Document Z4Mxm1pOEkOBBLE7pM59OzYj8

*m vnesiheuology 101-105. I WO Thrombocytopenia and Altered Platelet Kinetics Associated with Prolonged Pulmonary-artery Catheterization in the Dog Kenneth A. Richman. M.O.,' Yong Lack Kim, M.D., Ph.D.,f Bryan E. Marshall, M.D., F.R.C.P.% vTJ trope Irena* vin anJ iamb* 4! Ba#" aion ^ .i>ndo** im m* ,kuM#3 MCUI ^ J%0 OOUASfl TjSe authors studied platelet kinetics in healthy dogs sub jected to pulmonary-artery (Swan-Gam) catheterization/Ten dogs vitfc a mean weight of i 1.0 1.12 kg (SD) were equally divided (mo experimental and control groups. A fraction of platelets ha each dog waa harvested, labelled with J1Cr, and reinfused. Dally blood samples for determinations of radioactivity and platelet count were obtained. From the third to fifth day after platelet labelling, experimental dogs underwent catheterization with Swan-Ganx catheters. During 48 hours following catheterization, platelet counts 4w.mii.d 64.2 s 15.2 per cent from baseline. There was no corresponding change in the control dogs. Calculated platelet mrvival times (based on decay in platelet radioactivity over time) were 102 - 6.5 hours for the experimental group and 139.8 s ID hours for controls (I** < 0.01). Postmortem examination af one sample dog demonstrated thrombus formation along the Wugth of the catheter and in the pulmonary artery. (Significant thrombocytopenia with decreased platelet survival b associated with the use of Swan-Gins catheters In dogsjThe mechanism has not been defined. This observation adds an im portant consideration to the interpretation of platelet kinetics hserved in many pathologic state* in animal models. (Key *ords: Blood: hemostasia; platelets. Complications: tbrombocytopenia. Equipment: catheters, Swan-Ganx. Monitoring: presmu, pulmonary arterial.) Thrombocytopenia develops frequently in critically iO patients, and often contributes to morbidity and mortality.1 Flow-directed balloon-tipped (Swan-Ganz) catheters, commonly used in critically ill patients, are fcflown to be thrombogenic in man.1,3 To evaluate tbe kinetics of the platelet consumption associated these catheters and the extent to which this contributes to thrombocytopenia, we studied healthy subjected to 48 hours of pulmonary-artery Qdieterrzation. * Mutant professor. Depattment of Anesthesia. Hospital of the hbenity of Pennsylvania, Philadelphia. Pennsylvania 19104. * Assistant Professor. Department of Anesthesia. Medical College Seoul National University. Seoul. Republic of Korea. Professor. Department of Anesthesia, School of Medicine, and ~*Prtment of Comparative Anesthesia. School of Veterinary l9t04*C University of Pennsylvania. Philadelphia. Pennsylvania ^Pceivcd from the Department of Anesthesia. University ol r>sylvania, Philadelphia. Pennsylvania 19104. Accepted for Py ication February 10. 1980. Supported in part bv L'SPHS Number 1-T32-GM-07612-01 from The National Institute General Medical Sciences. National Institutes of Health, and project Grant Number 165-40-8480 from the National Heart. ng and Blood Institutes. Presented at the annual meeting of the '2o"Can ^oc`ty Anesthesiologists. October 1979. San Fran- ; ' California, where it was awarded second prize in the tfnts Research Essay faintest. Fig. 1. Composite platelet survival curve based on data from all dogs in the experimental (solid circles) and control (open circles) groups. The steeper slope of the line for the experimental group beginning at the lime of catheterization indicates more rapid platelet consumption. Materials and Methods Ten healthy male mongrel dogs weighing 9.3- 14. i kg(mean SDril.O 1.12) were divided intoexperimemal and control groups; each dog was studied over a period of nine days. On day 1, each dog was anes thetized with thiopental (20 mg/kg), the trachea was intubated, and anesthesia was maintained with halothane (1 per cent) in oxygen. The animals breathed spontaneously at an end-tidal C08 of 5 per cent. A total of 90 ml of whole blood was drawn from an external jugular vein into three plastic syringes each containing 5 ml of anticoagulant citrate dextrose solution. USP, formula A. Platelets were labelled with radioactive chromium in the following standard fashion.4 The platelet-rich fraction was obtained by differential centrifugation and incubated for one hour with 1.0 mCi slCr.H The platelets were washed once with platelet-poor plasma, resuspended, and injected. A sample of the injectate was saved for radioactivity Femval