Arch. Toxicol. 34, 129-- 136 (1975} 9 by Springer-Verlag t975
Paraquat Poisoning in Man A. v a n D i j k , R. A. A. Maes a n d R . H. D r o s t J . M. C. D o u z e a n d A. N. P . v a n I-Ieyst Center for Human Toxicology, University of Utrecht, Utrecht, The Netherlands Department of Reanimation and Clinical Toxicology, University Hospital, Utrecht, The Netherlands Received February t3, t975
Abstravt. In three cases of intoxication by Gramoxone| the concentration of paraquat dichloride in blood, dialysate, feces, and urine was determined speetrophotometrically after a clean-up of the biological material by means of ion exchange chromatography (with Dowex 50W-Xt2 or Zeo-Karb 225). Although good results were obtained after clean-up with Dowex 50W-X12, Zeo-Karb was preferred as ion exchange resin, especially when large sample volumes were needed for the determination. The reported findings indicate that: only 5 to 10% of an ingested dose of paraquat dichloride is absorbed in man, Pullers' earth is very useful, and that primary, e.g. immediate, hemodialysis is necessary. Key words: Paraquat-Poisoning -- Fullers' Earth -- Hemodialysis. Zusammen]assung: Paraquat Dichlorid wurde spektrophotemetrisch bestjmmt in Blur, I)ialysat, Stuhl und Urin in drei F/fllen yon Vergiftung durch Gramoxono| Aufarbeitung des biologischen Materials geschah durch Ionenaustausch-Chromatographie mit Hilfe yon Dowex 50W-Xt2 oder Zeo-Karb 225. Zeo-Karb 225 wurde fiir die Bestjmmung, besonders wenn grolle Volumina X~liissigkeit erforderlich waren, vorgezogen. Die Ergebnisse zeigen, dab nach oraler Einnahme nur 5 bis l0 % des Paraquat-Dichlorid resorbiert wird. T~gliche Verabreichung yon Fullers' Erde ist n/itzlich. Sofortige H~imedialyse ist begriindet und therapeutisch notwendig. S~li~sselw6rter: Paraquat -- Vergiftung -- Analyse -- Fullers' Erde -- Hiimodialyse. As a p a r t o f t h e i n t e n s i v e t h e r a p y after i n t o x i c a t i o n b y p a r a q u a t ( i , i ' d i m e t h y l 4 , 4 ' d i p y r i d y l i u m c a t i o n ) r e c e n t l y Douze eta/. (i974) a d v i s e d t h e use o f FuUers' e a r t h a n d hemodialysis. H o w e v e r , in t h e l i t e r a t u r e v e r y l i t t l e is k n o w n a b o u t t h e e x c r e t i o n o f p a r a q u a t in h u m a n feces a n d t h u s a b o u t t h e usefulness o f t h e a d m i n i s t r a t i o n o f ~ u l l e r s ' earth. G r a b e n s e e e t a / . ( t 9 7 i ) d e s c r i b e d t w o cases o f fecal p a r a q u a t excretion, b u t t h e y were n o t able to q u a n t i t a t e t h e p e r c e n t a g e o f p a r a q u a t being a b s o r b e d . I n t h i s s t u d y we were a b l e t o d e t e r m i n e t h e u r i n a r y a n d fecal p a r a q u a t e x c r e t i o n o f a n i n t o x i c a t e d p a t i e n t who e n t e r e d t h e U n i v e r s i t y H o s p i t a l s h o r t l y a~ter t h e i n g e s t i o n o f t h e h e r b i c i d e a n d w h o h a d n o t e x c r e t e d a n y p a r a q u a t o n arrival.
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A s f o r h e m o d i a l y s i s , t h i s t h e r a p y is still c o n s i d e r e d as d o u b t f u l d u e t o t h e f a c t i t is q u e s t i o n a b l e i f d i a l y s i s will r e m o v e p a r a q u a t o r n o t . F o r i n s t a n c e , G r a b e n s e e e$ al. ( i 9 7 1 ) c o u l d n o t d e t e c t p a r a q u a t i n t h e d i a l y s a t e . On the contrary we were able to demonstrate the usefulness of hemodialysis in t h r e e cases, a p r o v e o f D o u z e ' s s t a t e m e n t o n p r i m a r y , e.g. i m m e d i a t e h e m o d i a l y s i s (1974).
