176 I R I S H JOURNAL OF MEDICA L SCIENCE

hepatit is. I cannot give h im figures. He ment ioned l~imington's talks abou t uroporphyr in , not coproporphyrin. He also asked abou t the hirsuties being protective. I t was suggested in one of the papers tha t this was so. Rimington quoted the case of porphyr ia in cattle, especially in S. Africa. I-Ie il lustrated a case of porphyr ia whero the manifestat ions were only in the par t s covered by white hair, not by black. Hirsut ies occurs part icularly on exposed par t s such as legs and arms. The hair was black, the pat ient was dark with dark hair and eyes. She also had a certain amoun t of darkish pigmenta t ion in the eye. Gilhespy does not describe similar investigations in his ease, The effect of neostigmine impressed me though Rimington tended to pour scorn on the t rea tment . The appearance of m y pat ient resembled the appearance in Gilhespy's article and she responded in the same sort of way to t r e a t m e n t wi th neostigmine. I have no t tried ACTI-[. I was doubtful of its value, bu t it would appear in Dr. Counihan 's case he got an improvement after ACTI~. I am grateful to Dr. Barniville for the additional information he has given to us, and also to his colleague who described his ease in Liverpool wi th ascending paralysis, which has been noted by most of the authors . The cause of dea th is often bulbar paralysis.

Wi th regard to Dr. O 'Dwyer ' s question about the urine being always abnormal , R iming ton points out tha t the urine is not always abnormal . At t imes there m a y be a grossly abnormal a m o u n t of porphyr in in the faeces. I-~e describes a case of shun t f rom faeces to urine in acute a t tacks and back again in remission. Wi th regard to m y own pat ient , every t ime I examined the urine it has always been somewhat dis- coloured. Even if it is a pale pink it is noticeably pink. I have nothing fur ther to add.

Dr, COUNIHA~ : I t is interesting to note t ha t there are at least three eases of porphyr ia in Ireland. There was a case in hospital who died of an ascending type of paralysis, and after the pat ient died a s tudent said tha t the pat ient had a peculiar red urine. There are therefore about five cases and five families to be investigated. Certainly investigation is extremely difficult. I )r . Mulcahy asked about the examinat ion of porphyrins . We have done it in U.C.D., bu t they did no t go as far as differentiating tho type of coproporphyrin. The urine was extracted, treated, examined wi th a spectroscope which shows a characteristic absorpt ion band and a figure given for copropo1-ph)Tins which was extremely high. I feel t ha t a case should be made for somebody going into the mat te r , going to the locality in which the people live and tracing it in greater detail. Deane 's description of his investigation is certainly remarkable. He went into 12 families in S. Africa and quoted one in the B . M . J . who had 468 descendants. His investigations carried him as far afield as Cardiff. He wrote to the Mayor of Cardiff t ry ing to trace some of them. The am oun t of work covered in his series mus t have been phenomenal . He traced ur inary specimens and he regarded even a minor trace of porphyr in sufficient to make a diagnosis of porphyria .

OBSERVATIONS ON ANAESTHESIA FOR THORAOIO SURGERY *

By ARTHUR MOORE, M.B., D.A. ]Vest Regional Chest Hospital, Galway.

F OR a long period af te r the surgeon had learned how to deal with the main problems of abdominal surgery, and had rendered major procedures in the abdominal cavity a relatively safe undertaking,

his intervention within the thoracic cage remained a distinctly risky proceeding.

This was mainly due to the absence at that time of a satisfactory answer to the hazards of an open pneumothorax, and it may be no harm at this stage to recount these hazards.

When one side of the chest is opened the lung on that side collapses. The mediastinum, unless fixed by adhesions, is drawn over to the other

* Communicat ion to the Section of Anaesthetics, November 2nd, 1955.

ANAESTHESIA FOR THORACIC SURGERY 177

side, thereby reducing the volume of the other lung. During inspiration, air is drawn from the collapsed lung into the lung on the sound side. During expiration the condition tends to reverse, with the sound lung expelling part of its contents into the collapsed lung. Thus the patient tends to respire back and forth from one lung to the other---the state known as " paradoxical respiration " If the mediastinum is free, it moves back and forth with the respiratory efforts and causes intermittent kinking of the venae cavae. This kinking results in hypotension and ~aehycardia. It will be readily seen that these effects of an open pneu- mothorax, if not checked, can lead to the death of the patient in a short time.

In addition to the hazards of an open pneumothorax, intrathoracic operations may present a variety of other problems arising from the underlying pathology. The patient may have been suffering from tuberculosis, bronchiectasis or empyema, diseases which adversely affect his vitality and resistance. He may be in the early stages of malignant cachexia, or he may have experienced episodes of congestive cardiac ]~ailure from heart disease.

Such a patient is badly able to withstand the trauma and blood-loss that a thoracotomy entails. The risks are further increased by the presence of pus or mucus in the air-passages.

In cases of oesophageal obstruction, retained material may be regurgi- tated into the pharynx during induction of anaesthesia, and may be inspired in to the larynx.

Numerous workers sought the answer to these problems during the early years of this century. Sauerbruch was one of the best known of these. He placed his patients in an air-tight chamber in which the pressure had been reduced to 7 millimetres of mercury. The patient's head projected out through a hole in the chamber into the normal atmo- spheric pressure and he was anaesthetised in that position by means of ether and an open mask. Due, no doubt, to the fact that this was a cumbersome method, his low pressure chamber does not seem to have become very popular.

Another technique adapted to obtain the same end was the insuffiation technique, introduced by Elsberg. By this method a large flow of anaesthetic gases was insufilated at a pressure of 20 ram. of mercury through a small-bore catheter, the tip of which reached to within a few centimeters of the carina. Great claims were made for this form of anaesthesia before and during the first World War, but eventually its drawbacks (bad respiratory exchange) were generally admitted and it fell into complete disuse by the middle twenties.

Its eclipse was, no doubt, hastened by the development of the to-and-fro inhalational technique, through a wide bore tube, by Magill and Rowbotham.

A great advance was made by Guedel when he introduced his technique of controlled respiration in the early thirties. This blazed the trail for all the later advances made in anaesthesia for intrathoracic surgery. He caused apnoea by first hyperventilating the patient through a Waters' cannister, and so reducing the alveolar carbon dioxide tension. As the alveolar tension of carbon dioxide is lowered, so also is its tension in lhe blood reduced, until eventually it is insufficient to stimulate the

~78 I R I S H JOURNAL OF MEDICAL SCIENCE

respira tory centre. My experience with this form of anaesthesia led me to believe that other factors besides reduced carbon dioxide tension were responsible for the product ion of apnoea. I believe that the main cause of the apnoea is the stimulation of the Hering-Brewer reflex by the distension of the lungs. This technique was developed by Nosworthy for intrathoracic surgery. He used cyclopropane as the anaesthetic agent. This anaesthetic great ly facil i tated the initiation of apnoea and it also permit ted the use of a high concentration of oxygen ; unfor tunate ly it was not at all easy to maintain control of the respiration and at the same time prevent overdosage with the anaesthetic agent, but the intro- duction of curare led to the solution of this difficulty.

Dur ing the past six years, over 400 intrathoracic operations have been per formed in the West Regional Chest Hospital. The anaesthetic used in the major i ty of these operations was pentothal with nitrous oxide, oxygen and a muscle relaxant. The technique is based on that described by Gray and Hal ton in 1946 and is as follows :

Premedicat ion for the average, adult is by omnopon (gr. 1/3) and a t ropine (gr. 1/100), given at least 45 minutes before operation. An intravenous drip is set up in any convenient forearm vein, using a Guest r Interposed between the cannula and the drip tubing is a three- way stop-cock. The drip is connected to one arm of the stop-cock and the other is free for giving injections. Anaesthesia is induced with Pentothal in 5 per cent. solution, the average induction dose being 500 mgms. In the case of patients whose condition warrants it, the induction (lose may be considerably reduced and given very slowly. As soon as the Pentothal is given the muscle relaxant is injected. In our early cases the dose of relaxant was calculated according to the weight of the patient, but increasing experience showed that this method of calculation was seldom successful in providing adequate relaxation. On that account, the initial dose was fixed at 120 mgrms, of Gallamine or 20 mgrms. of curare for the average adult patient.

