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Continuous caudal anesthesia in obstetrics by means of lidocaine 1 per cent
Continuous caudal anesthesia in obstetrics by means of lidocaine 1 per cent GEORGE
J. ELLIS, M.D.
MICHAEL R. DEVITA, M.D. Washington, D. C.
LIn o cAINE (Xylocaine) is known to give excellent results as a local anesthetic agent by virtue of its rapid action and profound anesthesia. It is believed by many to be a toxic drug, but its toxicity, as with all anesthetic agents, is based on a dosage/time ratio. Esau, of our anesthetic staff, has used it in over 5,000 cases by the intravenous route as an adjunct to general anesthesia and has observed it to be a satisfactory and safe drug. This paper presents an evaluation of the drug for continuous caudal in obstetrics.
utes before the caudal anesthesia is started. This medication is omitted in cases of premature labor. These drugs have an additive effect with lidocaine and, when the anesthesia level has been established, the patient feels relaxed and drowsy. 2. The caudal needle is inserted and a test dose of 10 mi. is given. 3. After 5 minutes, an anesthetic dose of 20 mi. is given. 4. A maintenance dose of 20 mi. is given as required. The time interval between doses may be as long as one hour during early labor and as short as every 30 minutes as the cervix approaches full dilatation. The ideal anesthetic level is midway between the umbilicus and symphysis pubis. 5. The patient is turned on the opposite side before the second anesthetic dose is administered. This procedure allows a more even distribution of the agent. 6. If the anesthesia is continued longer than 3 hours, the patient's bladder is catheterized to prevent overdistention, as caudal anesthesia promotes diuresis.
Material and methods
Lidocaine 1 per cent without epinephrine is the agent used in this study. The actual technique of administering caudal anesthesia is not discussed other than to state that the malleable needle is used with the patient in the lateral Sims position. One hundred and seventy-eight successful continuous caudal anesthesias were done by this method. The purpose of the study was to determine the adequacy of anesthesia, the proper dose, and the effects of the drug on both mother and 1nfant. After repeated trials with the drug, the optimum volume and frequency of injections were determined, and the following schedule has been adopted: 1. A preanesthetic injection of 50 mg. meperidine HCI and 50 mg. promethazine HCI is given intramuscularly about 30 min-
Analysis of cases and observations The largest total volume of lidocaine per cent in the series was 240 ml., over a 7 hour period, and the smallest total volume was 30 mi. The latter patient was delivered with adequate anesthesia 15 minutes after the administration of the test dose. The onset of anesthesia action is first apparent by anal sphincter relaxation. This is detectable 5 minutes after the test dose and is so constant a sign that its absence
From the Department of Obstetrics and Gynecology of Providence Hospital.
1057
l 058
Ellis and DeVita
means that the needle is not in the caudal canal. When this occurs the anesthetic dose is not given until the needle is removed and properly positioned. This should not happen if one observes and obtains the "sphincter sign." Complete relief of labor pain occurred in 10 to 15 minutes after the anesthetic dose in 76 per cent of the cases. In the remainder. good anesthesia required more than 20 minutes and in one case required an hour. Medication prior to the administration of caudal anesthesia is not absolutely necessary. In 19 cases, no prior drugs were given and the lidocaine produced a saporific effect by virtue of its absorption. Nine of these patients experienced a warm, glowing feeling, drowsiness, and even sleep. The effect of the caudal anesthesia with lidocaine on blood pressure is most striking. There is a drop in systolic pressure of less than 10 mm. Hg in 66 per cent of the cases and between 10 and 20 mm. Hg in an additional 16 per cent. In the remaining 18 per cent, the drop exceeds 20 mm. Hg. The mean drop in systolic pressure is 10 mm.Hg. Complete or partial motor paralysis of the lower extremities occurs in 20 per cent of the cases. In the remaining 80 per cent, the patients are able to move without assistance from the labor bed to the cart and onto the delivery table. The relative absence of nausea and vomiting parallels the minimal drop in systolic blood pressure. Seventy-eight per cent of the patients experience neither nausea nor vomiting. The remaining 22 per cent have nausea. Vomiting was seen in 2 cases. A drop in the level of anesthesia occurred in 6 cases. With the administration of additional doses of lidocaine, according to our schedule, the level was completely regained in 3 cases but only partially in the remaining 3.