Laboratories, Deerfield. Illinois. " New England Nuclear. Boston. Massachusetts: I titCi/tnl. 0003-3022/80/0800/0101 $00,75 0 The American Society of Anesthesiologists. Inc, 10 l Tim irw in?: BFG06856 t PLATELET COUNT (x 10 * } / > / 102 R1CHMAN, KIM. AND MARSHALL V 51. No Fig. 2. Mean peripheral blood platelet counts (SE) for experi mental (solid circles > and control (open circles) animals. The progres sive decline occurring in experimental animals represents a 64.2 ~ 15.2 per cent (SD) reduction from baseline, with return toward baseline resulting from removal of the catheter. counting, and an accurate weight and specific gravity of the injectate were obtained prior to injection. Half an hour after injection, a 3-ml sample of heparinized whole blood was obtained via a peripheral vein for radioactivity counting. Anesthesia was then dis continued, approximately four hours after induction. Every 24 hours thereafter, 3-ml blood samples were taken from a peripheral vein of the awake animal for radioactivity counting. All radioactivity counting was done in triplicate in a gamma well counter.** In addition, we performed daily platelet counts in triplicate by phase-contrast microscopy (method of Brecher et a/.4). On day 3 (48 hours after platelet "* Intcnechnique Model 4000. labelling), the dogs were again anesthetized with pental and halothane; dogs in the experimental underwent cutdown of the right groin and insert^ a 7-Fr. double-lumen Swan-Ganz cathetertt femoral vein, with ligation of the distal femoral The catheter was advanced into the pulmonary a? with confirmation of the final position by recorc the pressure tracing on a Grass polygraph [av^i depth of insertion: 48.8 2.7 cm (SO)]. The catl was hushed with 5 ml of saline solution, 0.9 per The end of the catheter at the groin was occh with a heavy silk ligature tied tightly at the point* entry of the catheter into the vein, with the remair catheter external to the vein cut off. The wound closed and anesthesia discontinued. Dogs in the cor group underwent the same anesthetic and sui procedures for the same length of time (approxir an hour), with ligation of the femoral vein, but wit! insertion of the catheter. Blood samples for plat count and radioactivity determinations were obtaii six hours after the surgical procedure in addition the other daily samples. On day 5 (96 hours after pi let labelling), the catheters were removed from experimental animals, using thiopental-halotl anesthesia; control animals underwent anesthesia' opening and closure of the groin wound, the cedure requiring 45 min for animals in either grouj On day 9 (192 hours after platelet labelling), blc volumes of both control and experimental anh were determined by injecting radioactive iodinat (,331) serum albumin, 0.1 mCi.Jt The R1SA diluted, weighed, and counted in the gamma we counter prior to injection; three 1 -ml samples of whol blood were obtained for counting half an hour aft injection. t+ Edwards Laboratories. Santa Ana, California. tt Squibb Pharmaceuticals. New Brunswick. New Jersey. Table 1. Calculation of Platelet Consumption ; Experimental Mean - SI> Control Mean = SD Significance ol difference (experimental rv control) bt Student / test Blood Volume (mh 970 248.2 (IS I 15 5. S Y..S. Prr-S-G Platelet Count (/*! x 10*) 3.41 760 3.33 .604 .V.S Pre-S-C. Total Platelet* (x10") 3.33 1.230 3.30 .872 AS. Poti-S-G Platelet Count (ifd 10*1 1.20 .381 3.23 1 006 P < 0 01 Poti-s-c Total Platelet* 1x10") 1.28 1.029 3.20 1.230 a 1 1 1 ! | j j ] p < 0.03 BFG06857 l % if wt ur iption! >29 , .`. 'u< i'M) I HRUMBiH ) TOFKM A INDUCED 'iWA.N-G < V THE FERS 10J gectal temperature was recorded daily. Hematocrit, IY eighi. and leukocyte count were obtained just >r to and 48 hours alter catheterization. Blood eul- were obtained after 48 hours ot catheterization. One additional animal was sacrificed 48 hours after theieruatiun for obser\ation of clot formation ind the catheter and pulmonan arterv. This dog rived 3000 U heparin, iv. 15 min prior to sacrifice exsanguination. The catheter (ip from this dog was fixed in L percent jtaraldehyde, dehydrated in graded alcohols and lyl acetate, and finally subjected to critical-point (ring. A molecular layer of gold was deposited on the ce and the specimen was examined in a JEOL )A scanning electron microscope. Photomicro- at lOOOx magnification were obtained, segment of left main pulmonary artery from the dog was fixed in Bouin's solution, sectioned, sd with hematoxylin and eosin, and examined :r