Types of Anaesthetic

It was well recognised before the war that chloroform was a dangerous drug, especially in shocked and septic cases, and was quite unsuited to war conditions. Spinal anaesthesia was also banned in similar cases and was restricted to cases of civilian surgery.

Ether remained the basic general anaesthetic for ordinary purposes, but its grave disadvantage was rapid evaporation in tropical countries. (Lieutenant-Colonel Anson, senior anaesthetist, however, stated that there was no real difficulty found in its use in conditions of extreme heat.) It also produced vasodilatation which was deleterious in shock, though this condition could be counteracted by efficient treatment by transfusion.

The regular administration of intravenous fluids (blood, plasma, glucose-salines) rendered intravenous anaesthesia a very simple procedure.

Pentothal began to be used early in the war, and became the routine method of induction and the only anaesthetic for the majority of the cases. Care was necessary to prevent overdosage, and caution required in cases with any possible liver damage such as extensive burns. The average wounded man reacted well to pentothal, and there were few complications. The drug was usually given by intravenous dosage of fixed amounts, repeated as required up to a predetermined maximum. It was also administered by continuous intravenous injection, the total dose being controlled. In shocked cases care was necessary, and small doses sufficient. Pentothal was without question the most satisfactory anaesthetic used during the war for all ordinary wounded or civilian cases.

Ether was given in addition to the more severe cases, such as the abdominals. The introduction of the Macintosh ether apparatus, the Oxford inhaler, proved a very valuable method of administering ether, especially for the ordinary anaesthetist as distinct from the specialist. It was especially useful in the tropical areas.

Gas and oxygen was not often available in North Africa, but was utilised more in Italy. The supply of cylinders proved a difficulty. Cyclopropane was used wherever available and was the common anaesthetic in the chest centres, and was also utilised in the neurosurgical page 123 and faciomaxillary units. Trilene was also used in the latter part of the war.

Boyle's apparatus was part of the ordinary army equipment for hospitals and was freely utilised, but our New Zealand hospitals acquired the more elaborate and efficient American models such as the Heidbrinck, which no doubt should be a regular army supply.

Endotracheal administration was very commonly used by specialist anaesthetists in the chest, head, and facio-maxillary units.

The war conclusively proved the great value of trained anaesthetists in every surgical centre, and especially in the forward areas. Unfortunately the New Zealand force contained few specialists of this type, but it was fortunate in having British specialist anaesthetists attached to its forward medical units for long periods. The choice of anaesthetic varied according to the type of case and the medical unit.

Anaesthesia in Forward Areas in 2 NZEF

In the Field Ambulance: Pentothal was used for almost all the cases, supplemented at times with ether at first by open method and, after its introduction, by Macintosh's apparatus. On a few occasions induction was brought about by C₁E₂ mixture and the anaesthetic continued by open or closed ether. Local anaesthetic proved unsatisfactory. No special apparatus except that later introduced by Macintosh was available in the Field Ambulances except as part of the equipment of an attached FSU.

In the CCS: Boyle's apparatus was available, and gas and oxygen also in the latter part of the war, as was Macintosh's apparatus.

Types of Anaesthesia in CCS

Pentothal: This was the most frequently used anaesthetic and was given intravenously in small divided doses or added to the drip as required. It was well tolerated by the wounded and a relatively small dosage was required.

Gas and Oxygen: Given by Boyle's apparatus, was used in addition in prolonged cases, the oxygen percentage being kept high.

Ether: Was not usually given in an open mask because of quick evaporation, but was given by means of Boyle's or Macintosh's apparatus.

Anaesthesia in Relation to Type of Case

1.	For Light Cases: (a) Pentothal was the common and most useful anaesthetic. (b) Ethyl chloride or GE2 induction, followed by ether either by open method or by Macintosh's apparatus. page 124
2.	Prolonged Cases: (a) Pentothal supplemented by gas and oxygen. (b) Pentothal supplemented by gas and oxygen and ether. (c) Pentothal supplemented by gas, oxygen, and trilene. (d) Ether by Oxford vaporiser.
3.	Severely Shocked Cases: Pentothal was given in minimal dosage supplemented by gas and oxygen and, if relaxation was required, minimal dosage of ether.
4.	Severe Burns: Intravenous morphia. Any anaesthetic was poorly borne, and if any was required minimal doses of pentothal with oxygen or gas and oxygen were given.

Regional Types of Cases

1. Heads: A combination of local anaesthesia and pentothal was used by our forward surgeons. In special centres local anaesthesia was superseded by general anaesthesia, generally pentothal in small dosage, supplemented by gas and oxygen. Cyclopropane was also used when available in special units. Endotracheal anaesthesia was used when necessary in cases involving the sinuses and when operation had to be performed in the prone position. Pentothal was used for induction and then followed by gas and oxygen, supplemented if necessary by minimal dosage of trilene or chloroform.

2. Facio-maxillary: In minor cases pentothal was used when there was no interference with the airway. In severe cases an endotracheal tube was passed, the throat packed-off with gauze soaked in saline or paraffin, and the anaesthetic continued with gas and oxygen and minimal quantity of ether. An efficient airway was necessary at all times, both during the operation and afterwards, and a naso-pharyngeal tube was generally used in severe cases following operation. In cases with serious bleeding or when intubation was impossible, tracheotomy was performed.

3. Chests: In minor cases, such as for closing the wound or arresting haemorrhage, pentothal was used. In more serious cases after pentothal induction gas and oxygen with trilene was given using Boyle's apparatus. Cyclopropane was utilised in special units for these cases. Diathermy and naked lights were centra-indications to its use.

4. Abdomens: Pentothal was used for induction followed by gas and oxygen and ether, or by ether alone using Macintosh's apparatus. Relaxation necessitated the use of ether in these cases. Local anaesthesia was used by some surgeons either in the area of the incision or as an intercostal block below the ribs. Splanchnic block was also sometimes utilised. Intratracheal anaesthesia was employed at times.

Anaesthesia in the Ease Hospitals in 2 NZEF

Operations on patients were generally performed under pentothal, supplemented by ether or gas and oxygen, utilising anaesthetic machines, either the army Boyle's apparatus or more commonly the more elaborate American types. Macintosh's Oxford vaporiser was very efficient for the administration of ether, though specialist anaesthetists preferred the more elaborate machines. Continuous pentothal was used considerably at one period in our base hospitals. Cyclopropane became available in the latter part of the war and was used for special cases. For the routine civilian type of operation pentothal was also generally used.

Spinal anaesthesia was used by some surgeons for operations such as those for inguinal hernia and haemorrhoids. A heavy stovaine solution, the most readily available, was used in Egypt, but limited use was made of light nupercaine, chiefly for lower abdominal and kidney operations. Defective ampoules were detected when they were placed in coloured antiseptic. Severe post-operative headaches resulted from solutions prepared at the hospital. Pentothal, however, remained the routine anaesthetic not only for induction, but for the completion of the operation, and proved a reliable and safe drug.

An interesting step was taken at 2 General Hospital in the resurrection of the use of intravenous ether. This was found most useful for operations requiring comparatively light anaesthesia without profound relaxation—for instance, in operations on the limbs. The solution used was at first made up accurately as 6 per cent in normal saline or glucose saline. As the solubility of ether in these solutions is round about this mark, it was found unnecessary to do more than make a saturated solution by shaking up the ether with the saline and assuming a saturated solution if a small quantity of undissolved ether could be seen floating on the surface of the fluid. A simple infusion set was used and was mounted on a board attached to the anaesthetic table. The tube from the set terminated in a male fitting to connect with a record needle. This tube rested in a sterile dish when not in use. A 19 or 20 gauge needle was used for venipuncture, and when blood flowed the fitting on the end of the infusion set was pushed into the hub. A fast drip rate was immediately started, and it was found that even a continuous flow was often required. To expedite unconsciousness and minimise any undesirable manifestations of the second stage of anaesthesia a small dose up to 0–5 grammes of thiopentone was injected through the infusion tube. As the anaesthesia proceeded the rate of infusion of the ether solution could be greatly reduced and stabilisation in a light plane of page 126 anaesthesia was easily accomplished. At least eight hundred of these administrations were performed without any untoward reactions. In one hundred or more 5 per cent alcohol was used with the ether with some benefit in depth of anaesthesia, but a few cases of post-operative thrombosis of veins ensued. It was realised that very large quantities of fluid were being infused into each patient if the operation was in any way protracted, but it was found that no apparent harm resulted. Of course, this work was done in conditions of great heat and minimum humidity, and the patients were losing large quantities of water by evaporation from the skin, and it may well be that there would be some risk of ‘water-logging’ if the method was used in cool and humid climates.

