Role of positive airway pressure on pulmonary acinar perfusion heterogeneity

2000 ◽  
Vol 89 (5) ◽  
pp. 1943-1948 ◽  
Author(s):  
Nobuhiro Tanabe ◽  
Thomas M. Todoran ◽  
Gerald M. Zenk ◽  
Jun Aono ◽  
Wiltz W. Wagner ◽  
...  
Keyword(s):  
Airway Pressure ◽  
Positive Airway Pressure ◽  
Appearance Time ◽  
Capillary Networks ◽  
Pulmonary Acinus ◽  
Capillary Resistance ◽  
The Mean ◽  
Lung Lobes ◽  
Dilution Curves

Perfusion of the pulmonary acinus has been shown to be generally homogeneous, but there is a significant component that is heterogeneous. To investigate the contribution of the alveolar septal capillary network to acinar perfusion heterogeneity, the passage of fluorescent dye boluses through the subpleural microcirculation of isolated dog lung lobes was videotaped using fluorescence microscopy. As the videotapes were replayed, dye-dilution curves were recorded from each of the tributary branches of Y-shaped venules that drained single acini. For each Y-shaped venule, the mean appearance time difference between the pair of tributary branches was calculated from the dye curves. When the complex septal capillary networks were derecruited by high positive airway pressure, venular perfusion became proportionally more homogeneous. This result shows that septal capillary resistance and pathlength differences are important contributors to intra-acinar perfusion heterogeneity.

scholarly journals Perfusion heterogeneity in the pulmonary acinus

1998 ◽  
Vol 84 (3) ◽  
pp. 933-938 ◽  
Author(s):  
Nobuhiro Tanabe ◽  
Thomas M. Todoran ◽  
Gerald M. Zenk ◽  
Brenda R. Bunton ◽  
Wiltz W. Wagner ◽  
...  
Keyword(s):  
Blood Flow ◽  
Fluorescence Microscopy ◽  
Capillary Blood ◽  
Fluorescent Dye ◽  
Time Difference ◽  
Appearance Time ◽  
Pulmonary Acinus ◽  
The Mean ◽  
The Difference ◽  
Dilution Curves

There is little information on the distribution of acinar perfusion because it is difficult to resolve blood flow within such small regions. We hypothesized that the known heterogeneity of arteriolar blood flow and capillary blood flow would result in heterogeneous acinar perfusion. To test this hypothesis, the passage of fluorescent dye boluses through the subpleural microcirculation of isolated dog lobes was videotaped by using fluorescence microscopy. As the videotapes were replayed, dye-dilution curves were recorded from each of the tributary branches of Y-shaped venules that drained an acinus. From the dye curves, we calculated the mean appearance time of each curve. The difference in mean appearance times between venular tributary branches was small in most cases. In 43% of the observed venular branch pairs, the dye curves were essentially superimposable (the mean appearance-time difference was <5%); and in another 42%, the mean appearance-time difference between curves was 5–10%. From these results, we conclude that acinar perfusion is unexpectedly homogeneous.

scholarly journals Continuous Positive Airway Pressure-Mandibular Advancement Device Combination Therapy for Moderate-to-Severe Obstructive Sleep Apnea: A Preliminary Study

2021 ◽  
Author(s):  
Thyagaseely Sheela Premaraj ◽  
Jacob Stadiem ◽  
Shyamaly Arya Premaraj ◽  
Charles R. Davies ◽  
Matthew Dennis ◽  
...  
Keyword(s):  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Daytime Sleepiness ◽  
Airway Pressure ◽  
Positive Airway Pressure ◽  
Mandibular Advancement Device ◽  
Mandibular Advancement ◽  
Severe Obstructive Sleep Apnea ◽  
Obstructive Sleep ◽  
The Mean

Abstract Objectives The purpose of this pilot study was to determine whether compliance to auto-adjusting positive airway pressure (APAP) improves with the addition of a mandibular advancement device (MAD). Secondary outcome measures included were APAP pressure, subjective daytime sleepiness, apnea–hypopnea index (AHI), and mask leaks. Setting and Sample Population Participants included were diagnosed with moderate-to-severe obstructive sleep apnea (OSA) and became noncompliant to prescribed APAP. Thirteen participants with a mean age of 61.6 years were recruited for this study. Materials and Methods All participants were given a MAD to use with their APAP. Parameters measured included APAP pressure, AHI, mask leak reported via ResMed AirViewTM software, and self-reported daytime sleepiness (Epworth Sleepiness Scale [ESS]). A paired two-sample for mean t-test was performed to determine significance. Results The mean difference of pre- and postintervention APAP compliance was 23.1%, which was statistically significant (p = 0.015). The mean APAP air pressures were unchanged. The difference between pre- and postintervention mean ESS scores was 1.4 and was statistically significant (p = 0.027). The mean difference between pre- and postintervention AHI values and mask leak showed no significant difference. Conclusion This study showed that combination of APAP-MAD therapy, for patients with moderate-to-severe OSA who were noncompliant to APAP use, significantly increased compliance with APAP therapy, and significantly decreased the daytime sleepiness of participants.

