Ignite Creation Date:
2024-05-05 @ 11:48 AM
Last Modification Date:
2024-10-26 @ 9:13 AM
Study NCT ID:
NCT00135252
Status:
TERMINATED
Last Update Posted:
2008-01-08
First Post:
2005-08-23
Brief Title:
Method of Oxygen Delivery and the Effect on Transcutaneous PaCO2
Sponsor:
The University of Texas Health Science Center Houston
Organization:
The University of Texas Health Science Center Houston
Study Overview
Official Title:
Method of Oxygen Delivery Comparison Nasal Cannula vs Oxygen Hood and the Effect on Transcutaneous PaCO2
Status:
TERMINATED
Status Verified Date:
2007-12
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Investigator left institution
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
None
Brief Summary:
Infants of 1500 grams of birth weight who require a 1 week mechanical ventilation breathing machine or CPAP continuous positive airway pressure oxygen at a high flow through the nose may have prolonged oxygen requirements The nasal cannula oxygen through the nose at a low flow is the most commonly used method of oxygen administration despite a lack of data regarding its safety and efficacy Low birth weight infants are vulnerable to obstruction from secretions and blood as well as the presence of the nasal cannula Partially obstructed nostrils greatly increase the work of breathing Additional potential adverse effects include an increased need for suctioning increased risk for systemic infection and inadvertent positive end expiratory pressure CPAP No study has been conducted to evaluate the efficacy of the nasal cannula compared to an oxygen hood plastic hood that is placed over the infants head to provide oxygen on gas exchange or infection
Among infants who require supplemental oxygen by either a nasal cannula or an oxygen hood for clinical indications objectives the investigators hope to accomplish in a randomized blinded investigator trial
Aim 1 To determine the short-term effect of different flows of oxygen by the nasal cannula on transcutaneous PCO2 PTCO2
Aim 2 To determine once optimal flow is established in Aim 1 the effect of prolonged one week use of a nasal cannula compared to an oxygen hood on PTCO2
Among infants who require supplemental oxygen by either a nasal cannula or an oxygen hood for clinical indications objectives the investigators hope to accomplish in a randomized blinded investigator trial
Aim 1 To determine the short-term effect of different flows of oxygen by the nasal cannula on transcutaneous PCO2 PTCO2
Aim 2 To determine once optimal flow is established in Aim 1 the effect of prolonged one week use of a nasal cannula compared to an oxygen hood on PTCO2
Detailed Description:
Specific Question
Among low birth weight infants with a supplemental oxygen requirement do modifications in the flow Lmin of nasal cannula gas alter the level of transcutaneous PCO2 in the short term 30 minutes or longer term one week
Objectives
Aim 1 To determine the short-term effect of different flows of oxygen by the nasal cannula on transcutaneous PCO2
Aim 2 To determine once optimal flow is established in Aim 1 the effect of prolonged one week use of a nasal cannula compared to an oxygen hood on transcutaneous PCO2
Randomization Method
Following informed consent will be stratified based on weight 1250 grams and 1250 grams as well as oxygen delivery requirement NCPAPmechanical ventilation at time of enrollment Randomization will occur as soon as possible following eligibility criteria being met All enrolled infants will be randomized into one of two different sequences for evaluation of the short-term effect of gas flow rate on transcutaneous PCO2 Aim 1 Enrolled infants will be randomly assigned by numbered opaque envelopes containing a card that indicates the assigned treatment order block method using random number table by individuals not involved in care of the infants one of two group sequences Then infants who meet eligibility criteria as outlined above for Aim 2 will be randomized to either oxygen hood or ideal nasal cannula flow for a period of one week by numbered opaque envelopes containing a card that indicates the assigned treatment group
Intervention
In Aim 1 of the study enrolled infants will be randomly assigned to a sequence of either oxygen hood followed by 1 Lmin NC ½ Lmin NC ¼ Lmin NC 18 Lmin NC and then oxygen hood OR oxygen hood followed by 18 Lmin NC ¼ Lmin NC ½ Lmin NC 1Lmin NC and then oxygen hood Infants will remain on each flow for a minimum of 30 minutes with 5 minute interval readings of transcutaneous PCO2 heart rate and respiratory rate The optimal nasal cannula flow rate will be defined as the lowest flow rate that consistently maintains a SaO2 85 with FiO2 05 without increasing transcutaneous PCO2 more than 5 mm Hg above the oxygen hood PCO2
