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Combined spinal and epidural blockade for analgesia in labour
European Journal of Obstetrics & Gynecology and Reproductive Biology 59 Suppl. (1995) S59-S60
Combined spinal and epidural blockade for analgesia in labour B. Morgan Queen Charlotte's and Chelsea Hospital, Go/dhawk Road, Hammersmith, W6. OXG, UK
A Tuohy needle placed in the epidural space serves as an introducer to a very fine long pencil point spinal needle (119 mm 27 gauge Whitacre B-D) which, following a subarachnoid injection, is withdrawn and an epidural catheter passed through the Tuohy in the usual fashion to lie 3 cm in the epidural space. After the subarachnoid block regresses, central blockade can be maintained by bolus doses or continuous infusion into the epidural space. One of the disadvantages of using a lumbar epidural alone in obstetrics is the slow onset of sacral blockade which is an essential feature of this block [I]. This is particularly undesirable in advanced labour, especially in multiparous women, as it results in ineffective analgesia. Attempts to overcome this delay by using large doses of concentrated local anaesthetic result in the rapid onset of motor blockade which is known to decrease maternal satisfaction with analgesia [2]. Another disadvantage of placing the initial dose in the epidural space is that the milligrams of bupivacaine used per hour is greater than occurs when the block is started in the subarachnoid space. This results in early onset of motor block, especially disadvantageous in a woman having a long labour. For many years, spinal blocks were considered as contraindicated in obstetric practice because of post dural puncture headache (PDPH) which is devastating to the mother in the peuperium. Modern, very small, gauge pencil point needles have been shown not to be associated with a high incidence of PDPH [3] - nor is PDPH more common after labour [4]. Fine Whitacre or Sprotte spinal needles are, however, easy to bend and, when used with a short introducer, have been shown to become dangerously deformed while negotiating the spinal ligaments [5]. Passing one of these fine needles through a Tuohy helps to prevent it from bending, as only about I cm of the needle emerges from the protective cylinder of the Tuohy. An additional advantage of the combined technique is that most anaesthetists find it easier to locate the epidural space with a Tuohy needle than to access the subarachnoid Elsevier Science Ireland Ltd. SSDl 0028-2243(95)02066-2
space with a fine spinal needle and short introducer. This cuts down the number of needling attempts and, therefore, the number of headaches. The greatest benefit of using both spinal and epidural together is that the dose injected into the subarachnoid space can be decreased or altered. This allows the provision of less dense blocks that can be extended or made denser via the epidural catheter whenever it is necessary. With intrathecal opioids alone or in combination with local anaesthetics, subarachnoid analgesia used initially for labour can be tailored to the mother's needs. Onset of the analgesia is rapid with good sacral blockade and a bilateral well-distributed analgesia but with little or no motor block. The combined technique is readily taught to anaesthetic trainees who are familiar with epidural blocks. Several different opioids have been used intrathecally to provide either the initial analgesic dose or with the use of a spinal catheter continuous analgesia in labour. Morphine given intrathecally [6] has proved to have a high incidence of side effects, mainly nausea and pruritus, a slow onset of analgesia and poor perineal analgesia. The lipophilic opioids have been more successful. Fentanyl, Pethidine and Sufentanil have produced analgesia but are slow in onset and short acting [7]. The significant synergism of the combination of local anaesthetic drugs and opiates for both visceral and somatic pain has been observed clinically [8] and further investigated in laboratory animals [9]. This enhanced effect was obtained even when mixtures contained doses so low that they by themselves had little or no effect. Both the degree and duration of analgesia is improved by the use of drug combinations. Accordingly, these low doses will be likely to have fewer side effects and are indicated in situations where motor blockade and a feeling of numbness are undesirable, such as labour analgesia. Combinations of local anaesthetics and opioids have also been shown to enhance analgesia in the epidural space riO]. Clinically combined spinal epidural anaesthesia for caesarean section has been an established technique. In-
