Capnography Sampling Line Comparisons

Reliable access to a patient’s respiratory status is vital to help ensure patient safety and improve outcomes. And addressing respiratory compromise begins with detecting it — the earlier the better.

A key to obtaining an accurate etCO2 measurement and quality waveforms with any capnograph is the sampling line.  The monitor’s measurement technology can only report what is being delivered to the measurement chamber, if the sampling line is not providing a representative CO2 sample from the breath, the accuracy of the reading may be impacted.

Medtronic, Masimo, Salter Labs, and Teleflex Medical are all suppliers of capnography sampling lines in the United States. How does the Microstream™ capnography sampling line portfolio from Medtronic compare? In this blog post, we’ll discuss the features of Microstreamcapnography sampling lines along with other available sampling lines for use with patients in the ambulance, during procedural sedation, and on the general care floor.

While not an exhaustive list of every capnography sampling line available, this blog presents each product in the manufacturer’s own words. You may validate all features listed by the manufacturers by checking their websites or contacting their sales representatives.

Medtronic capnography sampling lines

To help you confidently monitor your patients, we offer a full array of sampling lines to meet virtually all patient and clinical needs, featuring oral and nasal sampling as well as an innovative supplemental oxygen delivery system. Microstream™ capnography sampling lines can be used with both intubated and non-intubated patients, from neonate to adult.

  • Uni-junction™ technology – patented design offers effective oral and nasal sampling when a patient alternates between mouth and nose breathing. It is engineered to sample from the oral or nasal source with the greatest pressure, without capturing ambient air.
  • Oral scoop – designed to provide quality breath samples when the patient is mouth breathing.  Design offers broad surface area to help enhance sampling accuracy during shallow breathing.
  • Oxygen delivery – flows from holes in front of nasal prongs within the oral scoop; delivers flow up to 5 L/min without diluting the CO2 sample.  Oxygen may be delivered via sampling line under a mask.
  • Moisture reduction technology – for use in high humidity environments and long-term monitoring. Options available for nonintubated and intubated patients.
  • Smart CapnoLine™ sampling line with Guardian bite block – delivers supplemental oxygen during upper endoscopy procedures.  The combined sampling and oxygen delivery line fits into a bite block, helping protect delicate endoscopy devices from damage.
  • OxymaskTM* ETCO2 with MicrostreamTM connector – engineered to deliver a wide range of O2 levels. It easily integrates with existing technology for oxygenation and ventilation management.

OxyMask™* is distributed by Medtronic. Manufactured by Southmedic.

Related: Find out how much capnography monitoring costs. Read the blog post.

Masimo capnography sampling lines

Designed for low-flow applications, with functionality in any orientation, NomoLine™* sampling lines can be used in a variety of clinical scenarios on both intubated and nonintubated adult, pediatric, infant, and neonatal patients.  Offered in both low- and high-humidity configurations, features include:1

  • Patented polymer collects and removes water in the sampling line
  • Designed for low tidal volumes and high breath rates
  • Hydrophobic bacteria filter
  • Cannulas with soft, ergonomically curved design
  • Leak-free, click-in gas sampling port connector

Teleflex Medical capnography sampling lines

All gas sampling lines from Teleflex Medical include a male luer connector on one end for connection to the patient circuit gas sampling port. Optional features include2:

  • Male or female luer for machine fitting PVC sampling lines for measurement of end-tidal CO2
  • Coextruded PVC/polyethylene sampling lines for precision measurement of anesthetic gases
  • Nafion™* Dryer Line for water vapor removal from sampled gases
  • Small SARA disc filters for placement on machine end of gas sampling lines to protect capnograph monitor from moisture

Flexicare capnography sampling lines

A variety of sampling lines are available that deliver oxygen while sampling CO2. Some of the options from Flexicare include3,4:

  • Dual nasal cannula. Designed to provide oxygen to both and nostrils while sampling CO2 at the same time.
  • Dual mask. Provides monitoring of carbon dioxide exhaled from both mouth and nose while delivering oxygen.

Salter Labs/SunMed† capnography sampling lines

A variety of sampling lines are available, both with and without oxygen delivery. These sampling lines are manufactured as a side-by-side, split nasal design.  This enables CO2 sampling from one side of the nose and through a small hole in the oral scoop, while oxygen is delivered through the other side.