The lungs are then inflated with the anaesthetic mixture of gases unti l muscular relaxation supervenes. The mixture used is equal parts of oxygen and nitrous oxide. A cuffed endotracheal tube is passed through the mouth into the trachea, as soon as relaxation is adequate, and is con- nected to a Waters ' canister. Then the patient is fixed in position on the table and prepared for the incision. In order to reduce haemorrhage the line of incision is infil trated with a 1/200,000 solution of adrenaline in normal saline, by the surgeon ; but if it is considered that the adrena- line might adversely affect a cardiac case this step is omitted.

In the earlier cases our usual procedure was to continue with ful ly controlled respirat ion unti l the effect of the muscle relaxant bad begun to wear off. Then, instead of giving more muscle relaxant the patient was carried on as long as possible with assisted respiration. Fu r the r small doses of Pentothal were given, if the slightest limb movements were noticed. The major i ty of these early cases, however, gave con- siderable trouble, due to the onset of shock. The train of events observed was as follows : shortly a f te r the induction of anaesthesia the blood- pressure began to rise, both systolic and diastolic. I t continued to rise slowly for sometimes as tong as one hour, but then fell to an unrecord- ,qble level in a very short time. The rising blood-pressure brought

A N A E S T H E S I A F O R T H O R A C I C SURGERY 179

carbon dioxide retent ion to mind, but, as the pat ient ' s colour appeared to be quite good, it was assumed that the pu lmonary ventilation was adequate. So, instead of a t t empt ing to increase the ventilation, the shock was t reated symptomatical ly. The head of the table was lowered ; the t ransfusion rate was increased and a pressor drug (usually methe- drine) administered.

The results of this procedure could hardly be called satisfactory. The operat ion had to be completed with undue haste. The pat ient was re- tu rned to the recovery room without a palpable pulse or recordable blood-pressure, and with a marked tracheal tug. This t racheal tug denoted the paralysis of all resp i ra tory muscles except the diaphragm, and the pa t ien t ' s life was in j eopardy for a considerable t ime a f te r operation.

I n an effort to remedy this state of affairs the use of Pentothal was abandoned, and a re turn made to ether. By the t ime that sixteen pat ients had been operated on, it was obvious tha t this change did not br ing about the desired improvement , and, as it had some drawbacks of its own, a re turn was made to the original method. Some changes were made however; it was decided that the use of curare would be dropped and Gallamine used for all operations, because we thought that histamine, released by curare, might have been a factor in the product ion of the shock. We also decided that the pu lmonary ventilation should be in- creased. To enable this to be done, the idea of assisted respirat ion was abandoned and the respirat ion was ful ly controlled throughout the operation.

The results, as reflected in the condition of the patients, were excellent, The blood~pressure remained much more stable throughout the opera- tion and the general condition at the close of operat ion was immeasure- ably better.

Wi th the insti tution of completely controlled respirat ion throughout the operation, it became impossible to know when fu r the r doses of Pentothal were required. Previous experience showed that a rise in the blood-pressure was not a helpful guide. Nei ther was a rise in the pulse rate, because this had a l ready risen due to the effect of the Gallamine. The number of in termi t tent doses of Pentothal was gradual ly reduced unt i l a t ime was reached when none was given af ter the induction dose. I t was obvious that this had no deleterious effects on the patients. On the contrary, the recovery period was much shorter, so much so that several pat ients were able to answer questions by the time the dressings had been applied. Dur ing the last four years, the total dose of Pentothal given to any pat ient has never exceeded 500 mgrms., and in the case of the average adult it has varied between 300 and 500 mgrms. Large quantit ies of muscle relaxant were required, the dose vary ing between 160 and 560 mgrms.

In six cases selected at random, the nitrous oxide-oxygen sequence was supplemented by intravenous pethidine. I was not satisfied that any worth-while improvement was discernable in the postoperative con- dition of the pa t i en t ; so the pethidine was discontinued. I believe that where muscle re laxants are required, and used, it is only necessary to have the pat ients unconscious.

Here I should like to refer to the amount of pressure used in inflating

180 I R I S H J O U R N A L OF M E D I C A L S C I E N C E

the lung in order to obtain an adequate exchange of gases. Many authori t ies have stated that it is dangerous to exceed a positive pressure of 10 mm. Hg. My experience has been that though this pressure may be adequate while the pat ient is lying on his back, it is inadequate when he is lying either on his side or face down. I have found that the average pressure needed to ensure adequate ventilation during opera- t ion was 15 mm. Hg. and to expand the remaining par t of the lung fully, at the close of operation, pressures of the order of 25 to 30 mm. Hg. have been required.

