Emergencies in the Pain Clinic

Asteghik Hacobian

Milan P. Stojanovic

Though an arrow is always approaching its target, it never quite gets there, and Saint Sebastian died of fright.

—Tom Stoppard

The use of fluoroscopic guidance and contrast injection markedly decreases the complication rate of pain procedures. However, complications do occur and can have disastrous consequences if the clinic is not prepared to deal with these emergencies. This chapter reviews some of the emergency problems encountered in the pain clinic. Every pain management clinic specializing in interventional pain management procedures should be equipped with emergency equipment including an airway cart, oxygen tanks, resuscitation equipment, and emergency medication, and all providers in the pain clinic should be familiar with their use and their location. There should always be personnel trained in resuscitation present in the clinic when there are patients in the clinic undergoing or recovering from procedures. Finally, a safety officer should be identified, and a regular check of the emergency equipment should be carried out and documented by him or her.

I. PROCEDURE-RELATED EMERGENCIES

1. Vasovagal Syncope

Syncope is one of the most common reactions that occur in a pain clinic. Patients commonly fear needles and procedures. The best prevention is reassurance. If there is any suspicion that the patient may be very anxious, insertion of an intravenous line with the consent of the patient is recommended. Sometimes, an anxiolytic agent before the procedure is helpful, although anxiolytic agents may provide pain relief and may diminish the diagnostic value of blocks. Unfortunately, vasovagal syncope can occur even during minor procedures.

Vasovagal syncope is always associated with brachycardia. During any kind of procedure, standard monitors, including noninvasive blood pressure cuff and pulse oximeter, and, in most cases, a three-lead electrocardiograph (ECG), should be used and patient baseline values should be documented.

To avoid possible patient injury from a fall due to loss of consciousness, avoid performing procedures with the patient in the standing or sitting position.

(i) Symptoms and Signs

Presyncopal symptoms and signs include nausea, epigastric distress, perspiration, light headedness, confusion, tachycardia, and pupillary dilatation. Syncopal signs include loss of consciousness, generalized muscle weakness, loss of postural tone, pallor or cyanosis, and brief tonic–clonic seizure-like activity. Hypotension can also occur.

(ii) Treatment

In the event of any complaint from the patient, including feeling faint, nauseated, or sweating, do the following:

Place the patient in the Trendelenburg position.
Administer oxygen, evaluate and protect the airway, and support ventilation, depending on the severity of the case.
Monitor oxygenation, ventilation, and vital signs.
Establish intravenous access (if not present), administer atropine 0.4 to 1 mg IV for a heart rate of less than 45 beats per minute or for a rapidly decreasing heart rate.
Apply standard monitors and evaluate ECG tracing for other possible causes of bradycardia (e.g., junctional rhythm).
Continue to monitor and keep patient supine.
Make sure that all the vital signs are stable and that the patient is stable before being discharged home.

2. Systemic Local Anesthetic Toxicity

Systemic local anesthetic toxicity can manifest as minor symptoms such as tinnitus, a metallic taste in the mouth, numbness of the lips, light headedness, or visual disturbance, and may progress to loss of consciousness, seizure activity, and decrease in myocardial contractility. Obviously, the toxicity depends on the dose of local anesthetic being absorbed into the systemic circulation. Toxicity may result from an accidental intraarterial injection, an overlarge bolus, a high infusion rate, or frequent boluses. Toxicity can present with central nervous system (CNS) manifestations or cardiovascular or both. The cardiotoxic effects of local anesthetic result in a depression of myocardial contractility and can also produce refractory arrhythmias. The CNS symptoms can progress to loss of consciousness, generalized seizure activity, or even coma.

(i) Treatment

Airway should be protected.
Oxygen should be administered by mask or bag as soon as the first sign of toxicity develops; in mild cases, this may be the only treatment needed.
Airway, breathing, and circulation should be assessed, and standard monitoring should be applied.
If seizure activity interferes with ventilation or if prolonged, give midazolam 1 to 2 mg IV or diazepam 5 to 10 mg IV.
If the patient’s airway is compromised, give thiopental 50 to 200 mg and intubate the trachea; succinylcholine 1.5 mg per kg IV may be given to facilitate intubation; it should be kept in mind that muscle relaxation abolishes muscle activity but the neuronal seizure activity continues.

(ii) Treatment of Cardiovascular Toxicity

Airway, breathing, and circulation should be supported according to the acute cardiac life-support (ACLS) protocol; oxygen should be administered and emergency assistance should be called.
Ventricular tachycardia should subside over time secondary to drug distribution; adequate circulatory support, including lidocaine 100 mg IV, should be provided in the meanwhile.
Bupivacaine-induced ventricular arrhythmia may be more responsive to bretylium 5 to 10 mg per kg IV every 15 to 20 minutes to a maximum of 30 mg per kg followed by lidocaine; prolonged cardiopulmonary resuscitation (CPR) or cardiopulmonary bypass may be required until the cardiotoxic effects subside.

3. Complications of Epidural and Intrathecal Procedures

(i) Epidural Hematoma

Epidural hematomas are extremely rare if coagulation parameters are normal. However, in a patient with rapid onset of neurologic deficit and severe back pain, the diagnosis of epidural hematoma should be entertained. Sometimes the only symptom is severe pain in the back. The treatment includes immediate magnetic resonance imaging (MRI), steroids, surgical consultation immediately for decompression, and laminectomy for evacuation of the hematoma.

(ii) Epidural Abscess

Epidural abscess is a rare complication, but it should be considered a possibility in a patient with severe back pain, local back tenderness, fever, and leukocytosis with or without neurologic deficit after an epidural or intrathecal injection or catheter placement. An immediate MRI, preferably with gadolinium, emergency surgical consultation for possible decompression laminectomy, and intravenous antibiotics will be needed.

(iii) High Spinal Anesthetics

With fluoroscopy and contrast dye, the incidence of complications in high spinal anesthetics is rare. However, it may still occur as a result of an unintentional subarachnoid injection of local anesthetic during an epidural block, celiac plexus block, lumbar sympathetic block, stellate ganglion block, or occipital nerve block.

SYMPTOMS AND SIGNS.

Only gold members can continue reading. Log In or Register to continue