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Introduction ⬇

Intermittent or continuous carbon monoxide (CO) oximetry can be performed noninvasively with a lightweight, portable display unit that’s connected to a sensor probe placed on an adult’s or a child’s fingertip or an infant’s foot. The sensor collects data about the patient’s carboxyhemoglobin saturation and sends the information to the oximeter, which then displays the calculated data in the form of a percentage. A carboxyhemoglobin saturation level greater than 3% for nonsmokers and greater than 15% for smokers indicates exposure to exogenous CO.1

CO levels can increase as a result of chronic exposure to cigarette smoke or from acute episodes, such as from exposure to a combustion heater; inhaling spray paint or methylene chloride vapors found in paint removers, degreasers, and solvents; and inadequate ventilation of natural gas, fire, or vehicle exhaust. It may also increase with exposure to the pesticide aluminum phosphide (ALP).2 Early clinical signs of CO poisoning include anxiety, tachypnea, dyspnea, tachycardia, arrhythmias, hypotension, hypertension followed by headache and confusion, and bradycardia followed by seizures, reduced level of consciousness, respiratory failure with pulmonary edema, coma, and death.3

CO poisoning is typically diagnosed using the patient’s health history, physical examination findings, and laboratory test results that reveal an elevated CO level. Recent studies show that CO oximetry can also help with first-line screening and monitoring CO trends; however, further study is necessary to confirm the accuracy of these findings.1,4,5

Equipment ⬆ ⬇

Equipment

Noninvasive pulse CO oximeter ▪ appropriate sensor (according to the patient’s age, weight, and digit size, and the anticipated duration of monitoring)6▪ disinfectant pads ▪ Optional: nail clippers, nail polish remover, batteries, connecting cable, gloves, facility-approved disinfectant.

Preparation of Equipment ⬆ ⬇

Preparation of equipment

Inspect all equipment and supplies. If a product is expired, is defective, or has compromised integrity, remove it from patient use, label it as expired or defective, and report the expiration or defect as directed by your facility.

Plug the CO oximeter into an electrical source, and then turn on the unit. Sensors connect directly to the device or to the connecting cable, depending on the type of sensor used. Connect a direct connect sensor directly to the oximeter unit. If using a patient cable, select a sensor that’s compatible with the particular device and appropriate for the patient, and connect it to the cable.6

If using a portable, handheld CO oximeter, ensure that the unit is charged; replace the batteries, as needed, according to the manufacturer’s instructions. Attach an appropriate patient sensor to the CO oximeter.6 Calibrate the CO oximeter, if required, following the manufacturer’s instructions.

Implementation ⬆ ⬇

Implementation
  • Verify the practitioner’s order for pulse CO oximetry.
  • Gather and prepare the necessary equipment and supplies.
  • Review the patient’s medical record for past medical history and history of present illness.
  • Perform hand hygiene.7,8,9,10,11,12
  • Confirm the patient’s identity using at least two patient identifiers.13
  • Provide privacy.14,15,16,17
  • Explain the procedure to the patient and family (if appropriate) according to their individual communication and learning needs to increase their understanding, allay their fears, and enhance cooperation.18 Answer any questions.
  • Select a finger for the test. Although the index finger is commonly used, you may use a smaller finger if the patient’s index finger is too large for the equipment. Select a finger that appears to be adequately perfused. If possible, avoid choosing a finger on the hand of an arm being used for blood pressure monitoring.19

PEDIATRIC ALERT If you’re testing a neonate or small infant, wrap the probe around the foot so that the light beams and detectors align opposite each other. For a large infant, use a probe that fits on the great toe and secure it to the foot.

  • To enhance the accuracy of the measurement, make sure the patient isn’t wearing false fingernails or nail polish. If present, remove nail polish and other substances that might interfere with the transmission of light between the sensor’s light source and the detector.6
  • Clean the patient’s finger and fingernail with a disinfectant pad, and allow it to dry.19
  • Place the sensor probe on the patient’s finger, making sure the light source and the detector align opposite each other.6 If the patient has long fingernails, position the probe perpendicular to the finger, if possible, or clip the fingernail.
  • Position the patient’s hand at heart level to eliminate venous pulsations and to promote accurate readings.
  • Look at the display panel on the CO oximeter; the perfusion indicator should begin registering a pulse. Adjust the sensor and sensitivity, as needed, to achieve an adequate pulse display, because without a pulse, signal readings are erroneous.19
  • During oximetry, determine whether blood flow to the site is adequate by assessing the patient’s pulse rate and capillary refill time. If it isn’t, loosen restraints, remove tight-fitting clothes, take off the blood pressure cuff, or check arterial and IV lines, as appropriate. If none of these interventions works, consider using an alternate site.6
  • Wait the amount of time recommended by the manufacturer before obtaining the reading.
  • Monitor the patient’s CO level and pulse rate on the display screen, and then obtain readings for both.
  • Press the SPCO key to obtain a CO reading. Confirm the value as needed by placing the sensor on another finger and obtain a reading.
  • For continuous monitoring, set the alarm limits appropriately for the patient’s current condition, and make sure the alarms are turned on, functioning properly, and audible to staff.20,21,22 Reposition reusable sensors at least every 4 hours; if using adhesive sensors, inspect the application site at least every 8 hours unless otherwise directed, and reapply sensors to different sites as needed.6 Keep the monitoring site clean and dry, and make sure that the skin doesn’t become irritated from the sensor.
  • Report critical test results to the practitioner within the time frame established by your facility to prevent life-threatening treatment delays.23
  • Record all measurements in the patient’s medical record.
  • Perform hand hygiene.7,8,9,10,11,12
  • Put on gloves.24,25
  • Clean and disinfect the oximeter, cable (as applicable), and sensor (if not disposable) with a facility-approved disinfectant, according to the manufacturer’s instructions.26,27
  • Remove and discard your gloves.28
  • Perform hand hygiene.7,8,9,10,11,12
  • Document the procedure.29,30,31,32

