Disorders of erythrocyte volume homeostasis.

Inherited disorders of erythrocyte volume homeostasis are a heterogeneous group of rare disorders with phenotypes ranging from dehydrated to overhydrated erythrocytes. Clinical, laboratory, physiologic, and genetic heterogeneities characterize this group of disorders. A series of recent reports have provided novel insights into our understanding of the genetic bases underlying some of these disorders of red cell volume regulation. This report reviews this progress in understanding determinants that influence erythrocyte hydration and how they have yielded a better understanding of the pathways that influence cellular water and solute homeostasis.

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.

[The effect of small doses of 7.5% NaCl on brain bulk during elective craniotomies]. / Wplyw malych dawek 7.5% NaCl na objetosc mózgu podczas planowych kraniotomii.

In 16 patients (ASA I i II) aged 16-76 years (48 +/- 15; mean +/- SD) operated on because of intracranial expanding mass, the effect of hypertonic saline (7.5%--1 ml/kg b.w.) on brain bulk (BB) was evaluated. Patients were anaesthetised with a slight hypocarbia (PaCO2 = 33.3 +/- 3.5 mmHg). BB was scored after opening the dura (T0) and 15 min. (T15) after hypertonic saline (HS) infusion. Five points BB scale was used. Brain bulk reduction (D BB) was calculated as a difference: BB15-BB0. Tomographic signs of intracranial expansion (TSIE) in preoperative CT were scored using the scale from 5 to 15 points assessing (1 to 3 points) the size of mass lesion, the size of perifocal oedema, midline shift, displacement of ventricles and basal cisterns compression. Systolic (SBP), diastolic (DBP) blood pressures and heart rate (HR) were monitored. Serum natrium (SNa), kalium (SK) and osmolarity (Sosm) were measured at T0, T15 and Tp0 (one hour after operation). Student's t-test, Wilcoxon test and Spearman correlation were used for statistical analysis. P < 0.05 was considered as statistically significant. HS caused significant decrease in BB (p = 0.002). In 12 patients with a solid brain tumor a negative correlation between BB and TSIE was found (r = -0.68). A slight but significant decreases in SBP and DBP at Tp0 and T15 as well as decrease in HR due to HS were stated. SNa and Sosm increased at T15 and reminded elevated at Tpo. We can conclude that 7.5% saline in a dose of 1 ml/kg b.w. reduces brain bulk during craniotomy in patients with supratentorial mass lesions. In patients with a solid brain tumor this effect correlates negatively with a size of expanding mass. A slight changes in blood pressure and heart rate due to HS as well as moderate decrease in SK are within limits of clinical acceptance.

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.