light microscopy for evidence of thrombus ition. .Decay of platelet radioactivity is expressed by the nng equation: Percentage activity at time counts 5,Cr/ml blood at time t x blood volume x 100 total counts injected initially 96 hours after labelling) m the experimental group, and ai the same time intervals in the control group. Changes in total numbers of platelets for all dogs during the interval of catheterization (experimental) or sham operation (control) were calculated. Tocal circulating platelets immediately prior to insertion and just before removal of the catheters (or sham operation) was derived by multiplying blood volume times peripheral blood platelet count. The net change in platelets is the difference in total platelets during the interval of catheterization (or between the two sham surgical procedures). The percentage change in radioactive labelled platelet activity during the time of catheterization (or sham operation): Activity pre-catheterization - activity post-cathe te rization x 100 k Activity pre-catheterization multiplied by the number of total platelets before catheterization estimates the number of total platelets consumed during that time interval. Effective produc tion is the sum of the total platelets consumed plus the overall net change in total platelets. Unpaired Student t tests were used to compare means of the two populations, with/* < .05 considered statistically significant. tg percentage activity as a function of time (t) > a platelet survival (decay) curve; typically, activity liately after injection of the labelled platelets is K 60 per cent due to initial splenic uptake of platelets ("per cent recovery"). Calculation of -t survival time was done in a standard fashion4 [the four points on the platelet survival curve (per I activity vs. time) obtained just prior to Swan-Ganz it insertion and during the two days when the Jr was in place (per cent activity 48, 54, 72, and Results The platelet survival curves for the control and experimental animals, with each curve derived from the average percentage radioactivity (SE) for the five dogs in the group, are almost identical in appearance until 48 hours, the time of catheterization in the experimental group (Fig. 1). Thereafter, the survival curve for the experimental group shows a more rapid decay (steeper slope). Mean platelet survival times n (S-G Swan-Ganz Catheterization) Total Rttleii tPoM-S-G - Pr-S-G) < *10**1 Per Cem Activity Pre-S-G Her Cew Activity Poo-S-C (Per Cent Ptr*Wi - per Cent PoM-S-Cl Per Cent Pre-S-G 100 Per Cent & Gmiumptun Per Cent A * Total Pre-SX; <*10'*) ilTevtive Production - Net * Contumption (X|t>") -2.07 .678 43.2 5.81 8.5 3.80 80.3 8.54 2.66 .910 0.59 .671 -.094 .443 44.6 10.96 21.8 7.60 51.7 8.206 1.70 .456 1.61 1.641 0 05 < 0-0005 .V 5*. P <0.01 P < 0.0005 P < 0.05 P < 0.05 c m ik n a n ? ' BFG06858 104 RICHMAN, KIM. AND MARSHALL V . No t. Fir.. 3. Organized thrombus surrounding the portion of the catheter that lies in the inferior vena cava, taken after 48 hours of catheterization from a dog svstemically heparinized just prior to sacrifice. calculated from the four points on the curve obtained just prior to and during catheterization were 102 6.5 hours (SD) for the experimental group and 139.8 16.3 hours for the control group, significantly different at P < 0.01. Average peripheral blood plalelei counts in th*i groups were the same at the beginning, but a deci in the experimental group began to become a as early as six hours after catheterization, wa$ nificant after 24 hours, and continued until rerrit of the catheter (fig. 2). The nadir of the curve after! hours of catheterization (96 hours after labelling) represents a 64.2 15.2 per cent (, i. SD) decline from the 48-hour baseline vale Within the next four days, platelet counts returned] baseline. The decrease of total platelets (table 1, column the experimental group (2.07 . .678 x 10") significantly larger than that in the control (.094 .443 x 10") (P < 0.0005). The total numt of platelets destroyed (column 10) in the experitner group (2.66 .910 x 10") was significantly great^ than that in the control group (1.70 .456 x Effective production (column 11) in the experiment group (.59 .67 x 10u) was significantly less tl that in the control group (1.61 1.641 x 10"). Table 2 shows average body weights, hematocrit and leukocyte counts for the dogs in both groups ji prior to and after 48 hours of catheterization or shj operation. There was no significant difference befl tween the groups. Cultures of blood from all dogil were sterile. Figure 3 shows organized thrombus surrounding the portion of the catheter that lay in the inferior vena cava of the dog that was systemically heparinized just before sacrifice after 48 hours of catheterization. Thrombus could be seen surrounding the entire length of the catheter, extending into the pulmonary artery, where it was firmly fixed to the arterial wall. The presence of polymorphonuclear leukocytes within the thrombus indicated its age to be at least 12-24 hours. A scanning electron photomicrograph of this catheter surfaced showed deposition of fibrin, erythrocytes*.