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SurgeryNCT00954733

A Comparison of the Detection of Hypoventilation During Deep Sedation Utilizing Nasal End Title CO@ Versus Transcutaneous CO2 Measurement Techniques

A study testing Arterial blood draw in people with Surgery and Hypoventilation, run by Northwestern University at 1 site in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

The estimation of the partial pressure of carbon dioxide (PCO2) in the arterial blood is used to judge the adequacy of ventilation during spontaneous and controlled ventilation. Although the gold standard for monitoring PCO2 remains arterial blood gas sampling, this requires an invasive procedure and provides only an… Read more about this study

Who is it for?
Ages 18 years and older, women only
Conditions the study is for
Surgery, Hypoventilation
What is being tested?
Arterial blood draw
Could I receive a placebo?
No, everyone receives an active treatment
How many people
40 participants
Where
1 siteUnited States
Study dates
Jun 2009to Aug 2009
Phase
Interventional
Are there results?
Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • Women only
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Age>18 years of age
  • Sex: Non-pregnant, Female
  • ASA PS: I, II
  • Surgery: Elective Hysteroscopy surgery
  • Consent: Obtained

Who cannot join

  • Age < 18 years old
  • Patients who refuses participation
  • History of lung disease
  • History of Obstructive sleep apnea

Trial locations and contacts

1 site in 1 country.

United States1 site
  • Northwestern University

    Chicago, Illinois, 60611

Other trials in United States

About this study

The estimation of the partial pressure of carbon dioxide (PCO2) in the arterial blood is used to judge the adequacy of ventilation during spontaneous and controlled ventilation. Although the gold standard for monitoring PCO2 remains arterial blood gas sampling, this requires an invasive procedure and provides only an intermittent estimate of what is frequently a continuously changing value. The solution to this problem has been the development and validation of accurate noninvasive monitoring techniques which provide a continuous intraoperative estimate of PCO2.The most commonly used noninvasive technique to monitor PCO2 is measurement of the end tidal CO2 (PECO2) . However, sampling errors and patient -related issues such as ventilation-perfusion mismatch, patient positioning or decreases in pulmonary blood flow may influence the accuracy of PECO2 monitoring (1-3). Nasal capnography has been proved to be an accurate monitor during the post-operative period (4) but its ability to accurately detect hypoventilation associated with deep sedation has not been studied.

According to the American Society of Anesthesiologist standards for basic monitoring, continuous capnography is required for all patients undergoing general anesthesia but it is optional for MAC/sedation cases. The need for CO2 monitoring has been studied by other medical specialties that use procedural sedation, including gastroenterology (12) and emergency medicine (13, 14) and many specialties now recommend capnography as a standard monitor.

Read more

Patients receiving supplemental oxygen may experience significant persistent hypoventilation leading to progressive hypercarbia and acidosis which may go undetected for a significant time interval since the routinely monitored SpO2 may be maintained within normal range. A recent study has shown that despite the fact that end tidal CO2 is reliable in detecting apnea , increasing oxygen flow rates decrease the amplitude of measured CO2, probably via dilution, making the quantitative value less reliable as an assessment of adequacy of ventilation (15). Furthermore, during hypoventilation there is reduced alveolar ventilation and the end tidal CO2 is not a true reflection of arterial CO2.

Transcutaneous measurement of PCO2(PtcCO2) is a non-invasive method of measuring PCO2 that has been used much less frequently due to technical difficulties with earlier transcutaneous electrodes. Preliminary studies of the reliability of the current PtcCO2 electrodes (TOSCA, Linde Medical Sensors, and Basel, Switzerland) have shown good correlation of arterial and transcutaneous measurements in both adult volunteers and anesthetized subjects (5). PtcCO2 is measured with a sensor attached by a low pressure clip to an earlobe. The sensor probe heats the earlobe to 42 degrees Celsius to enhance blood flow. The current sensors have also been evaluated in anesthetized children (7, 8), anesthetized adults (9, 10) and critically ill neonates (11) and all these studies revealed a good correlation between PtCO2 and PaCO2.

