[Application of shot-latency cortical somato-sensory evoked potentials for evaluation of swallowing disorders in early period after posterior fossa surgery].

UNLABELLED: Main tasks of early postoperative period in patients after posterior fossa surgery are the timely and safe weaning from mechanical ventilation and extubation. For clinical assessment of the hypopharynx function we use an algorithm developed in the intensive care unit (ICU) of the Burdenko Scientific Research Institute of Neurosurgery. Disadvantages of the clinical test for assessment of patient's readiness for extubation are subjectivity and impossibility to use it in conditions of even superficial sedation. Shot-latency somato-sensory evoked potentials (SSEP) can be applied in conditions of sedation and objectify the brain stem deficit. The goal of the study was to define the changes of cortical SSEP in patients with disorders of swallowing after posterior fossa surgery. To assess the swallowing disorders we used a scale of swallowing disorders in intubated patients with brain stem damage. We compared results of cortical SSEP, test of swallowing disorders in intubated patients and clinical results of extubation. 17 patients with tumors of posterior fossa were included in the study. All patients were divided into two groups depending on duration of mechanical ventilation. Patients of the group-1 were successfully extubated in 4.5 hours. Patients of the group-2 were mechanically ventilated more than 15 hours because of impossibility to pass the test of readiness for extubation. RESULTS: Central conduction time symmetry index after the surgery was lower in the group-1 than in group-2. There was inverse correlation between amplitude of cortical response N20 and time from the patient's admission to the ICU until the moment of extubation. CONCLUSIONS: Asymmetry of central conduction time and decreasing of N20 amplitude can be used as additional predictor of swallowing disorder.

[Intracranial pressure plateau waves in patients with severe traumatic brain injury].

The goal of the study was to assess frequency of plato waves, their influence on outcomes and define factors leading to plato waves. Ninety eight patients with severe traumatic brain injury (TBI) were included. Blood pressure (BP), intracranial pressure (ICP), cerebral perfusion pressure (CPP) and pressure reactivity index (Prx) were registered. Age was 34 +/- 13.6. There were 73 male and 25 female. Glasgow Coma Scale (GCS) was 6 +/- 1.4. Plato waves developed in 24 patients (group 1), 74 patients (group 2) did not have plato waves. Median of plato waves in the 1st group was 7[3.5; 7]. They developed on 3rd [2;4.5] day. Maximum level of ICP during plato waves was 47.5 [40;53] mmHg, its duration was 8.5 [7;27] minutes. In the group 1 Prx was significantly lower during first day, than in the group 2. Duration of ICP monitoring was longer in the group I due to presence of plato waves in these patients. CPP did not differ in groups, because CPP was strictly controlled. Patients of the group I had preserved autoregulation and less severe trauma (predominance of closed trauma and Marshall I, II type of brain damage). Plato waves did not predict bad outcomes.

[Analysis of thyroid homeostasis disorders in patients with severe traumatic brain injury].

Aim of the study was to investigate the status of thyroid homeostasis and the relationship between severe traumatic brain injury (TBI) and thyroid disorders. The study included 56 patients. Protocol of the study concluded: noninvasive and invasive hemodynamic monitoring, including PICCO, transcranial Doppler ultrasonography, measurement of intracranial pressure (ICP), indirect calorimetry, levels of thyroid stimulating hormone (TSH), T3, T4 and free fractions. Patients were divided into three groups. Group 1--with normal thyroid hormones (n = 20), Group 2--with the low T3 (n = 23) and Group 3 with the low T3 and T4 (n = 13). Correlation between the Glasgow Coma Scale (GCS) and thyroid hormone levels was obtained: the first group between GCS and T4 (r = 0.50), GCS, and free fraction T4 (r = 0.51); between the GCS and TSH (r = 0.51), T3 (r = 0.48) and T4 (r = 0.57) in the second group, and the third--with TSH (r = 0.67). Poor outcomes in the first group compound 15%, in the second group--39.2%, and in the third group--62.5% of patients. Doses of vasopressors were significantly higher in groups 2 and 3 compared with a first group. ICP was significantly higher in the group with the low T3 and T4. Development of intracranial hypertension correlated with the formation of thyroid insufficiency. Deficiency of thyroid hormones, especially the simultaneous reduction and T3, and T4 is associated with poor outcome in patients with severe TBI. Doses of sympathomimetic drugs used to optimize the parameters of systemic hemodynamics in acute severe head injury were higher in patients with deficiency of thyroid hormones.