^ and platelets. Table 2. Changes in Body Weight. Hematocrit, and [.eukocvte Count after Catheterization or Sham Operation Bndv Wright ikg) Pirraihrirruaimn Posirai helrnrattnn Hematocrit (Prr Cent) Hre rathrT^nrai ion Pnv* rafheiemaiion Leukorvtr Count t x 10'tmin1) Prrraihrtrnration Post. cathftrnrac*on Experimental Mean r SD I 1.0 11 o 41.2 38.8 98 M3 1.9 1 9 2 4 3.6 3.9 34 Control Mean = SD 10 6 ]o: 39.4 37.8 9.9 14 2 1.0 ).) 1.8 3.1 3 9 3.4 Significance of difference (experimental r.i control) Student r test .V. s .v.s. .V .V. \S. .V.S VS ____ - imliW i 2. ' BFG06859 fly So l. W< i'MW THROMBOCYTOPENIA INDUCED BY SW AN-CA N L C.K THf. TF.RS 105 Discussion The peripheral blood platelet count represents balance between platelet production in the marrow d consumption and dilution in the peripheral blood, th production, consumption, and blood volume tng constant at steady state.1* Thrombocytopenia ,uits from increased platelet consumption (or se* (ration), reduced production, or hemodilution, lemodilution does not explain the large decrease per cent) of platelet counts in our experimental , since other indices of increased plasma or total ter volume (i.e., hematocrit and body weight) did change during catheterization. Increased platelet consumption is evident from the per slope of the s,Cr platelet survival curve of the terized dogs. The absolute magnitude of total tclets consumed is dependent upon the size of the isting pool of circulating platelets, as well as the mber of newly formed platelets (ongoing marrow uction during the time of catheterization) that involved in the consumption process. Our calculan of total consumption only approximates the |tttcnt of this process. This calculation may be an underestimate, since it does not include the consump tion of newly formed unlabelled platelets, a number jhat we did not directly measure. The calculated "effective production" reflects the ^narrow's ability to restore the peripheral platelet nt to its normal level. It is unlikely that the presof a catheter in the circulation could alter the !vity of the marrow [which is chiefly under. rmonal (thrombopoietin) control), and actual let production at least as likely in the experimental UP as in the control group.7 Calculated "effective uction" (net platelets plus consumed platelets) is restimated to the same extent as is total platelet Eruption (see above). That the "effective producflion' in the experimental group was less than that in 3" control group restates the phenomenon that consumption is of a greater magnitude than producon. Eventually, a new steady state would arise hereby production and consumption would equalize ** * lower peripheral platelet count. In all likelihood, hJarrow would actually increase platelet producto compensate for the increased losses of platelets. : Many platelets taken out of the circulation appear clot on the catheter. Swan-Ganz catheters are */y7catod from polyvinylchloride, a known chromboMaterial.2-**9 The clot formation seen along the jl**eter anc! pulmonary arterv from one representa^g is similar to that found in man.2 However, i^J^ctor-induced thrombocytopenia has not been depreviously. Foreign surfaces have been shown <ncrgase platelet adhesiveness, resulting in clot *or,nation and predisposition to subsequent adhesion. causing continued deposition of platelets with time.91 Foreign surface-induced platelet activation increases platelet phagocytosis bv the reticuloendothelial svstem." This could account for the continuous decline in platelet count during catheterization. Such a mech anism remains unproved. Despite species differences, human and dog plate lets adhere similarly to polvvinvlchloride.',u~1!