Fumiharu Yanagi

Heparin bonding of the extracorporeal circuit reduces thrombosis during prolonged lung assist in goats.

This study investigated whether an artificial membrane lung of nonmicroporous polyolefin hollow fibers bonded with heparin could prolong venoarterial extracorporeal lung assist (ECLA) with low dose systemic heparin in goats. We compared heparin bonded circuits (Carmeda Bioactive Surface, “HB” group, n = 5) with non heparin bonded circuits (“NHB” group, n = 5) in venoarterial ECLA (V-A ECLA) for 7 days. Activated coagulation time (ACT) was maintained at approximately 130 sec by systemic infusion of small doses of heparin in the HB group, and at 200–230 sec in the NHB group. Thrombus formation was assessed by visual examination of the circuit, and possible cerebral embolization of thrombi was observed from behavioral abnormalities of the animals. The mean heparin dose given during ECLA was 20.4 ± 3.6 U/kg per hr in HB, and 50.9 ± 14.2 U/kg per hr in NHB, significantly less in HB than NHB (p < 0.01). Blood gas changes across the oxygenator, bypass flow rate, platelet aggregation activity, platelet counts, fibrin monomer (FM) test, and antithrombin-III (AT-III) activity did not differ between the two groups. In HB, thrombi were fewer and no abnormal neurologic symptoms were observed during ECLA. Numerous thrombi were observed in all oxygenators with NHB. One NHB goat developed convulsions and cerebral hemorrhage on the 6th day of ECLA. Nonmicroporous polyolefin hollow fibers can be bonded with heparin. An artificial membrane lung constructed of these fibers showed good anticoagulation by decreased thrombus formation with a small dose of infused heparin.

Accidental total subarachnoid block following local scalp anesthesia

Stereotactic biopsy is presently performed routinely in the histological diagnosis of brain tumors before the start of chemotherapy. We present a case of accidental total subarachnoid block (TSB) [1] in which neurosurgical stereotactic operations were repeatedly conducted under local anesthesia. There are reports of accidental TSB following durapuncture in spinal epidural anesthesia or intentional TSB for the treatment of intractable pain [2]. Our report describes a case of unexpected, temporary coma and apnea that are presumed to have resulted from accidental direct penetration of a local anesthetic agent into the cerebral ventricular system during local scalp anesthesia.