[The neuropathy of the autonomic nervous system. An additional anesthetic risk in diabetes mellitus].
Some 20-40% of diabetics suffer from an autonomic neuropathy. This complication of diabetes mellitus impairs the regulation and the reflexes of the cardiovascular system. This study compares the cardiovascular characteristics of diabetics and nondiabetic control patients. METHODS. 21 patients (11 diabetics, 10 nondiabetics) undergoing ophthalmic surgery were investigated. They were tested preoperatively for autonomic cardiovascular dysfunction by application of four established tests. These were: heart rate responses to the Valsalva maneuver, deep breathing and standing up (30/15 test) and the Schellong test. The anaesthesia was induced with fentanyl (0.1 mg), etomidate (2.5 mg/kg) and succinyl choline (1.5 mg) and maintained with oxygen/nitrous oxide (1.4:3 l/min) and isoflurane (0.2-0.8 vol%). Blood pressure and heart rate were automatically measured every minute during induction of anaesthesia and every 3 min during anaesthesia. Additionally the heart rate response to 0.5 mg atropine i.v. was evaluated. RESULTS. The autonomic function tests revealed pathologic reactions in all diabetics (two early, six definitive, three severe) and none in controls. Remarkable cardiovascular events occurred exclusively in the diabetic group, especially during induction of anaesthesia. The systolic blood pressure (SAP) increased in diabetics from a preinduction value of 150 mmHg (median, range 105-205 mmHg) to a maximum of 200 mmHg (160-250 mmHg) after intubation, in controls from 130 (100-150 mmHg) to 170 (110-190 mmHg). Following this peak, SAP fell in diabetics to 120 mmHg (80-160 mmHg), in controls to 110 (100-140 mmHg). Two diabetics had to be treated because of an SAP exceeding 220 mmHg, two other diabetics because of an SAP below 80 mmHg. After atropine administration the heart rate of diabetics showed a median increase of 15% (range 0-40%). In four diabetics, however, the increase was less than 10%. In control patients the increase was 50% (40-80%). All patients with severe cardiovascular reactions during induction of anaesthesia and with heart rate elevation following atropine of less than 10% had a definite or severe neuropathy of the autonomic nervous system revealed by the tests. DISCUSSION. In the only slightly stressful ophthalmic surgery, remarkable events were noted particularly during the induction of anaesthesia. The critical decreases and increases of SAP might be related to the autonomic dysfunction, because of the hypersensitivity of a partly damaged autonomic nervous system or its impaired function. This led to a loss of heart rate variation and adequate blood vessel tone. The severe cardiovascular reactions always went along with clearly pathologic findings in the tests performed. Normal test results in diabetics implied normal cardiovascular reactions, as could be observed in nondiabetics. CONCLUSION. Abnormal cardiovascular reactions in diabetics must be kept in mind. The simple tests specified here can identify such predisposed patients.
Linstedt
U
U
Klinik für Anästhesiologie und Operative Intensivmedizin im Klinikum der Christian-Albrechts-Universität zu Kiel.
Jaeger
H
H
Petry
A
A
D000328:Adult; D000368:Aged; D000758:Anesthesia; D001342:Autonomic Nervous System Diseases / Q000209:etiology* / Q000503:physiopathology; D002319:Cardiovascular System / Q000503:physiopathology*; D048909:Diabetes Complications; D003920:Diabetes Mellitus / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors
Die Neuropathie des autonomen Nervensystems. Ein zusätzliches Narkoserisiko beim Diabetes mellitus.