Related Experiment Video
Updated: Aug 29, 2026
How to Administer Near-Infrared Spectroscopy in Critically ill Neonates, Infants, and Children
Published on: August 19, 2020
Changes in transcutaneous carbon dioxide, oxygen saturation, and respiratory rate after interscalene block
Joseph D Tobias1, Louis Del Campo, Keith Kenter
1Department of Anesthesiology, University of Missouri, Columbia, MO 65212, USA. tobiasj@health.missouri.edu
Background:
We used transcutaneous (TC) carbon dioxide (CO2) monitoring to prospectively evaluate changes in respiratory status after interscalene anesthesia in 45 adults (40 successful and 5 unsuccessful blocks).
Methods:
TC-CO2 oxygen saturation and respiratory rate were recorded every minute for 5 minutes before block and every 2 minutes for a total of 30 minutes (15 data sets) after injection of the local anesthetic solution.
Results:
After successful block, TC-CO2 increased from 41 +/- 5 mm Hg to a maximum value of 44 +/- 6 mm Hg (P < 0.0001) and the respiratory rate increased from 14 +/- 2 breaths/min to a maximum of 20 +/- 4 breaths/min (P < 0.001). The increase in TC-CO2 was > or = 5 mm Hg in 11 patients and > or = 10 mm Hg in 4 patients, with a maximum increase of 12 mm Hg. Of the 600 TC-CO2 data points recorded (15 each from the 40 patients with a successful block), 62 (10.3%) showed a TC-CO2 value of 50 mm Hg or greater, with a maximum value of 57 mm Hg. No significant change in TC-CO2 or respiratory rate was seen in the five patients with unsuccessful block.
Conclusion:
After interscalene blockade, we found an increase in respiratory rate and hypercarbia that resulted in no clinically significant effect.
Related Concept Videos
01:19Special considerations while measuring oxygen saturation
Ensuring accuracy in vital sign recordings while prioritizing patient comfort and minimizing anxiety is important.
01:17Assessment of Diffusion and Perfusion
The Role of Diffusion in Respiration
Diffusion is the process by which molecules move from an area of higher concentration to an area of lower concentration. In the respiratory system, this principle...
01:20Assessment of Ventilation I: Respiratory Rate
A Ventilation assessment is critical for monitoring a patient's health status. Respiration, one of the most accessible vital signs, provides insights into the function of numerous body systems and can indicate serious health issues, such as brainstem injuries from head trauma.
Critical Guidelines for Assessing Ventilation: