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Saddle block anesthesia with nupercaine in obstetrics
SADDLE BLOCK ANBSTHESIA WITH NUPEROAINE IN OBSTETRICS RAY
T.
PARMLEY,
M.D.,
AND JoHN ADRIANI,
M.D.,
NEw ORLEANS, LA.
(From the Department of Anesthesia, ChCI!rity Hospital of Louisiana at New Orleans, and the Department of Surgery, Louisiana State University School of Medicine)
HE term, saddle block, is applied to a form of low spinal anesthesia confined exclusively to the perineal area. The technique for its induction has been described by both British and American writers. Pitkin, in 1928, 1 appears to be the first American writer who described a technique for producing this distribution of anesthesia. The block is ideal for perineal and rectal surgery. However, it failed to gain widespread popularity because the anesthesia did not remain localized in the originally intended spinal segments but spread over a more extensive area. This difficulty has been overcome by adding glucose to the solution of the drug. 2 Apparently, the glucose inhibits diffusion and, in addition, causes the solution to be hyperbaric or heavier than spinal fluid. When injected into the subarachnoid space with the patient in the sitting position, the solution gravitates downward and the drug becomes concentrated in the conus of the dural sac. Exact localization of anesthesia is thus possible. One desirable feature of the block, particularly from the standpoint of obstetrics, is that the distribution of anesthesia may be modified by varying the time the patient remains in the sitting position after injection. Thus, one can, uy certain manipulations, obtain complete loss of sensation in the perineum and relaxation of the perineal muscles and hypalgesia and analgesia over the legs and thighs without paralysis of the thigh and leg muscles. This distribution of anesthesia is desirable when the lithotomy position is indicated. In addition, the sensory fibers to the uterus are affected and the pain of labor is abolished. This distribution of anesthesia and analgesia resembles, in many ways, that distribution obtained by peridural (caudal) injection of local anesthetic drugs. Inasmuch as saddle block is merely a specialized form of a subarachnoid block, its induction is simpler, safer, and more precise than that of a caudal block. Heretofore, spinal anesthesia has been of limited value in obstetrics. One reason for the lack of enthusiasm has been that procaine has been the drug of choice. It is necessary to repeat the block frequently for analgesia early in labor when procaine and drugs of similar duration of action are used. The longer-acting and more potent drugs, such as pontocaine and nupercaine, have extended the usefulness of spinal anesthesia by the single injection method. Nupercaine, which possesses a duration of action ranging from three to five hours, has been used by certain workers for general surgery. Cosgrove 3 used it for obstetric anesthesia in 1930 but obtained unsatisfactory results. The extent of anesthesia was difficult to control, and he noted a high incidence of nausea, vomiting, and postlumbar puncture headaches. His experience, however, is not in accord with that of other workers using nupercaine. Jones/ Whitacre, and
T
636
PARMLEY AND ADRIAN! :
SADDLE BLOCK ANESTHESIA
637
Sankey, 5 Silverton, 6 Wilson, 7 and many other American and British workers have employed the drug with a high degree of satisfaction in all types of surgical procedures. Roman and Adriani 8 simplified the technique for using nupercaine for general surgery by mixing it with glucose and now use the drug for all lengthy operations at the Charity Hospital at New Orleans. Likewise, they have obtained a high degree of satisfaction with saddle block for rectal, urologic, and gynecologic surgery in which nupercaine was the drug of choice. There appeared to be no reason why saddle block using nupercaine could not be applied to obstetrics. This is a report of a detailed study of its use for analgesia during labor and anesthesia for delivery in 136 obstetric patients.