Case Histories 1. A 25-year-old epileptic m a n made a n a t t e m p t to commit suicide in a state of depression b y ingesting some Gramoxone| (20 % p a r a q u a t dichloride in water). I hr later he was admitted to a ward where a gastric lavage was applied. Later on he was transferred to the D e p a r t m e n t of Reanimation a n d Clinical Toxicology of the University Hospital, where he arrived 3 hrs after ingestion of the herbicide. On arrival he urinated for the first time after the intake of the poison; this (catheter) urine contained 4t.4 mg of p a r a q u a t dichloride ( = 63.8 ppm) in total. Moreover he vomitted; the vomit h a d a p a r a q n a t dichloride concentration of 100 mg. On alrival his blood concentration was 1.6 p p m p a r a q u a t dichloride. He was clinically treated as described b y Douze et al. (t974), s. "case 5". The basic treatm e n t included a n administration of nitrogen b y a nasal tube (4 1 nitrogen/rain), a forced diuresis a n d a n administration of a t 0 % suspension of Fullers' earth in water. 6 hrs after ingestion the m a n was s u b m i t t e d to hemodialysis. This t r e a t m e n t was performed with a Twin coil artificial kidney according to Kolff/Watschinger, equipped with a cuprophane membrane. Outcome: non-fatal. 2. A 62-year-old woman was brought into the D e p a r t m e n t of Reanimation a n d Clinical Toxicology of the University Hospital a b o u t 24 hrs after the ingestion of a large a m o u n t of Gramoxone| On arrival the (catheter) urine (40 ml) contained 3.45 mg of p a r a q u a t dichloride (86.3 ppm) a n d her blood concentration was 3.7 ppm. According to her clinical picture, hemodialysis was indicated. She died after 2 hrs of intensive therapy. 3. Shortly after a family trouble, a 45-year-old woman ingested a large amount of Gramoxone| 3 hrs after the intake of the herbicide she entered the University Hospital. Immediately, a gastric lavage was applied a n d Fullers' e a r t h was administrated. 5 hrs after ingestion her urine (223 ml) contained 394 mg of p a r a q u a t dichloride ( = 1766 p p m !) a n d her blood concent r a t i o n measured t9.4 ppm! Consecutively, she was submitted to a forced diuresis and hemodialysis was indicated. She suddenly died, due to a h e a r t failure, 35 hrs after ingesting the poison.
Methodology Analysis o/Feces. In in vitro experiments we found t h a t p a r a q u a t is rapidly and strongly adsorbed b y Fullers' earth a n d is not removed b y equilibration with water or diluted acid (e.g. 5 ~T HC1) when present in a concentration below the exchange capacity of this clay. T h a t means if p a r a q u a t is present in Fullers' earth containing feces, the herbicide cannot be extracted b y water or a diluted acid. We found the following extraction procedure to be the most suitable: 10 g of feces are refluxed with 20 ml of 18 1~ sulfuric acid for 6 hrs. After cooling down to room temperature the acid extract is filtered through a 3 G 2 glass filter a n d the residue is washed with l 0 ml of 18 N sulfuric acid. The filtrate is diluted with distilled water to a b o u t 400 ml and 41~ l~aOH is added until the acidity reaches t N sulfuric acid. The extract is filtered into a 500 ml volumetric flask a n d is adjusted with distilled water. A n aliquot of this solution is applied to a Dowex 50W-X12 column a n d chromatographed according to Tompsett (1970). The obtained eluate is evaporated to dryness in a Biichi evaporator under reduced pressure (30 mmHg) a n d the residue is dissolved in 10.00 ml of a buffer solution of borax-hydrochloric
P a r a q u a t Poisoning in Man
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acid (pH = 9.0). An aliquot of the mixture is placed in a 2- or 4-cm cuvette a n d a spectrum is scanned from 380 n m to 650 n m using the buffer as a reference solution. 50 rag of sodium dithionite are added to each euvette a n d a spectrum is scanned again. Since reference solutions (0 to 4 p p m of p a r a q u a t dichloride in buffer solution) follow Beers' law a t 602 nm, the difference of absorbance a t t h a t wavelength before a n d after reduction is estimated as a measure for the concentration of paraquat. Using the described m e t h o d we found a recovery of 90 % when t 5 ~tg of p a r a q u a t dichloride were added to t 0 ml of a :Fullers' e a r t h suspension. Because the concentration of p a r a q u a t in t h e feces of our p a t i e n t was considerable high (Table 1) we only needed small aliquots for column chromatography resulting in low background absorptions. I n t h e analysis of feces with low p a r a q u a t concentrations t h e use of Zeo-Karb 225 is preferred to Dowex 50W-Xt2. Handling the Dowex 50W-XI2, large aliquots m u s t be applied to the columns, resulting in eluates showing a too high background absorption for a n accurate determination. Using Zeo-Karb 225, t h e extract h a s to be adjusted to p H = 5.5 to 6.5 with 4 Iq N a O H prior to filtration into the 500 ml volumetric flask.