We have had no evidence to show tha t these pressures caused any t r auma to the alveolar wall. Af te r two lobectomies gross surgical emphysema appeared, but in both cases it was due to the p remature removal of the tube leading to the under -wate r seal and in both cases it d isappeared af ter the tube was re-inserted. Though intermit tent posi- t ive pressure causes small f luctuations in the blood pressure, these fluctua- tions do not appea r to affect the pa t ien t adversely.

I n an analysis of the anaesthetic char ts of 50 consecutive pat ients it was found that the pulse ra te was invar iab ly increased af ter the admini- s t ra t ion of Gallamine. The rate var ied between 100 and 120 per minute, where the preoperat ive rate was 70 to 80 per minute. This side-effect is a theoretical objection to its use in cardiac patients. In the West Regional Chest Hospi ta l it was used in 52 hear t operations. Five of these pat ients died, but, there was no reason to implicate this side-effect in any of these fatalities. We found tha t prost igmine given at the close of the operat ions reduced the pulse rate to more normal levels, in the major i ty of cases. We also found tha t the Gallamine caused a pro- fuse secretion f rom the mucous glands in the mouth, but those in the bronchi were not affected. This action was potent ia ted by prostigmine, and efforts to diminish it with a t ropine failed.

The problem of the secretions due to lung disease was tackled f rom different angles. The first 70 lung resections were per formed with the pa t ien t in the face-down position and with a 10 degree head-down tilt on the table. Wi th the pa t ien t in this position excellent control was mainta ined over all secretions. Then, a f te r the arr ival of a different surgeon, the lateral position was adopted. This position no doubt per- mits an easier surgical approach, but it makes the control of secretions much more difficult. I used a Thomson bronchus-blocker for " wet " cases, but I feel it is not the answer, for (a) it may become displaced dur ing operation, (b) it may become deflated, (c) it necessitates the use of a smaller endotracheal tube and (d) it is difficult to get an air t ight fit when it is in position.

On one occasion, the cuff became detached f rom the tube of the bronchus-blocker as it was being withdrawn. I t lodged in the bronchus of the remaining lung and a " crash " bronchoscopy was necessary to save the patient.

I have not used Car l in ' s tube because I feel that the lumina are not large enough. I believe tha t the face-down position is the simplest and safest way of controll ing the secretions in the " w e t " case. Of course it should not be forgot ten tha t no effort should be spared to have the pat ient as d ry as possible before operation. When full use is made of ])hysiothcrapy and antibiotic drugs, the " wet " case is a rar i ty. When

A N A E S T H E S I A FOR THORACIC SURGERY 181

in spite of these measures it was felt that there might be residual pus dammed up behind stenosed bronchi, bronchoscopy was performed immediately af ter the induction of anaesthesia, in order to at tempt to empty them. In the cases where serious spill-over occurred, the first thing noticed was a sudden increase in the resistance to inflation. There was no warning " bubbling " sound during inflation. Expirat ion was prolonged and was accompanied by rhonchi. The whole picture wa~s that of bronchial spasm.

Intra thoracic surgery is almost always accompanied by a heavy blood loss, especially when the operation is being performed on the lung. Measures such as infiltrating the line of incision with adrenaline solu- lion and really adequate use of the diathermy do much to reduce the loss, but the main combative measure is full replacement therapy. A resection of lung tissue would not be at tempted unless at least three pints of blood were immediately available. Still more blood is required to replace that lost by the general ooze into the thoracic cavity af ter opera- tion. The three-way stop-cock proved valuable for pumping blood in rapidly when sudden heavy haemorrhage occurred. This happened on three occasions when the l igature slipped off the stump of the main pulmonary artery. I t also helped when the drip rate was slowed by venospasm. I have not found any drug that will relieve vcnospasm, but have observed that it invariably passes off before the patient 's condition has deteriorated so much that rapid infusion was essential. Hypotensive drugs were not used at any time to lessen haemorrhage, because we con- sider the blood-pressure a very important index of the adequacy of the ventilation, which should not be lowered artificially. The average amount of blood used during the lung resections was 4 pints. Consider- ably less blood was used during operations on the heart : one pint was the average, with two fu r the r pints kept ready in case of a torrential haemorrhage.

