The effect of positive endexpiratory pressure, peak inspiratory pressure, and inspiratory time on functional residual capacity in mechanically ventilated preterm infants

1998 ◽  
Vol 157 (10) ◽  
pp. 831-837 ◽  
Author(s):  
U. Thome ◽  
A. Töpfer ◽  
P. Schaller ◽  
F. Pohlandt
Keyword(s):  
Preterm Infants ◽  
Functional Residual Capacity ◽  
Peak Inspiratory Pressure ◽  
Inspiratory Pressure ◽  
Inspiratory Time ◽  
Mechanically Ventilated ◽  
Residual Capacity ◽  
Pressure Peak ◽  
Positive Endexpiratory Pressure

Safe use of PEEP in patients with severe head injury

1985 ◽  
Vol 63 (4) ◽  
pp. 552-555 ◽  
Author(s):  
Kevin R. Cooper ◽  
Peter A. Boswell ◽  
Sung C. Choi
Keyword(s):  
Blood Pressure ◽  
Cardiac Output ◽  
Venous Pressure ◽  
Peak Inspiratory Pressure ◽  
Inspiratory Pressure ◽  
Content Type ◽  
Physiological Variables ◽  
Residual Capacity ◽  
Pressure Peak ◽  
Fine Print

✓ Thirty-three patients with severe head trauma were studied to determine whether the use of positive end-expiratory pressure (PEEP) would cause an increase in intracranial pressure (ICP). Changes in ICP induced by PEEP were then correlated with a panel of physiological variables to try to explain these changes. Mean ICP increased from 13.2 ± 7.7 mm Hg (± standard deviation) to 14.5 ± 7.5 mm Hg (p < 0.005) due to 10 cm H2O PEEP, but the eight patients with elevated baseline ICP experienced no significant increase. Cardiac output and venous admixture (Qs/Qt) declined significantly, while central venous pressure, peak inspiratory pressure, functional residual capacity, and arterial pCO2 increased significantly due to PEEP. Blood pressure and cerebral perfusion pressure were unchanged. The change in ICP due to PEEP correlated significantly with a combination of cardiac output, peak inspiratory pressure, Qs/Qt, and changes in blood pressure and arterial pCO2 due to PEEP, indicating that the effect of PEEP on ICP could be largely explained by its effect on hemodynamic and respiratory variables. No patient deteriorated clinically due to PEEP. It is concluded that 10 cm H2O PEEP increases ICP slightly via its effect on other physiological variables, but that this small increase in ICP is clinically inconsequential.

Positive end-expiratory pressure enhances development of a functional residual capacity in preterm rabbits ventilated from birth

2009 ◽  
Vol 106 (5) ◽  
pp. 1487-1493 ◽  
Author(s):  
Melissa L. Siew ◽  
Arjan B. te Pas ◽  
Megan J. Wallace ◽  
Marcus J. Kitchen ◽  
Robert A. Lewis ◽  
...  
Keyword(s):  
Functional Residual Capacity ◽  
Positive End Expiratory Pressure ◽  
Mechanically Ventilated ◽  
Very Preterm ◽  
Lung Aeration ◽  
X Ray Imaging ◽  
Airway Collapse ◽  
Distal Airway ◽  
Dead Space Volume ◽  
Residual Capacity

The factors regulating lung aeration and the initiation of pulmonary gas exchange at birth are largely unknown, particularly in infants born very preterm. As hydrostatic pressure gradients may play a role, we have examined the effect of a positive end-expiratory pressure (PEEP) on the spatial and temporal pattern of lung aeration in preterm rabbit pups mechanically ventilated from birth using simultaneous phase-contrast X-ray imaging and plethysmography. Preterm rabbit pups were delivered by caesarean section at 28 days of gestational age, anesthetized, intubated, and placed within a water-filled plethysmograph (head out). Pups were imaged as they were mechanically ventilated from birth with a PEEP of either 0 cmH2O or 5 cmH2O. The peak inflation pressure was held constant at 35 cmH2O. Without PEEP, gas only entered into the distal airways during inflation. The distal airways collapsed during expiration, and, as a result, the functional residual capacity (FRC) did not increase above the lung's anatomic dead space volume (2.5 ± 0.8 ml/kg). In contrast, ventilation with 5-cmH2O PEEP gradually increased aeration of the distal airways, which did not collapse at end expiration. The FRC achieved in pups ventilated with PEEP (19.9 ± 3.2 ml/kg) was significantly greater than in pups ventilated without PEEP (−2.3 ± 3.5 ml/kg). PEEP greatly facilitates aeration of the distal airways and the accumulation of FRC and prevents distal airway collapse at end expiration in very preterm rabbit pups mechanically ventilated from birth.