scholarly journals 0986 Positive Airway Pressure Care And Cleaning Practices In The Pediatric Home

SLEEP ◽  
2020 ◽  
Vol 43 (Supplement_1) ◽  
pp. A374-A375
Author(s):  
K K Pruss ◽  
D Willis ◽  
B J Spray ◽  
S Jambhekar
Keyword(s):  
Airway Pressure ◽  
Respiratory Symptoms ◽  
Positive Airway Pressure ◽  
Descriptive Statistics ◽  
Distilled Water ◽  
Respiratory Therapist ◽  
Clinic Appointment ◽  
Low Correlation ◽  
Water Chamber ◽  
The Mean

Abstract Introduction The Sleep Clinic at Arkansas Children’s follows approximately 300 children who require positive airway pressure (PAP) at home. The clinic respiratory therapist provides oral and written cleaning instructions while some physicians choose to provide their own instructions. The home equipment company who supplies PAP in the home also gives cleaning instructions. The different routes of information given may result in inconsistent practices. It is extremely important to clean PAP equipment as directed as infection and illness may result from improper cleaning. Methods Caregivers of children who utilize home PAP devices were invited to complete an anonymous survey regarding cleaning practices during a Sleep clinic appointment. Data were collected electronically. Descriptive statistics were utilized to summarize results. Results There were 96 participants of whom 90% (87/96) were parents/caregivers. The mean age of the equipment user was 12 years and most were male (69%, 66/96). The mean length of time the equipment had been used was 2.6 years (SD 3.2). The majority of respondents, 67% (64/95), identified the parent/caregiver as responsible for cleaning. Only 25% (24/96) reported cleaning the mask daily as recommended; 43% (41/96) of participants reported cleaning tubing weekly; 27% (26/96) reported cleaning the water chamber daily by while most reported at least weekly (47%, 45/96). The majority, 58% (56/96) reported emptying the water chamber daily and using distilled water (81%, 74/96). Most respondents did not note respiratory symptoms starting/increasing with PAP (67%, 64/96). Of those with respiratory symptoms attributed to PAP, congestion was the most common (79%, 11/14). Conclusion There is a discrepancy between recommended and actual practices for cleaning PAP equipment. No significant association was found between the duration of PAP use and cleaning practices. However, a moderately low correlation between age and cleaning was identified. Increased age was associated with decreased cleaning practices. Support  

scholarly journals Practical Aspects of Interface Application in CPAP Treatment

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Adel Bachour ◽  
Heidi Avellan-Hietanen ◽  
Tuula Palotie ◽  
Paula Virkkula
Keyword(s):  
Airway Pressure ◽  
Positive Airway Pressure ◽  
Medical Team ◽  
Cpap Therapy ◽  
Air Leak ◽  
First Line ◽  
First Line Therapy ◽  
Line Therapy ◽  
Nasal Stuffiness

While continuous positive airway pressure (CPAP) is an effective first-line therapy for sleep apnea, CPAP fails in one third of patients mainly due to poor adherence to the CPAP device and masks. The role of the medical team is to guide the patient in choosing the best mask, thus insuring good CPAP therapy adherence. Once a suitable mask is found, the brand of the mask does not affect patient satisfaction or CPAP adherence. For the majority of patients, nasal masks are by far more suitable than oronasal masks. Orosanal masks are indicated in case of nasal stuffiness or when an air leak manifests through the mouth. Re-evaluation of the efficacy of CPAP therapy is recommended when switching to oronasal masks.

scholarly journals Successful Extubation Using Heliox BiPAP in Two Patients with Postextubation Stridor

2017 ◽  
Vol 2017 ◽  
pp. 1-2
Author(s):  
Pragya Punj ◽  
Premkumar Nattanmai ◽  
Pravin George ◽  
Christopher R. Newey
Keyword(s):  
Airway Pressure ◽  
Positive Airway Pressure ◽  
Extubation Failure ◽  
Standard Medical Therapy ◽  
Bilevel Positive Airway Pressure ◽  
Postextubation Stridor ◽  
Nebulized Epinephrine ◽  
Intravenous Steroids ◽  
Successful Extubation

Postextubation stridor is associated with significant morbidity. It commonly results in extubation failure after established medical treatment fails, such as nebulized epinephrine and/or intravenous steroids. The role of heliox (i.e., combination of helium and oxygen) in managing patients with postextubation stridor has not been fully established. We report two cases of postextubation stridor successfully treated with heliox delivered with bilevel positive airway pressure (BiPAP) after failure of standard medical therapy.

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