In Aim 2 of the study infants will be randomized to nasal cannula at the optimal flow rate as determined in Aim 1 or oxygen hood for a period of one week At the end of one week transcutaneous PCO2 heart rate and respiratory rate will be monitored a total of 30 minutes at 5 minute intervals
Co-Interventions
Feeding To control for feeding related changes in functional residual capacity will standardize all infants to receive continuous feeds for 2 hours prior to and resume bolus feeds no sooner than 2 hours following outcome assessments
Suctioning As needed for secretions otherwise not scheduled more frequent than 4 times day
Methylxanthines At discretion of attending physician with recommendation that 1000 gram infants receive prophylactic methylxanthines per Cochrane Collaboration finding RR 058 and 95 CI 029116 Also request no changes be made during study period
Diuretics At discretion of attending physician with recommendation that if on diuretics at time of enrollment they not be discontinued during study period
Escalation Guidelines
Mechanical ventilation Recommendations for reintubation will be transcutaneous PCO2 70 or pH 72 2 apneabradycardia necessitating bag mask ventilation
NCPAP Recommendations may place on NCPAP if infant has multiple apneabradycardia 6day requiring moderate to vigorous stimulation despite optimization of the airway
Nasal cannula May increase nasal cannula flow or change from oxygen hood if saturations 85 consistently for more than 1 hour on a FiO2 of 10
Baseline variables
On entry into Aim 1 baseline variables that will be recorded include gender gestational age birth weight post-natal age diuretic use methylxanthine use oxygen delivery requirement NCPAP mechanical ventilation and duration of mechanical ventilation
Aim 1 Outcome Variables
During Aim 1 will determine the optimal nasal cannula flow rate defined by the lowest flow rate that consistently maintains a SaO2 85 on a FiO2 05 without increasing transcutaneous PCO2 more than 5 mmHg above the oxygen hood PCO2 Also plan to analyze average heart rate respiratory rate
Aim 2 Outcome Variables
During Aim 2 baseline variables on entry include the same as those listed above in Aim 1 At the conclusion of Aim 2 will record necessity of return to NCPAP or mechanical ventilation if the addition of methylxanthine or diuretics or steroids were necessary and if sepsis defined as by positive blood culture treated with antibiotics 5 days occurred
Assessment Methods
Aim 1 outcome The assessment of the association between oxygen flow and transcutaneous PCO2 in order to determine ideal nasal cannula flow is accomplished by graphing the average transcutaneous PCO2 measurement obtained for each Lmin flow Each enrolled patient will have transcutaneous PCO2 recorded every five minutes and will remain on each flow of oxygen for thirty minutes Then an average of the 6 transcutaneous PCO2 readings will be calculated for each flow rate All recorded data averages will then be plotted on a graph for each individual patient From this graph the flow at which minimal further change in PCO2 is obtained is the ideal flow for that patient
Aim 2 Outcome The assessment of the change in PCO2 at the end of one week among the two treatment groups will be accomplished by statistical analysis At the conclusion of one week of therapy to assigned arm of therapy transcutaneous recordings of PCO2 for a period of thirty minutes at five minute intervals will be made These recordings will then be compared to baseline recordings made during Aim 1
Blinding
The study clinicians and bedside nurses will be difficult to blind to intervention group The individual recording the transcutaneous PCO2 will be blinded to the flow of nasal cannula during the outcome assessment for Aim 1 A second individual will be blinded to treatment assignment during outcome assessment recordings of Aim 2
Sample Size
In order to demonstrate a difference as large as one standard deviation will require a sample size of 44 This calculation is based on
Standard Deviation No data is available to predict the standard deviation Alpha of 005 Beta 1-09 01 using the two sided t-test each group needs 22 patients
Stopping Rules
