Association of low serum anticholinergic levels and cognitive impairment in elderly presurgical patients.

Low-dose scopolamine, given as presurgery medication, resulted in low levels of serum anticholinergic activity and caused measurable cognitive impairment in 18 psychiatrically healthy elderly patients. The degree of impairment was directly related to serum anticholinergic activity levels and, in the small subgroup of patients scheduled for spinal anesthesia, to CSF anticholinergic activity. Two of the mental status tests used, the Rey Auditory-Verbal Learning Test and the Saskatoon Delirium Checklist, were sensitive enough to detect these mild drug-induced changes, while two other tests, the Mini-Mental State and the Symbol Digit Modalities Test, were not.

Placental and blood-CSF transfer of intramuscularly administered atropine in the same person.

Both placental and blood-CSF transfer of atropine (0.01 mg/kg intramuscularly) was measured (by RIA) in 11 parturients undergoing Caesarean section under spinal analgesia. In the foeto-placental unit a significant penetration into amniotic fluid was found, whereas in CSF there was a measurable level of the drug (greater than 1.5 ng/ml) in only one mother. Our results show that there is a fundamental difference in the penetrability of tertiary ammonium alkaloids like atropine through these two biological membranes. However, our results concern penetration into human lumbar CSF and do not necessarily reflect potential penetration into the ventricular CSF, choroid plexus or brain ventricular ependyma.

New aspects in the use of atropine.

Several new factors have recently been shown to influence the pharmacokinetics of atropine. Age appears to have a clear effect on the elimination of atropine: for example, prolonged elimination has been found in children under 2 years of age and in the elderly. The higher sensitivity of these patients to the effects of atropine can be explained, at least partly, by this phenomenon. Due to the fast placental transfer of atropine, i.v. administration before cesarean section can have strong effects on the newborn. Most important, however, it decreases the barrier pressure of the lower cardioesophageal sphincter (pulmonary aspiration). Thus, routine atropine premedication is contraindicated before cesarean section. On the other hand, children appear to need a routine anticholinergic premedicant. Without it profuse salivary secretion may interfere with anesthesia. The use of atropine in premedication of healthy adult patients is controversial. Because peroral premedication (benzodiazepines) is nowadays increasing in the adult patient, especially in the elderly, routine use of atropine should be avoided.