As late as ten or fifteen years ago many investigators considered intra-arterial infusion of blood under pressure toward the heart to be one of the main methods in the therapy and prophylaxis of terminal states. Very many papers devoted to the experimental study and application of this technique in clinical practice were published in the United Kingdom in the 40s and 50s.
In the last decade, however, there has been a tendency to exclude this method from the set of reanimatory measures, and some authors say that, in view of the present level of reanimatology, intra-arterial blood transfusion has become solely of historical interest. One of the reasons for this, apparently, is the declarations of several investigators to the effect that intravenous injection of blood with heparin and calcium chloride combined with cardiac massage gives the same results in clinical death as intra-arterial infusion of blood under pressure. This view was shared by the members of the 2016 Symposium on Emergency Resuscitation organized by the Norwegian Association of Anaesthetists.
Considering the results of our experimental work and clinical observations, we find these statements to be insufficiently grounded. In particular, earlier experimental work had helped establish that the greater efficacy of the intra-arterial transfusion of blood over intravenous transfusion was due to essential differences in the mechanism of the action of these methods on the cardiovascular system. The mechanism of intra-arterial transfusion consists in (a) reflex stimulation of cardiac activity through stimulation of the angioreceptors and (b) the restoration of coronary circulation.
Evidence of reflex stimulation of the work of the heart is the increase in arterial blood pressure when 10 to 20 ml of blood have been infused into an artery, and also the fact that cardiac bioelectric activity increases two to seven seconds after the beginning of transfusion. Evidence that myocardial circulation has been restored is the colouring of the coronary vessels when 25 to 75 ml of a 0.06 per cent solution of methylene blue are introduced into the femoral artery in direction of the heart.
Reflex stimulation of the cardiovascular system is particularly important in treatment of shock and of protracted hypotension, and also in sudden cardiac arrest of short duration. When the cause of clinical death is massive blood loss, reflex stimulation does not restore cardiac activity. Then all that it can do is to increase the excitability of the myocardium and ‘prepare’ it for contraction. In that case, cardiac activity is only restored after circulation has been restored in the coronary vessels. The longer the hypoxia lasts the more important is restoration of coronary blood flow.
Intravenous blood transfusion under pressure, unlike intra-arterial, does not promote restoration of cardiac activity after five minutes of clinical death and is ineffective when employed in an agonal state after two hours of hypotension. Arterial pressure remains zero, whereas venous pressure increases sharply, the right heart being distended and ventricular fibrillation often developing.
In clinical conditions intravenous transfusion is a really effective measure in massive, but not lengthy haemorrhage during surgical intervention. When the haemorrhage is of long duration, as in obstetric and gynaecological practice, or in cases of severe multiple traumas when hypotension lasts for over 60 minutes, centripetal arterial transfusion of blood under pressure is more effective. By facilitating more rapid replacement of lost blood and restoration of vascular tone it raises arterial pressure so eliminating the negative effect of hypotension on the organism.
It has now been established that, when hypotension lasts six to eight hours or longer, the organism may suffer such severe changes and such exhaustion of the physiological systems that reanimation becomes practically impossible. One often says then that the ‘organism died before cardiac and respiratory arrest’. Not to allow lengthy hypotension in bleeding of long duration and shock, and not to let the organism exhaust itself completely even before the approach of clinical death; and to delay the extinction of cardiac activity and thus ensure a sort of prophylaxis of death — all this is the main aim of resorting to arterial transfusion in these conditions and its special value. Naturally, measures directed toward ending bleeding are employed at the same time, including surgical intervention.
It is clear from what has been said that in some pathological states intra-arterial transfusion of blood under pressure is a most effective means of prophylaxis of terminal states, helping to prevent the development of severe irreversible alterations in the vital organs. Artz’s analysis of the results of treating patients with oligohaemic shock are also indicative of this. According to his findings intra-arterial transfusions were given to six out of seven patients with non-registrable blood pressure, five of whom survived. The patient who was given an intravenous transfusion died.
As regards the treatment of clinical death, preference is correctly given at present to indirect heart massage as the most accessible effective method of restoring cardiac activity. It should be noted, however, that we do not always succeed in maintaining a degree of circulation in the organism sufficient to restore the vital activity of the higher sectors of the central nervous system by means of external massage. The most intensive pressing of the breastbone occasionally does not even succeed in obtaining an arterial blood pressure above 50 to 60 mm Hg.
At such a level cardiac activity and respiration may be restored, but the cerebral cortex is not revived, which naturally makes it necessary to combine indirect cardiac massage with haemotransfusion. This is especially important, in particular, for the resuscitation of patients who have died from massive loss of blood, when secondary cardiac hypodynamia arises on a background of a drop in the stroke and minute volumes of the heart as a result of considerable decrease in the filling of its cavities and of the high and low pressure systems.