Read the detailed description

A group of _40 patients scheduled to undergo Hysteroscopy surgery with deep sedation will be studied. Standard monitors will be utilized. Additionally a transcutaneous CO2 electrode will be attached to the ear lobe and a BIS monitor will be applied to the forehead.

The anesthetic management will be left to the discretion of the anesthesia provider (Anesthesia resident or CRNA, under the supervision of a faculty attending anesthesiologist).All patients will receive supplemental oxygen at 3L/ minute via nasal cannula, to maintain oxygen saturation greater than 90%.

Both the end tidal CO2 (ETCO2) and transcutaneous CO2 (TcCO2) (Linde Medical Sensors, Basel , Switzerland ) will be calibrated before use, according to the manufacturer's instruction.. The anesthesia provider will be blinded to the TcCO2 monitor but will have access to the ETCO2 values. The ETCO2 and TcCO2 values will be recorded simultaneously by an independent observer.

One arterial blood samples will be collected from each subject for measurement of PaCO2 at a deep level of sedation defined by a modified Ramsey score greater or equal to 5 (1= anxious/agitated/restless; 2= cooperative/oriented/tranquil; 3= drowsy/responds to commands only; 4= brisk response to shaking/loud sound; 5= sluggish response to shaking/loud sound; 6= no response) The ETCO2 and .TcCO2 will be recorded throughout the time of obtaining the blood sample every 15 seconds and the mean value will be used for comparison. Hypoventilation will be defined as a PaCO2 level greater than 45mmHg.

Sedation score (OASS) will be recorded on admission to recovery area. Time to meet discharge criteria will be recorded.

The experimental procedures: ABG draw, ETCO2 monitor placement on the ear, 2 Ramey scale assessments.

Being tested
Arterial blood draw
Keywords
Hysteroscopic surgery, Hypoventilation, Co2, Transcutaneous Co2 Monitor
Medical subject headings
Hypoventilation

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Arterial blood drawOther

    One arterial blood draw

Study groups in NCT00954733
Study groupRoleWhat they receive
All participantsExperimentalAll participants, one arterial blood draw
Receives: Other: Arterial blood draw

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. TcCo2 vs PACo2 Difference

    Evaluate the correlation between PaCO2- TcCO2 in detecting hypoventilation for patients undergoing deep sedation Absolute mean difference between TcCo2 and the PA Co2

    Measured: 1 hour

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted7 Aug 2009 (estimated)
  2. Study startJun 2009
  3. Primary completionAug 2009
  4. Study completionAug 2009

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Diagnosis
Allocation
Non-randomised
Intervention model
Single group
Masking
None (open label)
Enrolment
40 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT00954733
Sponsor's protocol ID
STU00004382
Status last verified
Jun 2014
First submitted
5 Aug 2009
Last updated
24 Jul 2014
Data monitoring committee
No

Publications

  • Whitesell R, Asiddao C, Gollman D, Jablonski J. Relationship between arterial and peak expired carbon dioxide pressure during anesthesia and factors influencing the difference. Anesth Analg. 1981 Jul;60(7):508-12.

    PubMed 6787952
  • Yamanaka MK, Sue DY. Comparison of arterial-end-tidal PCO2 difference and dead space/tidal volume ratio in respiratory failure. Chest. 1987 Nov;92(5):832-5. doi: 10.1378/chest.92.5.832.

    PubMed 3117500
  • Grenier B, Verchere E, Mesli A, Dubreuil M, Siao D, Vandendriessche M, Cales J, Maurette P. Capnography monitoring during neurosurgery: reliability in relation to various intraoperative positions. Anesth Analg. 1999 Jan;88(1):43-8. doi: 10.1097/00000539-199901000-00009.

    PubMed 9895064

Questions about this trial

What is this clinical trial studying?

A study testing Arterial blood draw in people with Surgery and Hypoventilation, run by Northwestern University at 1 site in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 5 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 24 Jul 2014. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

Yes. Results are posted in the registry (first posted 24 Jul 2014). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

TcCo2 vs PACo2 Difference (time frame: 1 hour). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT00954733, which also lists 3 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 24 Jul 2014.

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