PERIPHERAL vascular collapse occurring

Transcription

1 Evaluaton of Plasma, Metaramnol, and Hydrocortsone n Expermental Endotoxm Shock Downloaded from by on January, 0 By WESLEY W. SPINK, M.D., AND JAMES VICK, M.S. PERIPHERAL vascular collapse occurrng n human bengs s commonly assocated wth nfectons due to Gram-negatve colform bactera and the release of endotoxn by the organsms. Procedures used n the management of human endotoxn shock have ncluded the nfusons of whole blood and plasma, the use of pressor agents, and the admnstraton of adrenocortcal sterods. Because multple procedures and drugs have often been employed smultaneously, t has been dffcult to evaluate the mert of each. For ths reason, the followng expermental studes were desgned n whch shock was establshed n dogs wth a standardzed preparaton of endotoxn; at the tme when rreversble shock appeared mmnent, attempts were made to reverse the process wth one or more agents. Methods The same lot of endotoxn, prepared by prevously descrbed methods from a stran of Eschercha col (E. col), was used throughout n a dose standardzed so that death usually followed a sngle ntravenous njecton wthn to hours. Adult male mongrel dogs were anesthetzed wth 0 mg. of sodum pentobarbtal per Kg. ntravenously, and suffcent barbturate was used subsequently so that constant relaxaton was produced. A dose of 0. mg./kg. of endotoxn was njected nto the femoral ven and recordngs and observatons were made contnuously for hours thereafter. Systemc arteral pressure was measured by placng a polyethylene catheter n the femoral artery, and, wth the ad of a Statham stran gauge, recordngs were made contnuously on a Sanborn TwnVso recorder. An ndwellng catheter was nserted nto the urnary bladder and urne was collected throughout the perod of observaton. The ph of femoral arteral blood was measured hourly wth a Beckman ph meter. Hematocrt determnatons were also carred out every hour on femoral arteral blood. The pro- From the Department of Medcne, Unversty of Mnnesota Medcal School, Mnneapols, Mnnesota. Receved for publcaton August, 0. cedures were not carred out under completely aseptc condtons. If the anmals survved for a perod of hours after recevng endotoxn, they were placed n a cage wth adequate food and water and permtted to recover from the anesthesa. Dogs were consdered to have recovered "permanently" from endotoxn shock after they had resumed normal physcal actvtes outsde of the cages. Plasma was obtaned from fastng donor dogs weghng approxmately 0 Kg. The blood was collected n sterle contaners; heparn was used as an antcoagulant n a concentraton of. mg. per cent. Only the frst 0 ml. of blood removed from the donor was used as a source of plasma, snce t has been observed n ths laboratory that the second 00 to 0 ml. contan vasoconstrctng substances, ncludng epnephrne and norepnephrne, that are a response to hemorrhagc shock. The freshly drawn blood was centrfuged n the cold, and the plasma removed and stored n a refrgerator. A per cent soluton of metaramnol btartrate* was used as a vasopressor agent. Metaramnol was gven ntravenously, as a soluton contanng mg. n 0 ml. of per cent dextrose and water. Constant efforts were made to delver a dose that dd not elevate the systolc arteral pressure over 0 to 00 mm. Hg. Cortsol was rapdly admnstered ntravenously as hydrocortsone sodum succnatet n a dose of 00 mg. An nfuson of 00 mg. of sterod n 0 ml. of per cent dextrose and water was then gven ntermttently, dependng upon the condton of the anmal. Results Crtera Indcatng the Onset of Irreversble Shock The clncal and hemodynamc changes that occur n canne endotoxn shock have been recorded elsewhere. ' The characterstc hemodynamc alteratons for one of the anmals n the present experment are shown n fgure. Wthn a mnute or two after the njecton of endotoxn there was a prompt declne n 'Suppled as Aranne Btartrate per cent by the Research Dvson of Merck Sharp and Dohme, Phladelpha, Pennsylvana. t Suppled as Solu-Cortef by the Upjohn Co., Kalamazoo, Mchgan. Crculaton Research, Volume IX, January

