Effects Of Postural Effects Of Postural Chances On Tidal Volumes Chances On Tidal Volumes Of Obese And Non-Obese Of Obese And Non-Obese

Healthy Adults While Healthy Adults While Breathing On BiPAPBreathing On BiPAP

Faculty Advisor / FacilitatorFaculty Advisor / Facilitator

Kelly Buzbee AAS, RRT-NPS, RCPKelly Buzbee AAS, RRT-NPS, RCP

Research MembersResearch Members

Courtney Coffman RCSCourtney Coffman RCS

Taiwo Roberts B.ED, CCNA, CPhT, RCSTaiwo Roberts B.ED, CCNA, CPhT, RCS

Cynde Heaton RCSCynde Heaton RCS

Dianna Herrington LRA, RCSDianna Herrington LRA, RCS

Bahaa Mahrous RCSBahaa Mahrous RCS

Jackie Hauser RCSJackie Hauser RCS

Hypothesis:Hypothesis:The tidal volume of obese and non-obese healthy The tidal volume of obese and non-obese healthy adults will be affected while breathing in various adults will be affected while breathing in various positions on BiPAP.positions on BiPAP.

Biological Question:Biological Question:Will the tidal volume of obese and non-obese Will the tidal volume of obese and non-obese healthy adults be affected while breathing in healthy adults be affected while breathing in various positions on BiPAP?various positions on BiPAP?

Background:Background:

Newest form of non-invasive ventilation.Newest form of non-invasive ventilation. Consist of two phases: inspiratory phase and Consist of two phases: inspiratory phase and

expiratory phase.expiratory phase. IPAP provides assistance in the form of pressure IPAP provides assistance in the form of pressure

support during the inspiratory phase (IPAP).support during the inspiratory phase (IPAP). EPAP prevents closure of airways during the EPAP prevents closure of airways during the

expiratory phase.expiratory phase. The BiPAP ventilator alternates between IPAP and The BiPAP ventilator alternates between IPAP and

EPAP levels at respiratory frequencies that EPAP levels at respiratory frequencies that synchronize with patient’s breathing pattern.synchronize with patient’s breathing pattern.

As the patient inspires, the ventilator delivers IPAP As the patient inspires, the ventilator delivers IPAP which stop as the patient expires, but pressure which stop as the patient expires, but pressure within airways remains positive because of EPAP.within airways remains positive because of EPAP.

Background cont.Background cont.IPAPIPAP Provides assistance during inspiratory phase by Provides assistance during inspiratory phase by

generating a positive pressure (greater than the generating a positive pressure (greater than the atmospheric pressure) at a level pre-set by atmospheric pressure) at a level pre-set by clinician.clinician.

Increases patient’s tidal volume thus minute Increases patient’s tidal volume thus minute ventilationventilation

Decreases carbon dioxide levels in arterial blood.Decreases carbon dioxide levels in arterial blood. IPAP (pressure support) ends at the start of IPAP (pressure support) ends at the start of

expiratory phaseexpiratory phase

Background cont.Background cont.EPAPEPAP On the BiPAP machine , PEEP/CPAP is termed On the BiPAP machine , PEEP/CPAP is termed

expiratory positive airway pressure (EPAP). expiratory positive airway pressure (EPAP). EPAP increases functional residual capacity of the EPAP increases functional residual capacity of the

lungs which results in the increase in arterial lungs which results in the increase in arterial oxygen levels, compliance and decreased airway oxygen levels, compliance and decreased airway closure.closure.

Areas of atelectasis can re-expand and fluid Areas of atelectasis can re-expand and fluid accumulation due to pulmonary edema can be accumulation due to pulmonary edema can be prevented or reduced.prevented or reduced.

Supplemental oxygen can be givenSupplemental oxygen can be given

Background cont.Background cont.ObesityObesity

Accumulation of excess body fatAccumulation of excess body fat Most common nutritional disorder in humansMost common nutritional disorder in humans Airway narrowing can result from additional fat depositsAirway narrowing can result from additional fat deposits Health problems increases with neck circumferences of 17 Health problems increases with neck circumferences of 17

or more.or more. Abdominal fat accumulation tend to be accompanied by a Abdominal fat accumulation tend to be accompanied by a

decrease in vital capacity and FEV1 among adultsdecrease in vital capacity and FEV1 among adults Expiratory reserve volume is decreased in obesse patients.Expiratory reserve volume is decreased in obesse patients. Airway resistances increases significantly with levels of Airway resistances increases significantly with levels of

obesityobesity People with lean mass are positively associated with People with lean mass are positively associated with

respiratory functions,respiratory functions, Fat mass in severely obese persons has a negative Fat mass in severely obese persons has a negative

association.association. The effects of position changes during each breath might The effects of position changes during each breath might

change the compliance and tidal volume as measured by change the compliance and tidal volume as measured by the BiPAP. the BiPAP.

