Potential Issues with Local Anesthesia

Although remote, there are possible issues to look out for when giving a patient a local anesthetic.

If the patient has liver damage/disease (cirrhosis, hepatitis), congestive heart failure, reduced cardiac output, Marfan’s Syndrome, or cardiac arrhythmia, prilocaine may be the preferred local anesthetic.

Also avoid local anesthetic if your patient is in the first trimester of a pregnancy.

If you are considering using epinephrine with the local anesthetic, there are issues with;

·        MAO inhibitors  (SSRIs - selective serotonin reuptake inhibitors) – which may potentiate the action of epinephrine. 

·        TCA’s like Amitryptiline – which could create a hypertensive crisis

·        Phenothiazines - which are organic compounds that occurs in various anti psychotic and anti histaminic drugs and could lead to hypotension and/or potentiate the action of epinephrine

·        Non-selective Beta blockers (like propranolol) – which could elevate blood pressure or induce reflex bradycardia

There are also issues with Xylocaine and Cimetidine which compete for the same binding sites and may increase the circulating half life of these amides (The H₂ receptor antagonists are a class of drugs used to block the action of histamine on parietal cells in the stomach, decreasing the production of acid by these cells – dyspepsia)

There are some potential local complications when administering a local anesthetic such as, nerve damage, tendon damage, vessel damage, tourniquet effect, a broken needle, infection and intravascular injection by error.

In addition there are other potential systemic complications such as;

·         possible cardiac arrest, a drop in blood pressure, the patient could lose consciousness

·         possible syncope (vaso-vagal attack) – the patient is warm, pale, sweaty, and has nausea and tachycardia, then later patient becomes tired, cold, dizzy and bradycardia

·         possible hypoglycemia – diminished cerebral function, faint, dizzy, anxious, sweating, tachycardia, cold skin, uncooperative

·         possible hypovolemia – pulse rate goes up, drop in blood pressure, loss of consciousness,

·         possible overdose – numbness in mouth, dizzy, tinnitus, slurring, eyes loose focus, shivering, seizure

·         possible anaphylaxis – general increase in permeability and drop in blood pressure (30 minutes after injection) – a lower risk for the amide anesthetics – urticaria, pruritis, flushing, rhinitis, sneezing, cramping, wheezing, weak fast pulse, light headed, hypo tension

Know your patient’s history and medications well…and always be prepared for a possible emergency situation.