Fig. 12.-Chart II. Pulse-rate and blood-pressure curves taken durig an operation for extirpation of the Gasserion ganglion; ether anesthesia. Upper line repres-nts bloodpressure; lower, pulse.

Note (1) Great excursions of blood-pressure during the paroxysms of the "neuralgia quinti major" prior to operation, unassociated with any change in pulse-rate. (2) The rise in blood-pressure from its "ether level" at 205 millimeters of Hg. to 230 millimeters during the elevation of the temporal lobe and associated compression of the brain. (3) The corresponding retardation of pulse-rate from sixty-five to thirty beats per minute due to vagus stimulation. (4) The return of pulse-rate and blood pressure to normal levels after the release of the brain from compression.

pressure were already low. In critical cases of ganglion extirpation, doubtless the structure should be cocainized before handling, as in the case of any sensory nerve.

CHART III. (Fig. 13.) Cerebral Group. Ganglion operation. Shows a rapidly fatal case of shock in an intracranial operation with paralysis of the vasomotor centre and consequent fall in blood-pressure. Here the normal response with rise in blood-pressure and slowing of pulse did not take place during the compression of the brain. Possibly this was due to extensive pathological alterations present in the blood-vessel walls. The rapid fall in blood-pressure even before there was any outspoken change in pulse-rate should have been an indication to immediately abandon the operation. Owing to the low blood-pressure the ganglion was removed with a minimum of bleeding in this case. The usual therapeutic measures to restore arterial tension proved futile.

CHART IV. (Fig. 14.) Peripheral Group. Stretching sciatic nerve. Shows the physiological response as a rise in bloodpressure consequent upon the handling of an important mixed peripheral nerve-trunk in a normal individual. Here an accelerator and pressor response are combined. In other instances there may be no increase in pulse-rate.

CHART V. (Fig. 15.) Peripheral Group. Complete breast operation. Shows the absence of any appreciable effect on pulserate or blood-pressure other than the usual rise during the primary stage of ether-anesthesia. In such an operation there is no loss of blood, and no important sensory nerve-trunks are divided or handled. (Contrast pulse-rate with Figs. 4 and 9.)

PHYSIOLOGICAL NOTES.

An attempt has been made in the introductory paragraphs of this communication to summarize briefly the present conception of the term "traumatic shock," its method of production under

and blood-pressure curves taken during a fatal

case of ganglion extirpation; ether anesthesia. Blood-pressure, heavy line; pulse-rate, light line.

Note (1) The comparatively high blood-pressure and rapid pulse during

the preparation of the patient and the early stage of anesthesia. (2) The fall in pulse-rate to 100, which should probably have been "ether level." (3) The drop in blood-pressure and acceleration of pulse from slight loss of blood during opening of skull. (4) The immediate fall in blood-pressure and rise in pulse. during elevation of temporal lobe, the opposite of the normal reaction shown in Fig. 12.

Fig. 14.- Chart IV. Pulse-rate and blood-pressure curves taken during the operation of stretching the sciatic nerve for sciatic neuritis; ether anesthesis. Upper line, bloodpressure; lower line, pulse-rate.

Note (1) Rise during primary stage of anesthesia and "ether level" of pulse, 95 to 100, and blood-pressure, 170 to 175. (2) The pressor effect (to 238 millimeters of Hg.) and accelerator response of pulse-rate, from 90 to 140 or 145. due to stretching the nerve for a period of ten minutes. (3) The return to "ether level" on releasing the nerve.

Fig. 15.- Chart V.- Pulse-rate and blood-pressure curves taken during the Halsted operation for carcinoma of the breast. Heavy line, blood-pressure: light line. pulse.

Note (1) Slight deviation from normal levels except during primary stage of anesthetization.

ordinary circumstances, and the means by which in certain cases may be avoided.

it

The experimental observations by Fischer, Goltz, Seabrook, Crile, and others have shown that the weakened or paralyzed -condition of the vasomotor center in the medulla, brought about