2 : ' - '! ENDOTOXIN, METARAMINOL, AND HYDROCORTISONE Downloaded from by on January, 0 mm. Hg I 0. mg./kg. E.Col : T ;. y _ ~ Mn / Survvors at Hrs. Avg. Survval tme. Hrs ' '. Mn Dog No 0 L m Hr. ' '. <J Hrs wt(kg) None ' -- Dog ll,.0 Kg.. Hrs. Hrs. Survval Tme (Hrs) Fgure A composte tracng showng the systolc blood pressure of a clog gven a lethal dose of endotoxn. Note the prompt drop n pressure wthn one mnute after the njecton of endotoxn, the gradual recovery n pressure, ad then the gradual declne after one hour. The table summarzes the survval tme of each of control dogs after the njecton of endotoxn. the systemc blood pressure. Ten to mnutes later the blood pressure tended to rse; ths was followed by a gradual and progressve fall. Ths secondary fall was assocated wth olgura and anura, a declne n the ph of arteral blood, and a rse n the hematocrt. Intaton of these hemodynamc alteratons ndcated the ascendance of rreversble shock. It was at ths pont that attempts were made to reverse the progresson of shock. Control Untreated Dogs wth Endotoxn Shock Twelve dogs weghng from to. Kg. were gven 0. mg./kg. of E. col endotoxn, whch proved to be lethal for all the anmals (fg. ). The average survval tme was. hours. The longest perod of survval after endotoxn was hours (dog no. ). Effect of Plasma Infusons on Endotoxn Shock Ten dogs weghng from.0 to Kg. were gven 0. mg./kg. of E. col endotoxn. Although large nfusons of canne plasma were gven, varyng between 0 and 0 ml., none Crculaton Research, Volume IX, January '0-A r V 0- V ^ ^, Ecol 0 mn. O.mg/Kg. 0/0 Survved at Hrs. Avg. Survval tme. hrs 0mn. Ihr. hrs. Plasmo 0 cc Dog Dog wt..0kg. jt~"~ wt. (Kg] Plasmo (ec) Ded Ihrs Survval Tme (hrs) Fgure A composte tracng of a dog treated wth j)lasma after the appearance of olgura and a secondary declne n systolc pressure. Plasma dd not correct the hypotenson or olgura. The table presents the outcome n dogs treated vth large doses of plasma at smlar perods of hypotenson and olgura. of the anmals survved beyond hours (fg. ). The average survval tme was. hours. The hemodynamc changes for one of the dogs that receved 0 ml. of plasma are shown n fgure. The admnstraton of plasma dd not prevent the appearance of acdoss, hemoconcentraton, or renal falure. Effect of Metaramnol on Endotoxn Shock Prevous studes on the effect of metaramnol on endotoxn shock n dogs had shown that the pressor agent tended to correct the venous poolng b r augmentng the venous return to the heart. 0 Others had reported that the njecton of metaramnol or norepnephrne accelerated the death rate from endotoxn when the vasopressor agents and endotoxn were gven smultaneously. Ten adult dogs weghng from. to. Kg. were gven 0. mg./kg. of E. col endotoxn. In order to correct the persstent hypotenson that followed ths njecton, an ntravenous nfuson of to mg. of meta-

3 SPINK, VIGK -- Dog wl 0. Kg. 0-- Dog '..0 Kg Downloaded from by on January, 0 E.col O.mg/Kg. /0 Survved at Hrs. Avg. Survval lme. Hrs. Oog wt. (Kg.) Metaramnol mg 0 mg mg. mg 0 mg 0mg mg 0 mg mg mg Survval Tme (hrsj 0 Fgure A composte tracng of the systolc pressure of a dog that faled to show a secondary rse n pressure after endotoxn. Ths occasonally has been observed n lethal endotoxn shoclc. Although metaramnol stablsed the pressure, death occurred. The dose of metaramnol necessary to sustan the pressure and the outcome of each of 0 anmals are presented n the table. ramnol was gven to mantan