Due to the small size of the study there will not be an interim analysis Hypoxia and respiratory distress can be associated with poor outcome Any patients developing significant respiratory distress as outlined by above reintubation and NCPAP recommendations will be taken off NC or oxygen hood and be placed back on assigned arm of treatment when attending physician determines infant is clinically able Given the small study size and low expectations of severe adverse events we do not plan a scheduled formal DSMB process Infants in the study will be monitored for serious adverse events that are study related eg respiratory distress necessitating escalation of care If more than 6 such events occur during the course of the study an independent ad hoc DSMB including at least one neonatologist and one biostatistician will be convened to make a judgment regarding continuation of the trial
Analysis Plan
The following analysis plan has been designed to allow every randomized infant to be included in the intention to treat analysis regardless of whether they require reintubation or NCPAP All infants will be assigned a rank at baseline and at outcome 1 week as follows
Infants on oxygen delivered by nasal cannula or oxygen hood will be ranked according to delta change transcutaneous PCO2 and this subgroup will receive the lowest ranks
Infants on oxygen hood who require nasal cannula or infants on nasal cannula who require higher flow will be assigned a higher rank than infants who remained on oxygen hood or did not require increased flow on nasal cannula
Infants who require NCPAP or mechanical ventilation will be assigned the highest rank
A rank sum test will be conducted to compare the two groups
Among low birth weight infants with a supplemental oxygen requirement do modifications in the flow Lmin of nasal cannula gas alter the level of transcutaneous PCO2 in the short term 30 minutes or longer term one week
Objectives
Aim 1 To determine the short-term effect of different flows of oxygen by the nasal cannula on transcutaneous PCO2
Aim 2 To determine once optimal flow is established in Aim 1 the effect of prolonged one week use of a nasal cannula compared to an oxygen hood on transcutaneous PCO2
Randomization Method
Following informed consent will be stratified based on weight 1250 grams and 1250 grams as well as oxygen delivery requirement NCPAPmechanical ventilation at time of enrollment Randomization will occur as soon as possible following eligibility criteria being met All enrolled infants will be randomized into one of two different sequences for evaluation of the short-term effect of gas flow rate on transcutaneous PCO2 Aim 1 Enrolled infants will be randomly assigned by numbered opaque envelopes containing a card that indicates the assigned treatment order block method using random number table by individuals not involved in care of the infants one of two group sequences Then infants who meet eligibility criteria as outlined above for Aim 2 will be randomized to either oxygen hood or ideal nasal cannula flow for a period of one week by numbered opaque envelopes containing a card that indicates the assigned treatment group
Intervention
In Aim 1 of the study enrolled infants will be randomly assigned to a sequence of either oxygen hood followed by 1 Lmin NC ½ Lmin NC ¼ Lmin NC 18 Lmin NC and then oxygen hood OR oxygen hood followed by 18 Lmin NC ¼ Lmin NC ½ Lmin NC 1Lmin NC and then oxygen hood Infants will remain on each flow for a minimum of 30 minutes with 5 minute interval readings of transcutaneous PCO2 heart rate and respiratory rate The optimal nasal cannula flow rate will be defined as the lowest flow rate that consistently maintains a SaO2 85 with FiO2 05 without increasing transcutaneous PCO2 more than 5 mm Hg above the oxygen hood PCO2
In Aim 2 of the study infants will be randomized to nasal cannula at the optimal flow rate as determined in Aim 1 or oxygen hood for a period of one week At the end of one week transcutaneous PCO2 heart rate and respiratory rate will be monitored a total of 30 minutes at 5 minute intervals
Co-Interventions
Feeding To control for feeding related changes in functional residual capacity will standardize all infants to receive continuous feeds for 2 hours prior to and resume bolus feeds no sooner than 2 hours following outcome assessments
Suctioning As needed for secretions otherwise not scheduled more frequent than 4 times day
Methylxanthines At discretion of attending physician with recommendation that 1000 gram infants receive prophylactic methylxanthines per Cochrane Collaboration finding RR 058 and 95 CI 029116 Also request no changes be made during study period
Diuretics At discretion of attending physician with recommendation that if on diuretics at time of enrollment they not be discontinued during study period
Escalation Guidelines
Mechanical ventilation Recommendations for reintubation will be transcutaneous PCO2 70 or pH 72 2 apneabradycardia necessitating bag mask ventilation
NCPAP Recommendations may place on NCPAP if infant has multiple apneabradycardia 6day requiring moderate to vigorous stimulation despite optimization of the airway