Indications:Indications:

Sleep apneaSleep apnea Exacerbation of COPD when intubation is not Exacerbation of COPD when intubation is not

recommended.recommended. Short term management of cardiogenic Short term management of cardiogenic

pulmonary edema when intubation is not pulmonary edema when intubation is not recommended.recommended.

PneumothoraxPneumothorax::The result of a tear in the pleura allowing air to leave the The result of a tear in the pleura allowing air to leave the

lung and lung and enter the plural space.enter the plural space.

Pathologically low B/PPathologically low B/P::Low blood pressure causing a decreased preload could be a Low blood pressure causing a decreased preload could be a contraindication.contraindication.

Severe cardiac arrhythmiasSevere cardiac arrhythmias::History of cardiac arrhythmias may become affected if History of cardiac arrhythmias may become affected if

sever alkalosis sever alkalosis occurs as a result of deep and fast breathing.occurs as a result of deep and fast breathing.

Coronary artery diseaseCoronary artery disease::Impaired coronary circulation due to positive pressure Impaired coronary circulation due to positive pressure

breathing resulting breathing resulting in an increased intrathoracic pressure decreasing venous in an increased intrathoracic pressure decreasing venous

return.5return.5SeizuresSeizures::

Results in inability to protect the airway.Results in inability to protect the airway.Bullous lung diseaseBullous lung disease::

Weakened lung parenchyma at increased risk for Weakened lung parenchyma at increased risk for pneumothorax.pneumothorax.

Contraindications:Contraindications:

Methodology:Methodology:

Individuals wishing to participate in the Individuals wishing to participate in the study were be asked to complete a health study were be asked to complete a health questionnaire. Selected individuals received a questionnaire. Selected individuals received a detailed explanation for the procedure and detailed explanation for the procedure and encouraged to ask questions before a consent encouraged to ask questions before a consent form was signed by all participants. Individuals form was signed by all participants. Individuals with potential health problems (existing with potential health problems (existing orthopedic problems which could be exacerbated orthopedic problems which could be exacerbated by positioning) were excluded from the study. A by positioning) were excluded from the study. A total of twelve participants were tested in this total of twelve participants were tested in this study. The subjects will remain anonymous by study. The subjects will remain anonymous by assignment of numbers. Participants will be assignment of numbers. Participants will be allowed access to final results on the internet at allowed access to final results on the internet at www.www.

Methodology Methodology cont:cont: Heart rate, blood pressure, and respiratory rate was be taken and Heart rate, blood pressure, and respiratory rate was be taken and

documented in the ICU classroom of Kingwood College in private. documented in the ICU classroom of Kingwood College in private. Skin color, auscultation, and accessory muscles use, was noted to Skin color, auscultation, and accessory muscles use, was noted to

observe the subject for any signs and symptoms of illness.observe the subject for any signs and symptoms of illness. Height and weight was be taken and documented (Scale used and Height and weight was be taken and documented (Scale used and

calibrated as per instruction manual).calibrated as per instruction manual). Individual BMI (body mass index) was be calculated.Individual BMI (body mass index) was be calculated. Subjects were be fitted with the Respironics BiPaP S/T-D breathing Subjects were be fitted with the Respironics BiPaP S/T-D breathing

mask, and mask adjusted with each subsequent position. mask, and mask adjusted with each subsequent position. Subjects were placed on Hill-Rom Contra multi positional standard Subjects were placed on Hill-Rom Contra multi positional standard

Hospital bed in four positions; supine, prone, left side and right Hospital bed in four positions; supine, prone, left side and right side. side.

Subjects were then will be placed on Respironics BiPAP S/T-D Subjects were then will be placed on Respironics BiPAP S/T-D ventilatory support system for a minimum of 3 minutes at the rate ventilatory support system for a minimum of 3 minutes at the rate of IPAP 10 cm H2O and EPAP of 5 cm H2O and titrated to patient’s of IPAP 10 cm H2O and EPAP of 5 cm H2O and titrated to patient’s comfort.comfort.

Tidal volume, minute ventilation, percent leak, heart rate, Tidal volume, minute ventilation, percent leak, heart rate, respiratory rate, oxygen saturation, and tolerance to the respiratory rate, oxygen saturation, and tolerance to the procedure was documented in each position by the digital read procedure was documented in each position by the digital read out from the Respironics machine, pulse oximeter and out from the Respironics machine, pulse oximeter and observation.observation.

After the allotted time was reached in each position individual’s After the allotted time was reached in each position individual’s post tidal volume, heart rate, blood pressure and respiratory rate post tidal volume, heart rate, blood pressure and respiratory rate was be recorded while in each position.was be recorded while in each position.

Data:Data:

patientall12.xlspatientall12.xls

Data Analysis:Data Analysis:Average Min. Volume Average Min. Volume

DifferencesDifferences

SupineSupine ProneProne LeftLeft RightRight

100100 88.9688.96 85.0485.04 80.9880.98

Normal BMI differences in Normal BMI differences in Min. VolumesMin. Volumes

SupineSupine ProneProne LeftLeft RightRight

100100 71.0371.03 79.1179.11 78.8578.85

Obese BMI differences in Obese BMI differences in Min volumesMin volumes

SupineSupine ProneProne LeftLeft RightRight

100100 124.83124.83 80.7580.75 89.8889.88

0

20

40

60

80

100

120

140

Average NormalBMI

Obese BMI

Supine

Prone

Left

Right

Recommendations:Recommendations:

Broader and diverse test group must be Broader and diverse test group must be considered.considered.

A larger group is required.A larger group is required. Active search for people that might have a mild Active search for people that might have a mild

cold or flu, but otherwise healthy.cold or flu, but otherwise healthy. Starting the IPAP at eight and the EPAP at three Starting the IPAP at eight and the EPAP at three

cmH2O and titrating from there for comfort to get cmH2O and titrating from there for comfort to get a baseline for each subject.a baseline for each subject.

Including sitting down as one of the positions.Including sitting down as one of the positions.

Changing the environment somewhat toChanging the environment somewhat to makemake the subject more comfortable.the subject more comfortable.

Limitations:Limitations:

The first and foremost limitation of our The first and foremost limitation of our experiment was the number of test subjects. In experiment was the number of test subjects. In order to conduct an experiment of this caliber and order to conduct an experiment of this caliber and for the experiment to be truly meaningful a much for the experiment to be truly meaningful a much broader and larger test pool must be considered. broader and larger test pool must be considered. From the twelve subjects, eight had a normal BMI From the twelve subjects, eight had a normal BMI status and four were of obese stature. A more status and four were of obese stature. A more acceptable test pool for an experiment this small acceptable test pool for an experiment this small would have considered perhaps, six normal, six would have considered perhaps, six normal, six obese, and six overweight subjects. Another major obese, and six overweight subjects. Another major limitation that we placed on ourselves because of limitation that we placed on ourselves because of time, legal, and ethical questions is that we only time, legal, and ethical questions is that we only evaluated healthy individuals. Where as a person evaluated healthy individuals. Where as a person with significant changes in tidal volume and minute with significant changes in tidal volume and minute ventilation due to postural changes would in fact, ventilation due to postural changes would in fact, probably be ill. The limitations of our experiment probably be ill. The limitations of our experiment included:included:

The IPAP and EPAP were set at 10 and 5 cmH2O The IPAP and EPAP were set at 10 and 5 cmH2O respectively, for all of the twelve subjects; this respectively, for all of the twelve subjects; this should have been titrated individually for the should have been titrated individually for the comfort of each subject.comfort of each subject.

The test group of twelve people should have been The test group of twelve people should have been more diverse in the sense of body types.more diverse in the sense of body types.

Four out of twelve of the test subjects complained Four out of twelve of the test subjects complained that the machine did not feel spontaneous and that the machine did not feel spontaneous and this probably affected their volumes.this probably affected their volumes.

Two of the twelve test subjects complained that Two of the twelve test subjects complained that they were unable to stop inspiration when they they were unable to stop inspiration when they wanted to, again affecting the volume.wanted to, again affecting the volume.

The Hawthorne effect, because of the setting The Hawthorne effect, because of the setting itself; the subject knows they were being watched itself; the subject knows they were being watched so this may have affected volumes.so this may have affected volumes.

