DOSAGE AND ADMINISTRATION
Spinal anesthesia with 5% Lidocaine Hydrochloride and 7.5% Dextrose Injection, USP may be induced in the right or left lateral recumbent or the sitting position. Since this is a hyperbaric solution, the anesthetic will tend to move in the direction in which the table is tilted. After the desired level of anesthesia is obtained and the anesthetic has become fixed, usually in 5 to 10 minutes with lidocaine, the patient may be positioned according to the requirement of the surgeon or obstetrician.
In clinical trials, the safety of hyperbaric lidocaine for single injection spinal anesthesia was demonstrated using 22 or 25 gauge spinal needles. In these studies, free flow of CSF was visible before injection of lidocaine.
Neurologic deficits have been reported with the use of small bore needles and microcatheters for spinal anesthesia. It has been postulated, based on in vitro models, that these deficits were caused by pooling and non-uniform distribution of concentrated local anesthetic within the subarachnoid space.1 Animal studies suggest mixing of 5% lidocaine hydrochloride with an equal volume of CSF or preservative-free 0.9% saline solution may reduce the risk of nerve injury due to pooling of concentrated local anesthetic2 (see PRECAUTIONS).
Intrathecal distribution of anesthetic may be facilitated by using a spinal needle of sufficient gauge to insure adequate withdrawal of CSF through the needle prior to and after anesthetic administration. If the technique is properly placed in the subarachnoid space, a separate injection is seldom necessary.
An incomplete or patchy block not responsive to patient repositioning may indicate misplacement or inadequate distribution of drug. To avoid excessive drug pooling, additional doses of lidocaine should not be administered with the same needle placement.
INJECTIONS SHOULD BE MADE SLOWLY. Consult standard textbooks for specific techniques for spinal anesthetic procedures.
There have been adverse event reports of chondrolysis in patients receiving intra-articular infusions of local anesthetics following arthroscopic and other surgical procedures. 5% Lidocaine Hydrochloride and 7.5% Dextrose Injection, USP is not approved for this use (see WARNINGS and DOSAGE AND ADMINISTRATION).
Normal healthy adults
The following recommended dosages are for normal healthy adults and serve only as a guide to the amount of anesthetic required for most routine procedures. In all cases, the smallest dose that will produce the desired result should be given.
If the technique is properly performed, and the needle is properly placed in the subarachnoid space, it should not be necessary to administer more than one ampul (100 mg).
Obstetrical low spinal or "saddle block" anesthesia
The dosage recommended for normal vaginal delivery is approximately 1 mL (50 mg). For Caesarean section and those deliveries requiring intrauterine manipulations, 1.5 mL (75 mg) is usually adequate.
The dosage recommendations in healthy adolescents, 16 years of age and older, is the same as for normal healthy adults. There is insufficient data in pediatric patients below the age of 16 years to make dosage recommendations (see PRECAUTIONS).
Note: Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration whenever the solution and container permit. Solutions that are discolored and/or contain particulate matter should not be used.
Unused portions of solutions should be discarded following initial use.
5% Lidocaine Hydrochloride and 7.5% Dextrose Injection, USP may be autoclaved once at 15 pounds pressure, 121°C (250°F) for 15 minutes. Since this preparation contains dextrose, carmelization may occur under prolonged heating and, in some instances, prolonged storage. Therefore this preparation should not be autoclaved more than once, according to the above instructions, and should not be permitted to remain in the autoclave any longer than necessary. Do not administer any solution which is discolored or contains particulate matter.