[Protein malnutrition in patient in the early postoperative period after uncomplicated removal of the brain tumors].

Malnutrition leads to adverse effects and may worsen clinical outcome. Surgery as a stress factor activates pathological reactions changing metabolism structure. The aim of this study was to evaluate changes of protein metabolism in patients after elective neurosurgical operation. 24 patients were prepared for elective surgery and were enrolled in this study. Evaluation of each patient included: measurement of anthropometric indices--height, weight, arm circumference and the triceps skinfold thickness, the definition of protein loss by determining the loss of nitrogen in the urine, assessment of protein catabolism, determining the violations of nutritional status upon the base of laboratory parameters. During the course of the conducted investigation significant (p < 0.05) decrease in the indices of total protein, albumin, transferrin and the absolute numbers of lymphocytes in the postoperative period was revealed. All the patients developed severe protein catabolism. It became clear that uncomplicated elective surgical intervention, together with the adopted scheme of the nutritional therapy leads to severe protein catabolism in all patients.

[Optimizing blood pressure in patients with sellar region tumors during complicated postoperative period].

Mechanism of arterial hypotension (AH) in patients with sellar region tumors (SRT) and complicated postoperative period consists in decrease of systemic vascular resistance and relative hypovolemia. Therapeutic directions for blood pressure (BP) stabilization are clear. However criteria of optimal BP in these patients are absent. Object of the study was defining such criteria. Prospective study was conducted from January, 2011 to January, 2012. Inclusion criteria were: adults; SRT; early postoperative period. Thirty patients were included into the study. Patients were divided into three groups. Group I (n=11) consisted of patients with uncomplicated postoperative period; group II (n=12) - patients with complicated postoperative and with stable hemodynamics; group III (n=7) - patients with complicated postoperative period and AH. Median of central venous saturation (ScvO2) was normal in all groups. ScvO2 was significantly higher than jugular vein saturation (SjvO2) in all measurement. In group I SjvO2 was normal, and it was higher, than in group II. In group SjvO2 did not achieve normal level during three days of the study. Mean BP did not change during these days. In group III SjvO2 was decreased if mean BP was between 70 and 90 mmHg. This level of SjvO2 did not differ from SjvO2 in group II. When mean BP increased up to 100-110 mmHg SjvO2 significantly increased too in the group III and achieved level of the group I (normal level). Outcomes were favorable in all patients of the group I (GOS=4, 5). Median of length of stay (LOS) in the ICU was 1 day. In group II outcomes were favorable in 10 (83.3%) patients, 2 (16.7%) patients died. Median LOS in ICU was 7 days. In group III outcomes were favorable in 6 (85.7%) patients, unfavorable outcome (GOS=3) was in 1 (24.3%) patient. Median LOS in ICU was 12 days. There were no significant differences in all groups in the lactate levels both in central vein and in jugular vein. ScvO2 can not be a criterion for BP optimization in patients with SRT. In patients with uncomplicated postoperative period SjvO2 is normal. In patients with complicated postoperative period and normal BP SjvO2 remains decreased. In patients with complicated postoperative period and arterial hypotension normal level of SjvO2 can be achieved if mean BP is increased up to 100-110 mmHg. SjvO2 normalization can improve outcomes in patients with SRT and complicated postoperative period.

[First experience of using adaptive support ventilation (ASV) mode in patients with severe traumatic brain injury].

