Biomedical subjects
Publications and source records attributed to V V Likhvantsev.
An information concept of nociceptive impulses is proposed. The device for quantitative analysis of information coming to CNS has been constructed and approved. It is demonstrated that monitoring of informative loading of EEG may be used for evaluation of anesthesia adequacy. Level of this index from 40 to 50% corresponds to effective protection.
The paper provides evidence for the pathogenetic approach to treating acute lung lesion (ALL) and adult respiratory distress syndrome (ARDS). An algorithm of the use of Russian lung surfactant preparations: CT-HL and CT-BL has been developed. In involves earlier (the first days following the onset of respiratory failure) use of surfactant, its combined bolus intratracheal or intrabronchial administration in doses of 200-400 mg/m2, followed by continuous (5-day) aerosol inhalation in doses of 20-30 mg/h for children and 30-75 mg/h for adults until pronounced clinical and X-ray effects are shown. Fifty three patients were found to develop ALL and ARDS in the presence of severe pneumonia, postperfusion lung disorders, reperfusion syndrome, pulmonary embolism, long-term artificial ventilation, combined car accident injury and gunshot wounds of the chest, heroine intoxication, septic shock, sepsis, postoperative sequels in cancer patients, and after hepatic transplantation or massive aspiration of gastric contents. Fifty patients were overcome their critical status, 44 survived. The duration of artificial ventilation (AV) ranged from 1 to 6 days. Earlier use of the drugs made it possible to transfer patients to safe AV regimens and to eliminate ALL and ARDS rapidly and to significantly reduce mortality due to critical states.
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In authors' opinion, the more precise methods for controlling the depth and efficiency of general anesthesia are those which are based on the direct control over the intraoperative status of the central nervous system which reflects the time course of the status in question. Whether monitoring of the early components of somatosensory evoked potentials could be used for multimodality anesthesia was analysed. As high as 50% or lower decreases in the amplitude of the complex N19-P23 were typical of adequate defense, irrespective of anesthesias. The authors provide evidence for the efficiency of their procedure for controlling the depth and efficiency of general anesthesia. Some electroencephalographic phenomena of anesthesia were analysed with computed monitoring. The authors showed that there was a relative value of such signs of inadequate anesthesia as interhemispheric asymmetry by the leading spectral frequency and the power index of deep rhythms. Despite the procedure used (neuroleptic analgesia, ataralgesia, inhalation anesthesia, etc.), the effective anesthesia exhibited pronounced power peaks, otherwise there was a chaotic activity of the central nervous system. The physiological and clinical values of the phenomena detected are discussed in the paper.
The authors analyse the early components of somatosensory evoked potentials (SSEP) during anesthesia in prolonged and traumatic operations on the abdominal organs (gastrectomy, hemihepatectomy, pancreatoduodenal resection, etc.). A total of 69 patients were examined, among them 32 underwent operations under conditions of classical NLA, 16 with the narcotic analgetics replaced by moradol, and 21 under modified NLA with dalargin. The results of the study and analysis of literature data allow monitoring of the early components of somatosensory evoked potentials to be considered a highly sensitive test for appraising the depth and adequacy of the modern methods of general anesthesia and to be recommended for use, at least in particularly difficult and venturesome operations. It is shown that most significant in the discussed plan is not the absolute value, but changes of the N19-P23 amplitude in the stages of the operation. Increase of the studied SSEP component by 20% and more in relation to the basal level (SSEP amplitude in the patient after adequate preanesthesia) is evidence of insufficient analgesia. Change of N19-P23 latency is less demonstrative. Monitoring of the early components (N19-P23) of SSEP showed that to ensure effective analgesia in prolonged concurrent and combined operations, if the NLA method is chosen, administration of fentanyl in a dose of no less than 12 micrograms/kg/hour is necessary. It is shown that replacement of narcotic analgesics, within the limits of the conducted NLA, by moradol, an agent of the group of agonists-antagonists is poorly effective.(ABSTRACT TRUNCATED AT 250 WORDS)
The article discusses variants of infusion-transfusion therapy (ITT) in early stages of expanded operations on the abdominal organs attended by massive blood loss (2 to 4 BCV and more). Seventy-three patients were examined, they underwent resection of the liver (30), pancreatoduodenal resection (37), or removal of a retroperitoneal tumor (6 patients). On the basis of precise study of central and peripheral hemodynamics, acid-base equilibrium, and blood oxygen transport function the authors find it necessary to increase the volumes of ITT to 70-80% BCV in the first stage of the operation with a colloid/crystalloid ratio of 1:4. The described method makes it possible to avoid critical fluctuations of cardiac output and blood pressure in massive bleeding. At the same time, such hemodilution causes no considerable decrease in hemoglobin concentrations (which was 79.0% of the initial level at the beginning of the main stage) and specific oxygen transport (85.0%, respectively). In absolute expression the specific oxygen transport before the hemorrhage is 465 + 29 ml/min/m2, which significantly exceeds the critical value. The authors believe the ITT method to be indicated in inevitable blood loss and absence of serious cardiovascular diseases. From comparative analysis of the different variants of general anesthesia, the authors conclude that the following combination of agents is preferable for the discussed category of patients: phentanyl, droperidol, seduxen, kalipsol (ketamine), and dalargin. Their balanced use ensures stability of the main homeostasis indices in all stages of the intervention; the hepato- and pancreatoprotective properties of dalargin are also of importance.
