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 1,513 records · Page 84Linked to original sources
PubMed2006

Open lung ventilation preserves the response to delayed surfactant treatment in surfactant-deficient newborn piglets.

OBJECTIVE: Delayed surfactant treatment (>2 hrs after birth) is less effective than early treatment in conventionally ventilated preterm infants with respiratory distress syndrome. The objective of this study was to evaluate if this time-dependent efficacy of surfactant treatment is also present during open lung ventilation. DESIGN: Prospective, randomized controlled animal study. SETTING: University-affiliated research laboratory. SUBJECTS: Thirty-eight newborn piglets. INTERVENTIONS: Following repeated whole-lung lavage, animals were randomly allocated to conventional positive pressure ventilation (PPVCON) using a positive end-expiratory pressure (PEEP) of 5 cm H2O and a tidal volume of 7 mL/kg or open lung positive pressure ventilation (PPVOLV). During PPVOLV, collapsed alveoli were actively recruited and thereafter stabilized with sufficient PEEP. Within each ventilation group, animals received surfactant (25 mg/kg) either after 2 hrs (PPVCON-2 and PPVOLV-2) or after 4 hrs (PPVCON-4 and PPVOLV-4) of ventilation. A control group received surfactant immediately after lung lavage. Following surfactant administration, all animals were conventionally ventilated for an additional 2 hrs. MEASUREMENTS AND MAIN RESULTS: Two hours after surfactant treatment, both oxygenation and lung mechanics showed a clear deterioration in the PPVCON-4 group compared with PPVCON-2 and the control group. However, this deterioration of the surfactant response over time was not observed during PPVOLV. Analysis of the bronchoalveolar lavage fluid obtained at the end of the experiment showed that the protein concentration and the conversion of large to small aggregate surfactant was significantly higher in the PPVCON-4 group compared with the PPVCON-2 group while comparable in both PPVOLV groups. In addition, interleukin-8 and myeloperoxidase levels tended to be higher in the PPVCON-4 group compared with the PPVOLV-4 group. CONCLUSIONS: In contrast to conventional ventilation, open lung ventilation preserves the response to delayed surfactant treatment in surfactant-deficient newborn piglets. This sustained response is accompanied by an attenuation of secondary lung injury.

Animals↗
PubMed2005

Ventilation tubes and cochlear implants: what do we do?

OBJECTIVE: To determine current practice management with respect to ventilation tubes and cochlear implants. STUDY DESIGN: Questionnaire. SETTING: All members of the American Neurotology Society were sent questionnaires. MAIN OUTCOME MEASURES: Members were asked a series of questions including how they deal with ventilation tubes before cochlear implantation, how they manage serous otitis media in patients undergoing cochlear implantation, and how they manage otitis prone children with cochlear implants. RESULTS: Two hundred and twenty members returned questionnaires. Surgeons who replied perform an average of 25 implants per year: 15 in adults and 10 in children. Analysis of the data revealed a wide practice variation between surgeons. Fifty-six percent of surgeons will place a cochlear implant in a patient with a clean, dry ventilation tube in place. More than half the surgeons will place a ventilation tube in a child with serous otitis media, let the ear settle down, and perform the cochlear implant at a second operation. Wide variation in the management of otitis prone children with cochlear implants exists with respect to placement of ventilation tubes. Only 5% of surgeons reported any complications with cochlear implants that they attributed to ventilation tubes. There were a number who suggested their practice had changed since the recent identification of issues involving meningitis in implantees. CONCLUSION: Wide practice variation exists with the management of ventilation tubes in cochlear implant patients. On the basis of the results of this survey, it is acceptable to place cochlear implants in patients with clean, dry ventilation tubes. It also acceptable to place ventilation tubes in otitis prone children with cochlear implants. Despite theoretic concerns, the reported incidence of complications is low.

Cochlear Implantation↗
PubMed1994

Reduced mite allergen levels in dwellings with mechanical exhaust and supply ventilation.