Technique The materials for performing a saddle block are those usually employed in spinal anesthesia-a wheal needle, a 20 guage short bevel spinal needle, and several 2 c.c. syringes. Glucose, 10 per cent, prepared in physiologic saline or distilled water, a l/200 solution of nupercaine, and 1 per cent procaine for infiltration are the necessary solutions and drugs. Two and one-half mg. of nupercaine (% c.c. of 1/200 solution) is thoroughly mixed with % c.c. of glucose solution and set aside in a 2 c.c. syringe. No spinal fluid is necessary in the preparation of the solution. It is preferable to prepare the solution before the lumbar puncture is performed to avert failures due to dislodgement of the needle by unexpected movements of the patient. The puncture must be performed with the patient in the sitting position. The puncture is simplified if the patient sits in the center of the delivery table or at the edge of the bed with the arms folded across the chest. She should lean forward with her shoulders supported by an assistant. An intradermal wheal is raised at the fourth lumbar interspace and the interspinous tissues are infiltrated with 1 per cent procaine. The third interspace may be employed if the fourth is not accessible. The use of the higher interspace does not appear to cause any appreciable difference in the extent of anesthesia. When spinal fluid flows freely the syringe containing the solution is attached to the needle and aspiration is attempted. A free flow of spinal fluid must be obtained to assure correct placement of the bevel of the needle in the subarachnoid space. In executing the maneuver, one should aspirate as little spinal fluid as possible (not more than 7{ 0 c.c.), otherwise dilution occurs which interferes when obtaining the desired distribution of anesthesia. The needle should be readjusted until a satisfactory flow is obtained if the spinal fluid does not flow freely. Most failures in spinal anesthesia are due to unsatisfactory lumbar puncture. The solution is injected as rapidly as gentle pressure upon the plunger of the syringe permits. The total time for completion of the injection is approximately two seconds. If the drug is injected slowly, the distribution of anesthesia will not be satisfactory. The needle is then withdrawn from the spinal canal and the patient is allowed to remain in the upright sitting position for thirty seconds, after which time she is placed in the recumbent position. This timing is particularly important and should be done by the clock. It is advisable to support the head on a pillow for at least fifteen minutes. The solution should not be introduced during a contraction because the spinal fluid pressure is increased at this time. Currents established in the subarachnoid space force the drug into the thoracic region and give greater distribution of anesthesia and halt labor. The patient must not move or shift about for five or ten minutes after completion of the injection. The straining, which may accompany such movements, also causes spreadL'r)_g of the drug in the spinal canal.
638
AMERICAN JOURNAL OF OBSTETRICS AND GYNECOLOGY
The sensory and autonomic fibers of a mixed nerve are more sensitive to the effects of a local anesthetic drug than the motor. When the patient is promptly restored to the recumbent position, a 2% mg. dose becomes distributed over a greater number of segments than if she sits up thirty seconds. The lumbar segments, however, are exposed to a more dilute solution than the sacral. The degree of anesthesia decreases as one ascends the cord. Still, the concentration of drug is sufficient to produce anesthesia and paralysis of the legs, thighs, and hypogastric areas in most cases. The sacral segments are exposed to a more concentrated solution of drug than the lumbar so that both motor and sensory fibers are profoundly affected. The perineal area, therefore, is completely relaxed. When the patient sits up thirty seconds, a greater concentration of drug localizes in the conus than in the former case. Anesthesia of the vulva and other perineal structures, likewise, is complete. The concentration of drug along the lumbar segments is less and, as a rule, insufficient to block completely all the sensory fibers in these segments. Hypalgesia and disseminated areas of analgesia are present in the legs and thighs. Little or no paresis of the leg and thigh muscle is obtained. The analgesia over the thighs gradually merges into an area of hypalgesia over the lower abdomen, sometimes as far as the umbilicus. However, the concentration of the drug is sufficient to block the sensory fibers to the cervix and uterus. The sensory fibers to the cervix and lower uterine segments are derived from the sacral and lower lumbar spinal nerves, those of the upper part and the fundus from the upper lumbar and twelfth thoracic segments. The motor innervation of the uterus is still a matter of question. It is believed that the motor fibers are derived from the lower thoracic segments. Consequently, there is no diminution in the number or force of the contractions unless the drug extends into the thoracic region. The recti are not affected and the patient can bear down if requested. The patient will not bear down unless told to do so, however, as the analgesia causes her to be unaware of the contractions.
