Clinical examination of a patient is very likely to reveal the factors making tracheal intubation difficult and thus increasing Many laryngoscopes have been designed since WilliamMacEwan in 1878 passed a tube from the mouth into the Irachea using his fmgees as a guide. J The purpose has been to provide appropriate and rapid access to the trachea and minimize damage to teeth, tempero mandibular joints, and other vulnerable structures.A laryngoscope consists of a handle joined by a folding fitting to a blade that incorporates arrangements for lighting. The blade comprises a fitting, spatula, beak and flange. The flange projects from the edge of the spatula and serves to deflect interfering tissues. In some models the flange is uniformly curved, in others it lies at right-angles to the spatula at first and then changes direction. This initial vertical piece and even the cross-

✓ The acute effects of experimental subarachnoid hemorrhage on cerebral blood flow were investigated in 14 adult rhesus monkeys injected with fresh autogenous blood through a needle positioned within the subfrontal subarachnoid space. Cerebral blood flow was measured by the xenon133 tissue clearance method before hemorrhage, and afterward at 30-minute intervals for a 3-hour period. Post-anesthetic neurological status was graded according to Botterell's classification. Twelve monkeys showed a significant decrease in cerebral perfusion, eight displayed focal neurological deficits, and four were moribund. There was a correlation between the degree of impaired circulation and the severity of neurological deficit. Four additional monkeys subjected to subarachnoid acidic saline injection showed no reduction in cerebral blood flow. In three animals cerebral perfusion was increased during the first hour after injection. It is suggested that measurement of cerebral blood flow may be a more valuable prognostic indication of cerebral function and survival than the angiographic demonstration of arterial vasospasm.

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✓ This study investigates the relationship between vasospasm and repeated subarachnoid hemorrhages in 18 monkeys. Sixteen received weekly 4 cc injections of autogenous blood into the subfrontal subarachnoid space. The weekly mortality rate for 4 weeks was 6%, 33%, 20%, and 37% respectively. The over-all mortality was 75%. The degree of vasospasm did not correlate with the morbidity and mortality. Vasospasm was limited to the intradural cerebral vessels and was diffuse. It never lasted longer than a few hours, late vasospasm did not occur, and the degree of vasospasm did not alter with repeated occasions of “subarachnoid hemorrhage.” Immediate electrocardiogram abnormalities were related to the height of the cerebrospinal fluid pressure rise following the subarachnoid hemorrhage (injected blood). Pathological examination of the vessels shown to be in spasm was normal. The study suggests that the increased mortality associated with repeated subarachnoid hemorrhage is due to cumulative structural damage rather than a heightened vasospastic response to repeated hemorrhages.

Oropharyngeal and nasopharyngeal airways: I (1880-1995)