Hysteresis of the cerebrospinal pressure-volume curve in hydrocephalus.

The objective was to study the displacement of the cerebrospinal fluid pressure-volume curve during the descent relative to the ascent of intracranial pressure recorded during the cerebrospinal fluid constant rate infusion test. This phenomenon can be interpreted as the hysteresis of the pressure-volume curve. The cerebrospinal fluid dynamics were tested in fifty-eight patients with clinical symptoms of hydrocephalus. After finished infusion, ICP was recorded until it returned to steady state level. Pressure-volume curves were plotted separately for ascending and descending phases of the test. The parameters of CSF compensation were estimated on the basis of mathematical mono-exponential model of CSF circulation. The pressure-volume curve post-infusion was visibly shifted upward in 69% of tests. Those who demonstrated the upward shift of the pressure-volume curve had greater an elastance coefficient of the cerebrospinal space (with shift: E1 = 0.26 +/- 0.14; without shift: E1 = 0.17 +/- 0.06; p < 0.05). Magnitude of the shift was positively correlated with pulse amplitude of ICP (r = -0.763; p < 0.0001). The accuracy of clinical examination of the pressure-volume compensatory reserve, which take into account both compression and decompression phase of the study, may be affected by this phenomenon.

Arterial to end-tidal carbon dioxide difference during craniotomy in severely head-injured patients.

Clinical data suggest that cerebral blood flow (CBF) can be abnormally low within the first four to eight hours after severe head injury (SHI). An aggressive hyperventilation can additionally worsen CBF and provoke cerebral ischemia. Therefore an accurate PCO2 monitoring in SHI patients (pts) is necessary. PetCO2 failed to reflect PaCO2 in SHI pts treated in neurosurgical ICU. Up to now, the validity of PetCO2 monitoring in estimating PaCO2 during an acute posttraumatic craniotomy has not been studied. Forty five adult SHI pts operated on because of an acute intracranial posttraumatic haematoma within 8 hours after head trauma entered the study. The standard anaesthetic protocol included N2O/O2, fentanyl and pancuronium bromide anaesthesia, and mechanical ventilation with respiratory rate 10 divided by 12 bpm and tidal volume in mL = body weight (kg) x 10 - 100. After obtaining a stable PetCO2 arterial blood sample was taken for PaCO2 measurement and P(a-et)CO2 = PaCO2 - PetCO2 was calculated. P(a-et)CO2 ranged -9 divided by 20 mm Hg (5 +/- 6; mean +/- SD). P(a-et)CO2 between 2 mm Hg and 6 mm Hg was found in 17 (38%) patients only. A negative P(a-et)CO2 was stated in 20% of patients. No relationships between P(a-et)CO2 and pts age and mean arterial pressure were found. P(a-et)CO2 was higher in normocapneic pts than in hyperventilated ones and tended to decrease with an increase in heart rate. We can conclude that during an acute craniotomy in SHI pts, PetCO2 does not reflect accurately PaCO2 and the monitoring of adequacy of ventilation should be based on repeated or continuous measurements of an arterial PCO2.

The relationship between cerebral blood flow velocities and the amount of blood clots in computed tomography after subarachnoid haemorrhage.

127 patients with aneurysmal subarachnoid haemorrhage (SAH) were analyzed for the relationship between the amount of blood clots as detected by initial computed tomography (CT) up to 48 hours after SAH and changes of blood flow velocities as measured using transcranial Doppler ultrasonography (TCD). All patients were operated on within 72 hours after SAH. Patients who presented with remarkable brain oedema or with pathological intracranial pressure (ICP) due to mass effects of a haematoma, and who were in a poor neurological condition classified according to Hunt-Hess as grade V were excluded from this study. Serial TCD examination of the middle cerebral arteries (MCA) and anterior cerebral arteries (ACA) started within 48 hours after SAH and were performed daily up to three weeks. A statistically significant correlation between blood load designated according to Fisher's grading as group CT I-CT IV and mean flow velocities (MFV) was found in groups CT I, II, and III. High values of MFV in MCA examinations were noted in patients with severe SAH (group CT III)--161 cm/s, and low values in patients without SAH (group CT I)--119 cm/s. Patients with haematocephalus and/or haematoma without a mass effect (group CT IV) had lower blood flow velocities than patients with severe SAH (group CT III) but values were higher than in patients without SAH (group CT I). The number of days for which MFV in the MCA was > 120 cm/s and was statistically (p < 0.05) correlated with the amount of blood clots as observed in the respective CT (in group CT I, II, and III). MFV values in the anterior cerebral artery (ACA) were lower than those obtained in the middle cerebral artery (MCA) in all groups. Statistically significant (p < 0.05) differences were noted between groups CT I and CT III (first and third week) and between groups CT I and CT IV (third week). If the SAH was extensive in the CT scan, pathological values of MFV > 90 cm/s were observed in ACA, and this was more pronounced in group CT III than in group CT IV. Blood flow velocities obtained via TCD were registered to compare side-to-side differences and particularly high differences were observed in patients with severe SAH. It is concluded that the amount of blood clots in the initial computed tomography after SAH is significantly correlated with cerebral blood flow velocity measurements by TCD.

Cerebral vasospasm detection by TCD after supratentorial brain tumours surgery.

Serial transcranial Doppler ultrasonography (TCD) studies were carried out in 61 patients, who had been operated due to supratentorial brain tumours. Among 61 cases have been 26 gliomas, 19 meningiomas and 16 metastases. The Mean Flow Velocity (MFV) exceeding 120 cm/s in Middle Cerebral Artery (MCA) and 90 cm/s in Anterior Cerebral Artery (ACA) has been admitted as pathognomonic for vasospasm. The vasospasm has been stated in 14 cases (23%)--10 gliomas and 4 meningiomas out of 61 patients. The vasospasm has been more intense in ACA on the operated (lesion) side than in MCA and on the non operated (opposite) side.

