Special Aspects of Anaesthesia in Terminal States

There exists a number of diseases and traumatic lesions that can only be treated effectively by surgical intervention. When they lead to the development of a terminal state, or threaten to do so, early surgical intervention can be considered a most reliable pro­phylactic and therapeutic measure. 

A main cause making early operations possible on patients in an extremely grave condition and terminal state was the adoption of modern multiple-component anaesthesiologic and reanimation facilities with obligatory artificial ventilation of the lungs. Arti­ficial ventilation is especially important since there is always hypoxia (of various forms) in terminal states. The use of low concentrations and doses of anaesthetics in order to obtain super­ficial general anaesthesia is also obligatory.

In this connection it is becoming obvious that single component mask anaesthesia is inapplicable in practice with such patients. The need not only to anaesthetize (i.e. to protect against patho­logical pain impulses from the area of the operation) but also mainly to regulate and maintain the organism’s vital functions during and after operation make it undesirable (and sometimes impossible) to use such a simple and practically harmless method of anaesthesia as local anaesthesia.

It must be remembered, however, that this situation has not by any means eliminated local anaesthesia from the complex of mea­sures to combat terminal states. The injection of procaine into the region of a fracture or the application of circumferential and con­duction anaesthesia on the spot in patients with severe multiple injury or during transportation of the victim, in order to block the arrival of pathological pain impulses, is an effective therapeutic measure, as well as one preventing further deterioration of the patient’s condition. Local anaesthesia in the form of block of reflexogenic zones also retains its value during surgical intervention of the category of patients under consideration, who are under superficial endotracheal narcosis and artificial ventilation.

We consider very promising the method of local anaesthesia in com­bination with neuroleptanalgesia using either large doses of dehydrobenzoperidol or small doses of Phentanil, which does not depress respiration, or dehydrobenzoperidol alone. Superficial nar­cosis and artificial ventilation have the advantage in that they depress the regulatory sectors of the brain only slightly so that the function of self-regulation so necessary to the organism does not suffer much and the compensatory mechanisms are not im­paired. But deep narcosis with any anaesthetic is quite out of the question for the extremely serious category of patients.

Damir and Axelrod recommend, when choosing and em­ploying the means of anaesthesia for patients in terminal states, so as to reduce operational risk to the minimum: (1) to consider how far a given method of anaesthesia is safe for a patient in such a serious condition; (2) how far it aids his withdrawal from that condition; and (3) how far it protects the organism from the trauma caused by surgical intervention.

The most responsible and complex stages for the anaesthetist, in anaesthetizing this type of patient, of course, are the initial and final ones.

In spite of the large number of papers reporting the depressive effect of barbiturates on the organism’s vegetative functions, these compounds are still those most widely used for producing initial narcosis. Dyachenko, and many others do not consider them to be contraindicated in principle in the extremely serious category of pa­tients but call for a certain caution in using them. Even in the most gravely affected patients, slow introduction of weak solutions of hexenal or sodium thiopenthal does not significantly affect haemodynamics. The use of Epontol, Talamonal-Epontol mixture, Epontol-calcium mixture, sodium oxybutyrate, and the inhalatory anaesthetics — nitric oxide, Fluothane, cyclopropane, Schein-Aschmen mixture, mixtures of helium and cyclopropane — for induction of anaesthesia cannot be exclu­ded. Unconsciousness can be induced in most patients in extremely grave condition, especially in those with long arterial hypotension before operation, by means of nitric oxide and oxygen in a con­centration of 2:1 or 3:1 and so avoid stimulation, and in such cases it should be considered one of the best variants of induction.

The main anaesthetic for maintaining anaesthesia throughout an operation must be chosen keeping in mind how far it has an unfavourable influence through possible aggravation of tissue oxygen starvation. At present most authors consider that modern inhalatory and non-inhalatory anaesthetics worsen gas exchange to some extent. Thus, according to Mitryakov, hypoxia was observed in 234 patients out of 3674 operated under endotracheal narcosis. Many cases of hypoxic hypoxia have been described in the early postoperative period as well.

