British Journal of Anaesthesia 1991; 66: 314-318

COMPARISON OF FOUR SUBARACHNOID SOLUTIONS IN A NEEDLE-THROUGH-NEEDLE TECHNIQUE FOR ELECTIVE CAESAREAN SECTION B. RANDALLS, J. W. BROADWAY, D. A. BROWNE AND B. M. MORGAN

Anaesthesia • obstetric, Caesarean section. Anaesthetic techniques: extradural. spinal. Anaesthetics, local: bupivacaine. PATIENTS AND METHODS

Extradural anaesthesia for Caesarean section has several advantages. It allows mothers to partake in the birth, decreases the stress response of surgery [1] and decreases postoperative requirement for analgesia. Patients experience less morbidity and mortality in comparison with those who have had a general anaesthetic [2]. Its intrinsic disadvantages are a failure rate (requirement for additional analgesia in 20% of patients [3]) and a time to onset of a full T4 block of at least 30 min [4] in patients in whom incremental techniques are used. Subarachnoid anaesthesia offers similar advantages, with greater muscle relaxation [5], more rapid onset [6], no missed segments [6], minimal risk of drug toxicity [6] and better surgical anaesthesia [7]. For these reasons, it has been proposed as the anaesthetic method of choice for urgent Caesarean delivery [8]. Disadvantages include less control of block height [9], more rapid

We studied 48 consecutive, healthy patients undergoing elective Caesarean section. Informed consent was obtained from all patients and the study was approved by the hospital Ethics Committee. The patients were allocated randomly to receive one of four subarachnoid solutions. All anaesthetics were given by four anaesthetists in training. Patient assessment was carried out by B. RANDALLS, B.SC, M.B., CH.B., F.C.ANAES., Department of

Anaesthetics, Southampton General Hospital, Tremona Road, Southampton SO9 4XY. J. W BROADWAY, B.SC, M.B., B.S.,

F.C.ANAES., Anaesthetics Department, St Thomas' Hospital, Lambeth Palace Road, London SE1 7EH. D. A. BROWNE, B.M., B.CH., B.A.O., F.F.A.R.C.S.I., Anaesthetics Department,

Hammersmith Hospital, Du Cane Road, London W12 OHS. B. M. MORGAN, M.B., B.S., F.C.ANAES., RPMS Institute of

Obstetrics and Gynaecology, Queen Charlotte's Hospital, London W6 OXG. Accepted for Publication: September 20, 1990. Correspondence to B. R.

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with a higher risk of hypotension [10], failure rate, non-continuous analgesia, and post-spinal headWe have used both spinal and extradural anaes- aches [11]. Some disadvantages of both these conduction thesia with a 26-gauge, long spinal needle through a 16-gauge Tuohy needle for elective anaesthetic techniques may be reduced by comCaesarean section. Four different subarachnoid bining them. Subarachnoid injection may be made solutions of bupivacaine were compared: 0.5% through a long, 26-gauge spinal needle introduced heavy bupivacaine alone, or with adrenaline, through an extradurally placed Tuohy needle fentanyl or adrenaline and fentanyl. The in- before insertion of an extradural catheter [5, 12]. Using this method, we have compared four cidence of complications and time of regression different subarachnoid solutions containing of the sensory block were analysed. The technique is recommended because it allows rapid bupivacaine to ascertain if improved intra- and onset of anaesthesia and the advantages of an postoperative pain relief could be achieved. extradural catheter. The subarachnoid solution Adrenaline has been used because of its possible of choice was 0.5% heavy bupivacaine 12.5 mg antinociceptive effect on the spinal cord [13] and improvement in quality of anaesthesia [14], and with fentanyl 10 fig fentanyl because opioids appear to potentiate the KEY WORDS antinociceptive effect of local anaesthetics [15]. SUMMARY

NEEDLE-THROUGH-NEEDLE SPINAL TECHNIQUE TABLE I. Solutions used in the subarachnoid technique

Group

0.5% Heavy bupivacaine (mg)

Fentanyl (HB)

Adrenaline Gig)

Saline (ml)