Method of Study The writers have been interested primarily in the applicability of the block to obstetrics. Therefore, in order to exclude all complicating factors, its use was limited exclusively to normal primiparas or multiparas. Patients presenting systemic abnormalities or obstetric complications were excluded. Sedation, likewise, was omitted in the first 100 patients. The block was performed after the inception of the first stage of labor. Usually, the contractions appeared at 3- to 4-minute intervals and the cervix was 5 to 6 em. dilated and approximately 60 to 80 per cent effaced. Blood pressure and pulse rate were observed at 3- to 4-minute intervals, shortly after induction of analgesia, and at 10- to 15minute intervals after the first thirty minutes. The anesthetist remained in constant attendance in all cases, closely observing the frequency and intensity of contractions, fetal heart tones, progress of labor, respiration, and other reactions of the patient. Emphasis cannot be placed too strongly upon the fact, in this procedure as in other forms of subarachnoid anesthesia, that the patient may not be left unattended until ready for delivery. In approximately half the <>..ases, analgesia was induced in the patient's bed. In the t•emaining cases, the block was induced in the delivery room, and the patients remained on the delivery table throughout labor. An anesthesia machine was in readiness for the administration of oxygen or artificial respiration or analgesia in the event that the block failed. Vasopressor drugs for overcoming hypotension were held in readiness as is the usual custom in all cases of spinal anesthesia. A second tray with drugs and needles was available for repeating the block for cases in which labor outlasted analgesia. In instances in which the block was repeated, the procedure was exactly as in the first block.
PARMLEY AND ADRIAN! :
SADDLE BLOCK ANESTHESIA
639
Results Satisfactory analgesia during labor and anesthesia at the time of delivery were obtained in the majority of cases. The average duration of analgesia was three hours. In some cases, the block lasted as long as five hours. In the majority of cases the pain of uterine contractions returned in three hours, but the perineum was still anesthetized. Eighty-one per cent of the patients obtained complete pain relief during labor and delivery. Fourteen per cent complained of slight pain in the upper abdomen upon application of forceps and a dragging sensation during the period of traction. In others, the traction caused a dull ache in the epigastrium or along the back in the lumbar region. No pain was felt in the perineum at this time or during repair of the episiotomy. Inhalation of analgesic mixtures of nitrous oxide-oxygen until the head was delivered obliterates this most satisfactorily. Surgical anesthesia with the gas with loss of consciousnt~Ss is not necessary. In 5 per cent of the cases the block was not satisfactory. Pain in the perineum or back due to poor distribution of analgesia resulted. Pain from uterine contractions, likewise, was not relieved. The failure, it was felt, was due to some error in technique. It is imperative that timing and measurements of volume of solutions be precise to insure success. The block was repeated after fifteen minutes and satisfactory analgesia was obtained the second time in every case. There is no objection to, or danger in, repeating the block in the event of failure because the doses of nupercaine employed are small. The patients were comfortable and cooperative throughout the lahar and delivery. Patients in pain or who were not cooperative before the block was performed invariably became quiet and cooperative as soon as analgesia was established. The absence of paralysis of the extremities permitted the patient to move about in bed and shift to comfortable positions. The hypotension and other circulatory changes caused by postural changes when extensive anesthesia is obtained by subarachnoid block were not present in these patients. The analgesia in the legs and thighs averts the discomfort usually experienced when the lithotomy position is instituted during the delivery. Seventy per cent of the patients were delivered by aid of low forceps and episiotomy. Anesthesia for repair of episiotomy was satisfactorily obtained in every single instanee. A single block was sufficient in 6S per cent of cases. In 32 per cent, labor outlasted analgesia and repeated blocks were necessary. The shortest time from the institution of analgesia until delivery was fifteen minutes; the longest was eleven hours and fifty-one minutes. In the latter case, three blocks were