On completion of the operation, it is vitally necessary to clear tile mucous secretion from the mouth before the endotraeheal tube has been removed, and a careful watch is necessary for the first twenty minutes af ter operation to make sure that any secretion that recurs is removed. Neglect to take this care on two occasions nearly led to the death of the patients concerned.

Postoperatively, oxygen is administered as a routine to all patients for at least 6 hours. The pulse-rate and blood-pressure-are recorded every 15 minutes by the nurse in charge of the patient, and any change reported immediately to the medical staff. As any major physiological insult (e.g., respira tory embarrassment by bronchial secretions, blockage of an underwater seal, or haemorrhage) is likely to manifest itself through changes in blood-pressure and /o r pulse rate this record will ensure its notice at an early stage, and timely correction.

By far the commonest postoperative complication was the onset of atelectasis. Preventive measures in the form of deep breathing and coughing went a long way to reduce its incidence. I f allowed to persist, the resultant anoxia led to the onset of shock, so, if the breath- ing exercises and coughing failed to clear the chest, brochoscopy was performed without delay. Children gave the greatest trouble in this respect, because they seldom co-operated. Stress is seldom laid on the

]82 I R I S H JOURNAL OF MEDICAL SCIENCE

need for having specially t ra ined nursing staff available, but it is most important that the nurses in charge of the recovery wards should be experts.

Opera t ion

Pneumonec- t omy .

L o b e c t o m y

S e g m e n t a l Resec t ion .

Tuberculos is No.

102

141

43

Bronchieetasis No.

Carc inoma No.

Adenoma No.

T o t a l No.

11

D e a t h s No.

13

3

4

Deco r t i c a t i on 11 - - - - - -

C A R D I A C O P E R A T I O N S

P a t e n t Mi t ra l P u l m o n a r y Per icardiec - Bla lock D u c t u s V a l v u l o t o m y V a l v u l o t o m y t o m y

29 16 4 2 2 2 d e a t h s 1 d e a t h 2 dea th s

O E S O P I - t A G E A L O P E R A T I O N S

Carc inoma I t e l l e r ' s Opera t ion H i a t a l t t e r n i a

7 2 5 2 d e a t h s

24

Mortality. Of the 146 lobectomies, three died. Two were due to spread of the

disease and the th i rd death occurred suddenly within an hour of the end of the operation. We believe that a spill-over during operation was the major factor responsible. Of 13 deaths af ter the 113 pneumo- nectomies, two were caused by spill-over, three from progressive lardaceous disease, five f rom sepsis, due to bronchial fistula, and spread of disease, and three died af ter discharge. Fo u r deaths occurred among the 50 segmental resections; two of these deaths were due to intractable haemorrhage-- the patients were " bleeders ", one was due to spread of the disease (tuberculosis), and one was due to asphyxia, caused by a cast of the trachea becoming impacted across the carina. Six patients presented this complication.

A pathological report was obtained oi1 three of the casts, which re- vealed that they were composed of a fibrinous exudate with enmeshed red blood cells. No specific organisms were found in any of the casts. An interesting feature concerning the occurrence of this complication, is that of our first 300 patients only one developed it. Then five de- veloped it in the following hundred.

Of the 52 cardiac patients 5 died (two mitral, and two Blalocks and one pulmonary valvulotomy. One mitral patient died from acute

ANAESTHESIA FOR THORACIC SURGERY 183

cardiac failure 6 hours after operation; the other died on the following day, also from cardiac failure. Both Blalocks died, presenting signs of cerebral damage, several hours after operation. The patient undergoing pulmonary valvulotomy died from ventricular fibrillation as the heart was being incised.

Discussion,

Dr. S. P. O 'TooLE: I have been very interested in the shock which Dr. Moore experienced in some pat ients in the earlier days. We have had the same trouble, and though t it was due to using too large a dose of pcntothal and a much smaller dose of curare t han is being given now. We found tha t a long extension on the water canister was the best way of telling anoxia. A small point found helpful was to use a large dose of thiopental and scoline and to in tubate wi th the largest tube possible, using a lubricant. W'e had one or two deaths from a cuff burst ing. We have had no trouble wi th secretions. Most pat ients come for operat ion far fitter now, due to the care they get and the drugs ; they do not present so much danger, bu t some pneumoper i toncum cases do cause trouble. We found tha t taking air off the abdomen did improve them. As regards secretions, we had one case which spilled over during operat ion and the pat ient died. We Mways do right-sided cases face downwards. We had some cases of casts in the t rachea and they caused a great deal of trouble.

