ISSN:
1432-055X
Keywords:
Schlüsselwörter: Propofol – Thiopental – Lokale zerebrale Sauerstoffversorgung – Spektrophotometrie
;
Key words: Propofol – Thiopentone – Local cerebral oxygen supply – Spectrophotometry
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Description / Table of Contents:
Abstract. Because the brain is highly vulnerable to damage from even a brief imbalance of oxygen delivery and demand, intraoperative disturbances of local oxygen supply must be avoided. Until now, there has been no method allowing fast and reliable intraoperative measurement of the local oxygen supply in the human brain. Intraoperative investigations were therefore performed using the Erlangen micro-lightguide spectrophotometer. Methods. Intraoperative investigations of local intracapillary haemoglobin saturation (SO2) were performed during neurosurgical interventions using the Erlangen micro-lightguide spectrophotometer (EMPHO). Measurements were performed in eight patients (age 31 – 67 years) during neurosurgical interventions. Three received thiopentone anaesthesia, and three received propofol. In two patients thiopentone anaesthesia was later changed to propofol. The EMPHO enables rapid, non-invasive measurement of local intracapillary SO2. White light from a Xenon-arc lamp is transmitted by a 250-µm micro-lightguide to the tissue. The remitted (reflected) light is led by 6 micro-lightguides surrounding the illuminating one to a rotating band-pass interference filter disk. Light in the range of 502 to 630 nm is detected with a photomultiplier. In this range haemoglobin shows an SO2-dependent spectrum, which is then analysed. Because the measurements are performed with micro-lightguides, high spatial resolution is attained. Representative measurements can be performed in a very short period of time (approx. 60 s); thus, the EMPHO enables rapid monitoring of local SO2 in the brain. Results. The effect of propofol and thiopentone anaesthesia on the distribution of local intracapillary haemoglobin saturation was investigated during neurosurgical interventions. The arterial PCO2 was similar in both groups (31±0.7 and 31±0.5 mm Hg, respectively). There were also no differences in arterial blood pressure. The FiO2 was 0.28±0.04 in the thiopentone group and 0.30±0.1 in the propofol group. In all patients receiving propofol anaesthesia higher local SO2 values were found, even if the patients first received thiopentone (values in parenthesis). The mean local SO2 amounted to 65.4% (57.3%) in the propofol group and 38.8% (45.2%) in the thiopentone group. The number of values below 25% SO2 was 5.6% (5.8%) in the propofol group and 18.7% (19.1%) in the thiopentone group.
Notes:
Zusammenfassung. Der Einfluß von Propofol- und Thiopentalnarkose auf die Verteilung der lokalen intrakapillären Sauerstoffsättigung des Hämoglobins (sO2) wurde bei 8 Patienten intraoperativ während neurochirurgischer Eingriffe untersucht. Die Patienten waren im Alter zwischen 31 und 67 Jahren. Drei der Patienten erhielten eine Thiopentalnarkose, 3 weitere eine Propofolnarkose. Zwei der Patienten erhielten in der ersten Hälfte der Operation Thiopental, in der zweiten Hälfte Propofol. Die Werte dieser Patienten sind in Klammern. Die mittlere lokale sO2 betrug in der Propofolgruppe 65,4% (57,3%). Während Thiopentalnarkose wurden 38,8% (45,2%) gemessen. Der Anteil der Werte unter 25% sO2 betrug in der Propofolgruppe 5,6% (5,8%), in der Thiopentalgruppe 18,7% (19,1%).
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s001010050089
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