The concept of cerebral circulatory-pressure index (CCPI).

The theoretical relations between blood pressure (MABP), intracranial pressure (ICP) and cerebral perfusion pressure (CPP) as well as the new Cerebral Circulation-Pressure Index (CCPI) are presented in the paper. The special nomogram collecting all of these parameters was constructed. CPPI was defined as a quotient of CPP and ICP: [formula: see text] CCPI reflects the relationship between the systemic MABP and ICP and for ensuring the normal conditions of intracranial circulation the MABP must be at least 4 divided by 5 times higher than ICP. The low values of CCPI, if they are not immediately corrected, results on severe brain disability or even death. We didn't find till now what should be the upper limit of CCPI, which overcrossing may be danger for the patient, especially with impaired autoregulation. Based on analysis of patients operated due to intracranial disorders as brain tumours, spontaneous and traumatic haematomas as well as ruptured aneurysms we find that the values of CCPI over 3 have a good prognosis, between 3 and 2 is a field for intensive treatment consisting on decreasing ICP or increasing the systemic blood pressure or both. If CCPI is below 1.5 the prognosis is pessimistic and all the patients died. CCPI together with the nomogram are useful in current evaluation of the state of patients and of the efficacy of treatment and prediction of the treatment results.

Tramadol for postoperative analgesia in intracranial surgery. Its effect on ICP and CPP.

An ideal analgesic for patients after craniotomy should neither cause respiratory depression, nor affect intracranial pressure (ICP) and cerebral perfusion pressure (CPP). The aim of the study was to evaluate the effect of Tramadol (T) on ICP and CPP, as well as to determine its analgetic efficacy in patients (pts) after craniotomy. Thirty five pts aged 16 divided by 78 years (mean 46) entered the study. Twelve had GCS (Glasgow Coma Scale) scores < or = 8 and 23 pts had scores > or = 12. Fourteen pts were mechanically ventilated and 21 pts were breathing spontaneously (BS). Tramadol was injected i.v. at a dose of 0.75 mg/kg over 3 minutes in 11 pts (Group 1), 1.0 mg/kg over 5 minutes in 13 pts (Group 2) and 1.0 mg/kg over 10 minutes in 11 pts (Group 3) PaCO2 was measured before T in all pts and at 8 minute after injection in 21 BS pts. Heart rate (HR), mean arterial blood pressure (MBP), ICP, CPP and respiratory frequency (f) were registered before and in the 1st, 3rd, 8th, and 15th minute after T. Analgetic effect was evaluated in 22 conscious pts by comparing the pain intensity before and 30 minutes after T using a five-point verbal response scale. Mean control ICP was 17 mmHg. ICP over 15 mmHg was diagnosed in 15 pts (mean ICP equal 26 mmHg). Mean CPP for all 35 pts was 85 mmHg. There were no statistically significant changes in HR, MBP, ICP, and CPP after T in any particular group, nor were there changes in ICP in subgroups with normal and elevated ICP. No significant changes in PaCO2 and f were found in BS pts. Satisfactory analgesia was obtained in 50% of pts of Group 1, and in 88% of pts of Groups 2 and 3. We conclude that tramadol in doses of 0.75 mg/kg and 1.0 mg/kg i.v. does not affect ICP and CPP in adult postcraniotomy patients and seems to be a safe and effective analgesic at a dose of 1.0 mg/kg for postcraniotomy pain control.

[Results of postoperative treatment of patients after brain tumor removal based on the cerebral circulatory pressure index (CCPI) in comparison with ICP and CPP]. / Wyniki pooperacyjnego leczenia pacjentów z usunietymi guzami mózgu w oparciu o mózgowy wskaznik krazeniowo-cisnieniowy (CCPI) i w porównaniu z ICP i CCP).

The aim of the study was the assessment of prognostic value of CCPI in relation to the results of treatment of patients with increased intracranial pressure after brain tumour operative treatment. The results of treatment of 107 patients with intracerebral tumours according to neurological state at the introduction of treatment (GCS) and initial values of ICP, CPP and CCPI as well as final results of treatment (GOS) are analysed. A special normogram collecting all of these parameters was constructed, as well as the directions of treatment depending on the areas of MABP, ICP and CPP were established. The CCPI seems to be more a sensitive and earlier signals suggesting the urgency and the direction of treatment than ICP and especially CPP alone. There seems to be a great consistence of the patient state evaluation according to GCS, GOS and CCPI which is also a prognostic factor. All the patients with initial CCPI below 1.5 died while all the patients with CCPI over 3.0 in good and very good neurological state, and all the patients with initial CCPI between 1.5 and 3.0 had neurological deficits.

[Analysis of own clinical material treated by conservative and aggressive control of intracranial hypertension]. / Analiza wlasnego materialu klinicznego przy zachowawczym i agresywnym zwalczaniu nadcisnienia wewnatrzczaszkowego.

These problems arising during the treatment of increased intracranial pressure (ICP) were analysed on the basis of own clinical material with consideration of different therapeutic methods--pharmacological and aggressive. Statistical analysis (contingency tables) showed that the treatment consisting of dexamethason, mannitol and furosemid was the most efficient in the group of patient with increased ICP in the range 15-30 mmHg. In patients with ICP in the range 30-50 mmHg, where other aggressive methods of treatment had failed, the most efficient treatment was cranio-dural decompression.