It must be taken into account that a grave condition in patients increases their tolerance to anaesthetics. Moreover, the risk to patients of this category involved in employing powerful volatile anaesthetics like ether or Fluothane is increased by insufficient dosage when using most common apparatus of the present time.

The anaesthetic most widely used for patients ‘on the border­line’ at present is nitric oxide or its combination with supplemen­tary traces of ether. We must emphasize once more that the point is not what anaesthetic to use but to reduce the dose to the mini­mum with simultaneous introduction of large amounts of oxygen into the organism.

Muscular relaxation achieved by injecting myorelaxants helps reduce the dose of anaesthetic needed, and lowers oxygen con­sumption by muscular tissue, now inactivated, thus ‘liberating’ it for use in other vital tissues. In extremely grave cases relaxants of the depolarizing type are naturally to be preferred in view of the great possibilities of controlling the degree and duration of curarization.

New non-inhalatory compounds for inducing anaesthesia have been adopted of late, namely, Viadril, haemithiamine, and sodium oxybutyrate. Their distinguishing feature is their similarity to na­tural metabolites. It has been shown both experimentally and clinically that sodium oxybutyrate enhances the organism’s resistance somewhat to severe oxygen starvation, improving its course by lowering oxygen consumption through eliminating muscular tremor and altering the processes of tissue respiration.

A method that seems very hopeful in extremely grave cases is neuroleptanalgesia by means of a combination of powerful anal­gesics and neuroleptics. The positive properties of these substances like negligible toxicity, good controllability, marked stabilization of haemodynamics during operation, elimination of peripheral spasm while preserving adequate vascular tone, and reduction of oxygen consumption, rapid recovery of consciousness and absence of unpleasant sensations, long persistence of postoperative anal­gesia without administration of any additional compounds, and the existence of reliable antidotes, naturally lead one to think that they can usefully be employed with patients in grave condi­tion.

Many of these favourable properties govern the so-called an­ti-shock effect of neuroleptanalgesia, cited in many publications, both in the United Kingdom and other countries, but it should not be forgotten that these compounds are not free of drawbacks. Along with very positive reports in our country on the possibilities of employing neuroleptanalgesia in patients in terminal states, there­fore, a call for extreme caution in such use was made at the I Con­gress of Anaesthesiologists and Reanimatologists. The subsequent experience of many anaesthesiologists here and abroad has confirmed the justice of this cautious approach. It is sometimes even recommended to reject the classical means of administering neuroleptanalgesia and to resort to its different variants, in particular of using it for in­duction of anaesthesia employing a thalamonal-epontol mixture.

There is no doubt that the choice of anaesthesia and induction of narcosis greatly depend on the causes of the terminal state, the duration of dying, or the character of the surgical intervention required.

Since the main indications for surgical intervention in most cases is continuing haemorrhage, special attention is paid to this point in the Mobile Reanimation Centre.

Analysis of the Centre’s work over four and a half years gave grounds for thinking that the induction of narcosis in patients with short periods of hypotension or unaffected by it does not differ much from normal cases, and does not lead to complications if a number of technical precautions are observed. In cases of prolonged hypotension or uncompensated bleeding the progressive impairment of peripheral and systemic circulation and the increase of metabolic acidosis sharply alter the organism’s reaction to the pharmacological agents and the anaesthetist’s ma­nipulations. The active period of depolarizing relaxants, for example, is increased five to sevenfold, tracheal intubation reduces arterial pressure rather than raises it, the abrupt transition from spontaneous to controlled ventilation with a completely new re­gime causes deterioration of haemodynamics, while artificial ven­tilation without active exhalation diminishes venous reflux of blood and the level of systolic arterial pressure, and reduces tole­rance to anaesthetics.