Dalargin is a Soviet synthetic analog of leu-enkephalin. It was used in a complex of anesthesiological protection (in the form of permanent infusion at a rate of 40-55 micrograms/kg/h) in 331 patients who suffered different operations on the heart, lungs and abdominal cavity. Potential mechanisms of the protective action of the drug were studied in experimental surgical distress. It was found advisable that dalargin may be included into combined general anesthesia to maintain intraoperative organ protection, to stabilize vital functions of the patient at the most crucial and traumatic stages of intervention, and to decrease requirements of narcotic analgetics. It is assumed that dalargin may interact with peripheral opiate receptors. The interaction is likely to be viewed as the main mechanism by which the protective properties of the drug are realized.
I/v dalargin injection (20-25 g/kg) to narcotized rats in case of total myoplegia effectively protect hemodynamic changes under nociceptive stimulation. Bilateral truncal vagotomy partially decrease the protective effect of dalargin. Protective effect of the medicine results in activation of central and peripheral opioid receptors.
The article analyses the possibilities of computed EEG monitoring for evaluation of the magnitude and adequacy of the modern methods of general anesthesia: NLA, NLA with halothane inhalation, NLA including Kalipsol bolus administration. An original coefficient, called the adequacy index (AI), was found, which reflects the percentage contribution of deep rhythms (delta and theta) to the total power of the EEG in the range of 0 to 20 Hz. It is shown that the dynamics of this index correlates with the degree of the blocking of entry of sensory nociceptive information into the CNS. The lower boundary of AI-70% was determined, below which the generally accepted signs of anesthesia inadequacy appear: hyperactivity develops, a shift of pH in the acid direction occurs, and the base deficiency increases. It is suggested that determination of AI is used as a highly sensitive and operative test for routine monitoring of the patient's intraoperative condition and express diagnosis of inefficacy of anesthesia.
The antinociceptive properties of dalargin (D) under nembutal anesthesia and artificial ventilation were studied in hemodynamic response to mechanical algesic stimulation in rats. D was introduced i/v (20 micrograms/kg) against a background of myoplegia with Arduan (0.1 mg/kg) and without it. The naloxon (100 micrograms/kg) prevented the protective effects of D. It is considered that injection of D (20 micrograms/kg) on the background of total myoplegia and artificial ventilation prevented hemodynamic response on algesic stimulus. Subsequent dose increase of opium peptide up to 3500 micrograms/kg does not cause amplification of protective properties.
The authors analyse experience in the use of the synthetic analogue of ++leu enkephalin dalargin in multicomponent balanced anesthesia in operations on the abdominal organs in 36 patients. With the use of the suggested method the intraoperative expenditure of narcotic analgesics is 6 times less but the efficacy of the anesthesia remains the same. Study of the activity of the liver-specific enzymes (histidase and urokinase) in blood plasma and biopsy material taken from the liver and the content of malonic dialdehyde in the hepatic biopsy specimen revealed hepatoprotective properties of dalargin. The decrease of the total peripheral resistance and increase of the elasticity of the arterial reservoir++ in the main group as compared to these values in patients treated by the traditional method were considered by the authors to be the consequence of the autonomic priming effect of the opiopeptide used. It is concluded that the use of synthetic analogues of endogenous opioids (dalargin) in the anesthesiological protection complex in operations on the abdominal organs is expedient.
A new method of electroencephalogram (EEG) processing is discussed: bispectral index (BIS), used for monitoring the depth of total anesthesia. The technology of BIS estimation is a principally novel approach to EEG processing, which can be denoted as an expert conclusion. EEG monitor Aspect A-100 (Aspect Medical System, USA) has been used for 3 years in the operation room during narcoses with barbiturates, propofol, midasolam, fentanyl, calypsol, isoflurane, and nitric oxide. BIS is a convenient and reliable method for evaluating the depth of total anesthesia with anesthetics with pronounced hypnotic effects at all stages of surgery. The disadvantages of the method are enumerated. The authors claim that monitors designed for expert evaluations hold good promise.
