Needle phobia: a neglected diagnosis

Journal of Family Practice, August, 1995 by James G. Hamilton

* Nerve-gate blocking distracts the patient by stimulating the area of needle use.

* Elevation of lower extremities in recumbent position with applied muscle tension augments the central venous reservoir, increases stroke volume, and helps maintain cerebral perfusion.

* Rapid-acting benzodiazepines, eg, diazepam or lorazepam, have an onset of action within 5 to 15 minutes from ingestion. A relatively large dose (eg, 10 to 20 mg po of diazepam) may be necessary and can be combined with nitrous oxide.

* Topical anesthesia at the needle site, eg, ice, ethyl chloride spray, or topical anesthetics. Topical anesthetics penetrate the skin much faster and deeper when driven by iontophoresis.

Alternative methods of drug delivery can sidestep the issue of needle fear by avoiding needles altogether. Nasal sprays that deliver vasopressin, calcitonin and insulin, sprays that immunize against influenza and dust-mite allergens, and an oral form of insulin are all now in investigative trials in the United States. Topical analgesic patches and opiate suppositories can be used in cases of severe pain, eg, metastatic cancer, which might otherwise be managed with intravenous drips. Many other medicines could obviously be administered without needles.

When needle use is necessary, any one of several methods or a combination of methods may be useful. Desensitization therapy by a psychiatrist or clinical psychologist is usually lengthy, expensive, and of variable efficacy.(1)(6)(7)(8) Nerve gate-blocking methods, eg, pinching or rubbing the area to distract the patient during a needle-stick, can be helpful. Shock and syncope are reduced among phobic patients by having them lie supine with legs elevated and tense their muscles during needle procedures to increase cerebral blood flow.(53) Needle-phobic patients should also be routinely premedicated with oral, sublingual, or intranasal benzodiazepines,(2) with N[O.sub.2],(8) or both. Sublingual atropine to block bradycardia also may be beneficial.(2) Since a vasovagal reaction can injure or even kill a patient, having on hand an oxygen source and a "crash cart" for cardiac resuscitation is mandatory with any needle-phobic patient undergoing a needle procedure.

Topical anesthesia of the autonomic sensory neural net at the needle site can be used to interrupt the vasovagal reflex at its origin so that the reflex is not triggered. Ethyl chloride spray can temporarily anesthetize the skin, but this affects only the superficial skin layers and lasts for only a few seconds. The skin can also be anesthetized by an ice pack, although freezing is unpleasant and can damage tissue. In placebo-controlled studies, topical anesthetics containing a mixture of lidocaine and prilocaine have been shown to work well in pediatric patients,(54) and topical mixtures of tetracaine, adrenalin, and cocaine (TAC ointment) or tetracaine, adrenalin, and lidocaine have been long used in emergency departments for surface anesthesia.(55) To work on intact skin, however, all these mixtures must be applied for 1 to 2 hours and have a depth of anesthesia of only 2 to 3 mm.