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Orifices: The ins and outs of the human body

As the population ages and healthcare needs surge, EMS is evolving beyond emergencies to provide critical support through body cavity access devices and expanded care procedures

It is obvious that we are facing a dramatic increase in healthcare needs due to an exploding population that is rapidly aging, served by inadequate numbers of physicians, mid-level providers and nurses, and burdened with spiraling healthcare costs.

So who do you think might be tagged to help take up some of the slack? EMS represents a huge healthcare resource and it cannot remain just for emergencies anymore. Although many countries have expanded roles for EMS, we are beginning to explore our capacity to provide a greater scope of care and community paramedicine.

With that, let me introduce you to the world of temporary and not-so-temporary body cavity access devices and procedures that may require your current or future patient care expertise.

Natural body openings

There are seven natural body openings or orifices providing access to an internal cavity through a natural passage called a canal, duct or meatus. So, from the top (superior) of the body down (inferior):

  • External auditory canal or meatus directs air waves from the outside to the tympanic membrane converting mechanical energy to electrical energy in the internal auditory canal or meatus that is sent to your brain.
  • Nares are the entrance to the nose and the slimy surface inside that collects dust, pollen, etc. to keep it out of your airways and helps warm the outside air before it hits your lungs.
  • Nasal meati are openings inside the nose leading to the four paired sinus cavities that also collect inhaled particles, warms the air and also lighten the weight of your skull, which gives some truth to the term “airhead.”
  • Mouth provides access to the gastrointestinal tract and the respiratory system
  • Urethral meatus transports urine from your bladder to the outside
  • Anus for solid waste output
  • Vagina, the conduit to the uterus from whence we were all delivered

Traffic control

A sphincter is a circular muscle surrounding a natural body opening or conduit. They range from very small as the thousands of capillary sphincters that open and close the smallest blood vessels, to large sphincters that manage higher flow volumes such as through the esophagus or out the anus.

The importance and intelligence of the sphincter is not to be taken for granted. This can be demonstrated by a thought experiment. Imagine your hands are cupped together and filled with water, sand and air; could you open your hands and allow only the air to escape? The anal sphincter does that routinely.

Temporary interventions following normal anatomic pathways

Nasogastric and orogastric tubes provide temporary access to the stomach for suction of contents or irrigation (lavage) or to administer medication or nutrition (gavage). These tubes are uncomfortable and careful manipulation will minimize discomfort.

The opening to the esophagus is close to the opening to the lungs (larynx), thus a displaced gastric tube is an aspiration risk. Tube placement is confirmed by X-ray and the distance of insertion is noted or marked to monitor any tube drift.

Intubation of the trachea can be accomplished via the nose or the mouth and is a familiar out-of-hospital intervention with potential problems of misplacement and displacement.

Urinary catheters are flexible, smooth tubes that can be inserted for a quick in-and-out procedure to obtain urine for testing. They can also be left in place for continuous drainage as an indwelling (residing inside the body) catheter.

Years ago Dr. Frederic Eugene Basil Foley developed the first flexible indwelling catheter with an inflatable balloon on one end to keep part of the tube inside the bladder. The Foley catheter is both friend and foe as it provides a portal for bacteria to enter the bladder and bloodstream thus increasing the incidence of urinary tract infections, sepsis and patient deaths.

We worsen the chances of such infections by inserting them too often and waiting too long to remove them, simply for our convenience as caretakers.

Rectal tubes are inserted into the rectum and used to introduce a variety of liquids to relieve constipation or to deliver medication such as lactulose that absorbs excess ammonia produced by the liver failure patient or kayexalate to help decrease high serum potassium levels though binding with potassium which is then excreted in the stool.

Some rectal tubes look like large Foley catheters as they have a balloon on one end to anchor the tube in the rectum. This may be useful when a patient has temporarily lost voluntary control of the anal sphincter. Continuous stooling can cause skin breakdown and prevent local wound healing.

Real-world, practical methods for identification, assessment and field treatment of life-threatening sepsis

Non-anatomical pathways

These interventions break through the skin to insert a tube or create a surgical opening to access an internal cavity. This exposes the incision and the organ cavity to potential infection, therefore requiring constant vigilance in maintaining aseptic technique. Where a tube is involved, security is the key to decreasing the movement that may result in discomfort or dislodgement.

An ostomy is a surgical opening to allow waste removal through the abdominal wall instead of the normal anatomic pathway. The stoma is the part of the bowel or ureter that you see on the skin surface and where the catch bag is located.

Proper placement of the bag over the stoma is essential to keep the flow contained and prevent skin damage from bowel content or urine.

A tracheostomy is a surgical opening in the trachea providing access to the lungs when the larynx is removed or becomes dysfunctional due to illness, injury or surgery. A tracheostomy tube is inserted into the opening to maintain patent access. It is essential to keep the skin clean and dry around the opening, and the tracheostomy tube clean and patent.

The other surgical airway is the cricothyroidotomy, a temporary, last-ditch emergency airway to insert a tube through an incision in the cricothyroid membrane to create a patent airway and ventilate the lungs.

The most common long-term feeding tube is a Percutaneous Endoscopic Gastrostomy or PEG tube. The tube is inserted through the skin and into the stomach while visualizing the stomach through the gastroscope. There is a bumper or inflatable balloon on the stomach side of the tube to keep it in place.

Gastrostomy tubes are used when a patient is unable to take oral nutrition long-term or permanently as in patients with neurologic disorders that prevent them from swallowing. Like all other tubes, careful skin care and close monitoring tube placement are essential.

Sometimes the need for a urinary catheter becomes a long-term proposition as in a patient with bladder damage from injury or disease. A suprapubic catheter is inserted through the skin above the pubic symphysis into the bladder, thus bypassing the urethra and decreasing the incidence of infection.

The Ostomy

Take the functional part of the colon, separate it from the diseased part, stick the good end through an incision in the abdominal wall to create a stoma by suturing the edge of the colon to the skin, and you have created a colostomy.

Some are temporary allowing the lower part of the diseased or injured colon to heal before reconnecting the two ends. Some are permanent because the distal part of the colon is removed or permanently damaged.

If the entire colon is out of action, an ileostomy can be created. Recall that the ileum is the distal part of the small intestine that connects to the cecum or first part of the colon. The ileostomy then diverts the waste before it hits the colon while allowing the absorption of nutrients by the rest of the small bowel.

Bladder problems from cancer or spinal cord injuries or spinal birth defects like spina bifida can result in a severely dysfunctional or absent bladder that requires external surgical drainage. There are a couple of options here.

The ureters connecting the kidneys to the bladder can be detached and bought out through the abdominal wall directly. The other option is the Ileal or colon conduit where a short segment of the ileum or colon is detached creating a pouch where the ureters are connected to one end while the other end of the colon or ileum is brought out through the abdominal wall as with the colostomy or ileostomy.


Now you have the basic body ins and outs. It is my prediction you will become more involved with these comings and goings the longer you stay in EMS. At least now you have a small opening to expand your knowledge.

This article, originally published on February 19, 2013, has been updated.

Jim Upchurch, MD, MA, NREMT, has focused on emergency medicine and EMS while providing the full spectrum of care required in a rural/frontier environment. He provides medical direction for BLS and ALS EMS systems, including critical care interfacility transport.