S60
B. Morgan / European Journal of Obstetrics & Gynecology and Reproductive Biology 59 Suppl. (1995) S59-S60
trathecal bupivacaine 5 mg is an effective analgesia in advanced labour but results in almost all women having motor block. A subarachnoid dose of 2.5 mg bupivacaine and 25 mcg fentanyl provides a more suitable analgesic block while retaining motor power. The epidural top up dose being 10 of a 0.1 % solution of bupivacaine + 0.0002% fentanyl which is the routinely used solution for either bolus top-ups or infusion in our hospital. An initial survey of 300 women has been reported (12]. The success of this refinement of epidural analgesia was so great that since the pilot study it has become the routine regional analgesic used in labour. In our initial 300 women, the rate of failure to perform the subarachnoid block was 10.6% but in the subsequent 1565 women, it was 5.3%. In the initial 300, the rate of dural tap with the Tuohy needle was 1% but in the following 1565, it was 0.45%. A similar improvement occurred in the rate of post spinal headache which was 1.3% in the initial group and 0.13% in the following 1565. Other details of the initial 300 women indicated that the duration of spinal analgesia was 90 min (range 20-245 min). The total duration from block to delivery was 318 min (25-1300) and the interval between epidural top-ups was 52 min. One remarkable feature of the CSE was the retention of motor power, with only 12% of women being immobile during the first stage of labour and 51 % getting out of bed to walk about or sit in a rocking chair during a part or the whole of the first stage of labour. Postpartum of the 1565 women, when questioned, 73.5% had felt an urge to bear down in the second stage of labour with no or mild pain and almost all of these women found this helpful during the pushing phase; 13% had pain at delivery. Overall, 95% were satisfied with their analgesia. No epidural top up caused an unexpected spinal block. Even if the top up dose was injected into the subarachnoid space, it would not result in a total spinal as 10 ml 0.125% bupivacaine intrathecally for caesarean section produced a block to T4 (13]. There was no incidence of maternal or neonatal respiratory depression from the mean total dose of 125 mcg fentanyl throughout the labour.
The combined spinal epidural block allows titration of the drugs to provide the barely perceptible sensory block ideal for labour. The purpose of pain relief in labour is to improve the woman's experience of childbirth and, by lessening the density of the regional blockade, mothers have a more satisfactory experience. References [11 Bromage PRo In: W.B. Saunders. Epidural Analgesia, Philadelphia 1978; 4: 132. [2) Murphy JD, Hutchinson K, Boweden MI, Lewis M, Cooper GM. Bupivacaine versus bupivacaine plus fentanyl for epidural analgesia: effect on maternal satisfaction. BMJ 1991; 302: 564-567. [3) Carrie LES. Whitacre and pencil point spinal needles: some points to consider. Anaesthesia 1990; 45: 1097-1098. [4) Ravindran RS, Viegas OJ, Tasch MD, Cline PJ et al. Bearing down at time of delivery and incidence of spinal headache in parturients. Anesth Analg 1980; 160: 524-526. [5) Chaney MA. Bent stylet upon removal from sprotte needle. Anesth Analg 1993; 77: 398-410. [6) Baraka A, Noveihid R, Hall S. Intrathecal injection of morphine for obstetric analgesia. Anesthesiology 1981; 54: 136-140. [7) Honet JE, Arkoosh VA, Norris MC, Huffnagle HJ, Silverman NS, Leighton BL. Comparison among intrathecal fentanyl, meperidine and sufentanil for labor analgesia. Anesth Analg 1992; 75: 734-739. [8) Kalso E. Effects of intrathecal morphine, injected with bupivacaine on pain after orthopaedic surgery. Br J Anaesth 1983; 55: 415-422. [9) Akerman B, Arwestrom E, Post C. Local anaesthetics potentiate spinal morphine antinociception. Anesth Analg 1988; 67: 943-948. [10) Hjortso NC, Luna C, Mogensen T, Bigler D, Kehlet H. Epidural morphine improves pain relief and maintains sensory analgesia during continuous epidural bupivacaine after abdominal surgery. Anesth Analg 1986; 65: 1033-1036. [II] Randalls B, Broadway JM, Browne DA, Morgan BM. Comparison of four subarachnoid solutions in a needle through needle technique for elective caesarean section. Br J Anaesth 1991; 66: 314-318. [12) Collis RE, Baxandall ML, Srikantharajah 10, Edge G, Kadim MY, Morgan BM. Combined spinal epidural analgesia with ability to walk throughout labour. Lancet 1993; 341: 767-768. [13) Van Zundert AA, Wolf AM, Vaes L, Soetens M. High volume spinal anaesthesia with bupivacaine 0.125% for Caesarean section. Anesthesiology 1988; 69: 998-1003.
