The growing need for lumbar puncture in order to obtain cerebrospinal fluid (CSF) for the diagnosis Alzheimer's disease is becoming increasingly apparent (Herskovits and Growdon, Reference Herskovits and Growdon2010). The concept of a CSF sampling unit specializing in lumbar puncture would seem the most plausible solution. Physicians and interns are not necessarily skilled in the procedure and neurologists perform lumbar puncture rarely.
As anesthetists and scientists involved in researching post-operative cognitive dysfunction (POCD), we have been sampling CSF in patients who receive spinal anesthesia for total hip joint replacement surgery. This can be done simply, quickly and efficiently before the spinal anesthetic is injected. Anesthetists have expertise in lumbar puncture because spinal anesthesia is an integral part of modern anesthetic practice. For example, in our non-obstetric hospital we perform 12,000 anesthetics a year of which at least 2000 are spinals. The majority of Caesarean sections in our region are performed using spinal anesthesia.
Spinal anesthesia has fluctuated in popularity over the years and in different countries. The introduction of small diameter atraumatic spinal needles in the 1990s was accompanied by an increase in its use. Atraumatic needles have a tip in the shape of a pencil point that tends to part rather than cut the dura resulting in a marked decrease in the incidence of post spinal headache. Current data suggest that the use of a small (27 gauge) atraumatic needle reduces the headache rate to less than 0.5%. (Santanen et al., Reference Santanen, Rautoma, Luurila, Erkola and Pere2004) Unfortunately, neurologists have been slow to adopt these needles (Arendt et al., Reference Arendt, Demaerschalk, Wingerchuk and Camann2009), despite recommendations from the American Academy of Neurology (Armon and Evans, Reference Armon and Evans2005). This may be due to the slight increase in technical difficulty with their use.
Anesthetists become skilled in this procedure as part of normal training. In particular, they are adept at following meticulous sterile techniques and are cognizant of the risks and complications. In addition to headache, these include rare complications such as bleeding, infection and neurological injury. Anesthetists are alert to the contraindications, such as abnormal clotting due to disease or more commonly due to the widespread use of anticoagulant and antiplatelet therapies, which are now so common among the elderly. Finally, anesthetists are able to perform blood patches to treat refractory post-spinal headache on the rare occasions it occurs.
It therefore seems most appropriate for anesthetists to be involved in performing lumbar punctures in CSF sampling clinics. The question of whether those receiving routine spinal anesthesia, should be given the option of having a CSF sample collected at the time deserves serious consideration, especially among the middle aged.
