METABOLIC RESPONSE TO COLONIC SURGERY: EXTRADURAL VS CONTINUOUS SPINAL

METABOLIC RESPONSE TO COLONIC SURGERY: EXTRADURAL VS CONTINUOUS SPINAL

British Journal of Anaesthesia 1991; 67: 467^469 METABOLIC RESPONSE TO COLONIC SURGERY: EXTRADURAL VS CONTINUOUS SPINAL J. WEBSTER, M. BARNARD AND F...

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British Journal of Anaesthesia 1991; 67: 467^469

METABOLIC RESPONSE TO COLONIC SURGERY: EXTRADURAL VS CONTINUOUS SPINAL J. WEBSTER, M. BARNARD AND F. CARLI

We have examined the effect of intraoperative and postoperative (4 h) continuous spinal anaesthesia for colonic surgery on the postoperative glucose, lactate and cortisol responses. Twenty-one patients were studied; the first group (control) received general anaesthesia, the second group (extradural) an extradural block (T4-S5) and the third group (spinal) a continuous spinal block (T4-S5). Plasma concentration of glucose increased significantly in the control and extradural groups (P < 0.05) after surgery, with a small change in the spinal group. Plasma concentration of lactate increased significantly (? < 0.05) in the control group only. The postoperative increase in plasma concentration of cortisol was similar in both control and extradural groups, and significantly greater than that of the spinal group (? < 0.05). Thus continuous spinal analgesia attenuated, but did not abolish, the increase in plasma concentration of cortisol associated with colonic surgery. KEY WORDS Anaesthetic techniques: extradural, spinal stress response. Surgery: colonic.

Metabolism:

It has been well documented that extradural analgesia (T4—S5) for lower abdominal surgery inhibits glucose and cortisol responses [1]. However, results vary in studies of the effectiveness of extradural anaesthesia for colonic surgery in modulating the variables considered to be part of the stress response [2]. This might be caused by a partially effective neural afferent block. The recent introduction of small-size spinal catheters has made possible the administration of low doses of local anaesthetics to establish a profound motor and sensory block during surgery with low risk of systemic toxicity caused by local

anaesthetics. The present study was designed to evaluate the effect of intraoperative afferent neural block, achieved with spinal local anaesthetics in patients undergoing colonic resection, on postoperative glucose and cortisol responses. METHODS AND RESULTS

Twenty-one patients undergoing sigmoid colectomy for adenocarcinoma were allocated randomly to three groups of seven patients: control, extradural and spinal (mean ages 67 yr (range 57-73 yr), 71 yr (58-78 yr) and 69 yr (64—78 yr), respectively). Body mass index was comparable in the three groups. The study received Ethics Committee approval. Premedication comprised papaveretum and hyoscine administered i.m. 60 min before surgery. All patients received general anaesthesia which consisted of thiopentone, pancuronium, enflurane, nitrous oxide and oxygen. In the extradural group patients, a catheter was inserted in the extradural space at T9-11 and segmental block (T4-S5) was established with 0.75 % bupivacaine 15 ml before induction of general anaesthesia. Additional 0.75 % bupivacaine 5-7 ml was administered every 45 min. At the end of surgery, the same extent of segmental analgesia was maintained with a continuous infusion of 0.25% bupivacaine 10-15 ml h"1. Patients in the spinal group received a continuous subarachnoid block via a spinal catheter (Kendall 28-gauge) at L2-3. After aspiration of CSF to confirm the position of the catheter, hyperbaric 0.5% bupivacaine 2-3 ml was administered and segmental

J.WEBSTER,

PH.D.;

M.BARNARD,

M.B.,

B.S.;

F. CARLI,

F.C.ANAES.; Department of Anaesthesia; Northwick Park Hospital and Clinical Research Centre, Watford Road, Harrow, Middlesex. Accepted for Publication: March 26, 1991. Correspondence to F.C.

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SUMMARY

BRITISH JOURNAL OF ANAESTHESIA

468

TABLE I. Mean (SD) plasma concentrations of glucose, lactate and conisol in the three groups studied before and after surgery. Significant differences: *P < 0.05, **P < 0.01 vs before surgery values; + P <0.05, ++P < 0.01 vs control group After surgery (h) Before surgery

1

2

3

4

5.5 (0.5) 5.4 (0.3) 5.6(1.1)

9.5(1.9)** 6.6(1.0)t 6.7(l.l)t

11.1 (3.4)** 7.1(1.3)t 7.3(1.2)f

11.0(3.5)** 6.0(1.3)*+ 7.6(1.5)+

10.5(3.1)** 7.1(1.1)*+ 7.2(1.4)+

9.9(3.1)* 7.1(1.1)*+ 7.3(1.6)

0.9 (0.3) 1.1 (0.2) 1.2(0.2)

1.9(0.9)* 1.5(0.8) 1.1 (0.3)t

2.0(1.1)* 1.5(0.9) 1.2(0.5)

1.8(1.0)* 1.4(0.8) 1.1 (0.3)

1.9(1.3)* 1.1 (0.6) 1.1 (0.2)

2.3(1.7)* 1.2(0.5) 1.0(0.2)

297 (83) 330(81) 393 (174)