Functional residual capacity and passive compliance measurements after antenatal steroid therapy in preterm infants

2001 ◽  
Vol 31 (6) ◽  
pp. 425-430 ◽  
Author(s):  
Cindy McEvoy ◽  
Susan Bowling ◽  
Kathleen Williamson ◽  
Marion Stewart ◽  
Manuel Durand
Keyword(s):  
Preterm Infants ◽  
Steroid Therapy ◽  
Functional Residual Capacity ◽  
Antenatal Steroid ◽  
Passive Compliance ◽  
Residual Capacity

Functional residual capacity and ventilation homogeneity in mechanically ventilated small neonates

1992 ◽  
Vol 73 (1) ◽  
pp. 276-283 ◽  
Author(s):  
C. T. Vilstrup ◽  
L. J. Bjorklund ◽  
A. Larsson ◽  
B. Lachmann ◽  
O. Werner
Keyword(s):  
Functional Residual Capacity ◽  
Very Low Birth Weight ◽  
Lung Model ◽  
Tracer Gas ◽  
Low Birth Weight Infants ◽  
Mechanically Ventilated ◽  
O2 Concentration ◽  
Residual Capacity ◽  
Requirement Change ◽  
Washout Curves

A modification of a computerized tracer gas (SF6) washout method was designed for serial measurements of functional residual capacity (FRC) and ventilation homogeneity in mechanically ventilated very-low-birth-weight infants with tidal volumes down to 4 ml. The method, which can be used regardless of the inspired O2 concentration, gave accurate and reproducible results in a lung model and good agreement compared with He dilution in rabbits. FRC was measured during 2–4 cmH2O of positive end-expiratory pressure (PEEP) in 15 neonates (700–1,950 g), most of them with mild-to-moderate respiratory distress syndrome. FRC increased with body weight and decreased (P less than 0.05) with increasing O2 requirement. Change to zero end-expiratory pressure caused an immediate decrease in FRC by 29% (P less than 0.01) and gave FRC (ml) = -1.4 + 17 x weight (kg) (r = 0.83). Five minutes after PEEP was discontinued (n = 12), FRC had decreased by a further 16% (P less than 0.01). The washout curves indicated a near-normal ventilation homogeneity not related to changes in PEEP. This was interpreted as evidence against the presence of large volumes of trapped alveolar gas.

Determinants of gas flow through a bronchopleural fistula

1989 ◽  
Vol 67 (4) ◽  
pp. 1591-1596 ◽  
Author(s):  
M. C. Walsh ◽  
W. A. Carlo
Keyword(s):  
Airway Pressure ◽  
Gas Flow ◽  
Bronchopleural Fistula ◽  
Peak Inspiratory Pressure ◽  
Intrathoracic Pressure ◽  
Transpulmonary Pressure ◽  
Inspiratory Pressure ◽  
Positive End Expiratory Pressure ◽  
Inspiratory Time ◽  
Mean Airway Pressure

To assess the determinants of bronchopleural fistula (BPF) flow, we used a surgically created BPF to study 15 anesthetized intubated mechanically ventilated New Zealand White rabbits. Mean airway pressure and intrathoracic pressure were evaluated independently. Mean airway pressure was varied (8, 10, or 12 cmH2O) by independent manipulations of either peak inspiratory pressure, positive end-expiratory pressure, or inspiratory time. Intrathoracic pressure was varied from 0 to -40 cmH2O. BPF flow varied directly with mean airway pressure (P less than 0.001). However, at constant mean airway pressure, BPF flow was not influenced independently by changes in peak inspiratory pressure, positive end-expiratory pressure, or inspiratory time. Resistance of the BPF increased as intrathoracic pressure became more negative. Despite increased resistance, BPF flow also increased. BPF resistance was constant over the range of mean airway (P less than 0.01) pressures investigated. Our data document the influence of mean airway pressure and intrathoracic pressure on BPF flow and suggest that manipulations which reduce transpulmonary pressure will decrease BPF flow.

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