Seventy similar bungalows constructed between 1968 and 1970 in the same suburban area of Stockholm were investigated regarding the content of house dust mite allergen, absolute indoor humidity, type of ventilation and basement construction. Houses with mechanical exhaust and supply ventilation had an indoor humidity above 7 g/kg less often than houses without this type of ventilation (Odds ratio 0.1, 95% confidence interval 0.0-0.2). Furthermore, only five of the 24 houses with exhaust and supply ventilation contained mattress dust mite allergen concentrations exceeding the median value (98.5 ng/g) compared with 30 of 46 hours which did not have such ventilation (odds ratio = 0.1, C.I. 0.0-0.5). Houses with both natural ventilation and crawl space basement harboured significantly less mattress mite allergen than houses having the same type of ventilation, but with a concrete slab basement. In a cold temperature climate, type of building construction and ventilation seem to be important for the occurrence of house dust mite allergens in dwellings. Our results indicate that modern energy-efficient houses should be equipped with mechanical exhaust and supply ventilation to reduce indoor air humidity during the dry winter months and the risk of mite infestation.

Air Pollution, Indoor↗
PubMed1988

Intermittent high frequency ventilation: a new mode to measure changes in lung volume and alveolar gas concentration, enhance CO2 elimination and reduce intrapulmonary pressures.

A new method of artificial ventilation, intermittent high frequency ventilation (IHFV), is described in which high frequency ventilation (HFV) is intermittently interrupted so that short periods of ventilation and pauses in ventilation occur in sequence several times a minute. During the pauses in ventilation the increase in lung volume, which occurs during the short periods of HFV, is either exhaled completely or to a predetermined level which prevents sustained hyperinflation of the lungs but allows the maintenance of PEEP if required. The volume of gas expired during the ventilation pauses, i.e. gas retained during the periods of HFV, is measured. When this trapped gas is exhaled completely, the mean airway and compliance pressures are reduced by up to 50% compared to continuous HFV at the same frequency, inspiration:expiration (I:E) ratio and low tidal volume (VT). The alveolar CO2 concentration was measured in gas expired towards the end of the pauses in ventilation. CO2 elimination was improved, especially at high frequencies of ventilation, which allowed a further reduction in inflation pressures while maintaining a constant PaCO2.

Animals↗
PubMed2006

Does measuring respiratory function improve neonatal ventilation?

AIMS: To determine whether using a respiratory function monitor alters clinicians' choice of ventilator settings, tidal volumes or blood gases in the first 48 h of ventilation. METHODS: Clinicians were trained to use a respiratory function monitor to optimize neonatal ventilation. Thirty-five infants, weighing < 2 kg, treated with the Infant Star ventilator were randomized to have a respiratory function monitor display visible or concealed. All reasons for altering ventilator settings were noted. Data on ventilator parameters and clinical care were collected hourly. The primary outcome was the mean peak pressure used during the first 48 h. RESULTS: There were no statistically significant differences in peak pressures, tidal volumes or arterial carbon dioxide levels between the two groups. CONCLUSIONS: Using the Florian respiratory function monitor in the first 48 h of ventilation with the Infant Star ventilator did not alter the choice of ventilator settings, tidal or minute volumes or arterial blood gases. Possible explanations for this result include lack of power due to the small numbers recruited and bias due to the unblinded nature of the trial.

Blood Gas Analysis↗
PubMed2000

Physiological implications of the fractal distribution of ventilation and perfusion in the lung.

Both regional ventilation and regional perfusion demonstrate progressive increases in heterogeneity as the resolution of measurement is improved. Because the efficiency of pulmonary gas exchange is dependent on the match between local ventilation and local perfusion, the correlation between these two parameters was examined over a range of scale. We marked regional ventilation and perfusion in three anesthetized pigs with aerosolized 1 microm fluorescent microspheres (FMS) and injected 15 microm FMS. The lungs were dried inflated, cut into approximately 2 cm3 cubes, and regional ventilation and blood flow were calculated from measurements of the fluorescence signals extracted from each piece. Adjacent pieces were clustered into successively larger aggregate volumes, and the averages of ventilation and of perfusion were calculated for each cluster size. While the coefficient of variation for both ventilation and perfusion increased predictably as the cluster size decreased, the correlation between ventilation and perfusion within clusters remained high, averaging between 0.82 and 0.92 among animals. Thus, while both ventilation and perfusion heterogeneity increase as the resolution of measurement improves, the strong correlation between these two parameters in a normal prone lung is nearly sample size invariant. This finding explains the observed efficiency of normal gas exchange in the face of the substantial degree of ventilation and perfusion heterogeneity observed in the normal lung with high-resolution measurement.

Administration, Inhalation↗
PubMed1995

Ventilation rate in office buildings and sick building syndrome.

