Policies,Clinical,UWHC Clinical,Department Specific,Respiratory Care Services,Patient Assessment

Capnography (3.22)

Capnography (3.22) - Policies, Clinical, UWHC Clinical, Department Specific, Respiratory Care Services, Patient Assessment


3.22 Capnography
Category: UWHC Patient Care Policy
Effective Date: October 1, 2015
Version: Revision
Manual: Respiratory Care Services
Section: Patient Assessment


Capnography is a non-invasive method of measuring partial pressure (or concentration) of CO2 in the
airway during the ventilatory cycle. This is plotted as CO2 versus time and is numerically displayed or
graphically displayed as a waveform. When ventilation and perfusion are well matched throughout the
lung, PaCO2 and the partial pressure of end tidal CO2 (PetCO2) are nearly equal.


A. All patients will be assessed by the Respiratory Care Practitioner (RCP).
B. Therapy will be provided in accordance with a provider’s order.
C. An accurate reading will be taken with a normal waveform containing:
1. Zero baseline during early exhalation.
2. Sharp upstroke during mid exhalation.
3. Relatively horizontal plateau throughout exhalation.
4. Sharp downstroke and return to a zero baseline with inhalation.
D. RCP's may obtain an ETCO2 per their discretion to use the information as an assessment tool.
E. Appropriate placement of the endotrachael tube and appropriate ventilation of the patient
immediately following intubation must, at minimum, be assessed by auscultation AND CO2
assessment, either by the physician/anesthetist or by an RCP.
F. The ETCO2 value should be correlated with an ABG or VBG whenever possible and evaluated
with the patient’s clinical condition.
G. PICU/NICU ventilated patients will have continuous ETCO2 monitoring.
H. All transported PICU/NICU ventilated patients will have continuous ETCO2 monitoring.
Continuous ETCO2 monitoring is also recommended for ventilated adults.
I. Ventilated patients in MRI will be monitored for ETCO2 during procedure to assure proper
ventilation. The monitor also serves as a disconnect alarm.
J. For continuous monitoring while asleep see P&P# 3:21, "Respiratory Sleep Studies".


A. Mainstream; Cosmo, Novametrix 1265, and airway adapter. Obtain appropriate adapter:
1. Neonatal sensor, for patients with VT’s 1-100ml and ETT’s 2.5-4.0.
2. Pediatric sensor, for patients with VT’s 30-400ml and ETT’s 3.5-6.0.
3. Pediatric/Adult sensor, for patients with VT’s 200-3,000ml and ETT’s 5.5 and greater.
4. See related link for use.
B. Sidestream; Capnostream 20; sampling rate is 50 ml/minute.
1. Airway adapter, sample line
a. Adult/Pediatric
b. Infant/Neonatal
2. Nasal canula or catheters for non-artificial airway.
a. Infant cannula
b. Pediatric cannula

c. Adult cannula
3. See related link.
C. GE Module: sampling rate is 200-250 ml/minute.
D. Easy cap/pedi cap.
E. MRI supplied ETCO2 machine with appropriate adapter.
F. Sen Tec digital monitor


A. Review and acknowledge provider's order.
B. Review patient's chart.
C. Obtain the appropriate equipment. See related links for details.
D. Introduce yourself to the patient and/or family. Explain the reason for the procedure.
E. Assess the patient throughout the procedure.
F. Use the appropriate monitor and assess for a normal waveform.
1. Continuous flow ventilators may cause inaccurate readings when placed in line with the
circuit due to gas mixing.
2. Sidestream capnometry will affect very small volumes with volume ventilation
(excluding pressure ventilation) by pulling volume to sample.
3. Mainflow capnography using a large adapter will increase deadspace ventilation.


A. RC P&P 1:40 "Cleaning and Changing of Patient Care Equipment"
B. Egan's Fundamentals of Respiratory Care, Patient Monitoring and Management
C. "Pediatric Critical Care" Fuhrman and Zimmerman 13th edition 2013

Approved by Director and Medical Director of Respiratory Care:

A copy of this Policy & Procedure is available in the Respiratory Care Office [E5/489].