scholarly journals 958 Different Gas Flow Rates and Effects on Tidal Volume and Mask Leak During Positive Pressure Ventilation

2010 ◽  
Vol 68 ◽  
pp. 478-478
Author(s):  
K Schilleman ◽  
G M Schmölzer ◽  
C O F Kamlin ◽  
A B Te Pas ◽  
C J Morley ◽  
...  
Keyword(s):  
Tidal Volume ◽  
Gas Flow ◽  
Positive Pressure Ventilation ◽  
Positive Pressure ◽  
Flow Rates

scholarly journals Evaluation of a Humidified Nasal High-Flow Oxygen System, Using Oxygraphy, Capnography and Measurement of Upper Airway Pressures

2011 ◽  
Vol 39 (6) ◽  
pp. 1103-1110 ◽  
Author(s):  
J. E. Ritchie ◽  
A. B. Williams ◽  
C. Gerard ◽  
H. Hockey
Keyword(s):  
Healthy Volunteers ◽  
Airway Pressure ◽  
Gas Flow ◽  
Air Entrainment ◽  
High Flow ◽  
Positive Pressure ◽  
Mean Airway Pressure ◽  
Flow Rates ◽  
Oxygen Fraction ◽  
Airway Pressures

In this study, we evaluated the performance of a humidified nasal high-flow system (Optiflow™, Fisher and Paykel Healthcare) by measuring delivered FiO2 and airway pressures. Oxygraphy, capnography and measurement of airway pressures were performed through a hypopharyngeal catheter in healthy volunteers receiving Optiflow™ humidified nasal high flow therapy at rest and with exercise. The study was conducted in a non-clinical experimental setting. Ten healthy volunteers completed the study after giving informed written consent. Participants received a delivered oxygen fraction of 0.60 with gas flow rates of 10, 20, 30, 40 and 50 l/minute in random order. FiO2, FEO2, FECO2 and airway pressures were measured. Calculation of FiO2 from FEO2 and FECO2 was later performed. Calculated FiO2 approached 0.60 as gas flow rates increased above 30 l/minute during nose breathing at rest. High peak inspiratory flow rates with exercise were associated with increased air entrainment. Hypopharyngeal pressure increased with increasing delivered gas flow rate. At 50 l/minute the system delivered a mean airway pressure of up to 7.1 cmH2O. We believe that the high gas flow rates delivered by this system enable an accurate inspired oxygen fraction to be delivered. The positive mean airway pressure created by the high flow increases the efficacy of this system and may serve as a bridge to formal positive pressure systems.

Effects of nasal positive-pressure hyperventilation on the glottis in normal awake subjects

1995 ◽  
Vol 79 (1) ◽  
pp. 176-185 ◽  
Author(s):  
V. Jounieaux ◽  
G. Aubert ◽  
M. Dury ◽  
P. Delguste ◽  
D. O. Rodenstein
Keyword(s):  
Tidal Volume ◽  
Positive Pressure Ventilation ◽  
Anterior Commissure ◽  
Minute Ventilation ◽  
Intermittent Positive Pressure Ventilation ◽  
Positive Pressure ◽  
Vocal Cords ◽  
Diaphragmatic Muscle ◽  
Inspiratory Resistance ◽  
Cyclic Changes

We have recently observed obstructive apneas during nasal intermittent positive-pressure ventilation (nIPPV) and suggested that they were due to hypocapnia-induced glottic closure. To confirm this hypothesis, we studied seven healthy subjects and submitted them to nIPPV while their glottis was continuously monitored through a fiber-optic bronchoscope. During wakefulness, we measured breath by breath the widest inspiratory angle formed by the vocal cords at the anterior commissure along with several other indexes. Mechanical ventilation was progressively increased up to 30 l/min. In the absence of diaphragmatic activity, increases in delivered minute ventilation resulted in progressive narrowing of the vocal cords, with an increase in inspiratory resistance and a progressive reduction in the percentage of the delivered tidal volume effectively reaching the lungs. Adding CO2 to the inspired gas led to partial widening of the glottis in two of three subjects. Moreover, activation of the diaphragmatic muscle was always associated with a significant inspiratory abduction of the vocal cords. Sporadically, complete adduction of the vocal cords was directly responsible for obstructive laryngeal apneas and cyclic changes in the glottic aperture resulted in waxing and waning of tidal volume. We conclude that in awake humans passive ventilation with nIPPV results in vocal cord adduction that depends partly on hypocapnia, but our results suggest that other factors may also influence glottic width.