Analysis o] the Dialysate. 3.5 g of Zeo-Karb 225 (sodium form, 52 to ~00 mesh, 8 % DVB, P e r m u t i t Company Ltd.) are washed with water into a chromatographic column ( ~ I cm i.d.; 40 cm length). Consecutively 50 ml of a saturated sodium chloride solution a n d 100 ml of distilled water are passed t h r o u g h the column, which is ready for use b y now. A n aliquot of the dialysate (500 ml to 1000 ml) is passed through the column a t a flow rate not exceeding 4 ml/min. Then the column is washed with 20 ml of distilled water, 100 ml of I N hydrochloric acid a n d i 5 0 ml of a 2.5 % a m m o n i u m chloride solution. The retained p a r a q u a t is eluted with a s a t u r a t e d a m m o n i u m chloride solution a t a flow rate of I ml to 2 ml per minute. The first 50.0 ml of the eluate are collected in a volumetric flask. l 0 ml of t h e eluate are pipetted into a glass stoppered tube of 20 ml a n d 2.00 ml of 4 N N a O H are added. 7 ml of this mixture are transferred to a 2 cm cuvette a n d a spectrum is scanned from 380 n m to 650 a m , using 7 ml of a mixture of i0.00 ml saturated a m m o n i u m chloride a n d 2.00 ml of 4 N l~aOH as a reference solution. After addition of 50.0 mg of sodium dithionite to b o t h cuvettes, the solutions are scanned again. The difference of absorbance a t 602 n m of 397 n m is noticed. B y addition of 30 ~g of p a r a q u a t dichloride to 500 ml of dialysate a recovery of 94 % was obtained. Analysis of Urine. :For the analysis of urine samples, a modification of Tompsett's m e t h o d (1970) was used: the colorimetric determination of p a r a q u a t was carried out as described before (see Analysis of feces). Reproducable q u a n t i t a t i o n only could be obtained when t h e urine samples did not exceed I00 ml. F r e q u e n t l y p a r a q u a t has to be determined in large urine samples containing relatively low concentrations of the herbicide (e.g. urine of patients s u b m i t t e d to forced diuresis). I n such cases 500 ml to 1500 ml of urine h a v e to be applied to a n ion exchange resin. As mentioned before, using the Dowex column, a high background absorption is obtained resulting in a low recovery. Therefore, we advise to use the Zeo-Karb resin as described for the analysis of the dialysate. Before applying urine to this ion exchange resin, t h e p H m u s t be adjusted to 5.5 to 6.5 a n d the sample filtered even when the urine looks limpid. I n this way a very low background absorption a n d a n excellent recovery are obtained (95 % recovery of 20 tzg p a r a q u a t dichloride added to 500 ml of urine). Analysis of Blood. l 0 ml of whole blood (or 6 ml of serum) are refluxed with 15 ml of 18 N sulfuric acid during I hr. After diluting the acid extract with distilled water to a b o u t 300 ml a n d a subsequent filtration, the p H of the solution is adjusted to 5.5 to 6.5 with 4 N l~aOH. After a second filtration, t h e extract is handled as described for the dialysate. A t the 1 p p m level a recovery of 95 % is obtained. A 20 ml sample is needed for the determination of p a r a q u a t blood levels below I ppm.
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Table 1. Paraquat dichloride concentrations (case 1) Days Concentration of paraquat dichloride after feces urine ingestion mg ppm mg ppm t 2 3 4 5 6 7
340 0.2 8t 102
1193 80 405 300
_a
_
--~
--
25.5
61.6 6.3 2.6 1.4 0.7 0.6 0.4
54
19.3 0.62 0.27 0.t3 0.06 0.06 0.03
a No defecation.
550 4
-------.feces
5004 4504
-8
400-~
350J 300 4
2502002 150100-: "6 80ol E 6040-
/ 9
9
,
:
:urine
20-
days otter ingestion
Fig. t. Cumulative excretion of paraquat dichloride in feces and urine (case 1)
Results
A. Fecal and Urinary Excretion o] Paraquat Dichloride T a b l e I shows t h e fecal a n d u r i n a r y p a r a q u a t dichloride e x c r e t i o n of t h e 25-year-old p a t i e n t (case l ) . I n Fig. I c u m u l a t i v e excretions are shown. T h e d a t a i n d i c a t e t h a t t h e concent r a t i o n of n o n - a b s o r b e d p a r a q u a t is m u c h g r e a t e r t h a n t h e a b s o r b e d c o n c e n t r a t i o n of t h e herbicide. F r o m Figs. I a n d 3 i t m a y be c a l c u l a t e d t h a t o n l y 87 m g o f p a r a q u a t dichloride h a s b e e n a b s o r b e d of a t o t a l a m o u n t o f 637 nag o f p a r a q u a t dichloride d e t e r m i n e d in urine, d i a l y s a t e , a n d feces. T h a t m e a n s a n a b s o r p t i o n o f less t h a n t 4 % .
Paraquat Poisoning in Man
133
A
503020lt,: 12-4
|
10o
8.
~.~
6
gl|
2,
I
hours after ingestion 01"0
E.c_
8'
Fig. 2. Urinary excretion and elimination of paraquat dichloride by hemodialysis (case I). (1) Catheter urine; (2) forced diuresis, l~umbers in parentheses show urine production in ml
801
Durine
| 70
H dia|ysate
A
B
C
D
Fig. 3. Comparison of the excretion of paraquat dichloride in urine at several time intervals and elimination by hemodialysis (case i). (A) Total excretion of paraquat dichloride in urine over a 14-day period compared to the elimination in the dialysates. (B) Excretion of paraquat dichloride caused by forced diuresis over 336 hrs compared to the elimination in the dialysates. (C) Excretion of paraquat dichloride in urine during forced diuresis on the first day of ingestion compared to the elimination over 4 hrs of hemodialysis. (D) As (C) on second day
B. Urinary Excretion and Elimination by Hemodialysis There is still little k n o w n a b o u t the excretion in m a n during the v e r y early period after ingestion. However, on arrival at the hospital the 25-year-old p a t i e n t (case i) a n d the 45-year-old w o m a n (case 3) b o t h urinated for the first time after the intake of the herbicide.
134
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30o
J-J urine 20~ diolysate
(3 O.