A B C D

12.5 12.5 12.5 12.5

0 010 10

0 30 0 30

0.5 0.2 0.4 0.1

ephedrine 5 mg by i.v. bolus administration. The following observations were noted (all timings were from completion of the subarachnoid injection): time to T4 sensory anaesthesia to ethyl chloride spray; height of sensory block every 5 min for 30 min; incidence of nausea and vomiting. If this was unrelated to hypotension it was treated with i.v. droperidol 1.25 mg. Any complaint of somnolence or pruritus was noted by direct questioning. Neonatal Apgar scores and samples of umbilical cord blood for blood-gas analysis were taken by the attending midwife. Following the procedure the mother was asked to score her discomfort during the procedure using a 0-100 mm visual analogue scale. As an attempted prophylaxis against post-subarachnoid headache, 0.9% saline 30 ml was infused through the extradural catheter at the end of the operation [17]. Time to first request for analgesia was noted and 2 % lignocaine 3 ml with adrenaline 15 ng was injected through the extradural catheter to exclude an intravascular or intrathecal position [9]. Ten minutes after this test dose, 0.25% plain bupivacaine 10 ml was injected. This was followed by preservative-free morphine 4 mg in normal saline 10 ml. The time to next request for analgesia was taken from the patient's notes. Pain was assessed using linear analogue pain scores (0 = no pain, 10 = maximum pain). Respiratory depression (denned as a ventilatory frequency < 10 b.p.m.) was observed by hourly monitoring of the ventilatory frequency for the first 24 h. The incidence of pruritus was ascertained by direct questioning. At 24 and 72 h, patients were questioned for maternal satisfaction, neurological problems and spinal headache. Statistical analysis was performed using an analysis of variance (ANOVA) for parametric data, any statistically significant difference among the four groups was analysed by an unpaired twotail t test. A chi-square test for non-parametric categorical data and a Mann-Whitney U test for non-parametric ordinal data were used. P < 0.05 was regarded as statistically significant. RESULTS

There were no significant differences between groups in age, weight, height, gestation, parity, duration of surgery or neonatal condition at delivery (table II). Subarachnoid block charac-

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two observers who were blind to the solutions, which were prepared freshly by an anaesthetist not involved in the study. Each patient was premedicated with oral ranitidine 150 mg the night before surgery, and ranitidine 150 mg with metoclopramide 10 mg orally 90 min before operation. A 16-gauge i.v. cannula was inserted and Hartmann's solution 1500 ml administered i.v. Monitoring of ECG, non-invasive arterial pressure and pulse oximetry was performed throughout the procedure. Intermittent fetal auscultation was performed until the start of surgery. The patients breathed oxygen 4 litre min"1 via a face mask until the baby was delivered. All patients were placed in the left lateral position. Using a midline approach at the L3-4 interspace, a 16-gauge Tuohy needle with a Huber point was introduced into the extradural space. No accidental dural puncture was noted. Through the extradural needle was threaded a 12-cm, 26gauge spinal needle with a Quincke point with the bevel parallel to the dural fibres [16]. Free flow of cerebrospinal fluid (CSF) occurred within an average of 12 s. Patients were then allocated randomly to receive 0.5 % hyperbaric bupivacaine 2.5 ml (group A) alone or with adrenaline 0.3 mg (group B), fentanyl 10 \ig (group C) or adrenaline 0.3 mg and fentanyl 10 |ig (group D). All solutions were made up to a final volume of 3 ml with saline (table I). The spinal injection was made over a period of 45 s and when the injection was completed, the spinal needle was removed and an extradural catheter inserted so that 3 cm remained in the extradural space. No injection was made through the catheter at this time. The patient was turned supine with a 15° right lateral tilt and a wedge placed under the left hip. Hypotension (denned as a 20% decrease in mean arterial pressure or a systolic arterial pressure < 100 mm Hg) was avoided by administration of ephedrine infusion (ephedrine 30 mg in Hartmann's solution 500 ml). If hypotension occurred despite this prophylaxis, it was treated with increments of

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TABLE II. Patient characteristics (mean (SD) or [range])

Group A in = 12) Age (yr) Weight (kg) Height (cm) Gestation (weeks) Range Nulliparous Duration of surgery (min)

34.3 [18-39] 77.4(10.5) 166 (7) 38(1) [37-39]

Group B (n = 12) 33.2 [22^11] 78 (5.0) 167 (8) 38(2) [32-41]

3

3

59(8)

Group C (n = 12)

Group D (n = 12)

31.5 [23-36] 74.9(11.4) 163 (7) 38(1) [37-39]

34.1 [20-37] 75.3(14.6) 160 (6) 38(2) [35-40]

5

66 (18)

4

72 (23)

63(11)

Time to T4 block (min) Max height of block to cold (range) Periop. pain scores (No. with VAS = 0) Regression time to T10 (min) Time to analgesia request (min)

Group A

Group B

7.9 (3.4) C3-T3

5.7(2.2) C2-T2

6.1(1.8) C3-T2

6/11

6/11

11/11

130 (21)

149(16)

150(24)

187 (33)*

145 (26)

161(18)

201 (29)***

229 (34)***

TABLE IV. Complications of the subarachnoid anaesthetic. *P = 0.033; chi-square analysis of association between nausea and adrenaline Group A Group B Group C Group D