Combined spinal and epidural blockade for analgesia in labour B. Morgan Queen Charlotte's and Chelsea Hospital, Go/dhawk Road, Hammersmith, W6. OXG, UK
A Tuohy needle placed in the epidural space serves as an introducer to a very fine long pencil point spinal needle (119 mm 27 gauge Whitacre B-D) which, following a subarachnoid injection, is withdrawn and an epidural catheter passed through the Tuohy in the usual fashion to lie 3 cm in the epidural space. After the subarachnoid block regresses, central blockade can be maintained by bolus doses or continuous infusion into the epidural space. One of the disadvantages of using a lumbar epidural alone in obstetrics is the slow onset of sacral blockade which is an essential feature of this block [I]. This is particularly undesirable in advanced labour, especially in multiparous women, as it results in ineffective analgesia. Attempts to overcome this delay by using large doses of concentrated local anaesthetic result in the rapid onset of motor blockade which is known to decrease maternal satisfaction with analgesia [2]. Another disadvantage of placing the initial dose in the epidural space is that the milligrams of bupivacaine used per hour is greater than occurs when the block is started in the subarachnoid space. This results in early onset of motor block, especially disadvantageous in a woman having a long labour. For many years, spinal blocks were considered as contraindicated in obstetric practice because of post dural puncture headache (PDPH) which is devastating to the mother in the peuperium. Modern, very small, gauge pencil point needles have been shown not to be associated with a high incidence of PDPH [3] - nor is PDPH more common after labour [4]. Fine Whitacre or Sprotte spinal needles are, however, easy to bend and, when used with a short introducer, have been shown to become dangerously deformed while negotiating the spinal ligaments [5]. Passing one of these fine needles through a Tuohy helps to prevent it from bending, as only about I cm of the needle emerges from the protective cylinder of the Tuohy. An additional advantage of the combined technique is that most anaesthetists find it easier to locate the epidural space with a Tuohy needle than to access the subarachnoid Elsevier Science Ireland Ltd. SSDl 0028-2243(95)02066-2
space with a fine spinal needle and short introducer. This cuts down the number of needling attempts and, therefore, the number of headaches. The greatest benefit of using both spinal and epidural together is that the dose injected into the subarachnoid space can be decreased or altered. This allows the provision of less dense blocks that can be extended or made denser via the epidural catheter whenever it is necessary. With intrathecal opioids alone or in combination with local anaesthetics, subarachnoid analgesia used initially for labour can be tailored to the mother's needs. Onset of the analgesia is rapid with good sacral blockade and a bilateral well-distributed analgesia but with little or no motor block. The combined technique is readily taught to anaesthetic trainees who are familiar with epidural blocks. Several different opioids have been used intrathecally to provide either the initial analgesic dose or with the use of a spinal catheter continuous analgesia in labour. Morphine given intrathecally [6] has proved to have a high incidence of side effects, mainly nausea and pruritus, a slow onset of analgesia and poor perineal analgesia. The lipophilic opioids have been more successful. Fentanyl, Pethidine and Sufentanil have produced analgesia but are slow in onset and short acting [7]. The significant synergism of the combination of local anaesthetic drugs and opiates for both visceral and somatic pain has been observed clinically [8] and further investigated in laboratory animals [9]. This enhanced effect was obtained even when mixtures contained doses so low that they by themselves had little or no effect. Both the degree and duration of analgesia is improved by the use of drug combinations. Accordingly, these low doses will be likely to have fewer side effects and are indicated in situations where motor blockade and a feeling of numbness are undesirable, such as labour analgesia. Combinations of local anaesthetics and opioids have also been shown to enhance analgesia in the epidural space riO]. Clinically combined spinal epidural anaesthesia for caesarean section has been an established technique. In-
S60
B. Morgan / European Journal of Obstetrics & Gynecology and Reproductive Biology 59 Suppl. (1995) S59-S60