10-
"6 E
A B C
Fig. 4. Excretion of paraquat dichloride in urine and the elimination by hemodialysis (case 2). Numbers in parentheses show urine production in ml. (A) Paraquat dichloride concentration of the catheter urine on arrival at the University Hospital. (B) Paraquat dichloride concentration of the urine produced over a 2-hrs period of hemodialysis. (C) The paraquat dichloride concentration eliminated over a 2-hr period of hemodialysis
Fig. 2 shows the results obtained from the samples of case i. From this figure it can be deducted that a therapy of 36 hrs of forced diuresis removed 26.5 mg of paraquat dichloride while a treatment of two times 4 hrs of dialysis eliminated t2 mg of paraquat dichloride. I n Fig. 3 a comparison is made between the ehmination of the herbicide by hemodialysis and the urine excretion at several time intervals. Fore this figure it can be deducted (3 B) that during 8 hrs of hemodialysis t2 mg of paraquat dichloride have been eliminated while a 2-week therapy of forced diuresis only removed 33 mg of paraquat dichloride, a prove that an immediate hemodialysis is to be preferred to a forced diuresis when an intoxicated patient enters a therapy unit. I n Fig. 4 the results of the therapy of case 2 are shown. I t is evident that the concentration of paraquat dichloride eliminated b y hemodialysis is much greater than the concentrations of the herbicide in the urine. A reason for the slight urinary excretion m a y be the fact the patient only had one kidney and suffered of renal insufficiency when she entered the University Hospital. I n this case we were able to determine blood levels of paraquat dichloride before and after dialysis of 3.7 ppm and 2.5 ppm, respectively. Fig. 5 shows the results obtained from the samples of case 3. This figure demonstrates the usefulness of an immediate hemodialysis as well as the benefit of hemodialysis in cases of renal insufficiency. As for the blood paraquat dichloride level, a blood concentration of 19.4 ppm was found before and of 2.7 ppm after 6 hrs of dialysis.
Discussion I n rat experiments Daniel and Gage (1966) found an absorption of paraquat dichloride of about 6 % to 14% depending on the strain of rats used. They con-
Paraquat Poisoning in Man
135
04 04
400300200-
,-0
|
100: 80-
6040200 20' 406080100-
!i x
01"O
E.~
A r
1'2
11
;b
2'0 ~
2'8
3'2
3'6
hours after ingestion
Fig. 5. Urinary excretion and elimination of paraquar dichloride during hemodialysis (case 3). (1) Catheter urine; (2) forced diuresis; (3) ~,o urine production. Numbers in parentheses show urine production in ml
cluded t h a t p a r a q u a t was poorly absorbed in the rat and t h a t a degradation of the herbicide occurred in the feces, caused b y a microbiological action. As mentioned before, (case l) less t h a n 14o/o of the ingested dose of p a r a q u a t dichloride has been absorbed. Since urine and feces analyses were performed over a period of t4 days and I week, respectively, considering the fact a microbiological degradation in r a t feces occurs (in agreement with Fletcher [1974]) we estimate t h a t about 5 % to i0 % of the ingested dose of p a r a q u a t dichloride was absorbed in case I. The permanent fecal paraquat excretion (at least 7 days after ingestion) was very surprising. A delayed defecation might be the cause, but this remains doubtful since 2 hrs after intake of the herbicide our patient received a laxans (sodium sulfate) which caused defecation. Furthermore, Daniel and Gage (1966) found t h a t rats receiving p a r a q u a t b y sc injection, excreted some of the herbicide in the feces and Litchfield et al. (1973) could demonstrate p a r a q u a t in the large intestine of a mouse 24 hrs after an iv injection. We also found a p a r a q u a t dichloride level of 27 p p m in the bile of a woman after autopsy. According to these arguments, we believe it is possible t h a t some of the absorbed p a r a q u a t is excreted into the gastrointestinal tract, a reason for a daily administration of Fullers' earth. As for the hemodialysis, high levels of p a r a q u a t dichloride could be demonstrated in the dialysate. Considering ease i, 8 hrs of dialysis are m u c h more effective than a 2-week therapy of forced diuresis because hemodialysis will lower paraquat dichloride levels in the lung (the target organ) faster t h a n a forced diuresis will do. Considering the cases 2 and 3, hemodialysis has demonstrated its usefulness in the case of renal failure, a s y m p t o m which often occurs after an intoxication b y paraquat dichloride. We approve t h a t Douze's advice (i974) on primary, e.g.
136
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i m m e d i a t e hemodialysis, h a s been a v e r y useful c o n t r i b u t i o n for t h e t r e a t m e n t o f patients intoxicated by Gramoxone | Acknowledgement. The authors are indebted to Mr. F. Dost for his technical assistance.