* That catheter-induced thrombocytopenia occurs in man re mains conjectural. This study also emphasizes that interpretation of platelet kinetics in dogs subjected to pathologic states (eg-, shock) must take into account the ab normalities induced by catheterization. The authors thank Richard H. Ochs, M.D.. and H. T. EnteHine, M.D.. for iheir work on the pathology specimens. References 1. Ellison N: Diagnosis and management of bleeding disorders. Anesthesiology 47:171-180. 1977 2. Hoar PF, Stone JG. Wicks AE, et al: Thrombogenesis asso ciated with Swan-Ganz catheters. Anesthesiology 48: 445-447, 1978 3. Foote GA. Schabel SI. Hodges M: Pulmonary complications of the flow-directed balloon tipped catheter. X Engl J Med 290:927-931. 1974 4. Belcher EH, Berlin Nl. Eernissc JG. et al: Recommended methods for radioisotope platelet survival studies. Blood 50: 1137--1144. 1977 5. BrecherG, Schneiderman M. Cronkite EP: The reproducibility and constancy of the platelet count. Am j Clin Pathol 23:15-26. 1953 6. Harker LA, Finch CA: Thrombokinetics in man. J Clin Invest 48:963-974. 1969 7. McDonald TP. Clift R. Lange RD. et al: Thrombopoietin production by human embryonic kidney culture, j Lab Clin Med 85:59-66. 1975 8. Sawyer PN. Stanczcwski 8. Garcia L, et al: Experimental and clinical evaluation of a new catheter material. Trans Am Soc Artif Intern Organs 22:527-537. 1976 9. Wilner GD. Casarella WJ, Baier R, et al: Thrombogenictty of angiographic catheters. Circ Res 43:424-428. 1978 10. Butruille YA. Leonard EF. Litwak RS: Platelet-platelet interactions and non-adhesive encounters on biomaterials. Trans Am Soc Anif Intern Organs 21:609-616. 1975 11. Addonizio VP. Edmunds l.H. (,'olman RW: The function of monkey (<W. muia/ta) platelets compared to platelets of pig. sheep and man. J Lab Clin Med 91:989-997. 1978 12. Grabowslcr F.F, Drdwheim P. Lewis JC. e al: Platelet adhesion to foreign surfaces under controlled conditions of whole blood flow: Human vs. rabbit, dog. calf, sheep, ptg. macaque, and baboon. Trans Am Soc Artif Intern Organs 23:241. 1977 13. Dodds WJ: Platelet function in animals: Species specificities. Edited bv G deG.tetano. S Garattini. New York. Raven Press. 1978. pp 45-59 14. Calkins J. Lane KP. l-oSasso B. et al: Comparative studv of platelet aggregation in various species. | Med 5:292-296. 1974 15. Sinakos Z. Caen JP: Platelet aggregation in mammalians (human, rat. rabbit, guinea-pig. horse, dog). A comparative study. Thromb Di.uh Haemorrh 17:99-111. 1967 sooeueoz BFG06860 materials. For more than twenty years, this company ana tn uauscry have Initiated and supported efforts to assure the safe use of these products. These efforts have included research dealing with product safety, the publication of appropriate product literature, and an un precedented level of cooperation with standard setting groups such as the National Sanitation Foundation. In keeping with our continuing efforts to evaluate the safety of our products and their uses, I am submitting the following comments on the Summary Report of Major Flndln of California Pipe Trades Council Health Survey, July 1980. 1. One of the major flaws in the survey is that there is no control (non-exposure) group. Without a control, a study is meaningless. 2. Another major weakness of this survey is that it lacks objectivity, particularly because it is not based on actual medical records. 3. The report does not Identify the total cohort to which a question naire was sent. Therefore, it is impossible to determine what portion the 10,200 analyzed questionnaires represents. 4. The report states (page 4) that 6,508 responses were omitted because they did not complete the questionnaire. While it is understandable that complete cooperation cannot be expected, this does not mean that this group Is not important to the study. The study also states (p. 4) that over 802 of non-respondents that were contacted did not respond because they no longer were working in the pipe trade. Again, this does not mean that their lack of inclusion in the study is not Important; in fact, they are very important. 5. The report (page 5) defines the high and low exposure cases on the basis of duration of work. This use of the toms "high'' and "low" are not appropriate since they denote high/low levels of unspecified agents and since duration of employment is not equivalent to level (high or low) of exposure. Secondly, there is no data available BFG06867 20806001 which indicates that exposure to "plastic" related chemicals are above levels that are harmful. In fact, studies reported by HALTS Indicate that exposure to certain solvents used in solvent cements are well below the OSHA and ACCIH TLV's based on time-weighted aver ages. A more appropriate category is "long and short duration of employment". 