Respiratory narcotic devices and monitoring devices have been rapidly improved since World War II; new effective and safe drugs and high-quality materials appeared. This resulted in a notable decrease of mortality caused by anesthesia: from 1 per 50 patients before the war to 1 per 200,000 patients during the last years of the twentieth century. Paradoxical as it is, anesthesia today is one of the most safe medical specializations. Then what, if not the problem of safety, makes anesthesiologists improve the methods of intraoperative protection? It will be only just to admit that the main trend in development of anesthesiology today is not improvement of its safety, but the desire to make the postoperative period as comfortable as possible for the patient and to facilitate anesthesiologist's work. The choice of method of anesthesia less and less affects the quality of intraoperative protection. Modern methods of total and local anesthesia are so universal, that can be used in patients of any age, physical status, in surgery of any duration and traumatization. One and the same method can meet the most strict requirements to outpatient and venture surgery. Hence, the initially rather long list of anesthesiological methods becomes shorter as it should meet modern requirements to the efficiency and safety of anesthesia and becomes quite short if we take into consideration patient's comfort and physician's convenience. The choice from 3-4 methods is completely determined by physician's habits or preferences or traditions of the hospital.
The depth of xenon anesthesia was never evaluated by modern methods of EEG monitoring, and hence, we studied changes in EEG, INEEG, and BIS during different stages of xenon narcosis and evaluated the possibility of using these values as criteria of xenon anesthesia adequacy. The study was carried out in 60 patients during laparoscopic operations on abdominal organs. The patients were divided into 2 groups receiving different gas anesthetics (xenon or nitric oxide). The results indicate that xenon monoanesthesia caused dose-dependent changes in the native and treated EEG; xenon is a good inhalation anesthetic providing adequate anesthesia for little traumatic operations even in case of mononarcosis; INEEG and BIS monitoring during xenon anesthesia allows an objective evaluation of its depth.
In order to elucidate the advantages of target control infusion (TCI) over common manually controlled infusion, we evaluated the results of 54 anesthesias carried out at department of roentgeno-endovascular surgery. All 54 patients received intravenous controlled sedation with propofol. The rate of arrest of sedation signs after the end of infusion, hemodynamics during anesthesia, comfort for the patient, and convenience for the anesthesiologist were evaluated. As regards intravenous controlled sedation, we observed no obvious advantages of the TCI method for the patient over common manually controlled infusion. Performed by a skilled anesthesiologist, both methods ensure sufficient comfort for the patient, stable hemodynamics, and easy regulation of the depth of sedation. However, TCI is more convenient for physician, and this is the reason why many specialists prefer it.
Twenty-nine angiosurgical patients with disordered ventilation-perfusion correlations were examined. Effects of CMV (controlled mechanical ventilation) + PEEP (positive end expiratory pressure) and IRV (inverse ratio of ventilation) on gas exchange and hemodynamics of the lungs were studied. Gas exchange improved in all patients, but sooner in the CMV + PEEP group. CI increase was more pronounced in the IRV group.
The effect of the balanced feeding formulas "Peptamen" and "Nutren" ("Nestle Swisse", Switzerland) on the immune status was studied in 30 patients immediately after pancreas surgery. 15 patients with full-fledged parenteral alimentation were controls. The catabolic trend of metabolic processes was detected in the early postoperative period. The use of "Peptamen" and "Nutren" inverts metabolism towards anabolism. Profound immunologic disorders were observed both in the cellular and humoral chains immediately after surgery. The early enteral feeding normalized, first, the immunity humoral chain (from the 1st postoperative day) and, then, the immunity cellular chain (by the 6th postoperative day).
The paper summarizes a 5-year experience of evaluating the safety of anesthetic management of patients with thermal lesions treated at the department of thermal lesions of Vishnevsky's Institute of Surgery, Russia's Academy of Medical Sciences. Regular internal auditings, based on the principles of registering the critical incidents, the course of 1473 general anesthesia managements was analyzed in 168 patients. The conclusion is that the introduction of protocols of anesthetic management as well as a regular monitoring over meeting the fixed targets cut the total frequency of critical incidents from 2.85 to 1.19 as estimated per one general anesthesia. Finally the authors suggest a concept whose essence in that the operation of the modern anesthesiology department must be based on a scientifically substantiated technology of anesthetic management.