References Daniel, J. W., Gage, J. C.: Absorption and excretion of diquat and paraquat in rats. Brit. J. industr. Med. 23, i33--136 (i966) Douze, J. M. C., van Dijk, A., Gimbr~re, J. S. F., van Heyst, A. N. P., Maes, R. A. A., Rauws, A. G.: Iatensive therapy after paraquat intoxication. Intensivmedizin 11 (5), 241--250 (1974) Fletcher, K. : Paraquat poisoning. In: Forensic toxicology (ed. Bryan Ballantyne) p. 86--98. Bristol: John Wright and Sons Ltd. i974 Grabensee, B., Veltmann, G., Miirtz, R., Borchard, F.: Paraquat poisoning. Dtsch. med. Wschr. 96, 498--506 (1971) Litchfield, M. It., Daniel, J. W., Longshaw, S. : The tissue distribution of the bipyridylium herbicides diquat and paraquat in rats and mice. Toxicology 1, 155--165 (1973) Tompsett, S. L. : Paraquat poisoning. Aeta pharmacol. (Kbh.) 28, 346--358 (i970) Dr. A. v a n Dijk Center for Human Toxicology Vondellaan t4 Utrecht/The Netherlands
Paraquat Poisoning in Man A. v a n D i j k , R. A. A. Maes a n d R . H. D r o s t J . M. C. D o u z e a n d A. N. P . v a n I-Ieyst Center for Human Toxicology, University of Utrecht, Utrecht, The Netherlands Department of Reanimation and Clinical Toxicology, University Hospital, Utrecht, The Netherlands Received February t3, t975
Abstravt. In three cases of intoxication by Gramoxone| the concentration of paraquat dichloride in blood, dialysate, feces, and urine was determined speetrophotometrically after a clean-up of the biological material by means of ion exchange chromatography (with Dowex 50W-Xt2 or Zeo-Karb 225). Although good results were obtained after clean-up with Dowex 50W-X12, Zeo-Karb was preferred as ion exchange resin, especially when large sample volumes were needed for the determination. The reported findings indicate that: only 5 to 10% of an ingested dose of paraquat dichloride is absorbed in man, Pullers' earth is very useful, and that primary, e.g. immediate, hemodialysis is necessary. Key words: Paraquat-Poisoning -- Fullers' Earth -- Hemodialysis. Zusammen]assung: Paraquat Dichlorid wurde spektrophotemetrisch bestjmmt in Blur, I)ialysat, Stuhl und Urin in drei F/fllen yon Vergiftung durch Gramoxono| Aufarbeitung des biologischen Materials geschah durch Ionenaustausch-Chromatographie mit Hilfe yon Dowex 50W-Xt2 oder Zeo-Karb 225. Zeo-Karb 225 wurde fiir die Bestjmmung, besonders wenn grolle Volumina X~liissigkeit erforderlich waren, vorgezogen. Die Ergebnisse zeigen, dab nach oraler Einnahme nur 5 bis l0 % des Paraquat-Dichlorid resorbiert wird. T~gliche Verabreichung yon Fullers' Erde ist n/itzlich. Sofortige H~imedialyse ist begriindet und therapeutisch notwendig. S~li~sselw6rter: Paraquat -- Vergiftung -- Analyse -- Fullers' Erde -- Hiimodialyse. As a p a r t o f t h e i n t e n s i v e t h e r a p y after i n t o x i c a t i o n b y p a r a q u a t ( i , i ' d i m e t h y l 4 , 4 ' d i p y r i d y l i u m c a t i o n ) r e c e n t l y Douze eta/. (i974) a d v i s e d t h e use o f FuUers' e a r t h a n d hemodialysis. H o w e v e r , in t h e l i t e r a t u r e v e r y l i t t l e is k n o w n a b o u t t h e e x c r e t i o n o f p a r a q u a t in h u m a n feces a n d t h u s a b o u t t h e usefulness o f t h e a d m i n i s t r a t i o n o f ~ u l l e r s ' earth. G r a b e n s e e e t a / . ( t 9 7 i ) d e s c r i b e d t w o cases o f fecal p a r a q u a t excretion, b u t t h e y were n o t able to q u a n t i t a t e t h e p e r c e n t a g e o f p a r a q u a t being a b s o r b e d . I n t h i s s t u d y we were a b l e t o d e t e r m i n e t h e u r i n a r y a n d fecal p a r a q u a t e x c r e t i o n o f a n i n t o x i c a t e d p a t i e n t who e n t e r e d t h e U n i v e r s i t y H o s p i t a l s h o r t l y a~ter t h e i n g e s t i o n o f t h e h e r b i c i d e a n d w h o h a d n o t e x c r e t e d a n y p a r a q u a t o n arrival.
A. v a n Dijk et al.
t30
A s f o r h e m o d i a l y s i s , t h i s t h e r a p y is still c o n s i d e r e d as d o u b t f u l d u e t o t h e f a c t i t is q u e s t i o n a b l e i f d i a l y s i s will r e m o v e p a r a q u a t o r n o t . F o r i n s t a n c e , G r a b e n s e e e$ al. ( i 9 7 1 ) c o u l d n o t d e t e c t p a r a q u a t i n t h e d i a l y s a t e . On the contrary we were able to demonstrate the usefulness of hemodialysis in t h r e e cases, a p r o v e o f D o u z e ' s s t a t e m e n t o n p r i m a r y , e.g. i m m e d i a t e h e m o d i a l y s i s (1974).