Dr. J. D. G A ~ F ~ u : I agree with Dr. Moore tha t the I~ering-Breucr reflex plays a large par t in producing apnoca during controlled respiration. Combining a muscle re laxant and a volatile narcotic calls for close scrut iny to prevent over-dosage of the latter. Since pente tha l is not an analgesic, it seems prudent to use a drug such as pethidine during a pentothal .gas-oxygen sequence, The colour of the pat ient is a guide only to the degree of oxygenation of his blood. Tracheal tug, which is taken as a sigl~ of anoxia, may in post-operat ive cases be indirectly caused by carbon dioxide accumulat ion producing respira tory depression.

Dur ing controlled respirat ion the pressure exerted on the re-breathing bag should, strictly speaking, bear some relationship to the pat ient ' s tidal air, bu t nevertheless it is always necessary during intra-thoracic operations to use high pressure f rom t ime to time, in order to overcome areas of atelectasis, define segments and prevent aspiration of blood, etc, I n practice, apar t f rom the remote risk of mediastinal emphysema no h a r m seems to come of this so long as secretions are removed f rom the air passages and the pressure is not mainta ined for long. The presence of an endotracheal tube during light anaesthesia causes profuse salivation. Atropine preceding prost igmin reduces it.

The face-down posit ion is mos t satisfactory f rom the anaesthetic point of view in " wet " cases, l.mt it can prolong the operat ing t ime by hamper ing the surgeon in certain cases where dissection is rendered d i~eu l t by the limited exposure. Blood transfusion into the a rm can be awkward in this position,

Venospasm can be overcome by introducing into the affected vein such drugs as pcthidine, atropine and coramine. The use of hypotensive drugs would seem to be dangerous during operat ions where very large blood vessels might be damaged wi th consequent brisk haemorrhage.

I f cases are likely to be haemorrhagic two blood drips (one in the a rm and one in the leg) are most useful.

Weighing swabs before and after use and measur ing the amoun t of blood in the suction bott le is a rough guide to blood loss. Suction should be used as a routine ra ther than when indicated as secretions can collect wi thout giving audible warning. I have found the Carlens tube quite wide enough for adequate aspiration.

There is always some carbon dioxide retention during intra-thoracic operations. no ma t t e r how efficient the absorber. Dur ing bronchograms on children diffusion respiration can be made use of while the pictures are being taken.

W h a t are Dr. Moore's views on prolonged postoperat ive adminis t ra t ion of oxygen ?

Dr. BLAYNEY : This is a very wide subject and everyone seems to fall into a set rout ine for these cases., I agree wi th Dr. Moore on the importance of the preparat ion of the pat ient and tha t operation should not be advised unti l the pat ient is in the best possible condition. For premeditat ion, we use Largactil 25 rag,, wi th Nembuta l gr l~ the night before operation. We give the pat ient another 25 rag. tab. of Largaetil with a glucose drink three hours before operat ion and omnopon-scopolamine, one hour before operation. We use Largactil because it is said to prevent swea~ing during the operation, because it is supposed to diminish the central emetic effects of the opiates, and to potent ia te the action of the anaesthetic drugs. We tried Largactil intravenously