OBJECTIVE: To examine the relation between ventilation rate and occurrence of symptoms of the eyes, nose, throat, and skin as well as general symptoms such as lethargy and headache, often termed the sick building syndrome. METHODS: A cross sectional population based study was carried out in 399 workers from 14 mechanically ventilated office buildings without air recirculation or humidification, selected randomly from the Helsinki metropolitan area. The ventilation type and other characteristics of these buildings were recorded on a site visit and the ventilation in the rooms was assessed by measuring the airflow through the exhaust air outlets in the room. A questionnaire directed at workers inquired about the symptoms and perceived air quality and their possible personal and environmental determinants (response rate 81%). The outcomes were weekly work related symptoms experienced during the previous 12 months and symptom groups defined either by their anatomical location or hypothesised mechanism. RESULTS: In logistic regression analysis, the adjusted odds ratio (OR) for any symptom of interest was 3.03 (95% confidence interval (95% CI) 1.13 to 8.10) in the very low ventilation category of below 5 l/s per person and 2.24 (0.89 to 5.65) in the high ventilation category of over 25 l/s per person compared with the reference (15- < 25 l/s). The ORs for ocular (1.27, 1.11 to 1.46), nasal (1.17, 1.06 to 1.29), skin symptoms (1.18, 1.05 to 1.32), and lethargy (1.09, 1.00 to 1.19) increased significantly by a unit decrease in ventilation from 25 to 0 l/s per person. CONCLUSION: The results suggest that outdoor air ventilation rates below the optimal (15 to 25 l/s per person) increase the risk of the symptoms of sick building syndrome with the sources of pollutants present in mechanically ventilated office buildings. The Finnish guideline value is 10 l/s per person.

Adult↗
PubMed1992

Induction of sleep apnoea with negative pressure ventilation in patients with chronic obstructive lung disease.

BACKGROUND: Negative pressure ventilation provides intermittent non-invasive ventilatory assistance for patients with advanced chronic obstructive lung disease. Upper airway obstruction during sleep, a reported complication of the technique, may, however, limit its clinical applicability. METHODS: The effects of nocturnal negative pressure ventilation on ventilation and on indices of sleep quality were investigated in five patients with severe chronic obstructive lung disease (mean (SE) FEV1 31% (3%) predicted) who had completed three months of nightly negative pressure ventilation. Subjects underwent overnight polysomnography on consecutive nights, the first night serving as a control and negative pressure ventilation being provided on the second night. Ventilators were adjusted to result in maximum suppression of the peak phasic electromyogram signal from the diaphragm. RESULTS: Negative pressure ventilation resulted in substantial increases in episodes of obstructive apnoea and hypopnoea (mean (SE)/h 59.3 (19.8) v 3.2 (1.3) on control nights). Most obstructive events, however, were associated with under 3% oxygen desaturation, and the lowest recorded values for overnight oxygen saturation were similar on the two study nights. Negative pressure ventilation was also associated with significant increases in the frequencies of movement arousals and changes in sleep stage. CONCLUSIONS: Negative pressure ventilation applied during sleep to patients with advanced chronic obstructive lung disease may result in the development of recurrent episodes of apnoea and hypopnoea as well as altered sleep quality, which could limit its clinical applicability.

Aged↗
PubMed1981

Collateral ventilation may protect against high-altitude pulmonary hypertension.

We propose that the pulmonary hypertension developed by cattle and swine at high altitude is associated with their lack of collateral ventilation. We reason that if collateral ventilation helps keep interregional oxygen tensions homogeneous, then in its absence, local ventilation-perfusion balance must rely on arterial constriction; the additional work causes arterial walls to be more muscular at low altitude, a characteristic of cattle and swine that appears prerequisite for the development of pulmonary hypertension at high altitude. In contrast, species with collateral ventilation, e.g., dogs, have thin-walled pulmonary arteries and therefore can not sustain pulmonary vasoconstriction at altitude. Sheep, however, challenge the hypothesis, because their thick lobular septae should block collateral ventilation, yet they have thin pulmonary arteries and resist high-altitude hypertension. We measured collateral ventilation by determining how long it takes air injected into isolated segments to escape. Cattle and swine had no collateral ventilation (time constants greater than 30 s), whereas dogs and sheep had collateral ventilation (time constants less than 0.8 s). These data support the hypothesis that only species without collateral ventilation develop pulmonary hypertension at high altitude.

