Question

"Lehne's pharmacology book for nursing care"

(pharmacology chapter 26-Local Anesthetic and Toxicity)

You are the operating nurse working with Mr.J, who was given lidocaine (Xylocaine)prior to suture repair of an open wound he sustained during a construction accident. Mr J Begins to mumble and seems agitated. You Suspect toxicity.

Answer the following questions with Rationals.( please provide rational too )

1-how can you reduce the risk factors are associated with toxicity?

2-what interventions will be necessary to manage this patient's toxicity?

3-what signs and symptoms support your suspicions?

4-what interventions will be necessary to manage this patient's toxicity?

Answer 1

there are several factors associated with toxicity. But in this case local anesthesia has induced the symptoms of toxicity.LA reaches the circulation via systemic absorption or accidental intravascular injection. Accidental i.v. injection is more common than arterial injection, can occur during any regional anesthetic, and results in rapid onset of symptoms and signs of toxicity. Systemic absorption normally has a delayed onset.

1. We can reduce the risk factors associated with toxicity,

During preoperative assessment, evaluation of the risks and benefits of regional anaesthesia for that individual should be discussed.

.The block should take place in a setting with monitoring as per AAGBI standards, resuscitation equipment, and capable help nearby.

The syringes should be labelled properly and keep separately.

Lowest effective dose should be used for local anesthesia.

Patient characteristics need to be considered and also the site of administration.

The risk of rapid absorption and toxicity due to the injection being in a highly vascularized area.Hence the site of administration should be considered.

Continuous administration can cause medication to accumulate in the blood. so it should be prevented.

Blood monitoring should be done.

Assess the vital signs for any fever or variations in the blood pressure.

2. Interventions to manage the patient's toxicity.

The immediate management involves the general safety and resuscitation measures that are crucial in any emergency. First, stop injecting the LA and call for help. Then concentrate in turn on airway, breathing, and circulation.

Administer 100% oxygen through a secured airway.

I.V. access needs to be confirmed or established.

Cardiovascular symptoms should be monitored.

If the patient is in cardiac arrest, give ILE and continue CPR, remembering that recovery from an LA-induced cardiac arrest may be prolonged.

3. Signs and symptoms support your suspicions. symptoms are organ wise.

In the central nervous system it causes  tinnitus, blurred vision, dizziness, tongue parathesias, and circumoral numbness. Excitatory signs such as nervousness, agitation, restlessness, and muscle twitching are the result of blockade of inhibitory pathways. Muscle twitching heralds the onset on tonic-clonic seizures. The early signs/symptoms advance to CNS depression with slurred speech, drowsiness, unconsciousness, and then respiratory arrest. Patients who have received CNS depressant drugs may present with only CNS depression without any preceding excitatory signs.

In the cardiovascular system ,prolonged QR intervals, arrhythmias, fibrillation etc.

it causes peripheral effects such as vasoconstriction.

4. Local anesthetic and systemic toxicity.

Local anesthetic toxicity can be seen in organs of the body that depend upon sodium channels for proper functioning. it include the central nervous system and heart. The CNS is more sensitive to the effects of local anesthetics than the cardiac system and will generally manifest signs/symptoms of toxicity first.