performed. No difference was noted in the third stage of labor if compared with cases delivered with other types of analgesia or anesthesia. Postpartum hemorrhage was not encountered, nor was excessive bleeding a problem. The babies cried spontaneously and none required resuscitation. Nausea and vomiting occurred in 13 per cent of the cases. It was a troublesome complication when the patient accepted food or fluids during lahor. It was encountered early in the series until the fact was recognized. It is advisable to restrict fluids and food during labor. A lowering of hlood pressure averaging 10 mm. systolic occurred in 50 per cent of the cases. The reduction was attributed to removal of psychic effects on blood pressure by the pain relief. In the other 50 per cent there was a momentary fall in systolic pressure, sometimes as low a level as SO mm. Hg shortly after completion of the injection. Recovery was, however, immediate. No therapy other than deep breathing was required. This drop in pressure must not be confused with the hypotension with bradycardia which is frequently seen with spinal anesthesia, particularly in the more extensive blocks. This type of circulatory disturbance was notably absent, save in three cases. In these, the blood pressure dropped to SO and 90 mm. Hg and remained at this level. It was, however, quickly restored by
640
AMERICAN JOURNAL OF OBSTETRICS AND GYNECOLOGY
ephedrine (15 to 30 mg.) intravenously. The number of spinal segments affected in saddle block is few, and the motor anesthesia is confined to a few small muscles. Physiologic changes, therefore, are less extensive and profound than in ' 'high' ' spinal anesthesia. Respiratory depression or embarrassment was not encountered in any case. Rectal or urinary incontinence during labor was not observed. Hysterographic and other studies of the effects of the block upon labor were not attempted. No remarkable effect upon the duration of labor was apparent, however. Postspinal headache, although not encountered in any case in this series, is the one complication which could limit the usefulness of the block. Backache, urinary retention, distention, ileus, meningismus, palsies, or other complications were, likewise, absent.
Comment Obviously, 136 cases is not a sufficient number to prove the merits or demerits of any method of analgesia or anesthesia. However, the number is sufficient to show the applicability of saddle block to obstetrics. Although the results were gratifying and untoward reactions were not encountered either during labor or delivery, one must bear in mind that the usual hazards and complications of spinal anesthesia may occur with this method as with others. The absence of headache, palsies, urinary retention, and other sequelae of spinal anesthesia in a series as small as this obviously is of no significance. Likewise, it must be emphasized that these were normal cases, free from complications. The applicabmty of this method of analgesia to other than uncomplicated obstetric cases requires further detailed study of a large series of cases. When spinal anesthesia is desired and not contraindicated, certainly, this is the technique of choice. Saddle block anesthesia with nupercaine offers many advantages over the continuous caudal technique. The uncertainty of locating the caudal canal, the presence of the indwelling needles and catheters, the repeated use of relatively large amounts of local anesthetic drugs, and the uncertainty of distribution of anesthesia are undesirable features which are eliminated by saddle block.
Summary Saddle block anesthesia is a :form of low spinal anesthesia distributed chiefly to the perineal area. A technique is described for producing prolonged anesthesia and analgesia by using nupercaine. The block was used in 136 normal cases with gratifying results. The ease and simplicity of induction, the safety allowed by the low dosage of drug, and the exact ll·(lalization of the distribution of anesthesia make the use of this block the technique of choice where spinal anesthesia is preferred or desired in obstetrics. The method is worthy of further use and clinical trial. References 1. Pitkin, G. P.: Surg., Gynec. & Obst. 47: 713-726, 1928. 2. Adriani, J., Roman-Vega, D. A.: Am. J. Surg. 71: 12-18, 1946. 3. Cosgrove, S. A.: AM. J. OBST. & GYNEC. 22: 763-767, 1930. 4. Jones, W. H.: Brit. J. Anesthesia 7: 99-113, 1930. 5. Sankey, B. B., Whitacre, R. J.: Anesthesiology 2: 203, 1941. 6. Silverton, R. J.: Australian & New Zealand J. Surg. 3: 223-234, 1934. 7. Etherington-Wilson, W.: Anesth. & Analg. 14: 102, 1935. 8. Roman, V. D., and Adriani, J.: Surg., Gynec. & Obst. 17: 524, 1945.
