Intranarkozny awakening – unguessed restoration of consciousness of the patient who is under the general anesthesia during surgical intervention. The main signs are expansion of pupils, fall of temperature of a body, growth of level HELL. In the absence of a muscular relaxation there are involuntary movements of extremities, attempts of independent breath. Diagnostics against the background of application of kurarepodobny means is complicated, the anesthesiologist is guided only by reaction of pupils which expansion can happen for other reasons. Specific treatment includes increase in a dose of narcotic medicine, use of the combined total anesthesia, change of a way of supply of anesthetic.
Intranarkoznoye, or the intraoperative, awakening (I,A) – a state at which the patient who is under the influence of narcotic medicines recovers consciousness. Meets in 9-11% of cases of a neyroleptanalgeziya and in 0,1-0,7% of cases of the anesthesia which is carried out with use of modern inhalation anesthetics. Frequency of a complication increases at introduction of kurarepodobny miorelaksant. At children of SP develops in 5-7 times more often than at adults. Restoration of consciousness in a complex with sensitivity arises in 1 case from 3 thousand. Other episodes of awakening are not followed by a pain syndrome and quite often are not remembered by the patient at the conscious level.
Reasons of intranarkozny awakening
The reasons of awakening are not finalized as the exact mechanism of effect of system anesthetics is not defined. There are several estimated mechanisms of this complication, however with their help it is impossible to explain all cases of this state. By results of the researches conducted from 1950 to 2005, restoration of consciousness during operation happens in the presence of the following contributing factors:
- Low-quality or outdated medicines. Intranarkozny awakening can arise if instead of modern narcotic medicines outdated means are used. Influence of ethyl oxide is 5 times weaker than effect of a ftorotan, force of effect of cyclopropane by 10 times exceeds hypnotic ability of nitrous oxide. In this group it is possible to refer also use of a medicine not to destination. For example, ZO cannot be used as the main anesthesia at volume interventions.
- Insufficient dose. Dosages of medicines pay off on age and the patient's weight. The wrong selection of a dose leads to an early exit from a necessary state. The probability of SP increases not only at mistakes in calculation of the supporting anesthesia, but also at the insufficient volume of the drugs necessary for providing a basic state. The introduction anesthesia does not influence risk of SP.
- Individual reaction of the patient. The organism of some patients is insufficiently sensitive to influence of anesthetics – medicines render necessary effect at the initial stage of operation at essential reduction of the general duration of action. The risk of similar reactions when using narcotic means and peripheral miorelaksant is increased at representatives of negroid race.
The mechanism of development of SP is closely connected with way of action of gipnotik on an organism. According to modern representations, molecules of medicine are fixed on a membrane of nervous cages, breaking processes of its depolarization. Thereof transfer of an impulse stops, painful sensitivity decreases. The main narcotic action is reached due to the braking influence of medicine on a retikulyarny formation of a brain and decrease in its activating impact on overlying departments.
Intranarkozny awakening develops at early deactivation of narkotiziruyushchy substance or its insufficient quantity. Momentum transfer is resumed, consciousness and painful sensitivity is restored. Psychological experiences and pain become the reason of emission of stressful hormones, formations of a characteristic clinical picture. If sensitivity comes back completely, system violations of haemo dynamics, centralization of blood circulation and other signs of shock are possible.
Pathology is classified by several parameters. The complication is divided on extent of restoration of painful sensitivity (with the full, incomplete, absent return), current duration (short-term at bystry definition, long-term at not diagnosed SP). Division on depth of the residual phenomena is possible (an exit from III2 to III1 or the II stage). However the key parameter on which systematization is carried out is existence or lack of post-narcotic memory:
- Lack of memoirs. Intranarkozny restoration of consciousness incomplete, painful shock does not arise, subsequently the patient does not remember this episode. About SP in that case it is possible to judge by existence of cognitive violations, changes in behavior of the patient after operation. The similar phenomena meet at the children more subject to influence of a psychological distress more often.
- Post-narcotic memory. The patient precisely describes the events which were taking place in operating time of operational crew. Practically always sensitivity is partially or completely restored. The risk of development of painful shock increases. Meets several times less than unconscious awakening with lack of memoirs.
Symptoms of intranarkozny awakening
It is shown in the form of the signs corresponding to the patient's exit to the previous stages of an anesthesia. At III2 of a stage in which the majority of operations is performed eyeballs of the patient are not mobile, reaction to light is kept, the corneal reflex is absent. The muscular tone is lowered, breath equal, slowed down, haemo dynamics stable. Perhaps insignificant decrease HELL. Skin of normal color, mucous membranes damp. Signs of toxic influence are not observed.
At an exit in III1 a stage the quiet dream remains. The muscular tone, some reflexes is restored. Eyeballs begin to make the slowed-down circular movements. There is a small increase in arterial pressure. Haemo dynamics is stable. Depth at the III1 level allows to continue operation if work does not mean high-traumatic manipulations. In the II stage there is an increase in a muscular tone, increase HELL and pulse rates. Emergence of unconscious or conscious movements by extremities is possible.
