OBJECTIVETo explore the changes and the clinical significance of 5-hydroxytryptamine (5-HT), dopamine (DA) levels in serum and cerebrospinal fluid (CSF) of patients with delayed encephalopathy (DEACMP) after acute carbon monoxide poisoning.

METHODSThe dynamic detection of 5-HT and DA levels in serum and CSF from 42 patients with DEACMP was performed with high performance liquid chromatography (HPLC). The condition changes of patients with DEACMP were analyzed with three types of scales: the activity of daily living scale (ADL), information memory concentration test (IMCT) and Hasegawa's dementia scale (HDS); these changes were compared with those from 38 other encephalopathy patients and 38 non-encephalopathy patients, respectively.

RESULTSBefore treatment, the serum 5-HT and DA levels [(662.61 ± 178.50) and (155.74 ± 60.32) nmol/L, respectively] of DEACMP group were both significantly lower than those [(914.08 ± 198.04) and (225.70 ± 48.53) nmol/L] of non-encephalopathy group (P < 0.05); the serum DA level of DEACMP group was also significantly lower than that [(243.57 ± 66.94) nmol/L] of other encephalopathy group (P < 0.05); the serum 5-HT level of DEACMP group was not significantly different from that [(729.54 ± 299.87) nmol/L] of other encephalopathy group (P > 0.05). After treatment, the serum 5-HT and DA levels [(714.08 ± 170.47) and (192.18 ± 33.07 nmol/L, respectively)] of DEACMP group elevated to various extent, but only serum DA level was significantly higher than that before treatment (P < 0.05). Before treatment, the CSF 5-HT and DA levels of DEACMP group were significantly lower than those of non-encephalopathy group and those of other encephalopathy group (P < 0.05). After treatment, the CSF 5-HT level (232.44 ± 54.28 nmol/L) was similar to normal level and significantly higher than that before treatment (P < 0.05); the CSF DA level [(56.83 ± 12.85) nmol/L] of DEACMP group increased only slightly (P > 0.05). In DEACMP group, ADL score (50.64 ± 7.23), HDS score (8.55 ± 8.08) and IMCT score (4.95 ± 7.30) before treatment were significantly different from those (8.5 ± 8.08, 4.95 ± 7.30 and 15.64 ± 10.90) after treatment (P < 0.01). In DEACMP group, there wasa negative correlation between DA level changes and HDS score changes, when the DA levels and HDS scores before treatment were compared with those after treatment (P < 0.05).

CONCLUSIONThe dynamic changes of 5-HT and DA levels in serum and CSF of patients with DEACMP consisted basically with the patient's condition change. The dynamically detected 5-HT and DA levels can be used as the biological indicators to reflect the condition change and treatment effects of DEACMP patients.