the systolc pressure at approxmately 0 to 00 mm. Hg. The course of one of the dogs recevng 0 mg. of the pressor agent s shown n fgure. As s also noted n fgure, only one of the treated dogs survved longer than hours after the njecton of endotoxn. The average survval tme was. hours. Ths s to be compared wth the average survval tme of.0 hours (fg. ) n the untreated control anmals. It s apparent that under the condtons of ths experment the pressor agent dd not accelerate the rate of death. On the other hand, metaramnol dd not sgnfcantly prolong the survval perod, even though the systemc blood pressure was mantaned; nether was renal functon aded by metaramnol. Effect of Hydrocortsone on Endotoxn Shock Eleven dogs weghng from.0 to. Kg. were gven 0. ng./kg. of E. col endotoxn. After the appearance of progressve shock n tcol lomln 0.mg/Kg / Survvors at Hrs. Avg. Survval tme. Hrs f 0 mn. Hydrocortsone 00 mg. 00 mg. IV. Drp n 0 ec. X Do, 0 wl(kgj I0O Theropy 00 mg, I.V. Srs I Ded 0 Iws. llhn. Survval Tme (hrs] O(mn) Fgure A composte tracng of the systolc pressure n a dog that receved hydrocortsone. Although n ths and other anmals the admnstraton of the sterod dd result n a rse n pressure and an ncrease n output of urne, these effects were not sustaned, and all of the anmals ded, as seen n the table. each of the anmals, a standardzed total dose of 00 mg. of hydrocortsone was gven, as shown n fgure. Under these crcumstances, the average survval tme was. hours, and three of the dogs survved beyond hours. "Whle the outcome n ths group of dogs was somewhat better than that recorded for the control dogs, there was no statstcally sgnfcant effect. Effect of Hydrocortsone and Metaramnol on Endotoxn Shock Ten adult dogs weghng between. and Kg. were gven 0. mg./kg. of E. col endotoxn. As n the prevous experment, the anmals were gven a total ntravenous dose of 00 mg. of hydrocortsone, whch was gven n a total of 0 cc. of per cent dextrose. Shortly thereafter, each of the dogs was gven an ntravenous nfuson of metaramnol n doses that stablzed the systolc blood pressure at 0 to 00 mm. Hg. The only permanent survvors n all of these studes occurred n ths group that receved a combnaton of hydrocortsone and metaramnol. Sx of Crculaton Research, Volume IX, January 0

4 ENDOTOXIN, METARAMINOL, AND HYDROCORTISOXE ST Downloaded from by on January, 0 the 0 anmals resumed normal physcal actvtes. The dfference between the control group and ths treated seres s statstcally sgnfcant (P >.0; <.). Another sgnfcant observaton was that after a large nfuson of hydrocortsone, consderably smaller amounts of metarannol were necessary to stablze the blood pressure, f the amounts used n ths group are compared wth those used n the anmals whch receved metaramnol alone (compare fgs. and ). When the combnaton was emplo r ed, only about oneeghth the amount of metaramnol was necessary to sustan the desred blood pressure. The average requrement for dogs recevng metaramnol alone was mg., whereas only. mg. were necessary for the anmals recevng the combnaton. Another feature about ths combnaton was that there was not a progressve deteroraton of renal functon n the anmals that survved. Dscusson Hemoconcentraton n endotoxn shock n the dog s due to poolng of blood n the lver and n the ntestnal tract, along wth a loss of plasma nto the walls of the colon. S However, large nfusons of canne plasma dd not prevent a lethal outcome n the present experments. Although metaramnol corrected the hypotenson, the anmals deterorated and ded wth the manfestatons of renal falure and acdoss. Whle large does of hydrocortsone alone dd not sgnfcantly prolong lfe, the sterod dd appear to augment the pressor effect of metaramnol, and the majorty of dogs survved a lethal dose of endotoxn when the two agents were employed. The role of exogenous hydrocortsone n endotoxn shock s not understood. The perpheral vascular collapse of endotoxn shock s not assocated wth a reducton n adrenocortcal actvty, snce excellent cortcal functon was demonstrated n anmals n profound shock. 