T.
PARMLEY,
M.D.,
AND JoHN ADRIANI,
M.D.,
NEw ORLEANS, LA.
(From the Department of Anesthesia, ChCI!rity Hospital of Louisiana at New Orleans, and the Department of Surgery, Louisiana State University School of Medicine)
HE term, saddle block, is applied to a form of low spinal anesthesia confined exclusively to the perineal area. The technique for its induction has been described by both British and American writers. Pitkin, in 1928, 1 appears to be the first American writer who described a technique for producing this distribution of anesthesia. The block is ideal for perineal and rectal surgery. However, it failed to gain widespread popularity because the anesthesia did not remain localized in the originally intended spinal segments but spread over a more extensive area. This difficulty has been overcome by adding glucose to the solution of the drug. 2 Apparently, the glucose inhibits diffusion and, in addition, causes the solution to be hyperbaric or heavier than spinal fluid. When injected into the subarachnoid space with the patient in the sitting position, the solution gravitates downward and the drug becomes concentrated in the conus of the dural sac. Exact localization of anesthesia is thus possible. One desirable feature of the block, particularly from the standpoint of obstetrics, is that the distribution of anesthesia may be modified by varying the time the patient remains in the sitting position after injection. Thus, one can, uy certain manipulations, obtain complete loss of sensation in the perineum and relaxation of the perineal muscles and hypalgesia and analgesia over the legs and thighs without paralysis of the thigh and leg muscles. This distribution of anesthesia is desirable when the lithotomy position is indicated. In addition, the sensory fibers to the uterus are affected and the pain of labor is abolished. This distribution of anesthesia and analgesia resembles, in many ways, that distribution obtained by peridural (caudal) injection of local anesthetic drugs. Inasmuch as saddle block is merely a specialized form of a subarachnoid block, its induction is simpler, safer, and more precise than that of a caudal block. Heretofore, spinal anesthesia has been of limited value in obstetrics. One reason for the lack of enthusiasm has been that procaine has been the drug of choice. It is necessary to repeat the block frequently for analgesia early in labor when procaine and drugs of similar duration of action are used. The longer-acting and more potent drugs, such as pontocaine and nupercaine, have extended the usefulness of spinal anesthesia by the single injection method. Nupercaine, which possesses a duration of action ranging from three to five hours, has been used by certain workers for general surgery. Cosgrove 3 used it for obstetric anesthesia in 1930 but obtained unsatisfactory results. The extent of anesthesia was difficult to control, and he noted a high incidence of nausea, vomiting, and postlumbar puncture headaches. His experience, however, is not in accord with that of other workers using nupercaine. Jones/ Whitacre, and
T
636
PARMLEY AND ADRIAN! :
SADDLE BLOCK ANESTHESIA
637
Sankey, 5 Silverton, 6 Wilson, 7 and many other American and British workers have employed the drug with a high degree of satisfaction in all types of surgical procedures. Roman and Adriani 8 simplified the technique for using nupercaine for general surgery by mixing it with glucose and now use the drug for all lengthy operations at the Charity Hospital at New Orleans. Likewise, they have obtained a high degree of satisfaction with saddle block for rectal, urologic, and gynecologic surgery in which nupercaine was the drug of choice. There appeared to be no reason why saddle block using nupercaine could not be applied to obstetrics. This is a report of a detailed study of its use for analgesia during labor and anesthesia for delivery in 136 obstetric patients.
