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

NCT00954733 | Completed Results

• 1 other identifier: STU00004382
• Study Type: interventional
• Target: 40
• Locations: 1 country
• Sites: 1

Brief 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 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. 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.

Conditions

Surgery; Hypoventilation

Keywords

Hysteroscopic surgery; Hypoventilation; Co2; Transcutaneous Co2 Monitor

Outcome Measures

Primary Outcomes (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

  1 hour

Study Arms (1)

All participants

EXPERIMENTAL

All participants, one arterial blood draw

Other: Arterial blood draw

Interventions

Arterial blood draw OTHER

One arterial blood draw

All participants

Eligibility Criteria

• Age: 18 Years+
• Sex: female
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

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

You may not qualify if:

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

Sponsors & Collaborators

• Northwestern University: lead

Study Sites (1)

Northwestern University

Chicago, Illinois, 60611, United States

Location

Related Publications (3)

• 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.

  PMID: 6787952 BACKGROUND

• 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.

  PMID: 3117500 BACKGROUND

• 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.

  PMID: 9895064 BACKGROUND

MeSH Terms

Conditions

Hypoventilation

Condition Hierarchy (Ancestors)

Respiratory Insufficiency; Respiration Disorders; Respiratory Tract Diseases; Signs and Symptoms, Respiratory; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Limitations and Caveats

We only included healthy, female subjects without significant co-morbidities which limit our ability to generalize our findings to elderly and sicker patients who bay benefit the most from this monitoring.

Results Point of Contact

• Title: Gildaasio De Oliveira, M.D.
• Organization: Northwestern University

gjr@northwestern.edu

312-472-3573

Study Officials

• Robert McCarthy, PharmD

  Northwestern University

  STUDY DIRECTOR

Publication Agreements

• PI is Sponsor Employee: No
• Restrictive Agreement: No

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: DIAGNOSTIC
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Study Record Dates

• First Submitted: August 5, 2009
• First Posted: August 7, 2009
• Study Start: June 1, 2009
• Primary Completion: August 1, 2009
• Study Completion: August 1, 2009
• Last Updated: July 24, 2014
• Results First Posted: July 24, 2014

Record last verified: 2014-06

Locations

US (1)