184 IRISH JOURNAL OF MEDICAL SCIENCE

on a few occasions, bu t found tha t these pat ients took literally hours to awaken f rom their anaesthetic. The type of induction m u s t depend on wha t assistance is available ; often one has to work single-handed. I always s ta r t wi th thiopentone and if this is followed by succinyl-choline, spray the cords wi th 4% Xylocaine prior to passing a large cuffed tube. I f I use curare for intubat ion, I inject a relatively large dose, mixed wi th pethidine, and give these before the thiopentone. I n all cases I follow on wi th gas .oxygen and pethidine. I have never tried h iberna t ion; it would be impossible to t ry drugs for hypotens ion wi thou t the assistance of a second anaesthetist . I a lways p u t up a drip wi th a p int of blood on one side and a litre of saline on the other, and always make sure t ha t I have a good needle in a good vein. I t is impor tan t to give the pa t ien t more blood than is lost to offset shock. At the end of the operation the pat ients go back to the recovery ward on a slow blood drip which is followed by 5% dextrose in water . I prefer curare to Flaxedi l ; by rhythmical ventilation I can control the pat ient on a very small dose of curare. As a routine at the end of the opera- t ion when the pa t ien t goes back to the ward the foot of the bed is raised, and the patient, is given oxygen and the blood pressure taken. I always give a small dose of methedrine befbre they leave the theatre. When Dr. Moore was dealing with mixed cases how did he ster-lise the appara tus ? How does Dr. Moore bronchoscope ~he pat ients at the end of the operat ion ? Does he give them a fur ther relaxant for this ? H o w does he deal wi th the difficulty of gett ing up a collapsed lobe at the end of operate;on ?

Dr. NAGLE : I t is very impor t an t t ha t anaesthet is ts outside Dublin, like Dr. Moore, should come to the Academy and tell of their experiences. I hope tha t it might be possible for some of the Dubl in anaesthet is ts to go to centres in the country for this purpose. I have had no experience of casts of the trachea. W h a t method does Dr. Moore u~e for sterilising endotracheal tubes ? Are they boiled, are chemicals used and how does he lubricate them ? Dr. Gaffney has said t ha t often pat ients re turn to the ward wi th very low or depressed respiration. I wonder why this should be so and who is in charge of the pat ient at this stage. The 30 minutes after leaving the theatre are often the most dangerous to the pa t ien t ' s well-being, even to his life. At one t ime it was common practice to collapse a pa t ien t ' s lung and make him used to breathing on one lung before thoracotomy. I s this ever done nowadays .9

Dr. LY~',qAM : Wi th regard to galamine as a relaxant , I am confident it is out of place to use a re laxant which would cause tarchycardia and I have found curare better. H a s Dr. Moore invest igated pos topera t ive shock ? Many of the cases are suffering f rom a loss of po tass ium or an overdose of carbon dioxide. H o w does he expand the lung in a case of excision of a s tenosed bronchus .9 I have found eyelopropane very sat isfactory for a speedy awakening after operation.

Dr. DAVYS : I t seems to me t h a t the pressure Dr. Moore used for expanding the lung was too high. I have found it quite easy to get the lung up at the end of the case if I insist on in te rmi t ten t ly br inging it up dur ing the operation, and insist on the surgeon allowing me always to do this. I have found procaine and coramine very helpful for the relief of venous spasm. A Mart in 's p u m p is mos t effective, bu t very b u m p y in use ; to p u t a little paraffin on the rollers makes it work quite smoothly. Pethidine makes a case much smoother and there is very little risk of the pat ient waking up during the operation. All chest cases should be very carefully pu t back to bed. ] never bronchoscope a pa t ien t at the end of operation.

Dr. D. Do~ovA-w : Wi th regard to the two pat ients who died f romhaemorrhage , could they have had afibrinogenacmia.9 The embar ras smen t in a pat ient with apne umo- per i toneum is due to the different diffusion of grades of gases.

Dr. MOOl~E : I agree wi th Dr. O'Toole t ha t the a m o u n t of pentothal used some years ago was excessive, bu t t ha t was no t the main cause of the high incidence of shock in our early cases. Pat ients coming to operat ion nowadays are much fitter than formerly and this was a mos t impor tan t factor in the reduction of the incidence of shock. The workers who use pethidine dur ing anaesthesia use as much pentothal during the induction as I myself use altogether, so I feel t ha t its use was superfluous. I f a segment of lung could not be expanded a t the end of operation, it should be removed. For non- tuberculous cases I use separate equipment . We seldom see cases of shock nowadays b u t the major i ty of cases of shock are due to inadequate ventilation or anoxia. The eolour of the pat ient is no guide to the adequacy of the ventilation. Our cases are not bronehoscoped post-operat ively nowadays unless there is a definite indication I do not give fur ther anaesthetic even if the pa t ien t appears to be wide awake. I have had no trouble from casts in the t rachea in the face-down position. All were in pa t ients in the lateral position. I used to pa in t the chords, b u t found this unnecessary when giving a large dose of muscle relaxant . The cases of hacmorrhage happened before there was widespread knowledge of afibrinogenaemia.