Tl block to cold Hypotension Nausea Sleepiness Pruritus

3/11 2/11 3/11 3/11

4/11 4/11 7/11* 3/11

4/11 2/11 0/11 2/11

0

0

0

5/12 3/12 8/12* 4/12 1/12

teristics are shown in table III. There was no significant association between the height of the subarachnoid block and patient height, weight or age. It was possible to commence surgery within 10 min of the subarachnoid injection in 46 of the 48 patients. There were two "failed" spinals. There was no significant difference of time to T4 sensory loss; all blocks reached their maximum height by 20 min; none had started to regress by 30 min. There was no relationship between maximum height of block and time to regress to T10. Addition of fentanyl or adrenaline singly had minimal effect on regression time of the subarachnoid block. The combination of adrenaline and fentanyl (group D), however, was associated

Group C

Group D 5.8 (2.2) C3-T2 12/12

with prolongation of block compared with groups A, B and C (P < 0.01). The addition of fentanyl (group C) or fentanyl and adrenaline (group D) resulted in a period of prolonged postoperative analgesia, compared with groups A and B (P 17 mm, and none required additional an- in which up to 50% of patients required i.v. algesia or sedation. All the patients receiving opioids during operation. This is probably attribfentanyl (groups C and D) had perioperative pain utable in part to the smaller dose of bupivascores of zero (table III). caine (average 9 mg) used in these studies. All After operation there were no differences be- patients given subarachnoid fentanyl (groups C tween groups for duration of analgesia provided and D) had intraoperative pain scores of zero, by extradural morphine or in the incidence of similar to the findings of other workers [15, 23]. pruritus (table V). One patient required treatment Groups C and D had a longer time until first with naloxone 0.4 mg i.v. for pruritus. request for analgesia, but there was no difference One patient developed post-spinal headache between them. It appears that the combination of which required an extradural blood-patch at 48 h. opioid with local anaesthetic is synergistic. This Forty-five mothers scored their satisfaction as has been shown for the combination of bupiva"excellent" immediately after operation, at 24 h caine and morphine [21]. In a retrospective and at 72 h. No patient developed any neuro- analysis of postoperative pain relief, McQuay logical symptoms. found that patients given both opioid and regional Three patients were excluded from analysis. block, before surgery, had a prolonged time to One patient had a prolonged procedure (because first request for analgesia [24]. It is now generally of bleeding fibroids); two patients had failed accepted that adrenaline has minimal effect in subarachnoid block. No patient exhibited any prolonging surgical anaesthesia, and group B had sign of respiratory depression either during or no prolongation of anaesthesia compared with after operation. We were unable to ascertain the groups A and C. existence of urinary retention because all the None of the solutions used resulted in a marked patients had indwelling urinary catheters for the lack of side effects, although the bupivacainefirst 24 h. fentanyl solution had no incidence of nausea and vomiting. This has been observed elsewhere for DISCUSSION extradural fentanyl during Caesarean section [25] All anaesthetics were performed by four anaes- and is in contrast with the adrenaline-containing thetists in training who had not used this solutions. technique before but were experienced in extraThe use of extradural morphine gave excellent dural blocks. prolonged postoperative analgesia in over 30 % of There were two "failed spinals", despite the patients, with no requirement for additional free flow of CSF. This is a failure rate of 4%, opioid analgesia. Twenty per cent of subjects which is comparable to those described by Moir complained of pruritus; one of them required [4] and Manchikanti [18]. naloxone treatment. The analgesia obtained, howThere were a large number of high blocks (33% ever, compares poorly with comparable studies above Tl), comparable to the results of Russell [26]. Four patients obtained less than 4 h an[19], but none of the patients in whom this algesia, and there was marked variation in duroccurred complained of ventilatory difficulties. ation of analgesia. There was no relationship with the incidence of All the patients expressed satisfaction with the hypotension, but the majority of these patients anaesthetic. Several who had undergone previous did complain of drowsiness. The addition of Caesarean section under extradural anaesthesia fentanyl 10 ug was not associated with sleepiness. remarked on the better quality of anaesthesia with The high level of sensory anaesthesia may relate this technique. TABLE V. Pain relief with extradural morphine {mean (SD) and [range])