Advantages as a continuous caudal anesthetic 1. The skin anesthesia over the caudal canal is immediately effective, which per-
Am.
Octnhu I j. I'lt)c Qh,l. & Cym:~:.
J.
mits the malleable nc<'dle to be inserted with a minimal sensation of discomfort to the
patient. 2. Preanesthetic medication is not absolutely essential which is an advantage in the delivery of a premature infant. 3. Rectal sphincter relaxation occurs 5 minutes after the test dose is given. 4. The anesthetic effect of lidocaine is rapid and the duration of anesthesia is longer than with several other drugs used for this purpose. 5. If the anesthesia level drops, it can usually be regained in several minutes by giving 20 ml. of the solution. 6. Lidocaine causes a minimal amount of motor paralysis of the lower extremities. 7. The drop in blood pressure is not as marked as with other agents, the mean fall in systolic pressure being 10 per cent. Nausea and vomiting were reduced. 8. All infants were born in good condition and required a minimal amount of resuscitation. This is attributed to the following: the small amount of drugs used during labor, the absence of inhalation anesthesia, and the maintenance of blood pressure at a good level.
Conclusion Lidocaine 1 per cent is a very satisfactory and safe drug for use as a continuous caudal anesthetic during labor and delivery. It is superior to the drugs commonly employed for this procedure. The major virtue of this drug is that it rarely produces maternal hypotension with its subsequent vomiting and fetal hypoxia.
Summary 1. A series of 178 cases of continuous caudal anesthesia using lidocaine HCI 1 per cent without epinephrine for labor and delivery are presented. 2. The dosage schedule is given. 3. Advantages of lidocaine as an anesthetic agent in obstetrics are enumerated. 4. It is concluded that lidocaine 1 per cent is a very satisfactory agent for use with continuous caudal anesthesia in obstetrics.
J. ELLIS, M.D.
MICHAEL R. DEVITA, M.D. Washington, D. C.
LIn o cAINE (Xylocaine) is known to give excellent results as a local anesthetic agent by virtue of its rapid action and profound anesthesia. It is believed by many to be a toxic drug, but its toxicity, as with all anesthetic agents, is based on a dosage/time ratio. Esau, of our anesthetic staff, has used it in over 5,000 cases by the intravenous route as an adjunct to general anesthesia and has observed it to be a satisfactory and safe drug. This paper presents an evaluation of the drug for continuous caudal in obstetrics.
utes before the caudal anesthesia is started. This medication is omitted in cases of premature labor. These drugs have an additive effect with lidocaine and, when the anesthesia level has been established, the patient feels relaxed and drowsy. 2. The caudal needle is inserted and a test dose of 10 mi. is given. 3. After 5 minutes, an anesthetic dose of 20 mi. is given. 4. A maintenance dose of 20 mi. is given as required. The time interval between doses may be as long as one hour during early labor and as short as every 30 minutes as the cervix approaches full dilatation. The ideal anesthetic level is midway between the umbilicus and symphysis pubis. 5. The patient is turned on the opposite side before the second anesthetic dose is administered. This procedure allows a more even distribution of the agent. 6. If the anesthesia is continued longer than 3 hours, the patient's bladder is catheterized to prevent overdistention, as caudal anesthesia promotes diuresis.