Capabilities and limitations of ASV mode in TBI patients are studied. 12 patients with severe TBI were enrolled in the study. ICP, MAP, CPP were monitored in all the patients. Cerebral regional blood flow was monitored by thermal diffusion in four patients. Hamilton G5 ventilator was used for mechanical ventilation and respiratory monitoring in all cases. Starting mode of mechanical ventilation was ASV with 100% mechanical substitution. The patient was regarded as ASV-nonresponder and switched to another mode when normoventilation was not possible with any percent of respiratory substitution. ASV mode provided normoventilation during all period of mechanical ventilation in 88 ou of 12 patients. In 4 out of 12 patients ASV mode led to hyperventilation with EtC02 decrease, cerebral regional blood flow slowing and P0,1 index increase. In three patients hyperventilation was induced by high rate of spontaneous breaths caused by brainstem irritation. Switching these patients to SIMV-VC led to normoventilation, normalization of etC02 and cerebral regional blood flow, and P0,1 index decrease. In one patient hyperventilation was caused by lung mechanics disorder when ventilator tried to achieve target minute volume by low tidal volume and high respiratory rate. ASV mode provides adequate lung ventilation during respiratory support period in most patients with severe TBI. It can prove ineffective for some patients with brainstem irritation or lung mechanics disorders.

[Using ASV mode for respiratory support withdrawal in patients after posterior fossa surgery].

The study gives data on how to improve the way from mechanical to spontaneous breathing in patients with weakened respiratory drive after posterior fossa tumor removal. We compared the effectiveness of two methods of weaning from mechanical ventilation in these patients. The main group consisted of 6 patients weaned from ventilator with ASV mode. The control group was made up of 10 patients weaned from ventilator with SIMV or PS modes. The duration of weaning from ventilator using ASV mode was significantly shorter than with SIMV or PS modes. During ASV ventilation spontaneous breath rate gradually increased. In all patients the level of P0,1 index representing respiratory center activity was initially lower than normal. While spontaneous breath activity increased the level of P0,1 index also gradually normalized. Plmax index (respiratory effort index) measured once a day increased as well. Weakened respiratory drive is accompanied by P0,1 and Plmax indexes' decrease in patients after posterior fossa tumor removal. ASV mode in these patients allows quicker weaning from mechanical ventilation.

[Secondary abdominal compartment syndrome in postoperative period in patients with tumors of sellar region].

The abdominal compartment syndrome (ACS) can lead to multiple organ dysfunction syndrome (MODS), sepsis and death. In neurosurgical patients ACS used to be interesting for specialists only in respect of its impact on ICP. However injury of diencephalic structures of the brain can theoretically cause ACS. The goal of the study is to assess the efficacy of conservative therapy and epidural anesthesia for ACS treatment in postoperative period in patients with tumors of the sellar region. 41 patients were enrolled in the study. The epidural anesthesia at T8-T9 level by bupivacaine was applied for three days in the case of ACS development and ineffective conservative therapy. Intra-abdominal hypertension (IAH) developed in 28 cases, ACS - in 9. IAN usually revealed itself on the second day after surgery, ACS - on the 3rd-6th day. Gastrointestinal tract paralysis developed earlier than IAH and continued longer than IAH. Conservative therapy was effective only in every third patient with ACS. Epidural anesthesia was used in 4 cases and appeared effective in all of them. All patients with ACS not provided by epidural anesthesia died. We conclude that conservative therapy is effective in IAH, but not in ACS cases. Epidural anesthesia is an effective method to treat ACS and should be used in all patients with ACS without sepsis.

[Monitoring of intracranial pressure difference between supra- and infratentorial spaces after posterior fossa tumor removal (case report)].

A clinical example shows that after a neurosurgical operation in posterior fossa there could appear intracranial pressure difference between supra- and infratentorial spaces. This difference develops due to pressure rise in posterior fossa and maintenance of this hypertension postoperatively. Hypertension in posterior fossa and intracranial difference are accompanied by brainstem reactions and temporary neurological disorders. While the pressure difference decreases and ICP in posterior fossa normalizes the neurological symptoms disappear. ICP in supratentorial space not necessarily correlates with ICP in infratentorial space. In some cases it is necessary to measure ICP in infratentorial space after posterior fossa surgery.