Impact of delivered tidal volume on the occurrence of intraventricular haemorrhage in preterm infants during positive pressure ventilation in the delivery room

2018 ◽  
Vol 104 (1) ◽  
pp. F57-F62 ◽  
Author(s):  
Qaasim Mian ◽  
Po-Yin Cheung ◽  
Megan O’Reilly ◽  
Samantha K Barton ◽  
Graeme R Polglase ◽  
...  
Keyword(s):  
Brain Injury ◽  
Tidal Volume ◽  
Preterm Infants ◽  
Positive Pressure Ventilation ◽  
Intraventricular Haemorrhage ◽  
Delivery Room ◽  
Positive Pressure ◽  
Reference Ranges ◽  
The Mean ◽  
Spontaneously Breathing

Background and objectivesDelivery of inadvertent high tidal volume (VT) during positive pressure ventilation (PPV) in the delivery room is common. High VT delivery during PPV has been associated with haemodynamic brain injury in animal models. We examined if VT delivery during PPV at birth is associated with brain injury in preterm infants <29 weeks’ gestation.MethodsA flow-sensor was placed between the mask and the ventilation device. VT values were compared with recently described reference ranges for VT in spontaneously breathing preterm infants at birth. Infants were divided into two groups: VT<6  mL/kg or VT>6 mL/kg (normal and high VT, respectively). Brain injury (eg, intraventricular haemorrhage (IVH)) was assessed using routine ultrasound imaging within the first days after birth.ResultsA total of 165 preterm infants were included, 124 (75%) had high VT and 41 (25%) normal VT. The mean (SD) gestational age and birth weight in high and normal VT group was similar, 26 (2) and 26 (1) weeks, 858 (251) g and 915 (250) g, respectively. IVH in the high VT group was diagnosed in 63 (51%) infants compared with 5 (13%) infants in the normal VT group (P=0.008).Severe IVH (grade III or IV) developed in 33/124 (27%) infants in the high VT group and 2/41 (6%) in the normal VT group (P=0.01).ConclusionsHigh VT delivery during mask PPV at birth was associated with brain injury. Strategies to limit VT delivery during mask PPV should be used to prevent high VT delivery.

Corrective steps to enhance ventilation in the delivery room

2020 ◽  
Vol 105 (6) ◽  
pp. 605-608 ◽  
Author(s):  
Kesi C Yang ◽  
Arjan B te Pas ◽  
Danielle D Weinberg ◽  
Elizabeth E Foglia
Keyword(s):  
Heart Rate ◽  
Tidal Volume ◽  
Preterm Infants ◽  
Prospective Observational Study ◽  
Positive Pressure Ventilation ◽  
Outcome Measure ◽  
Delivery Room ◽  
Positive Pressure ◽  
Mouth Pressure ◽  
Before And After

ObjectiveThe clinical impact of ventilation corrective steps for delivery room positive pressure ventilation (PPV) is not well studied. We aimed to characterise the performance and effect of ventilation corrective steps (MRSOPA (Mask adjustment, Reposition airway, Suction mouth and nose, Open mouth, Pressure increase and Alternative airway)) during delivery room resuscitation of preterm infants.DesignProspective observational study of delivery room PPV using video and respiratory function monitor recordings.SettingTertiary academic delivery hospital.PatientsPreterm infants <32 weeks gestation.Main outcome measureMean exhaled tidal volume (Vte) of PPV inflations before and after MRSOPA interventions, categorised as inadequate (<4 mL/kg); appropriate (4–8 mL/kg), or excessive (>8 mL/kg). Secondary outcomes were leak (>30%) and obstruction (Vte <1 mL/kg), and infant heart rate.ResultsThere were 41 corrective interventions in 30 infants, with a median duration of 15 (IQR 7–29) s. The most frequent intervention was a combination of Mask/Reposition and Suction/Open. Mean Vte was inadequate before 16/41 interventions and became adequate following 6/16. Mean Vte became excessive after 6/41 interventions. Mask leak, present before 13/41 interventions, was unchanged after 4 and resolved after 9. Obstruction was present before five interventions and was subsequently resolved only once. MRSOPA interventions introduced leak in two cases and led to obstruction in one case. The heart rate was <100 beats per minute before 31 interventions and rose to >100 beats per minute after 14/31 of these.ConclusionsVentilation correction interventions improve tidal volume delivery in some cases, but lead to ineffective or excessive tidal volumes in others. Mask leak and obstruction can be induced by MRSOPA manoeuvres.