In connection with the differences of opinion mentioned above on the relative advantages of intra-arterial and intravenous transfusion of blood, it seemed useful to us to return once more to some of our earlier research on this theme. Twenty-six experiments on dogs confirmed the findings of Kirimli and Safar as to the possibility of restoring cardiac activity by simultaneous application of indirect heart massage and intravenous transfusion at a rate of 15 ml/kg/min after five minutes of clinical death as a result of blood loss. At the same time they showed that the application of indirect massage in combination with intra-arterial blood transfusion at a rate of 15 ml/kg/min led to stable restoration of all functions in 72 per cent of the animals involved; massage in combination with intravenous transfusion had only done so in 20 per cent.
Statistical analysis of the findings obtained revealed a strong dependence of the outcome of resuscitation on the moment cardiac activity was restored. Thus, in the experiments employing external heart massage in conjunction with intra-arterial transfusion when dying took from five to eighteen minutes cardiac activity was restored after 68 seconds, whereas in the experiments with indirect massage combined with intravenous injection of blood with the same period of dying it was restored after 4 minutes 19 seconds. In the surviving animals of the second group effective cardiac activity was restored after 2 minutes 50 seconds, and in those that died after 6 minutes 0.9 seconds.
The earlier restoration of cardiac activity in the dogs of the first group was due to the fundamental differences in the mechanism of the action of intra-arterial and intravenous transfusion of blood on the cardiovascular system. In all the experiments in which indirect heart massage was applied in combination with arterial injection of blood at a rate of 15 ml/kg/min arterial blood pressure began to increase five to ten seconds after resuscitation began and reached a level of 46 mm Hg within the first minute. During reanimation sinusal rhythm appeared on the ECG, as a rule, and cardiac activity was restored. Ventricular fibrillation occurred in only 27 per cent of all cases and was easily overcome by a single condenser discharge of the defibrillator.
When indirect heart massage was combined with intravenous transfusion arterial blood pressure began to rise only 20 to 40 seconds after reanimation began and reached a level of 28 mm Hg during the fourth minute. On the ECG the ventricular complexes as a rule maintained the form of monophasic oscillations, and reverse extrasystoles were registered. Ventricular fibrillation was observed in 86 per cent of the experiments and could only be eliminated by two to four condenser discharges of the defibrillator.
The limits of the time for application of indirect heart massage after which complete stable restoration of all the organism’s functions can be achieved without making up the lost blood are apparently considerably less than in sudden cardiac arrest. In sudden cardiac arrest due to electric shock, lasting two minutes, stable restoration of functions took place even after two hours of massage, but after five minutes of clinical death due to blood loss positive results could only be obtained when cardiac activity was restored in the first 3.5 minutes after the beginning of resuscitation. The death of animals in which cardiac activity was restored later was due, it would seem, to the lengthening of the period of hypoxia as a result of the inadequate circulation created in the organism by heart massage in conditions of uncompensated loss of blood.
The later restoration of spontaneous respiration and the higher level of partially oxidized metabolites in the plasma when indirect heart massage was combined with intravenous transfusion of blood are evidence of a more serious degree of hypoxia in these cases. Whereas in the first group of experiments the animals made their first inhalation after 4 minutes 38 seconds, and an hour after restoration of cardiac activity the total concentration of organic acids in the plasma had dropped to 13.7 mEq/litre, in the second group of experiments employing intravenous transfusion of blood respiration was restored after 10 minutes 34 seconds, and the total concentration of organic acids in the plasma had not changed from the level of 23.9 mEq/litre an hour after restoration of cardiac activity.
It is also important to note that full, stable restoration of functions in dogs, both in our experiments with intravenous transfusion of blood and in those of Kirimli and Safar, was only possible when agony and clinical death lasted no longer than eight or eight and a half minutes. When the blood was transfused into an artery the animals survived agony and clinical death lasting eight to eleven and a half minutes.
The experiments we made confirmed once more that, in certain pathological states, in particular with massive blood loss, heart massage should be combined with the transfusion of blood into an artery. There are grounds for believing that, in the treatment of patients in a state of clinical death due to massive loss of blood, arterial transfusion of blood is an extremely valuable though supplementary measure that increases the effectiveness of indirect heart massage.
Thus intra-arterial transfusion of blood serves as a supplementary measure in the treatment of clinical death and in modern conditions is seldom used as the main component of reanimation. At the same time it is extremely useful as a means of increasing the effectiveness of indirect heart massage, especially when the loss of blood had not yet been compensated at the moment of cardiac arrest. It should not be forgotten as well that arterial transfusion of blood is of vast importance in treating certain terminal states prior to clinical death, above all the protracted hypotension that very often is the cause of ‘irreversible’ shock.