Nasal cannula May increase nasal cannula flow or change from oxygen hood if saturations 85 consistently for more than 1 hour on a FiO2 of 10
Baseline variables
On entry into Aim 1 baseline variables that will be recorded include gender gestational age birth weight post-natal age diuretic use methylxanthine use oxygen delivery requirement NCPAP mechanical ventilation and duration of mechanical ventilation
Aim 1 Outcome Variables
During Aim 1 will determine the optimal nasal cannula flow rate defined by the lowest flow rate that consistently maintains a SaO2 85 on a FiO2 05 without increasing transcutaneous PCO2 more than 5 mmHg above the oxygen hood PCO2 Also plan to analyze average heart rate respiratory rate
Aim 2 Outcome Variables
During Aim 2 baseline variables on entry include the same as those listed above in Aim 1 At the conclusion of Aim 2 will record necessity of return to NCPAP or mechanical ventilation if the addition of methylxanthine or diuretics or steroids were necessary and if sepsis defined as by positive blood culture treated with antibiotics 5 days occurred
Assessment Methods
Aim 1 outcome The assessment of the association between oxygen flow and transcutaneous PCO2 in order to determine ideal nasal cannula flow is accomplished by graphing the average transcutaneous PCO2 measurement obtained for each Lmin flow Each enrolled patient will have transcutaneous PCO2 recorded every five minutes and will remain on each flow of oxygen for thirty minutes Then an average of the 6 transcutaneous PCO2 readings will be calculated for each flow rate All recorded data averages will then be plotted on a graph for each individual patient From this graph the flow at which minimal further change in PCO2 is obtained is the ideal flow for that patient
Aim 2 Outcome The assessment of the change in PCO2 at the end of one week among the two treatment groups will be accomplished by statistical analysis At the conclusion of one week of therapy to assigned arm of therapy transcutaneous recordings of PCO2 for a period of thirty minutes at five minute intervals will be made These recordings will then be compared to baseline recordings made during Aim 1
Blinding
The study clinicians and bedside nurses will be difficult to blind to intervention group The individual recording the transcutaneous PCO2 will be blinded to the flow of nasal cannula during the outcome assessment for Aim 1 A second individual will be blinded to treatment assignment during outcome assessment recordings of Aim 2
Sample Size
In order to demonstrate a difference as large as one standard deviation will require a sample size of 44 This calculation is based on
Standard Deviation No data is available to predict the standard deviation Alpha of 005 Beta 1-09 01 using the two sided t-test each group needs 22 patients
Stopping Rules
Due to the small size of the study there will not be an interim analysis Hypoxia and respiratory distress can be associated with poor outcome Any patients developing significant respiratory distress as outlined by above reintubation and NCPAP recommendations will be taken off NC or oxygen hood and be placed back on assigned arm of treatment when attending physician determines infant is clinically able Given the small study size and low expectations of severe adverse events we do not plan a scheduled formal DSMB process Infants in the study will be monitored for serious adverse events that are study related eg respiratory distress necessitating escalation of care If more than 6 such events occur during the course of the study an independent ad hoc DSMB including at least one neonatologist and one biostatistician will be convened to make a judgment regarding continuation of the trial
Analysis Plan
The following analysis plan has been designed to allow every randomized infant to be included in the intention to treat analysis regardless of whether they require reintubation or NCPAP All infants will be assigned a rank at baseline and at outcome 1 week as follows
Infants on oxygen delivered by nasal cannula or oxygen hood will be ranked according to delta change transcutaneous PCO2 and this subgroup will receive the lowest ranks
Infants on oxygen hood who require nasal cannula or infants on nasal cannula who require higher flow will be assigned a higher rank than infants who remained on oxygen hood or did not require increased flow on nasal cannula
Infants who require NCPAP or mechanical ventilation will be assigned the highest rank
A rank sum test will be conducted to compare the two groups
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
None
Is a FDA Regulated Device?:
None
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None