Subjective stories of the people who endured intranarkozny awakening demonstrate that the patient can hear a talk of surgeons, understand what occurs around. It is the reason of a psychological trauma. Its probability increases if during work there were complications about which surgeons spoke aloud. The condition of reason confused, deafened. The most stressful situation is formed when consciousness comes back to the patient who is under a pharmacological relaxation and incapable to report about the arisen problem.
When using miorelaksant external clinical manifestations are absent. Kurarepodobny means block neuromuscular transmission, make impossible independent breath and the movement. Similar interventions are carried out against the background of artificial ventilation of lungs. The only symptom is reaction of pupils, the changes of haemo dynamics which are present not at all cases are possible. At an exit in the second stage of an anesthesia emergence of signs of independent breath which are fixed by the device IVL can be noted. However in most cases it comes to an end with repeated introduction of the medicines relaxing muscles.
Painful shock and postoperative psychological trauma belong to number of complications which intranarkozny awakening can cause. Changes from mentality are found in the form of unpleasant memories of an episode of awakening, dreadful dreams, a depression. Cases when patients made suicide attempts are known. Patients need the help of the psychotherapist capable to level the importance of memories of operation. Especially brightly consequences are shown at the children having high sensitivity and having not up to the end created mentality.
Painful (traumatic) shock is defined at a complete recovery of painful sensitivity. At the same time nervous impulses from a zone of damage pererazdrazhat and TsNS exhaust, promote development of processes of guarding braking. Violations of haemo dynamics, and also centralization of a blood-groove, failures in work of heart and other symptoms of a state of shock are observed. There is a high probability of death of the patient. It is possible to prevent a lethal outcome at early diagnostics and definition of the reasons of the arisen violations.
Intranarkozny awakening is easily diagnosed on clinical signs if to the patient miorelaksant were not entered, for definition of getting out of the patient of somnolence of additional researches it is not required. In the presence of a medicamentous relaxation determination of level of consciousness is complicated. Emergence of reaction of pupils is not considered a reliable sign of awakening as this phenomenon is often noted at the hypoxia connected with insufficient concentration of oxygen in respiratory mix. Use the following objective methods of diagnostics:
- Electroencephalography. EEG with control of the bispektralny index (BI) which represents the digital expression of results of a research made each 30 seconds is carried out. The indicator of less than 40 confirms a deep hypnotic stage. Figures within 45-60 testify to the average depth of oppression of the central nervous system. BI of more than 60 speaks about insufficient degree of a sedation.
- Monitoring. It is carried out constantly with use of the anesteziologichesky monitor. Indicators of pulse, arterial pressure, a saturation, body temperature are displayed. A sign of an exit of the patient from an anesthesia is increase in ChSS, increase HELL. Perhaps some decrease in temperature values and saturation. If in the anamnesis there is IBS, there are symptoms of the ischemia of a myocardium caused by a stenocardia attack (a depression or an elevation of a segment of ST, a negative tooth of T).
Treatment of intranarkozny awakening
Treatment basis – the increase in a dose of anesthetic allowing to deepen an anesthesia to necessary level. If the mask method of supply of inhalation medicine is chosen, it is recommended to carry out an intubation of a trachea and to pass to endotrakhealny introduction of a medicine. It will allow to improve absorbability and to increase concentration of means in blood without increase in amount of the given mix. Intravenous anesthetics or total intravenous anesthesia with use of combinations of medicines can be applied to bystry deepening of a dream.
At development of shock states begin antishock therapy. Introduction of colloidal solutions, glucocorticosteroids, proteolytic enzymes is shown. Maintenance of haemo dynamics at the acceptable level is made by titrovanny supply of pressor amines. For fight against metabolic acidosis perform infusions of 4% of sodium of a hydrocarbonate. Continue IVL with periodic use of 100% of oxygen for oxygenation of tissues of brain. Control of a diuresis, haemo dynamics indicators is obligatory. At an interval of 20-30 minutes carry out blood sampling for laboratory determination of parameters of acid-base balance.
Analgeziya with use of morphine and a promedol is not shown as the patient is in an anesthesia. The stage has to correspond to surgical III1. Less deep immersion leads to restoration of sensitivity and aggravation of a situation, deeper – to strengthening of haemo dynamic instability. In hard cases removal of the patient in the II stage with use of drugs and the proceeding IVL is possible. At not stopped shock operation is stopped, the wound is taken in, the patient is transferred to ORIT for elimination of the arisen complications.
Forecast and prevention
The forecast at timely diagnostics favorable. The Intranarkozny awakening defined and eliminated at early stages does not leave memoirs and does not lead to negative consequences. The situation worsens if consciousness of the patient manages to be restored completely. It becomes the reason of emergence of negative emotions, a psychological trauma. The most serious consequences arise at patients with the restored painful sensitivity. The forecast for life adverse owing to the developing traumatic shock.
Prevention entirely lays down on the anesthesiologist. It is necessary to carry out carefully collecting the anamnesis, considering existence of diseases of a narcological profile. Drug-addicted and alcohol-addicted patients, and also smokers of tobacco need increase in a dose of anesthetic. Before operation it is necessary to perfrom careful calculation of dosages, to check serviceability of the narcotic and respiratory equipment. Provide to patients with high risk of restoration of consciousness conditions for a continuous electroencephalography.