[First experience of using CoolGard system in intensive care patients after neurosurgical interventions: series of 10 observations].

Fever is a proven factor in secondary brain damage and worsens outcome in neuro intensive care patients. However, large randomized studies have shown neuroprotective effects of induced hypothermia only in patients with cardiac arrest and in neonates with perinatal hypoxic-ischemic brain damage. Nevertheless, now there is an active search for alternative modes of temperature correction, which would have been effective in other groups of patients with brain damage. Moreover, new management techniques of body temperature are being created. In this paper we presented a series of 10 observations when the used cooling system was CoolGard/CoolLine. 5 patients underwent hypothermia, 5 patients normothermia . Hypothermia was used for cerebroprotection in 1 case and for the correction of resistance to the therapy of intracranial hypertension in 4 cases. Normothermia was used for correction of resistance to pharmacological treatment of fever. In all cases the target temperature was achieved, and only for 1 patient to achieve hypothermia additional external cooling was used. Patients with normothermia did not need sedation, because they have not developed discomfort and muscle tremor. 2 patients died, in one case was due to intracranial hypertension and hemotamponade of brain ventricular system. Cause of second death was pulmonary embolism. Thus, the CoolGard system effectively lowers the body temperature to the target values for neuro intensive care patients. Application of this system is relatively safe. However, the most dangerous are the thromboembolic complications, thus the daily ultrasound scanning of lower limb veins and the possible early use of low molecular weight heparins is crucial.

[Intraabdominal hypertension and secondary abdominal compartment-syndrome in the patient with craniopharyngioma in postoperative period].

Currently problem of intraabdominal hypertension in patients with brain tumors is practically uninvestigated. Authors describe a case of complicated course of early postoperative period in the patient with craniopharyngioma due to secondary abdominal compartment-syndrome. Causes of intraabdominal hypertension in patients with CNS lesions requiring intensive care are analyzed. Risk factors of intraabdominal hypertension deserving attention in management of patients in neurolCU are determined.

[Severe thrombotic complications in the postoperative period in a child after removal of craneopharyngeoma].

The paper describes a rare clinical case of severe thrombotic complications (thrombosis of the subclavian, superior vena cava and femoral veins) of the child in the postoperative period, after removal of craniopharyngeoma. The development of complications was diagnosed based on clinical symptoms and results of ultrasound. Genesis of thrombotic complications has been clarified with the help of special hemostasiological studies that confirmed the presence of acquired protein S deficiency. The matters of discussion are the problems of diagnosis and therapy of this complication.

Unusual cause of cerebral vasospasm after pituitary surgery.

Cerebral vasospasm (CVS) was described in patients after trans-sphenoidal pituitary surgery due to intra-operative trauma of arteries or blood clots around the arteries of Willis' circle. We consider that in the two presented cases the main cause of CVS in early postoperative period was meningitis. Two patients with pituitary adenomas were operated with trans-sphenoidal approach. CVS developed in early postoperative period. Meningitis was revealed in both cases. CVS regressed only after successful treatment of meningitis. In the first case empiric antibiotic therapy was ineffective and CVS remained until Klebsiella pneumonia was detected in CSF and specific therapy was performed. In the second case empiric therapy was effective and CVS vasospasm regressed in 12 days. These cases show that meningitis can be a leading cause of CVS in early postoperative period in trans-sphenoidal pituitary surgery. Adequate treatment of meningitis shortens duration of CVS in these patients.

[A respiratory failure rating scale in neurosurgical patients].