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12. Carrie L, O'Sullivan G. Subarachnoid bupivacaine 0.5% for Cesarean section. European Journal of Anesthesiology 1984; 1: 275-283. 13. Moore DC, Chadwick MS, Ready WB. Epinephrine prolongs lidocaine spinal: pain in the operative site the most accurate method of determining local anesthetic duration. Anesthesiology 1987; 67: 416-418. 14. Abouleish El. Epinephrine improves the quality of spinal hyperbaric bupivacaine for Cesarean section. Anesthesia and Analgesia 1987; 66: 395-400. 15. Akerman B, Arwestrom E, Post C. Local anesthetics potentiate spinal morphine antinociception. Anesthesia and Analgesia 1988; 67: 943-948. 16. Mihic DN. Postspinal headache and relation of needle bevel to longitudinal dural fibres. Regional Anaesthesia 1985; 10: 76. 17. Craft JB, Epstein SB, Coakley CS. Prophylaxis of duralpuncture headache with epidural saline. Anesthesia and REFERENCES Analgesia 1973; 52: 228-331. 1. Loughran PG, Moore J, Dundee JW. Maternal stress 18. Manchikanti L, Hadley C, Markwell SJ, Colliver JA. A retrospective analysis of failed spinal anesthetic attempts response associated with Caesarean delivery during genin a community hospital. Anesthesia and Analgesia 1987; eral and epidural anaesthesia. British Journal of Obstetrics 66: 322. and Gynaecology 1986; 93: 943-949. 2. Morgan BM, Barker JP, Goroszeniak T, Aulakh JM, 19. Russell IF, Holmquist ELO. Subarachnoid analgesia for Caesarean section. British Journal of Anaesthesia 1987; Reginald PW, Trojanowski AJ. Anaesthetic morbidity 59: 347-353. following Caesarean section under epidural or general anaesthesia. Lancet 1984; 30: 328-330. 20. Chamberlain DP, Chamberlain BDL. Changes in the skin temperature of the trunk and their relationship to 3. Thorburn J, Moir DD. Epidural analgesia for elective sympathetic blockade during spinal anesthesia. AnesthesCaesarean section: technique and its assessment. Anaesiology 1986; 65: 139-143. thesia 1980; 35: 3-6. 4. Moir DD. Local anaesthetic techniques in obstetrics. 21. Abouleish E, Rawal N, Fallon K, Herandez D. Combined intrathecal morphine and bupivacaine for Cesarean secBritish Journal of Anaesthesia 1986; 58: 747-759. tion. Anesthesia and Analgesia 1988; 67: 370-374. 5. Rawl N, Schallin J, Wesstrom G. Epidural versus combined epidural block for Caesarean section. Acta 22. Santos A, Pederson H, Finster M, Edstrom H. Hyperbaric bupivacaine for spinal anesthesia in Cesarean section. Anaesthesiologica Scandinavica 1988; 32: 61—66. Anesthesia and Analgesia 1985; 63: 1009-1013. 6. Valli H, Rosenberg PH. Effects of three anaesthesia methods on haemodynamic responses connected with the 23. Hunt CO, Naulty JS, Bader AM, Hauch MA, Vartikar use of high tourniquet in orthopaedic patients. Acta JV, Datta S, Hertwig LM, Ostheimer GD. Perioperative Anaesthesiologica Scandinavica 1985; 29: 142—147. analgesia with subarachnoid fentanyl-bupivacaine for Cesarean delivery. Anesthesiology 1989; 71: 535-540. 7. Covino BG. Rationale for spinal anesthesia. International 24. MacQuay HJ, Carroll D, Moore RA. Postoperative Anesthesiology Clinics 1989; 27: 8-12. orthopedic pain—the effect of opiate premedication and 8. Marx GF, Luykx WM, Cohen S. Fetal-neonatal status local anaesthetic blocks. Pain 1988; 33: 291-296. following Caesarean section for fetal distress. British Journal of Anaesthesia 1984; 56: 1009-1012. 25. Ackerman WE, Juneja MM, Colclough GW, Kaczorowski DM. Epidural fentanyl significantly decreases nausea and 9. Stonham J, Moss P. Optimal test dose for epidural vomiting during uterine manipulation in awake patients anesthesia. Anesthesiology 1983; 53: 389-390. undergoing Cesarean section. Anesthesiology 1988; 69: 10. Birnbach DJ, Datta S, Ostheimer GW. Maternal hyA679. potension during regional anesthesia for Cesarean section. Current Opinions in Anesthesiology 1988; 1: 151—156. 26. Chadwick HS, Ready LB. Intrathecal and epidural morphine sulfate for postcesarean analgesia—a clinical 11. Hunt CO. Spinal anesthesia for obstetrics. International comparison. Anesthesiology 1988; 68: 925-929. Anesthesiology Clinics 1989; 27: 26-30.

In conclusion, we feel that the combined needle-through-needle technique for Caesarean section is useful in that it provides the advantages of both subarachnoid block and the continuity of extradural analgesia. We recommend the use of bupivacaine with fentanyl as it offers some benefits: minimal nausea, good intraoperative and prolonged postoperative analgesia, and a low incidence of complications. The problem of hypotension following subarachnoid anaesthesia remains the greatest disadvantage; this requires careful monitoring and anticipation to avoid its adverse consequences.

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