Document Type Doctoral Thesis Author Smith, Francois Jacobus URN etd-10102003-100731 Document Title Ondersoek na die invloed van die narkosetegniek (Ketamien plus Midasolam teenoor Sufentaniel) op breinskade tydens hartoperasies by die mens (Afrikaans) Degree MD Department Anaesthesiology Supervisor
Advisor Name Title Prof J M Hugo Prof P R Bartel Committee Co-Chair Prof W J H Vermaak Committee Co-Chair Keywords
- anaesthetic drugs
- neuropsychological deterioration
- anesthetic technique
- cardiac surgery
- brain ischaemia
Date 2003-04-15 Availability unrestricted AbstractIntroduction
The neuropsychological deterioration after cardiac surgery involving cardiopulmonary bypass (CPB), is ascribed to brain ischaemia caused by, amongst others, hypotension, cerebral hyperthermia, cerebral embolism, interaction between pharmacological methods and hypothermia during ischaemia, and the directly neurotoxic of anaesthetic drugs.
To investigate the effect of the anaesthetic techniques midazolam plus ketamine (MK) or sufentanil (S) on the quantitative EEG (QEEG), reaction time (RT), serum neuron specific enolase (NSE), and serum S-100b protein after cardiac surgery involving CPB in humans.
Patients and methods
The sample consisted of a total of 42 patients scheduled for elective coronary artery bypass (CABG) or valve replacement (VR). All patients were not available for all the postoperative tests. Patients were allocated randomly to group MK or S.
Anaesthetic technique: S or MK. Isoflurane was administered when necessary.
CPB technique: 30°C, membrane oxygenation, a 40 mm filter in the arterial cannula and a-stat-blood gas management, blood pressure of 50 to 70 mm Hg and a haematocrit > 22%. Patients were weaned from CPB when nasopharyngeal temperature reached a maximum of 37,5°C.
QEEG and RT was performed 1 to 2 days preoperatively and 5 to 6 days postoperatively.
Serum-NSE and -S-100b protein were measured preoperatively, 2 minutes after going on CPB, after rewarming to 37°C, just before the end of CPB and 2, 4, 10, 20, 30, and 48 hours after CPB.
QEEG: The most noticable finding was an increase in slow wave activity (relative q and s). The QEEG outcome was better after CABG than after VR (p < 0,001), but not different between MK and S (p = 0,5000). Dq% was better with MK than S (p = 0,0120). Dq% (p = 0,0010), Da/q% (p = 0,0090) and DPS% (p = 0,0025) was better after CABG than VR.
Reaction time: There was a significant deterioration in 5/18 (27,78%) of MK and 12/18 (66,67%) of S (p = 0,0220). The change in accuracy in sequential reation time 1 (p = 0,0100), and sequential reation time 2 (p = 0,0970) and the cumulative accuracy was better with MK than S(p = 0,0020).
Chemical markers: Over groups 14,8% of patients had a poor NSE and 61,9% a poor S-100b outcome. Within groups a poor NSE outcome was found in 14,8% of MK and 14,8% of S (p = 1,0000), and 4,8% of CABG but 23,8% of VR (p = 0,1840). Within groups as adverse S-100b outcome was found in 42,9% of MK but 81,0% van S (p = 0,0250; Fisher's exact test), and 66,7% of CABG and 57,1% of KV (p = 0,7510. According to area under the curve of corrected NSE, CABG had a better outcome than VR (p = 0,0040). According to both maximum S-100b level and the area under the curve of S-100b, an interaction occurred between the anaesthetic technique and the procedure, with VR doing better with MK while CABG did significantly better with S (p = 0,0180 en 0,0040 respectively).
Conclusion, shortcomings, significance and contribution
This study has shown that, in as far as brain damage is concerned, the outcome was probably better with MK than with S, and CABG better than VR. An interaction was found between the anaesthetic technique and the type of operation.
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28.8 Modem 56K Modem ISDN (64 Kb) ISDN (128 Kb) Higher-speed Access 00front.pdf 197.68 Kb 00:00:54 00:00:28 00:00:24 00:00:12 00:00:01 01chapter1.pdf 144.21 Kb 00:00:40 00:00:20 00:00:18 00:00:09 < 00:00:01 02chapter2.pdf 141.80 Kb 00:00:39 00:00:20 00:00:17 00:00:08 < 00:00:01 03chapter3.pdf 634.06 Kb 00:02:56 00:01:30 00:01:19 00:00:39 00:00:03 04chapter4.pdf 105.95 Kb 00:00:29 00:00:15 00:00:13 00:00:06 < 00:00:01 05chapter5.pdf 191.96 Kb 00:00:53 00:00:27 00:00:23 00:00:11 00:00:01 06chapter6.pdf 168.41 Kb 00:00:46 00:00:24 00:00:21 00:00:10 < 00:00:01 07chapter7.pdf 600.61 Kb 00:02:46 00:01:25 00:01:15 00:00:37 00:00:03 08chapter8.pdf 696.04 Kb 00:03:13 00:01:39 00:01:27 00:00:43 00:00:03 09chapter9.pdf 163.72 Kb 00:00:45 00:00:23 00:00:20 00:00:10 < 00:00:01 10appendix.pdf 259.51 Kb 00:01:12 00:00:37 00:00:32 00:00:16 00:00:01 11references.pdf 499.64 Kb 00:02:18 00:01:11 00:01:02 00:00:31 00:00:02