0 It s possble that n a state of vascular collapse the avalable quanttes of endogenous hydrocortsone are nadequate and exogenous sources of hormone are requred. Connolly reported that the progresson of hemorrhagc Crculaton Research, Volume IX. January 0 -j 00 J 0- ^^^^^ E.cd? l 0 mn 0 mn 0. mg/ Kg. Dog wl. K> (KgJ Theropy Hydro + Metorm. 00mg. mg. mg mg Dog I mhydrocortsone loomg STAT 00 mg. n Occ % Survvol Tme (hr) doys + days* hrs. hrs hrs days + doys+ doys + doys + doys + at..0 Kg. hrs Survved doys Metoromnol mg, n 0 cc % /0 Survvors Permanent - Doys before sacrfced In repeat run. Fgure A composte tracng of the pressure of a dog that receved a large dose of hydrocortsone and then metaramnol. Under the crcumstances, relatvely small doses of the pressor drug resulted n progressve mprovement, and sx out of 0 anmals' survved. Of the dogs used n the entre seres of experments, the only survvors were these sx anmals treated wth the combnaton. shock could be reversed wth large doses of adrenal sterods. Summary An expermental model of canne endotoxn shock was employed for evaluatng therapeutc agents that are used n the management of perpheral vascular collapse. An mportant feature of the present study was that an agent or agents were not admnstered untl hypotenson and olgura were present. Progressve endotoxn shock was not reversed by the nfuson of large amounts of canne plasma. Large doses of hydroeortsone dd not prevent a lethal outcome. Even though the blood pressure was stablzed near normotensve levels wth the vasopressor drug, metaramnol, progressve shock occurred. The most sgnfcant fndng was that lethal endotoxn shock was prevented n sx of the 0 anmals studed by the smultaneous use of hydrocortsone and metaramnol. Only one-eghth the

5 amount of metaramnol was necessary to mantan normotensve levels of blood pressure f a large dose of hydrocortsone was admnstered before the nfuson of the pressor drug. Acknowledgment The authors wsh to express ther apprecaton to Dr. Maurce Vsscher for hs helpful suggestons. References. WEIL, M. H., AND SPINK, W. W.: Shock syndrome assocated wth bacterema due to gramnegatve bacll. A.M.A. Arch. Int. Med. 0:,.. SPINK, W. W.: Pathogeness and management of shock due to nfecton. A.M.A. Arch. Int. Med. 0:, 0.. HALBERG, F., AND SPINK, W. W.: Influence of brucella somatc antgen (endotoxn) upon temperature rhythm of ntact mce. Lab. Invest. :,.. GILBERT, E. P.: Mechansms of hemodynamc effects of endotoxn. Physol. Rev. 0:, 0.. WEIL, M. H., AND SPINK, W. W.: Comparson SPINK, VICK of shock due to endotoxn wth anaphylactc shock. J. Lab. & Cln. Med. 0: 0,. 0. WEIL, M. H., HINSHAW, L. B., VISSCHER, M. B., SPINK, W. W., AND MACLEAN, h. D.: Hemodynamc effects of vasopressor agent (metaramnol) on hypotenson n dogs produced by endotoxn. Proc. Soc. Exper. Bol. & Med. : 0,.. LILLEHEI, E. C, AND MACLEAN, L. D.: Intestnal factor n rreversble endotoxn shock. Ann. Surg. :,.. MACLEAN, L. D., WEIL, M. H., SPINK, W. W., AND VISSCHER, M. B.: Canne ntestnal and lver weght changes nduced by E. col endotoxn. Proc. Soc. Exper. Bol. & Med. : 0,.. ATJST, J. B.: Dstrbuton knetcs of varous substances n endotoxn shock. Fed. Proc. :,. 0. MELBY, J. C, EGDAHL, E. H., AND SPINK, W. W.: Secreton and metabolsm of cortsol followng njecton of endotoxn. J. Lab. & Cln. Med. : 0, 0.. CONNOLLY, J. E.: Use of adrenal cortcal compounds n hemorrhagc shock. Journal-Lancet : 0,. Downloaded from by on January, 0 Crculaton Retcarch, Volume IX, January