Case Histories 1. A 25-year-old epileptic m a n made a n a t t e m p t to commit suicide in a state of depression b y ingesting some Gramoxone| (20 % p a r a q u a t dichloride in water). I hr later he was admitted to a ward where a gastric lavage was applied. Later on he was transferred to the D e p a r t m e n t of Reanimation a n d Clinical Toxicology of the University Hospital, where he arrived 3 hrs after ingestion of the herbicide. On arrival he urinated for the first time after the intake of the poison; this (catheter) urine contained 4t.4 mg of p a r a q u a t dichloride ( = 63.8 ppm) in total. Moreover he vomitted; the vomit h a d a p a r a q n a t dichloride concentration of 100 mg. On alrival his blood concentration was 1.6 p p m p a r a q u a t dichloride. He was clinically treated as described b y Douze et al. (t974), s. "case 5". The basic treatm e n t included a n administration of nitrogen b y a nasal tube (4 1 nitrogen/rain), a forced diuresis a n d a n administration of a t 0 % suspension of Fullers' earth in water. 6 hrs after ingestion the m a n was s u b m i t t e d to hemodialysis. This t r e a t m e n t was performed with a Twin coil artificial kidney according to Kolff/Watschinger, equipped with a cuprophane membrane. Outcome: non-fatal. 2. A 62-year-old woman was brought into the D e p a r t m e n t of Reanimation a n d Clinical Toxicology of the University Hospital a b o u t 24 hrs after the ingestion of a large a m o u n t of Gramoxone| On arrival the (catheter) urine (40 ml) contained 3.45 mg of p a r a q u a t dichloride (86.3 ppm) a n d her blood concentration was 3.7 ppm. According to her clinical picture, hemodialysis was indicated. She died after 2 hrs of intensive therapy. 3. Shortly after a family trouble, a 45-year-old woman ingested a large amount of Gramoxone| 3 hrs after the intake of the herbicide she entered the University Hospital. Immediately, a gastric lavage was applied a n d Fullers' e a r t h was administrated. 5 hrs after ingestion her urine (223 ml) contained 394 mg of p a r a q u a t dichloride ( = 1766 p p m !) a n d her blood concent r a t i o n measured t9.4 ppm! Consecutively, she was submitted to a forced diuresis and hemodialysis was indicated. She suddenly died, due to a h e a r t failure, 35 hrs after ingesting the poison.
Methodology Analysis o/Feces. In in vitro experiments we found t h a t p a r a q u a t is rapidly and strongly adsorbed b y Fullers' earth a n d is not removed b y equilibration with water or diluted acid (e.g. 5 ~T HC1) when present in a concentration below the exchange capacity of this clay. T h a t means if p a r a q u a t is present in Fullers' earth containing feces, the herbicide cannot be extracted b y water or a diluted acid. We found the following extraction procedure to be the most suitable: 10 g of feces are refluxed with 20 ml of 18 1~ sulfuric acid for 6 hrs. After cooling down to room temperature the acid extract is filtered through a 3 G 2 glass filter a n d the residue is washed with l 0 ml of 18 N sulfuric acid. The filtrate is diluted with distilled water to a b o u t 400 ml and 41~ l~aOH is added until the acidity reaches t N sulfuric acid. The extract is filtered into a 500 ml volumetric flask a n d is adjusted with distilled water. A n aliquot of this solution is applied to a Dowex 50W-X12 column a n d chromatographed according to Tompsett (1970). The obtained eluate is evaporated to dryness in a Biichi evaporator under reduced pressure (30 mmHg) a n d the residue is dissolved in 10.00 ml of a buffer solution of borax-hydrochloric
P a r a q u a t Poisoning in Man
t31
acid (pH = 9.0). An aliquot of the mixture is placed in a 2- or 4-cm cuvette a n d a spectrum is scanned from 380 n m to 650 n m using the buffer as a reference solution. 50 rag of sodium dithionite are added to each euvette a n d a spectrum is scanned again. Since reference solutions (0 to 4 p p m of p a r a q u a t dichloride in buffer solution) follow Beers' law a t 602 nm, the difference of absorbance a t t h a t wavelength before a n d after reduction is estimated as a measure for the concentration of paraquat. Using the described m e t h o d we found a recovery of 90 % when t 5 ~tg of p a r a q u a t dichloride were added to t 0 ml of a :Fullers' e a r t h suspension. Because the concentration of p a r a q u a t in t h e feces of our p a t i e n t was considerable high (Table 1) we only needed small aliquots for column chromatography resulting in low background absorptions. I n t h e analysis of feces with low p a r a q u a t concentrations t h e use of Zeo-Karb 225 is preferred to Dowex 50W-Xt2. Handling the Dowex 50W-XI2, large aliquots m u s t be applied to the columns, resulting in eluates showing a too high background absorption for a n accurate determination. Using Zeo-Karb 225, t h e extract h a s to be adjusted to p H = 5.5 to 6.5 with 4 Iq N a O H prior to filtration into the 500 ml volumetric flask.
