Liga injectable solutions for local anesthesia are available in the following range
LIGA 2% containing 2% of lidocaine hydrochloride. LIGA ADR with adrenaline – containing lidocaine hydrochloride 2 % and adrenaline 1: 80,000
Liga is a powerful anaesthetic agent effective in producing various clinical types of local anaesthesia with rapid onset and lasting for a sufficient long duration.
Addition of adrenaline to LIGA 2 % solution prevents the systemic absorption of lidocaine hydrochloride thus enhancing the anaesthetic potency, prolongs duration of action and minimizes the chances of occurrence of systemic toxic effects.
The use of LIGA should be avoided in patients with known hypersensitivity to it.
LIGA with adrenaline is contraindicated for producing anaesthesia of fingers, toes, ear lobule, nose and penis.
Though clinical tolerance for LIGA is remarkably good, overdosage or accidental intravascular injection may give rise to toxic reactions. These may be avoided by the following measures.
- Always use the lowest possible concentration.
- Aspirate before making an injection in order to avoid accidental intravascular injection especially when working in highly vascular areas like the oral cavity.
Premedication with a short-acting barbiturate or diazepam is advisable as a prophylactic measure especially if larger amount of anaesthetic are to be used.
The safety of LIGA is well established. The nature of adverse reactions is unpredictable and depends on dosage, route of administration and state of the patient. The toxic reactions are characterized by either the signs of stimulation and/or depression of the central nervous system.
Following overdosage of LIGA two types of toxic reactions are observed:
- Slow onset stimulation leading to nervousness, dizziness, blurred vision, tremors, convulsions and respiratory arrest.
- Rapid onset depression leading to respiratory arrest, cardiovascular collapse and cardiac arrest.
The recommended dosages to be employed for various types of local-anaesthesia in normal healthy adults are depicted in the table. This table only serves as a guide to the amount of anaesthetic required for most routine procedures. The actual volume and concentration to be used should be decided in the light of various factors such as type and extent of surgical procedures, depth and duration of local anaesthesia required, degree of muscle relaxation required, age and physical condition of the patient etc. children and debilitated patients should be given smaller dosages. In all cases the smallest dose and lowest concentrations should be administered. The maximum dose of LIGA plain should not exceed 300mg or 7mg/kg of body weight.
LIGA WITHOUT ADRENALINE
Conc. % Vol. Total
Subcutaneous 0.5 or 1.0 1-60 5-300
Intravenous regional 0.5 10-60 50-300
- Peripheral nerve blocks
Brachial 1.5 15-20 225-300
Dental 2.0 1-5 20-100
Intercostals 1.0 3 30
Paravertebral 1.0 3-5 30-50
Pudendal (Each side) 1.0 10 100
Paracervical (each side) 1.0 10 100
- Sympathetic nerve blocks
Cervical (Steilate ganglion) 1.0 5 50
Lumbar 1.0 5-10 50-100
- Central neural block
Thoracic 1.0 20-30 200-300
Lumbar 1.5 15-20 225-300
Obstetrical anaesthesia 1.0 20-30 200-300
Surgical anaesthesia 1.5 15-20 225-300