Nitrous Oxide for Outpatient Urologic Conditions

Today many procedures are being done in the office setting rather than in the hospital. By using nitrous oxide there is less pain and discomfort. This blog will discuss the use of nitrous oxide as a safe sedation for office procedures.

Nitrous oxide is commonly used in anesthesia; its use improves the quality and safety of induction of anesthesia, facilitates faster recovery and reduces costs compared to procedures performed in the office or the ambulatory treatment center.

Nitrous oxide or laughing gas as it is commonly known was first synthesized by Joseph Priestley in 1772. It was initially used as a dental analgesic forty years after this and has been used extensively in a wide range of surgical procedures for both sedation and analgesia.

The exact mechanism of action of nitrous oxide is unknown, but its effects take place within the pain centers of the brain and spinal cord. It is thought to have an effect on the Gamma Aminobutyric Acid (GABA) cells increasing inhibition of nerve cells causing drowsiness and sleep.  It also is related to the release of endogenous neurotransmitters such as opioid peptides and serotonin. The release of these neurotransmitters is thought to activate descending pain pathways that inhibit pain transmission.

Nitrous oxide has a role in some of the following procedures:

In dentistry, nitrous oxide is frequently used to decrease the pain and anxiety associated with procedures. It is commonly delivered by a nasal mask in combination with oxygen.

Other indications

Although not standard practice, additional described uses may include colonoscopy, sigmoidoscopy, laser procedures, obstetrical labor pain, ophthalmic procedures, emergency medical care of patients in accidents and during ambulance transport, and minor invasive medical procedures, including joint injections.

Contraindications

There are certain situations where the use of nitrous oxide is contra-indicated.  For example, in patients who have undergone recent eye surgery, involving gas bubble insertion (vitrectomy), as there is a risk that the nitrous oxide will diffuse into the bubble, causing the bubble to expand and cause injury to the eye.

Nitrous oxide can cause a rise in intra-cranial pressure, so it should not be used in cases of head injury and it must never be used if the patient has any conditions where air is trapped in the body and expansion would be dangerous, for example:

• pneumothorax
• abdominal distension
• suspected intestinal obstruction
• bullous emphysema
• middle ear procedures
• following a recent dive
• maxillo-facial injuries,
• impaired consciousness,
• intoxication

Complications

When used properly, nitrous oxide is a very safe inhalational anesthetic gas. Complications up to and including death have been described. They are relatively uncommon with standard medical and dental use.

Adverse effects that may be associated with nitrous oxide include post procedure nausea and vomiting (PONV)

Short-term impairment in mental performance, manual dexterity, and audiovisual senses has been described with nitrous oxide use. This is not common and most patients can walk out of the office without assistance and even drive themselves home especially if they have not received any other sedatives like Valium or Ativan.

Bottom Line: Nitrous oxide is a very safe to provide sedation during office urologic procedures. It reduces the pain and anxiety of the procedure. For more information speak to your urologist.