Material and methods
Lidocaine 1 per cent without epinephrine is the agent used in this study. The actual technique of administering caudal anesthesia is not discussed other than to state that the malleable needle is used with the patient in the lateral Sims position. One hundred and seventy-eight successful continuous caudal anesthesias were done by this method. The purpose of the study was to determine the adequacy of anesthesia, the proper dose, and the effects of the drug on both mother and 1nfant. After repeated trials with the drug, the optimum volume and frequency of injections were determined, and the following schedule has been adopted: 1. A preanesthetic injection of 50 mg. meperidine HCI and 50 mg. promethazine HCI is given intramuscularly about 30 min-
Analysis of cases and observations The largest total volume of lidocaine per cent in the series was 240 ml., over a 7 hour period, and the smallest total volume was 30 mi. The latter patient was delivered with adequate anesthesia 15 minutes after the administration of the test dose. The onset of anesthesia action is first apparent by anal sphincter relaxation. This is detectable 5 minutes after the test dose and is so constant a sign that its absence
From the Department of Obstetrics and Gynecology of Providence Hospital.
1057
l 058
Ellis and DeVita
means that the needle is not in the caudal canal. When this occurs the anesthetic dose is not given until the needle is removed and properly positioned. This should not happen if one observes and obtains the "sphincter sign." Complete relief of labor pain occurred in 10 to 15 minutes after the anesthetic dose in 76 per cent of the cases. In the remainder. good anesthesia required more than 20 minutes and in one case required an hour. Medication prior to the administration of caudal anesthesia is not absolutely necessary. In 19 cases, no prior drugs were given and the lidocaine produced a saporific effect by virtue of its absorption. Nine of these patients experienced a warm, glowing feeling, drowsiness, and even sleep. The effect of the caudal anesthesia with lidocaine on blood pressure is most striking. There is a drop in systolic pressure of less than 10 mm. Hg in 66 per cent of the cases and between 10 and 20 mm. Hg in an additional 16 per cent. In the remaining 18 per cent, the drop exceeds 20 mm. Hg. The mean drop in systolic pressure is 10 mm.Hg. Complete or partial motor paralysis of the lower extremities occurs in 20 per cent of the cases. In the remaining 80 per cent, the patients are able to move without assistance from the labor bed to the cart and onto the delivery table. The relative absence of nausea and vomiting parallels the minimal drop in systolic blood pressure. Seventy-eight per cent of the patients experience neither nausea nor vomiting. The remaining 22 per cent have nausea. Vomiting was seen in 2 cases. A drop in the level of anesthesia occurred in 6 cases. With the administration of additional doses of lidocaine, according to our schedule, the level was completely regained in 3 cases but only partially in the remaining 3.
Advantages as a continuous caudal anesthetic 1. The skin anesthesia over the caudal canal is immediately effective, which per-
Am.
Octnhu I j. I'lt)c Qh,l. & Cym:~:.
J.
mits the malleable nc<'dle to be inserted with a minimal sensation of discomfort to the
patient. 2. Preanesthetic medication is not absolutely essential which is an advantage in the delivery of a premature infant. 3. Rectal sphincter relaxation occurs 5 minutes after the test dose is given. 4. The anesthetic effect of lidocaine is rapid and the duration of anesthesia is longer than with several other drugs used for this purpose. 5. If the anesthesia level drops, it can usually be regained in several minutes by giving 20 ml. of the solution. 6. Lidocaine causes a minimal amount of motor paralysis of the lower extremities. 7. The drop in blood pressure is not as marked as with other agents, the mean fall in systolic pressure being 10 per cent. Nausea and vomiting were reduced. 8. All infants were born in good condition and required a minimal amount of resuscitation. This is attributed to the following: the small amount of drugs used during labor, the absence of inhalation anesthesia, and the maintenance of blood pressure at a good level.
Conclusion Lidocaine 1 per cent is a very satisfactory and safe drug for use as a continuous caudal anesthetic during labor and delivery. It is superior to the drugs commonly employed for this procedure. The major virtue of this drug is that it rarely produces maternal hypotension with its subsequent vomiting and fetal hypoxia.
Summary 1. A series of 178 cases of continuous caudal anesthesia using lidocaine HCI 1 per cent without epinephrine for labor and delivery are presented. 2. The dosage schedule is given. 3. Advantages of lidocaine as an anesthetic agent in obstetrics are enumerated. 4. It is concluded that lidocaine 1 per cent is a very satisfactory agent for use with continuous caudal anesthesia in obstetrics.