Summary
One must distinguish between what is medically safe and what is legally safe. The authors have the impression that in order to be “legally safe” one must perform a test dose. This is despite the fact that it has not been conclusively shown that the use of test doses improve the safety margin of epidural anaesthesia, when administered by a competent person, with the proper resuscitative equipment immediately available. Until a controlled study is performed, test doses should be done for continuous epidural anaesthesia with the understanding that they are neither 100 per cent sensitive nor specific in preventing complications. It is however one more manoeuvre that may be useful in recognizing some of the patients with accidental subarachnoid placement of epidural catheters.
The literature suggests that lidocaine 1.5 per cent in dextrose 7.5 per cent should be the test dose of choice in obstetric epidural anaesthesia in an amount known to produce spinal anaesthesia (30-50 mg). The use of epinephrine in test doses in unpremedicated healthy women in active labour is neither sensitive nor specific in signalling intravascular injection, and it may also be detrimental to fetal wellbeing. Epinephrine 15 μg as a test dose for intravenous injection appears to create more problems than it solves.
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Hodgkinson R, Husain FJ. Epidural test dose in obstetrics. Anesth Analg 1980; 59: 811.
Scott DB. Analgesia in labour. Br J Anaesth 1977; 49: 11–7.
Moore DC, Batra MS. The components of an effective test dose prior to epidural block. Anesthesiology 1981; 55: 693–6.
Cartwright PD, McCarroll SM, Antzaka C. Maternal heart rate changes with a plain epidural test dose. Anesthesiology 1986; 65: 226–8.
Fortuna A. Epidural test doses. Anesth Analg 1981; 60: 616.
Crawford JS. Some maternal complications of epidural analgesia for labour. Anaesthesia 1985; 40: 1219–25.
Kenepp NB, Gutsche BB. Inadvertent intravascular injections during lumbar epidural anesthesia. Anesthesiology 1981; 54: 172–3.
Leighton BL, Norris MC, Sosis M, Epstein R, Carijani GE. Limitations of an epinephrine epidural anesthesia test dose in laboring patients. Anesthesiology 1986; 65: A403.
Hood DD, Dewan DM, Rose JC, James III FM. Maternal and fetal effects of intravenous epinephrine containing solutions in gravid ewes. Anesthesiology 1983; 59: A393.
Chestnut DH, Weiner CP, Martin JG, Herrig JE, Wang JP. Effect of intravenous epinephrine of uterine artery blood flow velocity in the pregnant guinea pig. Anesthesiology 1986; 65: 633–6.
Albright GA, Joupilla R, Hollmen A et al. Epinephrine does not alter human intervillous blood flow during epidural anesthesia. Anesthesiology 1981; 54: 131–5.
Dawkins CJ. Discussion on extradural spinal block. Proc Roy Soc Med 1945; 38: 299–306.
Bromage PR. Epidural analgesia. Philadelphia: WB Saunders, 1978, p 201.
Abboud TK, David SD, Shakuntula N et al. Maternal, fetal, and neonatal effects of lidocaine with and without epinephrine for epidural anesthesia in obstetrics. Anesth Analg 1984; 63: 973–9.
Abraham RA, Harris AP, Maxwell LG, Kaplow S. The efficacy of 1.5% lidocaine with 7.5% dextrose and epinephrine as an epidural test dose for obstetrics. Anesthesiology 1986; 64: 116–9.
Stoneham J, Moss P. The optimal test dose for epidural anesthesia. Anesthesiology 1983; 58: 389–90.
Nicholas ADG. The optimal test dose for epidural anesthesia. Anesthesiology 1984; 60: 79.
Cameron AE, Arnold RW, Ghoris MW, Jamison V. Spinal analgesia using bupivacaine 0.5% plain: variation in extent of the block with patient age. Anaesthesia 1981; 36: 318–45.
Fine PG, Wong KC. Cranial nerve block after test dose through an epidural catheter in a pre-eclamptic parturient. Can Anaesth Soc J 1984; 31: 565–7.
Shnider SM, Levinson G. Anesthesia for Cesarian section.In: Anesthesia for Obstetrics. 2nd Edition. Shnider SM, Levinson G (Eds). Baltimore: Williams and Wilkins, 1987, p 161.
Blass NH, Roberts BR, Wiley JK. The case of the errant epidural catheter. Anesthesiology 1981; 54: 419.
Verniquet AJW. Vessel puncture with epidural catheters. Experience in obstetric patients. Anaesthesia 1980; 35: 660–2.
Cousins MJ. Epidural neural blockade.In: Neural Blockade. Cousins MJ, Bridenbaugh PO (Eds). Philadelphia: J.B. Lippincott, 1980, p 234.
Eisen SM, Rosen N, Winesanker H et al. Routine use of lumbar epidural anaesthesia in obstetrics: a clinical review of 9,532 cases. Can Anaesth Soc J 1960; 7: 280–9.
Hellman K. Epidural anaesthesia in obstetrics: a second look at 26,127 cases. Can Anaesth Soc J 1965; 12: 398–403.
Dawkins CJM. An analysis of the complications of extradural and caudal blocks. Anaesthesia 1969; 24: 554–63.
Bonica JJ (Ed). Principles and Practice of Obstetrical Analgesia and Anesthesia. Philadelphia: F.A. Davis Co., 1972, p 579
Scott DB. Analgesia in labour. Br J Anaesth 1977; 49: 11–7.
Galloon S. Test doses in extradural anaesthesia. Br J Anaesth 1977; 49: 304.
Boys JE. Analgesia in labour. Br J Anaesth. 1977; 49: 841.
Rolbin SH, Hew E, Ogilvie G. Comparison of two types of epidural catheters. Can J Anaesth 1987; 34: 459–61.
Kumar CM, Dennison B, Lawler PGP. Excessive dose requirements of local anaesthetic for epidural analgesia. How far should an epidural catheter be inserted? Anaesthesia 1985; 40: 1100–2.
Abouleish E, Bourke D. Concerning the use and abuse of test doses for epidural anaesthesia. Anesthesiology 1984; 61: 344–5.
Koch J, Nielsen JU. Rare misplacements of epidural catheters. Anesthesiology 1986; 65: 556–7.
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Dain, S.L., Rolbin, S.H. & Hew, E.M. The epidural test dose in obstetrics: is it necessary?. Can J Anaesth 34, 601–605 (1987). https://doi.org/10.1007/BF03010519
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DOI: https://doi.org/10.1007/BF03010519