Biomedical subjects
Publications and source records attributed to A Iu Lubnin.
An extremely rare case is described: massive gas (oxygen) embolism resultant from erroneous intraventricular administration of 3% hydrogen peroxide solution, which manifested by total systems hemodynamic and respiratory disorders. Hydrogen peroxide, which is still widely used in surgery, is a serious risk factor as regards gas embolism.
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The paper describes a rare combination of atypical meningioma of the base of the skull, which was greatly extended, with a life-time unrecognized small vascular malformation of the brain stem at the level of the pons. Intraoperative hemorrhage into the stem from the micromalformation was a cause of the female patient's death. A detailed account of the operation and the postoperative period and a review of literature on the main aspects of the problem in the diagnosis of cerebral micromalformations are given.
The paper presents a clinical case of severe excess cerebrospinal spinal fluid drain syndrome with hematomas of the cerebral hemispheres being formed in a 18-year-old young man undergone ventriculoatriostomy with mean-pressure pump implantation. A complication occurred 6 months after surgery and ran progressively. Closed external drainage of hematomas greatly reduced their volumes, but deteriorated the patient's condition due to the development of excess drain syndrome. Replacement of the mean-pressure pump by a high-pressure one rapidly normalized the patient's status.
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The paper presents two cases of high-surgical-risk deep arteriovenous malformations (AVM) concurrent with aneurysms of the middle portion of the anterior ciliary artery (a male aged 35 years and a female aged 24 years). In the former case, aneurysm and large AVM in the left visual tuber were causes of 4 hemorrhages. In the latter, AVM of subcortical nodes and internal capsule were responsible for single hemorrhage. The patients underwent intraoperative embolization of the anterior ciliary artery followed by its clipping. This allowed the authors to exclude aneurysm and to achieve obliteration of the bulk of AVM. Operation were performed under intraoperative guidance of motor and speech functions. Residual AVM were exposed to proton beam radiation. The outcomes of treatment were good. After 4 months of surgery, the male had no neurological disorders; in the female motor and speech disorders were associated with prior hemorrhage.
Epidural analgesia (EA) was used in 29 patients undergoing surgical removal of lumbar discal hernia. Marcain EA with controlled medicinal sleep and non-assisted breathing allowed to perform the whole operation in 27 patients. EA may be ineffective in combination of sequestrated disk hernia with scarry adhesive process. The technique of the operation demands a single use of the anesthetic drug which is potent enough to make blockade throughout the operation up to the end.
A method of anesthesia allowing patient's awakening to the level of verbal contact after trephination and opening of the dura mater was used in 37 patients with bulky formations (33 patients with tumors and 4 with arteriovenous malformations) in the speech zones of speech-dominant hemisphere. Speech mapping of the brain, carried out in alert patients, helped eliminate permanent speech deficiency during the postoperative period in all patients. The protocol of anesthesia was as follows: locoregional anesthesia of soft tissues of the head with a mixture of 2% xylocaine and 0.5% marcaine with epinephrine intravenous diprivan at stages requiring no patient's alertness, clopheline, fractionated midazolam (after identification of speech zones). The study showed that this protocol helps solve the problem and adequately protects the organism from surgical stress, provides good conditions for manipulations on the brain, involves no unpleasant sensations for the patient, and in 70% patients helps attain complete amnesia of the perioperative period. The most severe complication is an epileptic attack. Respiratory monitoring (pulse oximetry and capnography in the lateral duct) is obligatory for preventing respiratory disorders in patients on spontaneous respiration who were not intubated.
A total of 144 neurosurgical interventions were performed in 138 patients with cerebrovascular diseases (arterial aneurysms in the acute and cold periods after a subarachnoidal hemorrhage, arteriovenous malformations, and carotid-cavernous anastomoses). Intraoperative monitoring of regional saturation of hemoglobin with oxygen in the blood flowing in brain vessels was carried out by a cerebral oximeter INVOS 3100 for early intraoperative diagnosis of cerebral ischemia. This paper analyzes factors affecting changes in rSO2 parameter during surgery and discusses the prognostic significance of the detected shifts. Various factors affected the time course of rSO2: decrease in AP within the framework of controlled arterial hypotone and other causes, insertion of autosupported retractor spatulae, temporary clipping and embolism of cerebral arteries, vasospasm, aneurysm rupture, dissection of arteriovenous malformation, etc. Any intraoperative shift of rSO2 surpassing 5%, no matter of what direction (decrease or increase), deserves special attention of anesthesiologist, as it indicates development of cerebral ischemia with a high degree of probability.
Simultaneous monitoring by cerebral oximetry and electrophysiological methods (electroencephalography and electrocorticography) was performed in 21 patients with arterial cerebral aneurysms during direct intracranial interventions, endovascular interventions, and Matas' test. Electrophysiological methods are sufficiently accurate indicators of cerebral ischemia even at a functionally reversible level. The results of simultaneous monitoring were similar in 80% cases, indicating cerebral ischemia even at functionally reversible level, which was detected by both electrophysiological methods and cerebral oximetry. Variously directed shifts were detected in 4 cases; the causes are discussed. Cerebral oximetry detects cerebral ischemia with a sensitivity similar to that of electrophysiological methods. The method does not depend on temperature or anesthetics. Limitations of the method are due to its local application.