Effects of nasal positive-pressure hyperventilation on the glottis in normal sleeping subjects

1995 ◽  
Vol 79 (1) ◽  
pp. 186-193 ◽  
Author(s):  
V. Jounieaux ◽  
G. Aubert ◽  
M. Dury ◽  
P. Delguste ◽  
D. O. Rodenstein
Keyword(s):  
Tidal Volume ◽  
Positive Pressure Ventilation ◽  
Sleep Stage ◽  
Minute Ventilation ◽  
Significant Negative Correlation ◽  
Intermittent Positive Pressure Ventilation ◽  
Positive Pressure ◽  
Rapid Eye Movement Sleep ◽  
Inspiratory Resistance ◽  
Co2 Level

We have previously observed that, in normal awake subjects passively hyperventilated with intermittent positive-pressure ventilation delivered through nasal access (nIPPV), the glottis could interfere with the ventilation. We report on data obtained in the same subjects during stable sleep. In all cases, the glottis was continuously observed through a fiber-optic bronchoscope, and other indexes were also continuously recorded. Mechanical ventilation was progressively increased up to 30 l/min. We have observed during passive nIPPV in stable sleep that increases in delivered minute ventilation (VEd) resulted in progressive narrowing of the glottic aperture, with increases in inspiratory resistance and progressive reductions in the percentage of the delivered tidal volume effectively reaching the lungs. For a given level of VEd, comparisons showed that the glottis was significantly narrower during sleep than during wakefulness and that the glottis was significantly narrower during stage 2 than during stages 3/4 non-rapid-eye-movement sleep. Moreover, when CO2 is added to the inspired air, glottic aperture increased in five of nine trials without changes in sleep stage. We also observed a significant negative correlation between glottic width and the VED, independent of the CO2 level. We conclude that during nIPPV glottis narrowing results in a decrease in the proportion of the delivered tidal volume reaching the lungs.

Influence of tidal volume on the distribution of gas between the lungs and stomach in the nonintubated patient receiving positive-pressure ventilation

1998 ◽  
Vol 26 (2) ◽  
pp. 364-368 ◽  
Author(s):  
Volker Wenzel ◽  
Ahamed H. Idris ◽  
Michael J. Banner ◽  
Paul S. Kubilis ◽  
Jonathan L. Williams
Keyword(s):  
Tidal Volume ◽  
Positive Pressure Ventilation ◽  
Positive Pressure

scholarly journals Anesthesia in a horse with diaphragmatic hernia

2018 ◽  
Vol 87 (5) ◽  
pp. 263-270
Author(s):  
A. J. H. C. Michielsen ◽  
A. Binetti ◽  
J. Brunsting ◽  
F. Gasthuys ◽  
S. Schauvliege
Keyword(s):  
Tidal Volume ◽  
Diaphragmatic Hernia ◽  
Positive Pressure Ventilation ◽  
Intermittent Positive Pressure Ventilation ◽  
Positive Pressure ◽  
Thoracic Cavity ◽  
High Respiratory Rate ◽  
Midline Laparotomy ◽  
Low Tidal Volume ◽  
Abdominal Organs

An eight-year-old Thoroughbred mare was presented with acute colic symptoms. Clinical and ultrasonographic examination revealed a suspicion of diaphragmatic hernia, which was confirmed during an emergency midline laparotomy performed the same day. Patients with diaphragmatic hernia pose a challenge for the surgeon and the anesthesiologist, because of the disturbed function of the diaphragm and the displacement of the abdominal organs into the thoracic cavity. Achieving optimal ventilation and oxygenation without causing damage to the lungs is not simple. In this case, assisted-controlled, intermittent positive pressure ventilation with a low tidal volume, low pressure and relatively high respiratory rate was applied. Alongside the difficulties during ventilation, the patient was cardiovascularly compromised. Due to the extent and position of the hernia, euthanasia was performed after obtaining the owner’s consent during surgery.

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