Altitude↗
PubMed1994

Increased and more consistent tidal volumes during synchronized intermittent mandatory ventilation in newborn infants.

We compared expiratory tidal and minute ventilation during conventional and synchronized intermittent mandatory ventilation (IMV and SIMV) in 30 infants with respiratory failure. Identical ventilator settings were used during each mode in each infant. Tidal volumes of ventilator breaths were smaller during IMV than during SIMV (6.2 +/- 1.8 versus 7.4 +/- 1.9 ml/kg; p < 0.01). The coefficient of variation of tidal volumes was higher during IMV than SIMV for both ventilator (25 +/- 12% versus 15 +/- 8%) and spontaneous breaths (39 +/- 15% versus 24 +/- 10%, p < 0.001). Minute ventilation, however, was the same during both modes. During IMV, one infant breathed synchronously and two were phase-locked in asynchrony with the ventilator. The infants with a mixed interaction on IMV (27 of 30) had tidal volumes that depended on the phase of spontaneous breathing at the time of onset of each ventilator breath. Tidal volumes of IMV breaths that began during the first half of spontaneous expiration had the smallest tidal volumes (5.4 +/- 1.8 ml/kg, p < 0.01), followed by those that began during the last half of inspiration (6.4 +/- 1.8 ml/kg, p < 0.01). Thus, the synchrony produced by SIMV allowed the ventilator to deliver larger and more consistent tidal volumes than during IMV.

Humans↗
PubMed2001

Noninvasive ventilator triggering in chronic obstructive pulmonary disease. A test lung comparison.

To be most effective, noninvasive ventilation (NIV) ventilators should synchronize well with patients' breathing. However, the speed with which different ventilators can respond to the transitions between inspiration and expiration may vary, and abnormal respiratory mechanics and mask leaks may exacerbate this problem. This study explored synchronization using a new test lung model designed to simulate acute exacerbations of chronic obstructive pulmonary disease (COPD). Thirteen ventilators were tested against different combinations of tidal volume (VT), airways resistance (Raw), FRC, and mask leak. These combinations ranged from those of a severe exacerbation of COPD, to a mild condition reflecting the optimal triggering conditions a ventilator is likely to encounter. The triggering delays from the beginning and end of "inspiration" of the test lung, to the appropriate responses from the ventilators were measured. Three of the ventilators had trigger delays less than approximately 120 ms at both the beginning and end of expiration under all conditions. Trigger delays of other ventilators were mainly in the range of 120 to 300 ms, although exceptionally as long as 500 ms. Varying the conditions had a variable but generally small effect on triggering times, suggesting that there is a largely unavoidable element to the triggering delays intrinsic to the design of the ventilators.

Acute Disease↗
PubMed1979

Ventilation-perfusion distributions in the adult respiratory distress syndrome.

The distribution of ventilation-perfusion ratios, as determined by the multiple inert gas elimination technique, was measured in 16 patients with the adult respiratory distress syndrome. In each case, the distribution of ventilation-perfusion ratios was bimodal. The upper mode consisted of units with normal ventilation-perfusion ratios that received a mean of 52% of the cardiac output. The lower mode, which received the remainder of the cardiac output, consisted of either pure shunt or shunt plus a small number of units with very low ventilation-perfusion ratios (less than 0.01). The measured arterial PO2 and that predicted from the distribution of ventilation-perfusion ratios were very closely correlated (r = 0.93), indicating that the hypoxemia was completely explained by the measured ventilation-perfusion inequality. In 12 patients, the effect of positive end-expiratory pressure on the distribution of ventilation-perfusion ratios was also determined. The addition of positive end-expiratory pressure uniformly resulted in a decrease in blood flow to the lower mode and an increase in the ventilation of unperfused alveoli. Increasing positive end-expiratory pressure also led to a uniform decrease in cardiac output. We conclude that the hypoxemia of the adult respiratory distress syndrome is caused by the presence of shunt or units of very low ratio of ventilation to perfusion and that positive end-expiratory pressure increases the arterial PO2 by decreasing the perfusion of unventilated lung. The mechanism of this decrease is yet to be defined.

Adult↗
PubMed2005

5-Lipoxygenase deficiency prevents respiratory failure during ventilator-induced lung injury.