Technique The materials for performing a saddle block are those usually employed in spinal anesthesia-a wheal needle, a 20 guage short bevel spinal needle, and several 2 c.c. syringes. Glucose, 10 per cent, prepared in physiologic saline or distilled water, a l/200 solution of nupercaine, and 1 per cent procaine for infiltration are the necessary solutions and drugs. Two and one-half mg. of nupercaine (% c.c. of 1/200 solution) is thoroughly mixed with % c.c. of glucose solution and set aside in a 2 c.c. syringe. No spinal fluid is necessary in the preparation of the solution. It is preferable to prepare the solution before the lumbar puncture is performed to avert failures due to dislodgement of the needle by unexpected movements of the patient. The puncture must be performed with the patient in the sitting position. The puncture is simplified if the patient sits in the center of the delivery table or at the edge of the bed with the arms folded across the chest. She should lean forward with her shoulders supported by an assistant. An intradermal wheal is raised at the fourth lumbar interspace and the interspinous tissues are infiltrated with 1 per cent procaine. The third interspace may be employed if the fourth is not accessible. The use of the higher interspace does not appear to cause any appreciable difference in the extent of anesthesia. When spinal fluid flows freely the syringe containing the solution is attached to the needle and aspiration is attempted. A free flow of spinal fluid must be obtained to assure correct placement of the bevel of the needle in the subarachnoid space. In executing the maneuver, one should aspirate as little spinal fluid as possible (not more than 7{ 0 c.c.), otherwise dilution occurs which interferes when obtaining the desired distribution of anesthesia. The needle should be readjusted until a satisfactory flow is obtained if the spinal fluid does not flow freely. Most failures in spinal anesthesia are due to unsatisfactory lumbar puncture. The solution is injected as rapidly as gentle pressure upon the plunger of the syringe permits. The total time for completion of the injection is approximately two seconds. If the drug is injected slowly, the distribution of anesthesia will not be satisfactory. The needle is then withdrawn from the spinal canal and the patient is allowed to remain in the upright sitting position for thirty seconds, after which time she is placed in the recumbent position. This timing is particularly important and should be done by the clock. It is advisable to support the head on a pillow for at least fifteen minutes. The solution should not be introduced during a contraction because the spinal fluid pressure is increased at this time. Currents established in the subarachnoid space force the drug into the thoracic region and give greater distribution of anesthesia and halt labor. The patient must not move or shift about for five or ten minutes after completion of the injection. The straining, which may accompany such movements, also causes spreadL'r)_g of the drug in the spinal canal.
638
AMERICAN JOURNAL OF OBSTETRICS AND GYNECOLOGY
The sensory and autonomic fibers of a mixed nerve are more sensitive to the effects of a local anesthetic drug than the motor. When the patient is promptly restored to the recumbent position, a 2% mg. dose becomes distributed over a greater number of segments than if she sits up thirty seconds. The lumbar segments, however, are exposed to a more dilute solution than the sacral. The degree of anesthesia decreases as one ascends the cord. Still, the concentration of drug is sufficient to produce anesthesia and paralysis of the legs, thighs, and hypogastric areas in most cases. The sacral segments are exposed to a more concentrated solution of drug than the lumbar so that both motor and sensory fibers are profoundly affected. The perineal area, therefore, is completely relaxed. When the patient sits up thirty seconds, a greater concentration of drug localizes in the conus than in the former case. Anesthesia of the vulva and other perineal structures, likewise, is complete. The concentration of drug along the lumbar segments is less and, as a rule, insufficient to block completely all the sensory fibers in these segments. Hypalgesia and disseminated areas of analgesia are present in the legs and thighs. Little or no paresis of the leg and thigh muscle is obtained. The analgesia over the thighs gradually merges into an area of hypalgesia over the lower abdomen, sometimes as far as the umbilicus. However, the concentration of the drug is sufficient to block the sensory fibers to the cervix and uterus. The sensory fibers to the cervix and lower uterine segments are derived from the sacral and lower lumbar spinal nerves, those of the upper part and the fundus from the upper lumbar and twelfth thoracic segments. The motor innervation of the uterus is still a matter of question. It is believed that the motor fibers are derived from the lower thoracic segments. Consequently, there is no diminution in the number or force of the contractions unless the drug extends into the thoracic region. The recti are not affected and the patient can bear down if requested. The patient will not bear down unless told to do so, however, as the analgesia causes her to be unaware of the contractions.