Special Considerations ⬆ ⬇

Special considerations
  • Low CO levels don’t rule out exposure, especially if the patient has already received 100% oxygen or if significant time has elapsed since exposure. In addition to CO oximetry, monitor the patient’s clinical status and other laboratory parameters, such as arterial or venous blood gas values.
  • Individuals who chronically smoke may have mildly elevated CO levels as high as 10%. Persistence of fetal hemoglobin may also falsely elevate levels.1
  • The Joint Commission has issued a sentinel event alert concerning medical device alarm safety, because alarm-related events have been associated with permanent loss of function and death. Among the major contributing factors were improper alarm settings, inappropriately turned-off alarms, and alarm signals that weren’t audible to staff. Make sure that alarm limits are appropriately set and that alarms are turned on, functioning properly, and audible to staff. Follow facility guidelines for preventing alarm fatigue.22

Documentation ⬆ ⬇

Documentation

Document the date and time that you attached the oximeter unit to the patient. Record the initial percentage of carboxyhemoglobin registered as well as pulse rate and oxygen saturation level. Record the date, time, and name of the practitioner notified of abnormal results, if applicable; the prescribed interventions; and the patient’s response to those interventions. Document teaching provided to the patient and family (if applicable), their understanding of that teaching, and any need for follow-up teaching.

References ⬆

  1. ClardyP. F., et al. (2019). Carbon monoxide poisoning. In: UpToDate, TraubS. J., & BurnsM. M,. (Eds.).
  2. MashayekhianM., et al. (2016). Elevated carboxyhaemoglobin concentrations by pulse CO-oximetry is associated with severe aluminum phosphide poisoning. Basic and Clinical Pharmacology and Toxicology, 119(3), 322–329. https://onlinelibrary.wiley.com/doi/full/10.1111/bcpt.12571 (Level IV)
  3. KacmarekR. M., et al. (2021). Egans fundamentals of respiratory care (12th ed.). St Louis, MO: Mosby.
  4. SebbaneM., et al. (2013). Emergency department management of suspected carbon monoxide poisoning:

    Role of pulse co-oximetry

    . Respiratory Care, 58(10), 1614–1620. http://rc.rcjournal.com/content/58/10/1614 (Level IV)
  5. American College of Emergency Physicians, et al. (2017). Clinical policy:

    Critical issues in the evaluation and management of adult patients presenting to the emergency department with acute carbon monoxide poisoning

    . Annals of Emergency Medicine, 69, 98–107. https://emcrit.org/wp-content/uploads/2017/01/PIIS0196064416313452.pdf (Level I)
  6. Masimo Corporation. (2011). Rad-57 operator’s manual. http://vasinc.net/pdf/LAB5813D.pdf
  7. The Joint Commission. (2021). Standard NPSG.07.01.01. Comprehensive accreditation manual for hospitals. Oakbrook Terrace, IL: The Joint Commission. (Level VII)
  8. Centers for Disease Control and Prevention. (2002). Guideline for hand hygiene in health-care settings:

    Recommendations of the Healthcare Infection Control Practices Advisory Committee and the HICPAC/SHEA/APIC/IDSA Hand Hygiene Task Force

    . MMWR Recommendations and Reports, 51(RR-16), 1–45. https://www.cdc.gov/mmwr/pdf/rr/rr5116.pdf (Level II)
  9. World Health Organization. (2009). WHO guidelines on hand hygiene in health care: First global patient safety challenge, clean care is safer care. https://apps.who.int/iris/bitstream/handle/10665/44102/9789241597906_eng.pdf?sequence=1 (Level IV)
  10. Accreditation Association for Hospitals and Health Systems. (2020). Standard 07.01.21. Healthcare Facilities Accreditation Program:

    Accreditation requirements for acute care hospitals

    . Chicago, IL: Accreditation Association for Hospitals and Health Systems. (Level VII)
  11. Centers for Medicare and Medicaid Services, Department of Health and Human Services. (2020). Condition of participation:

    Infection control. 42 C.F.R. § 482.42

    .
  12. DNV GL-Healthcare USA, Inc. (2020). IC.1.SR.1. NIAHO accreditation requirements, interpretive guidelines and surveyor guidancerevision 20.0. Milford, OH: DNV GL-Healthcare USA, Inc. (Level VII)
  13. The Joint Commission. (2021). Standard NPSG.01.01.01. Comprehensive accreditation manual for hospitals. Oakbrook Terrace, IL: The Joint Commission. (Level VII)
  14. Accreditation Association for Hospitals and Health Systems. (2020). Standard 15.01.16. Healthcare Facilities Accreditation Program:

    Accreditation requirements for acute care hospitals

    . Chicago, IL: Accreditation Association for Hospitals and Health Systems. (Level VII)
  15. Centers for Medicare and Medicaid Services, Department of Health and Human Services. (2020). Condition of participation:

    Patient’s rights. 42 C.F.R. § 482.13(c)(1)

    .
  16. DNV GL-Healthcare USA, Inc. (2020). PR.2.SR.5. NIAHO accreditation requirements, interpretive guidelines and surveyor guidancerevision 20.0. Milford, OH: DNV GL-Healthcare USA, Inc. (Level VII)
  17. The Joint Commission. (2021). Standard RI.01.01.01. Comprehensive accreditation manual for hospitals. Oakbrook Terrace, IL: The Joint Commission. (Level VII)
  18. The Joint Commission. (2021). Standard PC.02.01.21. Comprehensive accreditation manual for hospitals. Oakbrook Terrace, IL: The Joint Commission. (Level VII)
  19. World Health Organization. (2011). Pulse oximetry training manual. https://www.who.int/patientsafety/safesurgery/pulse_oximetry/who_ps_pulse_oxymetry_training_manual_en.pdf?ua=1
  20. The Joint Commission. (2021). Standard NPSG.06.01.01. Comprehensive accreditation manual for hospitals. Oakbrook Terrace, IL: The Joint Commission. (Level VII)
  21. GrahamK. C., & CvachM. (2010). Monitor alarm fatigue:

    Standardizing use of physiological monitors and decreasing nuisance alarms

    . American Journal of Critical Care, 19, 28–37.
  22. The Joint Commission. (2013). Sentinel event alert 50: Medical device alarm safety in hospitals. https://www.jointcommission.org/assets/1/6/SEA_50_alarms_4_26_16.pdf (Level VII)
  23. The Joint Commission. (2021). Standard NPSG.02.03.01. Comprehensive accreditation manual for hospitals. Oakbrook Terrace, IL: The Joint Commission. (Level VII)
  24. Accreditation Association for Hospitals and Health Systems. (2020). Standard 07.01.10. Healthcare Facilities Accreditation Program:

    Accreditation requirements for acute care hospitals

    . Chicago, IL: Accreditation Association for Hospitals and Health Systems. (Level VII)
  25. SiegelJ. D., et al. (2007, revised 2019). 2007 guideline for isolation precautions: Preventing transmission of infectious agents in healthcare settings. https://www.cdc.gov/infectioncontrol/pdf/guidelines/isolation-guidelines-H.pdf (Level II)
  26. Accreditation Association for Hospitals and Health Systems. (2020). Standard 07.02.03. Healthcare Facilities Accreditation Program:

    Accreditation requirements for acute care hospitals

    . Chicago, IL: Accreditation Association for Hospitals and Health Systems. (Level VII)
  27. RutalaW. A., et al. (2008, revised 2019). Guideline for disinfection and sterilization in healthcare facilities, 2008. https://www.cdc.gov/infectioncontrol/pdf/guidelines/disinfection-guidelines-H.pdf (Level I)
  28. Occupational Safety and Health Administration. (2012). Bloodborne pathogens, standard number1910.1030. https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_id=10051&p_table=STANDARDS (Level VII)
  29. The Joint Commission. (2021). Standard RC.01.03.01. Comprehensive accreditation manual for hospitals. Oakbrook Terrace, IL: The Joint Commission. (Level VII)
  30. Accreditation Association for Hospitals and Health Systems. (2020). Standard 10.00.03. Healthcare Facilities Accreditation Program:

    Accreditation requirements for acute care hospitals

    . Chicago, IL: Accreditation Association for Hospitals and Health Systems. (Level VII)
  31. Centers for Medicare and Medicaid Services, Department of Health and Human Services. (2020). Condition of participation:

    Medical record services. 42 C.F.R. § 482.24(b)

    .
  32. DNV GL-Healthcare USA, Inc. (2020). MR.2.SR.1. NIAHO accreditation requirements, interpretive guidelines and surveyor guidancerevision 20.0. Milford, OH: DNV GL-Healthcare USA, Inc. (Level VII)