RATIONALE: Mechanical ventilation with high VT (HVT) progressively leads to lung injury and decreased efficiency of gas exchange. Hypoxic pulmonary vasoconstriction (HPV) directs blood flow to well-ventilated lung regions, preserving systemic oxygenation during pulmonary injury. Recent experimental studies have revealed an important role for leukotriene (LT) biosynthesis by 5-lipoxygenase (5LO) in the impairment of HPV by endotoxin. OBJECTIVES: To investigate whether or not impairment of HPV contributes to the hypoxemia associated with HVT and to evaluate the role of LTs in ventilator-induced lung injury. METHODS: We studied wild-type and 5LO-deficient mice ventilated for up to 10 hours with low VT (LVT) or HVT. RESULTS: In wild-type mice, HVT, but not LVT, increased pulmonary vascular permeability and edema formation, impaired systemic oxygenation, and reduced survival. HPV, as reflected by the increase in left pulmonary vascular resistance induced by left mainstem bronchus occlusion, was markedly impaired in animals ventilated with HVT. HVT ventilation increased bronchoalveolar lavage levels of LTs and neutrophils. In 5LO-deficient mice, the HVT-induced increase of pulmonary vascular permeability and worsening of respiratory mechanics were markedly attenuated, systemic oxygenation was preserved, and survival increased. Moreover, in 5LO-deficient mice, HVT ventilation did not impair the ability of left mainstem bronchus occlusion to increase left pulmonary vascular resistance. Administration of MK886, a 5LO-activity inhibitor, or MK571, a selective cysteinyl-LT(1) receptor antagonist, largely prevented ventilator-induced lung injury. CONCLUSIONS: These results indicate that LTs play a central role in the lung injury and impaired oxygenation induced by HVT ventilation.

Animals↗
PubMedDate not supplied

Protocol-driven ventilator management in children: comparison to nonprotocol care.

The purpose of this study was to compare ventilator weaning time, time to spontaneous breathing, and overall ventilator hours duration with use of a ventilator management protocol (VMP) versus standard nonprotocol-based care in a pediatric intensive care unit. A multidisciplinary task force developed a comprehensive protocol for ventilator management with four specific phases: initial ventilator set up and adjustment, weaning, minimal settings, and spontaneous mode prior to extubation. Medical records of ventilated patients both before and after protocol implementation were reviewed. A total of 187 patients were studied (89 nonprotocol and 98 VMP patients). No differences were seen between groups in PRISM scores, Murray scores, or oxygenation indices, but VMP patients were significantly younger (P =.03). Ventilator weaning times (P =.005) and time to spontaneous breathing modes (P =.006) were significantly decreased in VMP patients compared to nonprotocol patients, but overall ventilator duration was not significantly different. No significant differences were seen in extubation failure, use of corticosteroids, or use of racemic epinephrine between groups. Use of an institution-specific VMP developed by a multidisciplinary team was associated with significantly reduced ventilator weaning time and time to spontaneous breathing. Further studies are needed.

Adolescent↗
PubMed2006

Evaluation of the user-friendliness of 11 home mechanical ventilators.

The home ventilator market has grown in size and complexity. The aim of this study was to determine if common home ventilators are user-friendly for trained intensive care unit (ICU) physicians. Eleven ventilator models were tested by 13 ICU physicians without practical experience in home mechanical ventilation. Six tests were defined (start-up, unlocking, mode and setting recognition, mode change, pressure setting and alarm). For each test, the physicians were timed and their performance compared with a reference time established by a technician. The physicians also had to rate their global assessment of each machine on a visual analogue scale. The start-up test was the only test for which there was no significant difference between the physicians and the technician, except for two ventilators. The physicians were slower than the technician to unlock the ventilator and change the ventilatory mode, with some complete failures during these tests and heterogeneous results between physicians and between ventilators. Mistakes occurred in close to 50% of cases during the ventilatory mode and settings recognition test. The mean time for the most rapid of the physicians for all the tests was 58+/-53 s, compared with 15+/-9 s for the technician. In conclusion, trained intensive care unit physicians perform poorly when confronted with home mechanical ventilators without specific prior training. Therefore, it is hypothesised that the user-friendliness of home ventilators for other categories of users might be questionable.

Attitude of Health Personnel↗
PubMed1996

Supplemental oxygen and nasal intermittent positive pressure ventilation.