Conclusion:Conclusion:After analysis of all the data, the experiment After analysis of all the data, the experiment

was inconclusive at best and actually may indicate was inconclusive at best and actually may indicate that obese people in the prone position had larger that obese people in the prone position had larger tidal volumes and minute ventilations. Respiration tidal volumes and minute ventilations. Respiration rates varied from 12 to 20 breaths per minute with rates varied from 12 to 20 breaths per minute with a standard deviation of 3.27 and an average of a standard deviation of 3.27 and an average of 16.75. Tidal volumes averaged from 891 mls in the 16.75. Tidal volumes averaged from 891 mls in the supine position, 727 mls in the prone position, 673 supine position, 727 mls in the prone position, 673 mls lying on the left-hand side to 666 mls lying on mls lying on the left-hand side to 666 mls lying on the right hand side, with a standard deviation of the right hand side, with a standard deviation of 334, 296, 214, and 225 mls, respectively. Results 334, 296, 214, and 225 mls, respectively. Results indicated that the supine position had the highest indicated that the supine position had the highest tidal volumes for both groups. Significant tidal volumes for both groups. Significant decreases in the tidal volumes for all other decreases in the tidal volumes for all other positions with the exception of the prone position positions with the exception of the prone position in 3 out of 4 of the obese subjects occurred. in 3 out of 4 of the obese subjects occurred. However, because of the limited number of However, because of the limited number of subjects in the obese category it would be subjects in the obese category it would be irresponsible to determine that obese subjects in irresponsible to determine that obese subjects in the prone position with BiPAP had larger tidal the prone position with BiPAP had larger tidal volumes and minute ventilations.volumes and minute ventilations.

1.1. Preston R (2001) Introducing non-invasive positive pressure ventilation. Preston R (2001) Introducing non-invasive positive pressure ventilation. Nursing Standard. Nursing Standard. 15,26,42-45. Date of acceptance: October 24, 2000.15,26,42-45. Date of acceptance: October 24, 2000.

2.2. M. Ohayon, C. Guileminault, R. Priest, M. Caulet (1997) Snoring and M. Ohayon, C. Guileminault, R. Priest, M. Caulet (1997) Snoring and breathing pauses during sleep: telephone interview survey of a United breathing pauses during sleep: telephone interview survey of a United Kingdom population sample. Kingdom population sample. BMJ, BMJ, March 22, 1997; 314:860.March 22, 1997; 314:860.

3.3. A. DeLorenzo, C. Maiolo, E. Mohamed, A. Andreoli, P. Petrone-De Luca, P. A. DeLorenzo, C. Maiolo, E. Mohamed, A. Andreoli, P. Petrone-De Luca, P. Rossi (2001) Body Composition Analysis and Changes in Airways Rossi (2001) Body Composition Analysis and Changes in Airways Function in Obese Adults Hypocaloric Diet. Function in Obese Adults Hypocaloric Diet. Chest.Chest. 119:1409-1415. Date 119:1409-1415. Date of acceptance: December 18, 2000.Retrieved September 16, 2005, fromof acceptance: December 18, 2000.Retrieved September 16, 2005, fromhttp://www.ems.doh.ms.gov/pdf/selfstudy/mod_iii_objectives_and outlinehttp://www.ems.doh.ms.gov/pdf/selfstudy/mod_iii_objectives_and outlines_Part1.pdfs_Part1.pdf

4.4. R. Wilkins, J. Stoller, C. Scanlan (2003) Egan’s Fundamentals of R. Wilkins, J. Stoller, C. Scanlan (2003) Egan’s Fundamentals of Respiratory Care, Eighth Edition. Respiratory Care, Eighth Edition. Mosby. Mosby. St. Louis (2003).St. Louis (2003).

5.5. R. Schwab (2003) Pro: Sleep Apnea Is an Anatomic Disorder. R. Schwab (2003) Pro: Sleep Apnea Is an Anatomic Disorder. American American Journal of Respiratory and Critical Care MedicineJournal of Respiratory and Critical Care Medicine Vol 168. pp. 270-271. Vol 168. pp. 270-271. Date of acceptance: October 27, 2005.Date of acceptance: October 27, 2005.

6.6. Dr. Woodson (2005) Evaluation of Upper Airway in Obstructive Sleep Dr. Woodson (2005) Evaluation of Upper Airway in Obstructive Sleep Apnea Syndrome. Apnea Syndrome. Medical College of Wisconsin. Medical College of Wisconsin. Date of acceptance: Date of acceptance: October 24, 2005.October 24, 2005.

7.7. G. Gibson (2005) Obstructive sleep apnea syndrome: underestimated G. Gibson (2005) Obstructive sleep apnea syndrome: underestimated and Under treated. and Under treated. British Medical Bulletin. British Medical Bulletin. 72 (1):49-65 Date of 72 (1):49-65 Date of acceptance: October 24, 2005.acceptance: October 24, 2005.

References:References: