Advanced Education In General Dentistry

Module 01: Advanced Pain Control and Sedation

Medical Emergencies and Complications

IV Complications


Complications of gaining I.V. may include infiltration, hematoma, an air embolism, phlebitis, extravascular drug administration, and intraarterial injection. Intraarterial injection is more rare, but as threatening.


Infiltration is the infusion of fluid and/or medication outside the intravascular space, into the surrounding soft tissue. Generally caused by poor placement of a needle or angiocath outside of the vessel lumen. Clinically, you will notice swelling of the soft tissue surrounding the IV, and the skin will feel cool, firm, and pale. Small amounts of IV fluid will have little consequence, but certain medications even in small amounts can be very toxic to the surrounding soft tissue.


A hematoma occurs when there is leakage of blood from the vessel into the surrounding soft tissue. This can occur when an IV angiocatheter passes through more than one wall of a vessel or if pressure is not applied to the IV site when the catheter is removed. A hematoma can be controlled with direct pressure and will resolve over the course of 2 weeks.

Air Embolism

Air embolism occurs as a result of a large volume of air entering the patient's vein via the I.V. administration set. The I.V. tubing holds about 13 CCs of air, and a patient can generally tolerate up to 1 CC per kilogram of weight of air; small children are at greater risk. Air embolisms are easily prevented by making sure that all the air bubbles are out of the I.V. tubing; fortunately, it is an extremely rare complication.

Phlebitis and Thrombophlebitis

Phlebitis and thrombophlebitis occur more frequently. Phlebitis is inflammation of the vein which occurs due to the pH of the agent being administered during the administration of the I.V, while thrombophlebitis refers to inflammation associated with a thrombus. Both are more common on the dorsum of the hand than on the antecubital facia and may occur especially in hospitalized patients where an I.V. may be in for several days, where use of an angiocatheter, as opposed to a needle, can increase the risk of phlebitis, as the metal needle is less irritating to the endothelium. (Needles are generally used for short term IV access of less than three hours, while angiocaths are used for longer periods of time.) The infusate itself may cause phlebitis and may be irritating to the skin. Older patients are also more susceptible to phlebitis.

Treatment is generally elevating the site, providing warm compresses and administering non-steroidal agents to the patient. Anticoagulants and antibiotics are usually not required.

Extravascular Injection

Extravascular injection of a drug may result in pain, delayed absorption and/or tissue damage (if the pH of the agent being administering is too high or too low). If large volumes have been injected and the skin is raised and looks ischemic, then 1% procaine should be infiltrated. Procaine is a vasodilator, which will improve the blood supply both to the area and improve venous drainage away.

Intraarterial Injection

An intraarterial injection occurs rarely, but is much more critical. The most important measure is prevention, by making sure that the needle is inserted in a vein. Remember that veins are more superficial than arteries. If you cannulate an artery, there should be a pumping of bright red blood back into your angiocath, which would not be seen when you cannulate a vein. Intraarterial injection frequently causes arterial spasm and eventual loss of limb, usually from gangrene.

In the case of intraarterial injection, recognition is paramount; observe the color of the skin, observe capillary refill, and feel the radial pulse. Capillary refill, which is observed by squeezing a fingertip and then watching the red color return, is a reflection of perfusion. If capillary refill is decreased, then perfusion to that extremity is decreased. Treatment: In the case of intraarterial injection, it is the intravenous drugs which pose severe problems, rather than the I.V. solution. Leave the needle in the artery, and slowly inject approximately 10 CCs of one percent procaine. Procaine is a vasodilator. It is slightly acidic, with a pH of 5, and will counter the alkaline drugs that were just administered. Following treatment, the patient must be hospitalized, and may often require a sympathetic nerve block. An endarterectomy and heparinization may also be necessary to prevent further complications.

A Note About Oxygen

The number one emergency drug in the office is not epinephrine, or atropine, or diazepam for patients with seizures it is OXYGEN. Therefore it is important to always be prepared to ventilate the patient with 100% oxygen. Preparation includes knowing where your 100% oxygen source is (should be easily accessible), know that you have an ambubag and knowing how to deliver oxygen via positive pressure in the case of an emergency.