Narcosis is easily induced in patients of this group by a mixture of nitrous oxide and oxygen in a 6:3 ratio with sodium oxybuty­rate. In the preparations for operation a gastric tube is not used. Selik’s method properly applied avoids regurgitation. The operation is carried out under nitrous oxide-oxygen or Fluothane anaesthesia with depolarizing relaxants. Use of Viadril is permissible.

It goes without saying that blood, protein preparations, electro­lytes, and dextrans must be transfused continuously during the operation. At the end sodium bicarbonate is administered and, if coagulatory capacity of the blood is low, fibrinogen and epsilon-aminocaproic acid. For uterine amputation or extirpation, the ope­ration is carried out in three stages: (1) laparotomy; temporary haemostasis — application of clamps to the main uterine vessels without drawing it out into the wound; (2) 100 per cent replace­ment of lost blood with staunching of haemorrhage; correction of acidosis; a procaine block of the reflexogenic zones of the true pelvis; treatment of afibrinogenaemia and fibrinolysis; (3) traction and removal of uterus.

It has been established that the course of anaesthesia is com­plicated by toxaemia of pregnancy and severe forms of nephropathia and eclampsia. A spasmodic type of peripheral circulation is then observed, the permeability of the vascular walls is in­creased, and hypoproteinaemia, hypovolaemia, and anaemia de­velop. Hepato-renal and suprarenal insufficiency is often ob­served.

In patients with eclampsia, the least, however inoffensive, mani­pulation can provoke a spasmic attack. In order to avoid that complication anaesthesia should be begun by inhalation of Fluo-thane, which is known not to stimulate noticeably, and has a gan­glionic action. Subsequently, venepuncture, premedication, and intubation are all done on a background of narcosis. During the operation the anaesthesia should be nitrous oxide-oxygen or Viadril.

After operation, the anaesthetist must decide a very important point: was the disturbance of vital functions adequately corrected during the operation and narcosis, and can the patient’s sponta­neous respiration at the given moment ensure the introduction of sufficient oxygen into the organism for subsequent adequate supply to the tissues? Extubation can only be carried out when that question can be answered in the affirmative. Premature ex­tubation can lead to the deve­lopment of hypoxia and all that that involves.

The following extract from a case history can serve as an example of the results of premature extubation.

Finally, the possibilities of employing electric narcosis as a me­thod of general anaesthesia, at present still only in its first stages of application in experimental and clinical reanimatology, present interest.

In that connection it must be emphasized that narcosis by in­terference currents stimulates the amygdaloid complex, has a mo­dulatory effect on the hypothalamus-hypophysis-adrenal cortex system in conditions of severe hypoxia, and activates formation extremely sensitive to oxygen starvation, namely the hypocampus.

Research carried out in our Laboratory showed that electric narcosis lengthens the duration of the pre­agonal period and of agony during the dying of dogs from exsanguination, and also retards subsequent restoration of the life-sup­port systems compared with controls. At the same time electric anaesthesia promoted survival of approximately half the dogs that suffered ten minutes’ clinical death, and in which vital functions were restored by means of intra-arterial blood transfusion and artificial respiration. A favourable outcome was observed in ani­mals that had high content of free 17-oxycorticosterone in the blood plasma during development of the terminal state and in the early stages of the restorative period. That gives grounds for supposing that the formations of the central nervous system that regulate compensatory reactions, in particular those of the system hypophysis-adrenal cortex, are in a state of increased rea­diness during electric narcosis and ensure a level of these proces­ses adequate to the organism’s needs.

Electric anaesthesia by a current of 180-200 mA is induced by an impulse through two pairs of electrodes, located on the mastoid processes in the frontal-occipital position, as is employed in surgical practice. Of late in our Laboratory, electric narcosis has been successfully induced as a special form of anaes­thesia during electric impulse therapy of patients suffering from protracted attacks of paroxysmal tachycardia or paroxysmic fibril­lation of the auricles.