Post-anaesthetic Complications

Chest complications were common, often being associated with collapse of the lung and sometimes with infection. Collapse of the lung was considered by all to be due to bronchial obstruction from mucous plugs. Infection was most commonly associated with pre-operation infection such as common colds and bronchitis. Preventive measures were adopted, firstly, by the institution of regular breathing exercises before operation, and, secondly, by the exclusion of patients with infection from operation. Treatment in the cases with collapse of the lung consisted in continuing breathing exercises and encouraging movement and coughing. In cases with infection, sulphonamides and penicillin were given when the type of infection was suitable to their use.

Organisation of Anaesthetic Services in 2 NZEF

There was provision for an anaesthetist on the staff of our general hospitals, and Captain Slater was appointed to 1 NZ GH, Major Anson to 2 NZ GH, and Captain Taylor to 3 NZ GH. Captain Slater was captured in Greece and remained a prisoner of war for the greater part of the war. Major Anson, after service for some time at the Helwan hospital, was transferred to administrative work.

The anaesthetic work was of necessity carried out by medical officers largely without much previous experience in anaesthesia, though many later proved very capable anaesthetists. There was no special anaesthetic organisation, medical officers being delegated to anaesthetic duty by the OCs of the units or attached to a surgical team or FSU as anaesthetist. The unit anaesthetist was generally utilised in quiet periods for other medical work such as the control of the blood bank.

page 127

New Zealand had very few whole-time anaesthetists in civil practice available as anaesthetic specialists. The 2nd NZEF was thus at a great disadvantage compared with the British and American forces, where specialist anaesthetists were readily available, many of them very highly qualified for the work. The 2nd NZ Division was fortunate in having attached to its forward units British FSUs containing very capable specialist anaesthetists, who not only provided excellent service in our units, but helped in training many of our young medical officers. The British anaesthetists were given definite status as specialist anaesthetists or graded specialists, but this did not apply to 2 NZEF.

Recommendations for the Future

It is beyond our scope to go into the question of the value of newer methods of anaesthesia, such as the use of curare, in a future war. Perhaps newer methods will supersede those used in the Second World War. We can only give an impression of what seemed most practicable at the end of the war. Elaborate machines were utilised freely at the end of the war, and if these and supplies of gas and oxygen were readily available it would seem that they should be utilised at the CCSs and the General Hospitals.

In the field units intravenous anaesthesia by pentothal or similar drug, and ether by Macintosh's apparatus, would appear to be the most satisfactory methods to adopt.

If circumstances rendered elaborate methods impossible, then pentothal and ether by Macintosh's apparatus for the wounded man, and spinal and local with whatever other methods of anaesthesia were available for the civilian surgery type of cases, would provide efficient anaesthesia.

Staffing: With the utilisation of more elaborate methods of anaesthesia it will be necessary to have specialist anaesthetists. Specialist or graded anaesthetists should be appointed to the base hospitals, to the CCS, and to the FSUs. They would not only give the anaesthetics, but would be available for training MOs for work both in the forward and base units, and, if required, to train nursing sisters or orderlies to give simple anaesthetics under supervision.

There should be a senior anaesthetist available in an advisory capacity as regards the appointment of specialist and graded anaesthetists and the anaesthetic service in general.

If highly trained anaesthetists are available and are suitably employed, and their advice sought and taken, then a satisfactory service would be ensured, as the provision of apparatus and supplies is, in comparison, a secondary consideration.

page 128

Lieutenant-Colonel Anson has stressed the necessity for having trained anaesthetists in the New Zealand Medical Corps. He has also urged the standardisation of relatively simple, foolproof, ruggedly-constructed anaesthetic apparatus, easily serviced and maintained; an agreement on such apparatus within the British Commonwealth, or even farther afield, would be of great benefit not only in war but in civilian practice also.