 129 +/- 44 mL; P < 0.001). There were no differences in Spo(2), respiratory drive, mean arterial blood pressure, and heart rate. We conclude that PSV improves gas exchange and reduces WOB during ProSeal laryngeal mask airway anesthesia compared with CPAP in ASA physical status I children aged 1-7 yr.

Anesthesia, Inhalation↗