Method of Study The writers have been interested primarily in the applicability of the block to obstetrics. Therefore, in order to exclude all complicating factors, its use was limited exclusively to normal primiparas or multiparas. Patients presenting systemic abnormalities or obstetric complications were excluded. Sedation, likewise, was omitted in the first 100 patients. The block was performed after the inception of the first stage of labor. Usually, the contractions appeared at 3- to 4-minute intervals and the cervix was 5 to 6 em. dilated and approximately 60 to 80 per cent effaced. Blood pressure and pulse rate were observed at 3- to 4-minute intervals, shortly after induction of analgesia, and at 10- to 15minute intervals after the first thirty minutes. The anesthetist remained in constant attendance in all cases, closely observing the frequency and intensity of contractions, fetal heart tones, progress of labor, respiration, and other reactions of the patient. Emphasis cannot be placed too strongly upon the fact, in this procedure as in other forms of subarachnoid anesthesia, that the patient may not be left unattended until ready for delivery. In approximately half the <>..ases, analgesia was induced in the patient's bed. In the t•emaining cases, the block was induced in the delivery room, and the patients remained on the delivery table throughout labor. An anesthesia machine was in readiness for the administration of oxygen or artificial respiration or analgesia in the event that the block failed. Vasopressor drugs for overcoming hypotension were held in readiness as is the usual custom in all cases of spinal anesthesia. A second tray with drugs and needles was available for repeating the block for cases in which labor outlasted analgesia. In instances in which the block was repeated, the procedure was exactly as in the first block.
PARMLEY AND ADRIAN! :
SADDLE BLOCK ANESTHESIA
639
Results Satisfactory analgesia during labor and anesthesia at the time of delivery were obtained in the majority of cases. The average duration of analgesia was three hours. In some cases, the block lasted as long as five hours. In the majority of cases the pain of uterine contractions returned in three hours, but the perineum was still anesthetized. Eighty-one per cent of the patients obtained complete pain relief during labor and delivery. Fourteen per cent complained of slight pain in the upper abdomen upon application of forceps and a dragging sensation during the period of traction. In others, the traction caused a dull ache in the epigastrium or along the back in the lumbar region. No pain was felt in the perineum at this time or during repair of the episiotomy. Inhalation of analgesic mixtures of nitrous oxide-oxygen until the head was delivered obliterates this most satisfactorily. Surgical anesthesia with the gas with loss of consciousnt~Ss is not necessary. In 5 per cent of the cases the block was not satisfactory. Pain in the perineum or back due to poor distribution of analgesia resulted. Pain from uterine contractions, likewise, was not relieved. The failure, it was felt, was due to some error in technique. It is imperative that timing and measurements of volume of solutions be precise to insure success. The block was repeated after fifteen minutes and satisfactory analgesia was obtained the second time in every case. There is no objection to, or danger in, repeating the block in the event of failure because the doses of nupercaine employed are small. The patients were comfortable and cooperative throughout the lahar and delivery. Patients in pain or who were not cooperative before the block was performed invariably became quiet and cooperative as soon as analgesia was established. The absence of paralysis of the extremities permitted the patient to move about in bed and shift to comfortable positions. The hypotension and other circulatory changes caused by postural changes when extensive anesthesia is obtained by subarachnoid block were not present in these patients. The analgesia in the legs and thighs averts the discomfort usually experienced when the lithotomy position is instituted during the delivery. Seventy per cent of the patients were delivered by aid of low forceps and episiotomy. Anesthesia for repair of episiotomy was satisfactorily obtained in every single instanee. A single block was sufficient in 6S per cent of cases. In 32 per cent, labor outlasted analgesia and repeated blocks were necessary. The shortest time from the institution of analgesia until delivery was fifteen minutes; the longest was eleven hours and fifty-one minutes. In the latter case, three blocks were