When supplementary oxygen is necessary with nasal intermittent positive pressure ventilation (NIPPV), the optimal route by which it should be added to the ventilator circuit is unknown. We investigated the oxygen concentration received when oxygen was supplied at flow rates between 0 and 6 L.min-1 into the proximal ventilator tubing or the nasal mask whilst patients were ventilated with air. Eleven patients with stable chronic hypercapnic respiratory failure were studied. A calibration curve was produced for each by supplying different known oxygen concentrations through a Monnal D or DCC ventilator and measuring the arterial oxygen saturations achieved. Oxygen was then supplied into the ventilator tubing or nasal mask and arterial saturation again measured. The oxygen concentration received was estimated using the calibration curve. Tracheal oxygen concentration throughout the respiratory cycle was studied in one patient when oxygen was supplied by both routes. Peak inspired oxygen concentration occurred at end-inspiration when oxygen was supplied into the ventilator tubing, but at mid-inspiration when supplied into the nasal mask. However, there was no significant difference between the two routes in the inspired oxygen concentration achieved at all flow rates: 1 L.min-1 supplied approximately 31% oxygen; 2 L.min-1 37%; 3 L.min-1 40%; and 4 L.min-1 44%. Flow rates above 4 L.min-1 had little additional effect. In conclusion, oxygen supplementation during nasal intermittent positive pressure ventilation can be provided into the ventilator tubing or the nasal mask with equal efficiency.

Female↗
PubMed1996

A laboratory comparison of four positive pressure ventilators used in the home.

Four brands of ventilator used for noninvasive positive pressure ventilation in the home were assessed to determine their performance on a patient simulator. We tested the tidal volume (VT) preset Companion 2801 (Puritan Bennett), minute volume preset Monnal D (Taema), and two pressure preset ventilators, the Nippy (Friday Medical) and the Bilevel Positive Airway Pressure (BiPAP) (Respironics). A patient simulator was employed to investigate the relationships between VT, peak airway pressure (PAP) and mean airway pressure (MAP), the responses to an additional leak in the circuit and patient effort of a variable duration, which was modelled using a negative pressure pump. For equivalent VTs, >300 mL, the Monnal D and Nippy generated a PAP up to 100% greater than the Companion 2801 and BiPAP. When an additional leak was introduced to the circuit, the VT of the Companion 2801 and Monnal D fell by >50%, while the Nippy and the BiPAP responded by increasing flow and maintained VT close to the level achieved with no leak. When the ventilators were triggered by a simulated patient effort of 0.25 s duration with a frequency 33% greater than that of the ventilator, the minute volume increased by 41% for the Companion 2801, by 18% for the Monnal D (no change expected), and by 17% for the Nippy (less than expected), and fell by 7% for the BiPAP due to irregular triggering. When patient effort was prolonged to 1.5 s, a similar length to the inspiratory time of the ventilators, there was no further change in the minute volume of the Companion 2801 and Monnal D, while that of the Nippy and of the BiPAP increased by 38 and 71%, respectively, compared to baseline. These results show that distinct brands of ventilator respond to changes in the patient and patient circuit in different ways, which are not always predictable from a simple description of their operating principles. This should be borne in mind when choosing a positive pressure ventilator for noninvasive ventilation.

Equipment Design↗
PubMed1992

Hypoventilation and apnea in children during mechanically assisted ventilation.

Uncuffed tracheostomy tubes are used for long-term mechanical ventilation in children. However, upper airway mechanics differ between sleep and wakefulness; this may affect air leak around tracheostomies. We studied 19 children with high cervical spinal cord injury on portable positive pressure ventilators, age range birth to 19 years. Ventilator settings were adjusted while awake to achieve PaCO2 less than 45 mm Hg and PO2 greater than 90 mm Hg. Clinically several children with uncuffed tracheostomies became unstable at night with seizures and sleep disruption. Nine of 11 children on volume controlled systems were found to be inadequately ventilated during sleep. Substitution with a cuffed tracheostomy allowed adequate ventilation both awake and asleep, suggesting that inadequate ventilation during sleep was due to an uncompensated leak around the uncuffed tracheostomy. To avoid cuffed tracheostomies, eight children received pressure controlled ventilation. Gas exchange was adequate throughout the day and night. We conclude that children receiving volume controlled mechanical ventilation via uncuffed tracheostomy tubes can exhibit hypoventilation due to uncompensated air leak. Pressure controlled ventilation improves adequacy of gas exchange during sleep and wakefulness.

Apnea↗