A respiratory failure (RF) rating scale has been developed to objectify indications for artificial ventilation (AV). The scale consists of three blocks gauging the level of consciousness, the degree of swallowing problems, cough, airway patency, and lung parenchymatous injury. The scale was tested in the period December 2009 to March 2010. Selection of patients in accordance with the chosen study inclusion and exclusion criteria allowed 15 patients to be enrolled in the study. Of them there were 8 (53%) women and 7 (47%) men. The patients' age was 25 to 68 years; median age was 42 years. There were cerebrovascular aneurysms and brain tumors of various locations and histology in 7 and 8 cases, respectively. Three groups of patients were identified. The first two groups included patients with successful extubation, but Group 2 patients were further reintubated because of neurological deterioration. In Group 3 patients, extubation was unsuccessful, i.e. these required reintubation within 48 hours after extubation. Groups 2 and 3 patients developed inflammatory complications, such as nosocomial pneumonia and sepsis; there were worse outcomes. If the tactics of AV initiation were determined from scale scores, it should not differ in Groups 1 and 2. Based on the scale scores, AV should be regained much more early than was practised. The developed scale allows one to optimize the time of AV initiation. Single patient assessment can ascertain a direct cause of respiratory failure (RF) while dynamic assessment can determine the sequence of changes in the magnitude of individual determinants of RF. In patients with unsuccessful tracheal intubation, the scale will optimize the time of reintubation, thereby reducing the incidence of nosocomial and aspiration pneumonia.

[Continuous mechanical ventilation in a neurosurgical intensive care unit (one-year analysis of results)].

This was a retrospective study. Its inclusion criterion was mechanical ventilation (MV) for more than 48 hours. One hundred and eighty-four case records of 184 neurosurgical intensive care unit patients were analyzed. Ventilation modes, upper airway cares and prosthetic replacement were chosen by the protocol accepted at the Institute. Great differences were found in the structure of indications for MV and in the duration of respiratory support in relation to the neurosurgical nosological entity and the site of a major process. The upper airway care protocols accepted at the Institute were shown to reduce the incidence of ventilator-associated pneumonia. Some risk factors for ventilator-associated pneumonia were identified.

[Comatose state caused by seizure-free status epilepticus in postoperative period].

We present a rare clinical observation of progressive development of neurological symptoms up to comatose state in a child with extra-intraventricular craniopharyngioma in delayed postoperative period due to seizure-free status epilepticus which was diagnosed only by EEG-monitoring. Concerning this case report, we discuss genesis of seizure-free status epilepticus and its possible role in development of severe condition in patients with different kinds of neurosurgical pathology in postoperative period.

[The first experience in monitoring the cerebral vascular autoregulation in the acute period of severe brain injury].

The paper presents the first experience in monitoring the pressure reactivity index (Prx) of cerebral vascular autoregulation in a group of patients with severe brain injury. This autoregulation index along with the monitored parameters of intracranial pressure (ICP) and cerebral perfusion pressure (CPP) allows the outcome to be predicted in brain injury: the outcome is poor at a Prx of > 0.2. The continuous estimation of the autoregulation index makes it possible to determine the optimum CPP value for each patient and to timely diagnose decompensation of cerebral vascular autoregulation, which is of importance in selecting treatment policy.

[Intraoperative and early postoperative complications of puncture-dilation tracheostomy in neurosurgical patients].

The paper provides a detailed analysis of the most common and clinically significant complications due to percutaneous dilation tracheostomy performed in 479 patients with neurosurgical diseases in 2002-2007. It also considers such complication of the technique, which is specific to neurosurgical patients, as elevated intracranial pressure (ICP), and describes a procedure of tracheostomy in patients with elevated ICP. Percutaneous dilation tracheostomy made by a skilled surgeon is shown to be effective and safe.

[Choice of optimal respiratory therapy in patients operated for tumors of the posterior cranial fossa].

The results of two different approaches to respiratory support after surgical intervention into the structures of the posterior cranial fossa (PCF) are analyzed in 74 neurosurgical patients, including 41 patients having synchronized pressure support ventilation and 50-80% spontaneous intermittent mandatory ventilation (SIMV + PSV) (Group 1) and 33 patients receiving continuous positive end-expiratory airway pressure (CPAP + PSV) (Group 2). Respiratory therapy has been ascertained to provide at least 50-80% of the minute ventilation volume in neurosurgical patients after interventions into PCF when respiratory failure develops in the postoperative period. Diminished respiratory support may be performed only after neurological stabilization and within 24 hours. Early transition to spontaneous respiration increases the duration of artificial ventilation and worsens neurological symptoms.