Analysis o] the Dialysate. 3.5 g of Zeo-Karb 225 (sodium form, 52 to ~00 mesh, 8 % DVB, P e r m u t i t Company Ltd.) are washed with water into a chromatographic column ( ~ I cm i.d.; 40 cm length). Consecutively 50 ml of a saturated sodium chloride solution a n d 100 ml of distilled water are passed t h r o u g h the column, which is ready for use b y now. A n aliquot of the dialysate (500 ml to 1000 ml) is passed through the column a t a flow rate not exceeding 4 ml/min. Then the column is washed with 20 ml of distilled water, 100 ml of I N hydrochloric acid a n d i 5 0 ml of a 2.5 % a m m o n i u m chloride solution. The retained p a r a q u a t is eluted with a s a t u r a t e d a m m o n i u m chloride solution a t a flow rate of I ml to 2 ml per minute. The first 50.0 ml of the eluate are collected in a volumetric flask. l 0 ml of t h e eluate are pipetted into a glass stoppered tube of 20 ml a n d 2.00 ml of 4 N N a O H are added. 7 ml of this mixture are transferred to a 2 cm cuvette a n d a spectrum is scanned from 380 n m to 650 a m , using 7 ml of a mixture of i0.00 ml saturated a m m o n i u m chloride a n d 2.00 ml of 4 N l~aOH as a reference solution. After addition of 50.0 mg of sodium dithionite to b o t h cuvettes, the solutions are scanned again. The difference of absorbance a t 602 n m of 397 n m is noticed. B y addition of 30 ~g of p a r a q u a t dichloride to 500 ml of dialysate a recovery of 94 % was obtained. Analysis of Urine. :For the analysis of urine samples, a modification of Tompsett's m e t h o d (1970) was used: the colorimetric determination of p a r a q u a t was carried out as described before (see Analysis of feces). Reproducable q u a n t i t a t i o n only could be obtained when t h e urine samples did not exceed I00 ml. F r e q u e n t l y p a r a q u a t has to be determined in large urine samples containing relatively low concentrations of the herbicide (e.g. urine of patients s u b m i t t e d to forced diuresis). I n such cases 500 ml to 1500 ml of urine h a v e to be applied to a n ion exchange resin. As mentioned before, using the Dowex column, a high background absorption is obtained resulting in a low recovery. Therefore, we advise to use the Zeo-Karb resin as described for the analysis of the dialysate. Before applying urine to this ion exchange resin, t h e p H m u s t be adjusted to 5.5 to 6.5 a n d the sample filtered even when the urine looks limpid. I n this way a very low background absorption a n d a n excellent recovery are obtained (95 % recovery of 20 tzg p a r a q u a t dichloride added to 500 ml of urine). Analysis of Blood. l 0 ml of whole blood (or 6 ml of serum) are refluxed with 15 ml of 18 N sulfuric acid during I hr. After diluting the acid extract with distilled water to a b o u t 300 ml a n d a subsequent filtration, the p H of the solution is adjusted to 5.5 to 6.5 with 4 N l~aOH. After a second filtration, t h e extract is handled as described for the dialysate. A t the 1 p p m level a recovery of 95 % is obtained. A 20 ml sample is needed for the determination of p a r a q u a t blood levels below I ppm.
A. van Dijk et at.
132
Table 1. Paraquat dichloride concentrations (case 1) Days Concentration of paraquat dichloride after feces urine ingestion mg ppm mg ppm t 2 3 4 5 6 7
340 0.2 8t 102
1193 80 405 300
_a
_
--~
--
25.5
61.6 6.3 2.6 1.4 0.7 0.6 0.4
54
19.3 0.62 0.27 0.t3 0.06 0.06 0.03
a No defecation.
550 4
-------.feces
5004 4504
-8
400-~
350J 300 4
2502002 150100-: "6 80ol E 6040-
/ 9
9
,
:
:urine
20-
days otter ingestion
Fig. t. Cumulative excretion of paraquat dichloride in feces and urine (case 1)
Results
A. Fecal and Urinary Excretion o] Paraquat Dichloride T a b l e I shows t h e fecal a n d u r i n a r y p a r a q u a t dichloride e x c r e t i o n of t h e 25-year-old p a t i e n t (case l ) . I n Fig. I c u m u l a t i v e excretions are shown. T h e d a t a i n d i c a t e t h a t t h e concent r a t i o n of n o n - a b s o r b e d p a r a q u a t is m u c h g r e a t e r t h a n t h e a b s o r b e d c o n c e n t r a t i o n of t h e herbicide. F r o m Figs. I a n d 3 i t m a y be c a l c u l a t e d t h a t o n l y 87 m g o f p a r a q u a t dichloride h a s b e e n a b s o r b e d of a t o t a l a m o u n t o f 637 nag o f p a r a q u a t dichloride d e t e r m i n e d in urine, d i a l y s a t e , a n d feces. T h a t m e a n s a n a b s o r p t i o n o f less t h a n t 4 % .
Paraquat Poisoning in Man
133
A
503020lt,: 12-4
|
10o
8.
~.~
6
gl|
2,
I
hours after ingestion 01"0
E.c_
8'
Fig. 2. Urinary excretion and elimination of paraquat dichloride by hemodialysis (case I). (1) Catheter urine; (2) forced diuresis, l~umbers in parentheses show urine production in ml
801
Durine
| 70
H dia|ysate
A
B
C
D
Fig. 3. Comparison of the excretion of paraquat dichloride in urine at several time intervals and elimination by hemodialysis (case i). (A) Total excretion of paraquat dichloride in urine over a 14-day period compared to the elimination in the dialysates. (B) Excretion of paraquat dichloride caused by forced diuresis over 336 hrs compared to the elimination in the dialysates. (C) Excretion of paraquat dichloride in urine during forced diuresis on the first day of ingestion compared to the elimination over 4 hrs of hemodialysis. (D) As (C) on second day
B. Urinary Excretion and Elimination by Hemodialysis There is still little k n o w n a b o u t the excretion in m a n during the v e r y early period after ingestion. However, on arrival at the hospital the 25-year-old p a t i e n t (case i) a n d the 45-year-old w o m a n (case 3) b o t h urinated for the first time after the intake of the herbicide.
134
A. van Dijk et al.
30o
J-J urine 20~ diolysate
(3 O.
