Nitrous Oxide in the ED


Playback Speed

No me gusta!

The flash player was unable to start. If you have a flash blocker then try unblocking the flash content - it should be visible below.

Nurses Edition Commentary

Kathy Garvin, RN and Lisa Chavez, RN

Playback Speed

No me gusta!

The flash player was unable to start. If you have a flash blocker then try unblocking the flash content - it should be visible below.

Dallas H. -

We are likely becoming a pilot site for introducing NO into my hospital system. Neither myself or any of the other docs are super familiar with it's use. Are there any resources (outside of this great review) for training on the nuts and bolts of using NO?

Marylene C. -

We use NO in the resus bay but very infrequently. Does anyone have a protocol for its use outside the resus bay, including relevant monitoring please? We are trying to use it more. We have 50-50 with an on demand valve.

Alexis L. -

I will share ours with you

Tharwat E. -

Could you please share your protocol with me as well?
I am working on implementing it in our ED. I appreciate if you can share your protocol with me.

Marylene C. -

Thank you!

Karen M. -

me too, for the protocol. Trying to get it in our EDs as well.
Thank you!!

Scott G. -

Appreciate anything protocols can share:

Karla N. -

I’m surprised that you didn’t mention, as a possible downside, the potential for abuse. When I started working at my current department I asked about it and my director immediately responded that it was turned down as an option due to the potential for staff abusing this drug. I also know a dentist who has decided not to have it in their office for the same reason. Can you comment on this?

Alexis L. -

The devices are made with abuse potential in mind. For example the mobile unit has to be plugged into wall oxygen and wall suction. Which is very difficult to accomplish outside of an active clinical area. Additionally the breathing masks have to be pulled out of the omni cell in order to make the device work. We also keep the device in our trauma bay which is under 24 hour video surveillance. So you need to get a breathing circuit from a nurse from the omi cell, get the device from the video monitored trauma bay, plug into wall oxygen and then wall suction which is loud. These steps make abuse very difficult. Previous to these devices abuse was much easier. But now it’s Extremely difficult.


It was mentioned that Nitrous is not a billable procedure but could you not apply a charge to the mask when pulled from the Omnicell that could recoup the expense on having this available. Thank you, DSL

Anand S. -

Below is the protocol we use at our hospital via Dr. LaPietra:
Nitrous Oxide (N2O) is a tasteless colorless gas administered in combination with oxygen via inhalation as an analgesic and sedative agent. N2O is rapidly absorbed via the pulmonary vasculature into the bloodstream, and does not combine with hemoglobin or other body tissues. N2O rapidly reaches the central nervous system within minutes. Administration of N2O can achieve similar analgesia as compared to opioid analgesia, with the added benefit of noninvasive administration, and the ability to titrate up and down to achieve rapid onset and elimination. It has an impeccable safety record with few side effects and requires only minimal monitoring during use.
Indications (Ages 1 year and older)
Reduction of joint dislocations
Adjunct to other analgesia in fracture reduction
Adjunct to local anesthetic for laceration repair
Adjunct to local anesthetic for incision and drainage of soft tissue/bartholin’s abscesses
Advanced wound or burn care
Foreign body removal
Adjunct to local anesthetic for Central Venous Access
Peripheral Venous Access
Adjunct to local anesthetic for Lumbar Puncture
Fecal Disimpaction
Nitrous oxide has 15 times higher solubility ratio as compared to nitrogen, and in high doses can cause gaseous expansion in enclosed air spaces. Additionally, in patients who breathe via a hypoxemic drive secondary to lung disease may have respiratory compromise with the administration of high concentrations of N2O.
Complete obstruction of nasal passages (severe acute bacterial sinusitis)
Severe COPD
1st and 2nd trimester pregnancy
Severe asthma
Altered level of comprehension secondary to psychiatric disease, intoxication, or head injury
Complex advanced cardiac disease
High suspicion of otitis media, bowel obstruction, or pneumothorax

Nitrous oxide will be stored in the ED and maintained by Medical Director of EM Pain Management, respiratory therapy will provide new nitrous tanks . Apply a face mask suitable for the patient’s face size; sizes include small, medium, and large. Position patient as needed for procedure or analgesia.
N2O will be administered by licensed independent provider.
N2O is administered along with oxygen at varying levels of concentration. The maximum safe concentration is a 70% N2O: 30% mixture oxygen. Titration of the mixture should start at 10% N2O: 90% oxygen. The optimal concentration of nitrous oxide to achieve desired analgesia or sedation will vary with each patient, and can vary in the same patient presenting with different pain or sedation needs. The operator can assess when the correct level of analgesia is met by using a verbal pain scale or when the patient no longer adversely responses to the painful stimuli but is still able to communicate. The correct level of sedation can be assessed when the patient appears sedated, has minimal to no response to painful stimuli, but is able to communicate without significant stimulation.
Special Considerations in pediatrics- there is an increase rate of emesis in younger children post- administration. The risk increases with younger age, increased concentration, and increased duration of administration. For complicated lengthy (>30 minutes) procedures prophylactic treatment with an anti-emetic is recommended.
Set the mixture dial to 100% oxygen and allow the patient to breathe through their nose for one minute
Turn the mixture dial to 70% oxygen (30% nitrous oxide) and allow patient to breathe through their nose for approximately one minute
Turn the mixture dial to 50% oxygen (50% nitrous oxide) and allow patient to breathe through their nose for approximately one minute
Continue to titrate oxygen level down (allowing the nitrous oxide concentration to rise) until desired level of analgesia or sedation is achieved. Be aware that the mixture will not go below 30% oxygen or 70% nitrous oxide
Continue administration of gas at the desired concentration throughout procedure or as needed for analgesia. If at any point the patient becomes over-sedated titrate oxygen concentration back up. The operator may continue to titrate the gas mixture up and down as needed. The effects of changing the nitrous oxide concentration should be apparent within one to two minutes.
Once the procedure is completed or the patient’s analgesic needs have been met the operator should turn the dial back down to 100% oxygen and allow the patient to breathe through their nose for 2-5 minutes before removing the face mask.
Allow the patient to remain in a chair or the bed for an additional 2-5 minutes while breathing room air before safely discharging.
Patients will not require any restriction on activity or driving if only nitrous oxide was administered.
Vital signs – pre administration, 2 times every hour and post administration.
O2 saturation via pulse oximetry during administration
Level of consciousness to be monitored via direct observation by provider
Discharge Criteria:

Vital signs should be checked prior to discharge,
Patient must maintain or achieve a return of their baseline vital signs and mental status prior to discharge.

Aboumarzouk OM, Agarwal T, Syed Nong Chek SA, Milewski PJ, Nelson RL. Nitrous oxide for colonoscopy. Cochrane Database Syst Rev. 2011 Aug 10;(8):CD008506.

American Dental Association and Council on Dental Education, 2016. Guidelines for the use of sedation and general anesthesia by dentists.
American Dental Association Oral Health Topics: Nitrous Oxide. Center for Scientific Information, ADA Science Institute, 2017.

American Society of Anesthesiologists Task Force on Sedation and Analgesia by Non-Anesthesiologists. Practice guidelines for sedation and analgesia by non-anesthesiologists. Anesthesiology. 2002 Apr;96(4):1004-17.

Annequin D, Carbajal R, Chauvin P, Gall O, Tourniaire B, Murat I. Fixed 50% nitrous oxide oxygen mixture for painful procedures: A French survey. Pediatrics. 2000 Apr;105(4):E47.

Babl FE, Grindlay J, Barrett MJ. Laryngospasm With Apparent Aspiration During Sedation With Nitrous Oxide. Ann Emerg Med. 2015 Nov;66(5):475-8.

Babl FE, Oakley E, Seaman C, Barnett P, Sharwood LN. High-concentration nitrous oxide for procedural sedation in children: adverse events and depth of sedation. Pediatrics. 2008 Mar;121(3):e528-32.

Becker DE, Rosenberg M. Nitrous oxide and the inhalation anesthetics. Anesth Prog. 2008 Winter;55(4):124-30.
Brodsky JB, Cohen EN. Adverse effects of nitrous oxide. Med Toxicol. 1986 Sep-Oct;1(5):362-74.

Cleary AG, Ramanan AV, Baildam E, Birch A, Sills JA, Davidson JE. Nitrous oxide analgesia during intra-articular injection for juvenile idiopathic arthritis. Arch Dis Child. 2002 Jun;86(6):416-8.

Coté CJ, Wilson S; American Academy of Pediatrics; American Academy of Pediatric Dentistry. Guidelines for Monitoring and Management of Pediatric Patients Before, During, and After Sedation for Diagnostic and Therapeutic Procedures: Update 2016. Pediatrics. 2016 Jul;138(1).

Craven P, Cinar O, Madsen T. Patient anxiety may influence the efficacy of ED pain management. Am J Emerg Med. 2013 Feb;31(2):313-8.

Ducassé JL, Siksik G, Durand-Béchu M, Couarraze S, Vallé B, Lecoules N, Marco P, Lacombe T, Bounes V. Nitrous oxide for early analgesia in the emergency setting: a randomized, double-blind multicenter prehospital trial. Acad Emerg Med. 2013 Feb;20(2):178-84.
Duncan GH, Moore P. Nitrous oxide and the dental patient: a review of adverse reactions. J Am Dent Assoc. 1984 Feb;108(2):213-9.
Emmanouil DE, Quock RM. Advances in understanding the actions of nitrous oxide. Anesth Prog. 2007 Spring;54(1):9-18.

Furuya A, Ito M, Fukao T, Suwa M, Nishi M, Horimoto Y, Sato H, Okuyama K, Ishiyama T, Matsukawa T. The effective time and concentration of nitrous oxide to reduce venipuncture pain in children. J Clin Anesth. 2009 May;21(3):190-3.
Gozal D, Mason KP. Pediatric sedation: a global challenge. Int J Pediatr. 2010;2010:701257.

Gross RT, Collins FL. On the relationship between anxiety and pain: A methodological confounding. Clinical Psychology Review. 1981.

Michelle Reina -

I'M A CHAMPION FOR NITROUS! I WANT IN! We are in the process of figuring this out in our ED too. I'd be very interested in contacting Dr. LaPietra to obtain a list of equipment and any training that you gave to providers and nurses/RTs in your facility. I really appreciate everyone's time and energy with this!

Anand S. -

Michelle - see above regarding protocol, equipment and indications

Frank M. -

Hello, curious if you could share specifically which equipment you are using. I am particularly interested in the scavenging circuit. We used to have nitrous in our department but the program was cancelled by the hospital due to concerns for staff exposures. If we can demonstrate that there is a piece of equipment out there that significantly reduces the risk of staff exposure we can probably get nitrous back. Thanks!

Glen B. -

I was wondering about diffusion hypoxia (Fink effect) occurring after its use? I was taught this could happen after N2O use in the OR and was wondering whether this is a concern in the ED. My current practice in the OR is to stop N2O (seldom used) use 5 minutes before beginning waking a patient and give a minimum of 50% FiO2.

To join the conversation, you need to subscribe.

Sign up today for full access to all episodes and to join the conversation.

To earn CME for this chapter, you need to subscribe.

Sign up today for full access to all episodes and earn CME.

6 AMA PRA Category 1 Credits™ certified by PIM

  1. Quiz Not Required
  2. Complete Evaluation
  3. Print Certificate