trathecal bupivacaine 5 mg is an effective analgesia in advanced labour but results in almost all women having motor block. A subarachnoid dose of 2.5 mg bupivacaine and 25 mcg fentanyl provides a more suitable analgesic block while retaining motor power. The epidural top up dose being 10 of a 0.1 % solution of bupivacaine + 0.0002% fentanyl which is the routinely used solution for either bolus top-ups or infusion in our hospital. An initial survey of 300 women has been reported (12]. The success of this refinement of epidural analgesia was so great that since the pilot study it has become the routine regional analgesic used in labour. In our initial 300 women, the rate of failure to perform the subarachnoid block was 10.6% but in the subsequent 1565 women, it was 5.3%. In the initial 300, the rate of dural tap with the Tuohy needle was 1% but in the following 1565, it was 0.45%. A similar improvement occurred in the rate of post spinal headache which was 1.3% in the initial group and 0.13% in the following 1565. Other details of the initial 300 women indicated that the duration of spinal analgesia was 90 min (range 20-245 min). The total duration from block to delivery was 318 min (25-1300) and the interval between epidural top-ups was 52 min. One remarkable feature of the CSE was the retention of motor power, with only 12% of women being immobile during the first stage of labour and 51 % getting out of bed to walk about or sit in a rocking chair during a part or the whole of the first stage of labour. Postpartum of the 1565 women, when questioned, 73.5% had felt an urge to bear down in the second stage of labour with no or mild pain and almost all of these women found this helpful during the pushing phase; 13% had pain at delivery. Overall, 95% were satisfied with their analgesia. No epidural top up caused an unexpected spinal block. Even if the top up dose was injected into the subarachnoid space, it would not result in a total spinal as 10 ml 0.125% bupivacaine intrathecally for caesarean section produced a block to T4 (13]. There was no incidence of maternal or neonatal respiratory depression from the mean total dose of 125 mcg fentanyl throughout the labour.
The combined spinal epidural block allows titration of the drugs to provide the barely perceptible sensory block ideal for labour. The purpose of pain relief in labour is to improve the woman's experience of childbirth and, by lessening the density of the regional blockade, mothers have a more satisfactory experience. References [11 Bromage PRo In: W.B. Saunders. Epidural Analgesia, Philadelphia 1978; 4: 132. [2) Murphy JD, Hutchinson K, Boweden MI, Lewis M, Cooper GM. Bupivacaine versus bupivacaine plus fentanyl for epidural analgesia: effect on maternal satisfaction. BMJ 1991; 302: 564-567. [3) Carrie LES. Whitacre and pencil point spinal needles: some points to consider. Anaesthesia 1990; 45: 1097-1098. [4) Ravindran RS, Viegas OJ, Tasch MD, Cline PJ et al. Bearing down at time of delivery and incidence of spinal headache in parturients. Anesth Analg 1980; 160: 524-526. [5) Chaney MA. Bent stylet upon removal from sprotte needle. Anesth Analg 1993; 77: 398-410. [6) Baraka A, Noveihid R, Hall S. Intrathecal injection of morphine for obstetric analgesia. Anesthesiology 1981; 54: 136-140. [7) Honet JE, Arkoosh VA, Norris MC, Huffnagle HJ, Silverman NS, Leighton BL. Comparison among intrathecal fentanyl, meperidine and sufentanil for labor analgesia. Anesth Analg 1992; 75: 734-739. [8) Kalso E. Effects of intrathecal morphine, injected with bupivacaine on pain after orthopaedic surgery. Br J Anaesth 1983; 55: 415-422. [9) Akerman B, Arwestrom E, Post C. Local anaesthetics potentiate spinal morphine antinociception. Anesth Analg 1988; 67: 943-948. [10) Hjortso NC, Luna C, Mogensen T, Bigler D, Kehlet H. Epidural morphine improves pain relief and maintains sensory analgesia during continuous epidural bupivacaine after abdominal surgery. Anesth Analg 1986; 65: 1033-1036. [II] Randalls B, Broadway JM, Browne DA, Morgan BM. Comparison of four subarachnoid solutions in a needle through needle technique for elective caesarean section. Br J Anaesth 1991; 66: 314-318. [12) Collis RE, Baxandall ML, Srikantharajah 10, Edge G, Kadim MY, Morgan BM. Combined spinal epidural analgesia with ability to walk throughout labour. Lancet 1993; 341: 767-768. [13) Van Zundert AA, Wolf AM, Vaes L, Soetens M. High volume spinal anaesthesia with bupivacaine 0.125% for Caesarean section. Anesthesiology 1988; 69: 998-1003.