  • Salter-style cannulas. Available in a variety of lengths at standard 3, 6, and 15 LPM flow rates for neonatal to adult patients with TLC ear wraps for relieving pressure on the ears and in standard quiet and micro styles.5
  • Demand cannulas. Specifically designed for dual port oxygen conservation delivery systems in a full range of sizes and flow rates up to 6 LPM.6
  • Conventional (non-curved) cannulas. Conventional cannulas standard facepieces and tubing that are available in multiple lengths for flow rates up to 6 LPM for pediatric and adult patients.7
  • 16SOFT™* Cannulas. 16SOFT™* cannulas are available in a variety of lengths, specialty styles and 3, 6 and 15 LPM flow rates for neonatal to adult patients.8
  • ETCO2 Cannula Standard and Fits-All Connector. Dual nasal cannula, three-channel tubing, male/female adapter with luer lock connector, and available three tubing lengths.9,10
  •  The ETCO2 Cannula + Scoop. Offers the same features as noted above, but with optional O2 delivery.11

†Salter Labs and SunMed recently merged.

Dispo-Med capnography sampling lines

There are several sampling line designs offered, including nasal only and oral scoop style cannulas.  Options are available with and without supplemental oxygen delivery.  The overall design is split side-by-side design that samples from one side of the nose.  Some of the cannulas include12:

  • Nasal CO2 sampling cannula with O2 delivery
  • Nasal/Oral Dual CO2 Sampling Cannula with O₂ delivery
  • Duo Flow O2 + CO2 sampling cannula
  • Lo-Flo nasal/oral CO2 sampling cannula
  • Nasal pressure cannula 

What to consider before you purchase a capnography sampling line

We’ve provided you with several supplier options. What else do you need to know before you buy? We recommend taking into consideration the following:

Microstream™ technology compatibility. Imitation sampling lines are not validated with Microstream™ technology and may lead to inaccurate or unreliable readings. It’s also important to note that Medtronic hardware warranty may become invalid if imitation sampling lines are used.

Split Design. Both Salter Labs and Dispo-Med offer capnography sampling lines with split design. Be aware of these potential issues with this design.  Considerations that may impact CO2 sampling include:13-15

  • Blockage on either side can impair oxygen delivery and/or CO2 sampling; there is less surface area for oral CO2 sampling
  • Anatomical obstructions such as deviated septum, nasal polyps, enlarged adenoids, etc.
  • Physical obstructions such as NG tube, feeding tube
  • Medical obstructions such as nasal/sinus congestion, allergic rhinitis, etc.
  • Nasal cycling
  • Limited oral scoop surface area can produce lower CO2 readings
  • Oral CO2 sample hole can drop out as patient position moves

Contact us to learn more about our capnography sampling lines.


1. Masimo.
2. Teleflex Medical.
3. Flexicare.
4. Flexicare.
5. Salter Labs.
6. Salter Labs.
7. Salter Labs.
8. Salter Labs.
9. SunMed.
10. SunMed.
11. SunMed.
12. Dispo-Med.
13. Colman Y, David U. Comparison of capnography filter lines for nose and mouth breathing of end tidal carbon dioxide sampling with and without supplemental oxygen. Society for Technology in Anesthesia Annual Meeting. Abstract No. 43, January 13-14, 2009.
14. Dungan G, Colman J, Lain D. Evaluation of oxygen delivery via a novel smart CapnoLinedelivery system during simultaneous oxygen therapy and carbon dioxide monitoring. Society for Technology in Anesthesia Annual Meeting. Abstract No. 20, January 18-21, 2012.
15. Karpenkop I. Capnography sample line design and oxygen delivery influence etCO2accuracy. Society for Technology in Anesthesia Annual Meeting.  January 10-13, 2018.

OxyMask™* is distributed by Medtronic. Manufactured by Southmedic.

About the Author

Jennifer Fruitticher is a senior monitoring clinical product specialist for Medtronic’s Respiratory and Monitoring Solutions portfolio. As a registered nurse with more than 20 years’ of experience in the medical field, her work has always been focused in the Critical Care ICU (trauma/neuro).

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