The authors discuss the results of pharmacological protection of the brain, consisting in intraarterial or intravenous infusion of drugs (sodium thiopental, nimodipine, ketamine) during intracranial interventions in 13 patients with giant arterial aneurysms of the anterior portions of Willis' circle. In some patients drug protection of the brain prevented the development of ischemic focus in the basin of temporarily occluded vessel. Intraarterial infusion of protector drugs is preferable because it allows decreasing the doses and severity of untoward hemodynamic effects.
The study was carried out in 22 patients operated on for vertebral disk hernias and spinal tumors at lumbosacral level. The patients were divided in 2 groups depending on the type of anesthesia (epidural or neuroleptanalgesia-EA and NLA). In the test group all patients were operated under EA with local anesthetics combined with intravenous sedative drugs (diprivan + relanium) under conditions of spontaneous respiration and O2 inhalation through a mask. In the control group combined total intravenous anesthesia by myorelaxants and tracheal intubation were carried out (relanium + diprivan: induction dose 1.95 +/- 0.5 mg/kg, maintenance dose 5.3 +/- 0.4 mg/kg/h, and phentanyl). The purpose of the study was to compare the efficiency of anesthesiological protection under EA and traditional NLA in interventions on the spine, when surgical injury is inflicted in the immediate vicinity to the central structures responsible for pain impulsation. Only EA ensured adequate protection of the patients from surgical stress, as was seen from hemodynamic (arterial pressure and heart rate) and endocrine metabolic parameters (glucose, epinephrine, norepinephrine, hydrocortisone, and prolactin levels). Hence, EA fully demonstrated its protective properties during operations on the spine, and therefore can be regarded as a method of choice in this patient population.
Effects of epidural anesthesia (EA) on early components of somatosensory evoked potentials (SSEP) were studied and the objectiveness and efficiency of SSEP monitoring during interventions on the spine under EA were evaluated. Evoked potentials were studied in 21 patients operated on for vertebral disk hernias and extra-intradural tumors of the spine (lower thoracic and lumbar levels) under bupivacaine EA. Cortical SSEP were recorded and analyzed on a Viking IV neuroaverager (Nicolet, USA) stimulating n. tibialis posterior for obtaining a greater amplitude of evoked potentials. The following SSEP characteristics were measured: latency of PI (P37), NI (N45), and PII (P60) peaks, amplitude of PINI peak, and inter-peak latency of PI-NI and PI-PII. The major changes in cortical SSEP caused by EA (local anesthetic 0.5% bupivacaine) involve only PI and NI components which reflect the entry of information on an external stimulus into the cortex and objective physical parameters of this stimulus; this helps predict the onset of full-value epidural block and its duration. General anesthetic (propofol) affect mainly a later component of response, PII peak, which is responsible for processing of primary information about an external stimulus and reflects the activation of associative areas of the brain. Hence, SSEP regulation can be used together with traditional methods (pin prick test and Bromage scale) for evaluating epidural block in patients with spinal diseases.
A young patient without history of epilepsy developed a pronounced motor reaction simulating an epileptic attack in response to diprivan. Possible causes of motor excitation in response to diprivan and probability of their prediction are discussed.
The efficiency of a procedure of intravascular blood aspiration (IVBA) in patients with large and giant parawedge aneurysms of the internal carotid. The study was based on the analysis of clinical data and outcomes of surgical treatment in 20 patients with the aneurysms. The paper presents different procedures for IVBA, a complex of methods for preoperative examination of patients and intraoperative prediction of possible ischemic complications and defines indications for the IVBA procedure. Complete and partial aneurysm exclusion was achieved in 15 (75%) and 2 (10%) patients; the neck and walls of aneurysm were strengthened with surgical gauze in 2 (10%) patients. Incompetent clipping was observed in one case. There was recovery in 17 (85%), improvement in 2 (10%), 1 (5%) patients. No deaths occurred. The IVBA procedure for aneurysm is indicated for large and giant thin-walled non-thrombotic aneurysms of the parawedge carotid segment. It permit effective proximal monitoring of carotid blood flow and creates favourable conditions for preparing and excluding aneurysm, and, if necessary, forming a carotid lumen. Intraoperative monitoring of brain function is highly important and obligatory for early prediction and prevention of ischemic complications. Under intraoperative monitoring of brain function, fractional IVBA makes it effective even if collateral circulation is inadequate.
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Automated reinfusion of autoerythrocytes prepared from blood lost during removal of tumors was the main component of transfusion therapy in 49 patients (52 operations) with brain tumors. All patients developed massive blood loss of 0.5-5 TCB during the intervention, reinfusion device cell saver C.A.T.S 2-02 (Fresenius, Germany) was used. Various aspects of clinical application of this method are discussed, its efficiency and factors affecting it are analyzed. Special attention is paid to time course of hemostasis values during automated reinfusion and the problem of tumor contamination of reinfused suspension. This latter problem was solved by using the last-generation leukocyte filter RC-400 Klev (Pall, Germany). Automated reinfusion of autoerythromass effectively compensated for massive intraoperative blood loss, on condition of correction of hemostasis disorders by fresh frozen plasma and purification of reinfused suspension from tumor cells by filtering through leukocytic filters. Moreover, our results indicate that utilization of cell saver is obligatory for some patients with supermassive hemorrhages.
The paper outlines a rare clinical case of cavernous angioma of the brain stem in a female who was operated on in the sitting position and who intraoperatively developed 6 episodes of massive venous air embolism in tandem from the transverse sinus defect undetectable by the cervical vein compression test. Why it is difficult to diagnose this complication in this case is considered. Preventive and therapeutical measures are given.