On the relief of pain in labour: with special reference to the use of relaxation, pethidine hydrochloride and trichlorethylene

Abstract

In the Autumn of 1947, the Writer of this thesis, in search of a suitable subject for study, prepared, with the aid of Individual case -papers, Midwive's Registers and Report Books, a detailed Annual Report of the work done during the year 1946 at the Lucy Baldwin Maternity Hospital, Stourport-on-Severn, Worcestershire, the Writer having been on the Medical Staff of this hospital since 1932. This report is included in the Appendix at pages 40-65.

This hospital has no resident medical officer.

Consideration of the 191+6 report, and, hearing in mind the increasing use of Pethidine hydrochloride in current obstetrical practice, it was decided to study the action of this drug, already in somewhat tentative use at this hospital since 1944, as it became more fully used during the year 1948. As a control, the hospital results over the ten years period 1938 - 47 were prepared in a similar manner to the 1946 report, this being considered the only practicable control series obtainable.

At the same time, during the trial year of 1948 it was decided to intensify the instruction of patients in "Relaxation" already in use at this hospital for some years, and to study the action of Trichlorethylene as an analgesic for self -administration in later labour. Supervision of Trichlorethylene administration limited the number of cases to 100 in hospital and 15 in private domiciliary practice.

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Instruction of the mother in the physiology of Pregnancy and Mechanism of labour, and encouragement in the practice of muscle control and relaxation are of value. They augment morale in the expectant mother and help to secure less painful and less tedious labour.

The use of Pethidine in 1ebour in 71- of Primigravidae and 43 ¡0 of multigravidae carried out in 1948 in hospital, undoubtedly re &$fved a considerable amount of suffering, apparently shortened the second stage of labour, was probably an important factor in lowering the rate of obstetric interference, and during the year of its full employment the hospital statistics for infant mortality shower. a desirable downward trend.

But, the incidence of 7.4¡,, of asphyxia neonatorum in the pethidine series studied is high, as is also the incidence of 11:5 ¡0 of mothers losing 20 fluid ounces or more of blood post-partum.

It is concluded that in hospital practice -

1. 700 of Primigravidae receiving Pethidine is not an unduly high figure if adequate first stage pain relief is the aim. But Pethidine should be withheld in cases of Premature Labour and given sparingly in cases of Toxaemia at Term.

It should he the aim to administer pethidine at least 3 hours before anticipated delivery, but it is realised that this is impracticable to define as a strict rule, as in a considerable number of normal primigravid labours delivery occurs more rapidly when pethidine has been administered at the optimum time.

In cases therefore, in which delivery within 3 hours of the administration of pethidine is imminent, it is suggested that Nitrous Oxide and Air analgesia be given if required in later labour, Trichlorethylene being reserved, and used if considered necessary, for crowning and delivery only.

In these ways the incidence of asphyxia, neonatorum in Primigravidae may be reduced,-

2. 43% of the Multigravidae receiving Pethidine is a high figure. It is suggested that multigravidae appearing in need of first stage sedation or analgesia, and advancing normally could be adequately relieved by Chloral hydrate and the earlier use of Nitrous -Oxide and Air, Trichlorethylene being given later if required, Pethidine being reserved for Multigravidae in slower more tedious labour, often with a history of difficult labour previously.

In these ways it is suggested that 'late pethidine' in multigravidae may be avoided in a number of cases, thereby possibly reducing the high figure of post-partum blood loss, and at the same time the incidence of asphyxia.

3. In cases where Pethidine has inadvertently been given within 3 hours of delivery, ecbolic drugs should be administered as a routine IMMEDIATELY on delivery of the placenta.

4. Until further information on the use of Trichlorethylene in labour is forthcoming,this analgesic should be withheld in cases of premature labour and cases of toxaemia of Pregnancy at term, and used,as described above, in cases of 'late' Pethidine, if required,only at CROWNING and DELIVERY.

5. In hospital, without resident medical staff, and where ante-natal and intra-natal care, care in the conduct of the 3rd stage of labour, and ante -natal and post- natal paediatrics are kept constantly in mind, there is a strong case for permitting the use of Trichlorethylene, as an analgesic in late labour, by the sisters and staff midwives provided they have had a Period of supervised training in its use.

6. While considering that the hospital results shown in this thesis, in respect particularly of the FORCEPS rate, are clear evidence of the importance of skill and devotion to duty on the part of the Nursing staff in gaining the willing co- operation of the mother in labour, yet it must be constantly borne in mind, that is methods of alleviation of pain in labour increase in effectiveness there is an increased risk that, on occasion, the mother's efforts may harm herself oil the child more than would a timely intervention with forceps.Provided then, that this risk is constantly borne in mind, it is considered that the methods of pain relief examined in this thesis, and used with discretion, c n form a basis of safe, effective, relief of pain in labour, capable of augmentation when necessary, and applicable to a large number of mothers.