1025 (104)** 903 (244)** 602 (206)*ft

1194(88)** 1083 (420)** 613(208)*tt

block (T4-S5) established before induction of anaesthesia. Additional hyperbaric 0.5 % bupivacaine 0.5-1 ml was administered every 45 min. At the end of surgery, a continuous subarachnoid infusion of 0.25 % bupivacaine 2-4 ml h"1 was started and the same extent of analgesia maintained for 4 h. At the end of surgery the control group received a continuous s.c. infusion of papaveretum 2-5 mg h"1. All patients received an i.v. infusion of 0.9 % normal saline 6-8 ml kg"1 h"1. No blood products were used during the period of the study. Dextran 70 in 0.9 % sodium chloride was administered when the blood loss exceeded 10% of the circulating volume. On arrival of the patient in the anaesthetic room, a 16-gauge cannula was inserted under local anaesthesia in the right internal jugular vein and 20-ml samples of blood were taken before anaesthesia, at the end of surgery and 1, 2, 3 and 4 h after operation for measurement of plasma concentrations of glucose (hexokinase method), lactate (enzymatic assay, lactate dehydrogenase) and cortisol (radioimmunoassay). Power calculations were performed to determine the smallest difference between the spinal and the control groups that could be detected as significant at 5 % level, with a between patient SD of any change as 10%. If seven patients were allocated to each group, a difference of approximately 15% between the groups could be detected. Analysis of variance was applied and comparisons were made within groups and between groups using Student's t test. Mean duration of surgery was 175 min (range 125-240 min) and fluids administered amounted

1271 (154)** 1257 (239)** 1379(196)** 1207 (349)** 1438 (382)** 1495 (382)** 786(217)**+1\ 845 (237)**++ 840 (256)**++

to 2700 ml (range 1800-3850 ml). Ephedrine was required in only three patients (two in the spinal group and one in the extradural group); the maximum dose administered was 9 mg. The PCV decreased with surgery in all three groups (mean 16%, range 13-18%). Plasma concentration of glucose increased in all groups after surgery; in the control and extradural groups the increase was significant at all times (P < 0.05), while in the spinal group it was just significant 2 h after surgery (P = 0.05) (table I). The control group had significantly greater plasma concentrations of glucose at each time than either the extradural or spinal groups. Plasma concentration of lactate in the control group increased significantly at all times after surgery. In contrast, no significant change was observed in the other groups. Plasma concentration of lactate in the control group was significantly greater (P < 0.05) than that in the spinal group at the end and 4 h after surgery. Plasma concentration of cortisol increased significantly (P < 0.05) after surgery in all three groups. The increase in the spinal group was significantly less than that in both extradural (P = 0.02) and control groups (P = 0.007). No significant difference was observed at any time between control and extradural groups. COMMENT

This study has shown that the increase in plasma concentration of cortisol associated with colonic surgery may be attenuated, but not abolished, with spinal anaesthesia. The postoperative increase in plasma concentrations of glucose and

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Glucose (mmol litre"1) Control (n = 7) Extradural (n = 7) Spinal (n = 7) Lactate (mmol litre"1) Control (n >= 7) Extradural (n = 7) Spinal {n = 7) Cortisol (mmol litre"1) Control (n = 7) Extradural (n = 7) Spinal (n = 7)

End of surgery

METABOLIC RESPONSE TO COLONIC SURGERY

to inhibit the postinjury hypersensitivity to pain and abolish the increase in plasma concentrations of cortisol [4]. It remains to be seen if continuous spinal anaesthesia alone or in combination with other pain relief techniques leads to a significant effect on the stress response over a longer period of time. ACKNOWLEDGMENT We thank the Kendall Company for supplying the 28-gauge spinal catheters

1.

2. 3. 4.

REFERENCES Engquist A, Brandt MR, Fernandes A, Kehlet H. The blocking effect of epidural analgesia on the adrenocortical and hyperglycaemic responses to surgery. Ada Anaesthesiologica Scandinavica 1977; 21: 330-335. Kehlet H. Surgical stress—the role of pain and analgesia. British Journal of Anaesthesia 1989; 63: 189-195. Kehlet H. The stress response to surgery: release mechanisms and the modifying effect of pain relief. Acta Chirurgica Scamtinavica 1988; (Suppl. 550): 22-28. Dahl JB, Rosemberg J, Dirkes WE, Mogensen T, Kehlet H. Prevention of postoperative pain by balanced analgesia. British Journal of Anaesthesia 1990; 64: 518-520.

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lactate with either spinal or extradural anaesthesia was less than that observed with the control group. Spinal or extradural administration of local anaesthetics has been shown to prevent a major part of the classical endocrine—metabolic response to surgical procedures such as lower abdominal (for example gynaecological) surgery and operations on the lower extremities, but these techniques have been less effective for colonic surgery [2]. This is probably a result of differences in extradural or spinal analgesic techniques and dosage of local anaesthetic. However, it appears that by using large doses of local anaesthetics with sufficient sensory analgesia extending beyond the dermatomes of surgical procedure, there might be a pronounced inhibition of the stress response [3]. In this context, the attenuated increase in plasma concentration of cortisol observed at the end of surgery with spinal block, compared with extradural, could be explained by an effective, but not definite, preoperative neural block. More recently, the combined use of subarachnoid and extradural local anaesthetics have been reported

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