10-
"6 E
A B C
Fig. 4. Excretion of paraquat dichloride in urine and the elimination by hemodialysis (case 2). Numbers in parentheses show urine production in ml. (A) Paraquat dichloride concentration of the catheter urine on arrival at the University Hospital. (B) Paraquat dichloride concentration of the urine produced over a 2-hrs period of hemodialysis. (C) The paraquat dichloride concentration eliminated over a 2-hr period of hemodialysis
Fig. 2 shows the results obtained from the samples of case i. From this figure it can be deducted that a therapy of 36 hrs of forced diuresis removed 26.5 mg of paraquat dichloride while a treatment of two times 4 hrs of dialysis eliminated t2 mg of paraquat dichloride. I n Fig. 3 a comparison is made between the ehmination of the herbicide by hemodialysis and the urine excretion at several time intervals. Fore this figure it can be deducted (3 B) that during 8 hrs of hemodialysis t2 mg of paraquat dichloride have been eliminated while a 2-week therapy of forced diuresis only removed 33 mg of paraquat dichloride, a prove that an immediate hemodialysis is to be preferred to a forced diuresis when an intoxicated patient enters a therapy unit. I n Fig. 4 the results of the therapy of case 2 are shown. I t is evident that the concentration of paraquat dichloride eliminated b y hemodialysis is much greater than the concentrations of the herbicide in the urine. A reason for the slight urinary excretion m a y be the fact the patient only had one kidney and suffered of renal insufficiency when she entered the University Hospital. I n this case we were able to determine blood levels of paraquat dichloride before and after dialysis of 3.7 ppm and 2.5 ppm, respectively. Fig. 5 shows the results obtained from the samples of case 3. This figure demonstrates the usefulness of an immediate hemodialysis as well as the benefit of hemodialysis in cases of renal insufficiency. As for the blood paraquat dichloride level, a blood concentration of 19.4 ppm was found before and of 2.7 ppm after 6 hrs of dialysis.
Discussion I n rat experiments Daniel and Gage (1966) found an absorption of paraquat dichloride of about 6 % to 14% depending on the strain of rats used. They con-
Paraquat Poisoning in Man
135
04 04
400300200-
,-0
|
100: 80-
6040200 20' 406080100-
!i x
01"O
E.~
A r
1'2
11
;b
2'0 ~
2'8
3'2
3'6
hours after ingestion
Fig. 5. Urinary excretion and elimination of paraquar dichloride during hemodialysis (case 3). (1) Catheter urine; (2) forced diuresis; (3) ~,o urine production. Numbers in parentheses show urine production in ml
cluded t h a t p a r a q u a t was poorly absorbed in the rat and t h a t a degradation of the herbicide occurred in the feces, caused b y a microbiological action. As mentioned before, (case l) less t h a n 14o/o of the ingested dose of p a r a q u a t dichloride has been absorbed. Since urine and feces analyses were performed over a period of t4 days and I week, respectively, considering the fact a microbiological degradation in r a t feces occurs (in agreement with Fletcher [1974]) we estimate t h a t about 5 % to i0 % of the ingested dose of p a r a q u a t dichloride was absorbed in case I. The permanent fecal paraquat excretion (at least 7 days after ingestion) was very surprising. A delayed defecation might be the cause, but this remains doubtful since 2 hrs after intake of the herbicide our patient received a laxans (sodium sulfate) which caused defecation. Furthermore, Daniel and Gage (1966) found t h a t rats receiving p a r a q u a t b y sc injection, excreted some of the herbicide in the feces and Litchfield et al. (1973) could demonstrate p a r a q u a t in the large intestine of a mouse 24 hrs after an iv injection. We also found a p a r a q u a t dichloride level of 27 p p m in the bile of a woman after autopsy. According to these arguments, we believe it is possible t h a t some of the absorbed p a r a q u a t is excreted into the gastrointestinal tract, a reason for a daily administration of Fullers' earth. As for the hemodialysis, high levels of p a r a q u a t dichloride could be demonstrated in the dialysate. Considering ease i, 8 hrs of dialysis are m u c h more effective than a 2-week therapy of forced diuresis because hemodialysis will lower paraquat dichloride levels in the lung (the target organ) faster t h a n a forced diuresis will do. Considering the cases 2 and 3, hemodialysis has demonstrated its usefulness in the case of renal failure, a s y m p t o m which often occurs after an intoxication b y paraquat dichloride. We approve t h a t Douze's advice (i974) on primary, e.g.
136
A. van Dijk et al.
i m m e d i a t e hemodialysis, h a s been a v e r y useful c o n t r i b u t i o n for t h e t r e a t m e n t o f patients intoxicated by Gramoxone | Acknowledgement. The authors are indebted to Mr. F. Dost for his technical assistance.
References Daniel, J. W., Gage, J. C.: Absorption and excretion of diquat and paraquat in rats. Brit. J. industr. Med. 23, i33--136 (i966) Douze, J. M. C., van Dijk, A., Gimbr~re, J. S. F., van Heyst, A. N. P., Maes, R. A. A., Rauws, A. G.: Iatensive therapy after paraquat intoxication. Intensivmedizin 11 (5), 241--250 (1974) Fletcher, K. : Paraquat poisoning. In: Forensic toxicology (ed. Bryan Ballantyne) p. 86--98. Bristol: John Wright and Sons Ltd. i974 Grabensee, B., Veltmann, G., Miirtz, R., Borchard, F.: Paraquat poisoning. Dtsch. med. Wschr. 96, 498--506 (1971) Litchfield, M. It., Daniel, J. W., Longshaw, S. : The tissue distribution of the bipyridylium herbicides diquat and paraquat in rats and mice. Toxicology 1, 155--165 (1973) Tompsett, S. L. : Paraquat poisoning. Aeta pharmacol. (Kbh.) 28, 346--358 (i970) Dr. A. v a n Dijk Center for Human Toxicology Vondellaan t4 Utrecht/The Netherlands