performed. No difference was noted in the third stage of labor if compared with cases delivered with other types of analgesia or anesthesia. Postpartum hemorrhage was not encountered, nor was excessive bleeding a problem. The babies cried spontaneously and none required resuscitation. Nausea and vomiting occurred in 13 per cent of the cases. It was a troublesome complication when the patient accepted food or fluids during lahor. It was encountered early in the series until the fact was recognized. It is advisable to restrict fluids and food during labor. A lowering of hlood pressure averaging 10 mm. systolic occurred in 50 per cent of the cases. The reduction was attributed to removal of psychic effects on blood pressure by the pain relief. In the other 50 per cent there was a momentary fall in systolic pressure, sometimes as low a level as SO mm. Hg shortly after completion of the injection. Recovery was, however, immediate. No therapy other than deep breathing was required. This drop in pressure must not be confused with the hypotension with bradycardia which is frequently seen with spinal anesthesia, particularly in the more extensive blocks. This type of circulatory disturbance was notably absent, save in three cases. In these, the blood pressure dropped to SO and 90 mm. Hg and remained at this level. It was, however, quickly restored by
640
AMERICAN JOURNAL OF OBSTETRICS AND GYNECOLOGY
ephedrine (15 to 30 mg.) intravenously. The number of spinal segments affected in saddle block is few, and the motor anesthesia is confined to a few small muscles. Physiologic changes, therefore, are less extensive and profound than in ' 'high' ' spinal anesthesia. Respiratory depression or embarrassment was not encountered in any case. Rectal or urinary incontinence during labor was not observed. Hysterographic and other studies of the effects of the block upon labor were not attempted. No remarkable effect upon the duration of labor was apparent, however. Postspinal headache, although not encountered in any case in this series, is the one complication which could limit the usefulness of the block. Backache, urinary retention, distention, ileus, meningismus, palsies, or other complications were, likewise, absent.
Comment Obviously, 136 cases is not a sufficient number to prove the merits or demerits of any method of analgesia or anesthesia. However, the number is sufficient to show the applicability of saddle block to obstetrics. Although the results were gratifying and untoward reactions were not encountered either during labor or delivery, one must bear in mind that the usual hazards and complications of spinal anesthesia may occur with this method as with others. The absence of headache, palsies, urinary retention, and other sequelae of spinal anesthesia in a series as small as this obviously is of no significance. Likewise, it must be emphasized that these were normal cases, free from complications. The applicabmty of this method of analgesia to other than uncomplicated obstetric cases requires further detailed study of a large series of cases. When spinal anesthesia is desired and not contraindicated, certainly, this is the technique of choice. Saddle block anesthesia with nupercaine offers many advantages over the continuous caudal technique. The uncertainty of locating the caudal canal, the presence of the indwelling needles and catheters, the repeated use of relatively large amounts of local anesthetic drugs, and the uncertainty of distribution of anesthesia are undesirable features which are eliminated by saddle block.
Summary Saddle block anesthesia is a :form of low spinal anesthesia distributed chiefly to the perineal area. A technique is described for producing prolonged anesthesia and analgesia by using nupercaine. The block was used in 136 normal cases with gratifying results. The ease and simplicity of induction, the safety allowed by the low dosage of drug, and the exact ll·(lalization of the distribution of anesthesia make the use of this block the technique of choice where spinal anesthesia is preferred or desired in obstetrics. The method is worthy of further use and clinical trial. References 1. Pitkin, G. P.: Surg., Gynec. & Obst. 47: 713-726, 1928. 2. Adriani, J., Roman-Vega, D. A.: Am. J. Surg. 71: 12-18, 1946. 3. Cosgrove, S. A.: AM. J. OBST. & GYNEC. 22: 763-767, 1930. 4. Jones, W. H.: Brit. J. Anesthesia 7: 99-113, 1930. 5. Sankey, B. B., Whitacre, R. J.: Anesthesiology 2: 203, 1941. 6. Silverton, R. J.: Australian & New Zealand J. Surg. 3: 223-234, 1934. 7. Etherington-Wilson, W.: Anesth. & Analg. 14: 102, 1935. 8. Roman, V. D., and Adriani, J.: Surg., Gynec. & Obst. 17: 524, 1945.