6. The Union report (page 5) states that welders were excluded from this survey in order to eliminate another variable which might produce health effects. It is Interesting that while the Union is concerned about potential health effects that might result from plastics use, it seems less concerned about potential health hazards to its members who also weld. Further, if the Union is interested In singling out "plastics", an objective study based on actual medical records should be conducted and should separate those people who are exposed to potential hazard from metal pipe use. Any study of this nature should identify and separate those who were involved with metal pipe use, and it should detail the kinds of pipe and what types of joints (e.g. soldering, brazing, pouring hot lead, gas welding, electric welding). It is difficult to find the merit, that the Union apparently sees, in identifying "plastics" as "the" hazard. 7. On page 5, it Is stated that an effort to establish reliability and validity of the data was made by telephone Interviews with a number of non-respondents. It is difficult to see how this addresses relia bility and validity since it does not Include any objective base such as medical records. Furthermore, the report does not state how many telephone interviews were conducted (l.e., were 6 eligible cases found out of 10 calls, 6 out of 100, etc.). 8. The report states that "trained telephone survey interviewers" were used. However, it does not indicate the nature of this training. This is important since the interviewer, in addition to the question naire, can bias the response. 9. On pages 6 and 7, the report suggests the use of this survey for a case controlled analysis. Because of the numerous flaws in. this survey, there is no way that this study is now or will be of any use in studying potential occupationally-related health effects. 10. On page 10, the report implicates butadiene-styrene and PVC with in duction of malignancies of the lymph system. It should be noted that the referenced NIOSH survey found an excessive number of leukemias but determined that they were not statistically different from the control population. Secondly, PVC has never been shown to cause cancer of the lymph system. 11. On page 13, the report states that many of the chemicals used in plastic pipe fabrication are proven or suspected carcinogens. This statement is false. It is not referenced nor can it be. 12. The results reported on pages 7 through 11 note many effects which are suggested to bo due to chemicals used in plastic fabrication. Again, we emphasize that without a control, it is impossible to 080600. t: t: BFG06868 "T determine whether these are above the normal range. Also, the HALTS data does not indicate that exposure levels in the workplace are even close to a level which could produce an effect. 13. There is no attempt in this study to adjust the data for the effects of age, smoking, or drinking. Figure 1 is a prime example of this. Muscle weakness is a general symptom and can be caused by certain chemicals or by aging. 14. It is difficult to understand why the Union has used such a subjective approach when every suggested effect except sleepiness can be measured by common diagnostic techniques. 15. It is Interesting to note that the report states that there is no effect of smoking noted. Since the effects of smoking are so dramatic, every study shows this effect. The absence of any smoking effect further serves to emphasize the inability of such a survey to identify major or minor compound-related effects and clearly shows that the survey is suspect as a tool in the investigation of occupationally-related diseases. I believe that properly conducted epidemiology studies can play an important role in providing a low-risk environment. However, inadequate and ill-conceived studies such as this one do not serve the interest of either the public or the workers. In fact, such surveys are more inclined to disservice, since they can unduly alarm the workers and the public, erroneously direct research efforts, and can potentially result in unwarranted regulation causing unnecessary expen diture of resources. Sincerely, BFGOODRICH CHEMICAL GROUP /kjs Robert K. Hinderer, Ph.D. Manager, Toxicology Senior Environmental Toxicologist bcc: R. Wilging P. Dunrtigan R. Toole J. Church, PPFA 0806003 BFG06869