Halothane Hepatitis—A Preventable Disease?

Eleven patients with acute hepatitis following multiple anaesthetics with halothane have been seen at two hospitals during the last four years. Six had massive hepatic necrosis and died. Unexplained fever occurred in nine of the patients; two of these and one other had had previous episodes of jaundice after halothane anaesthesia. Thus, in ten patients the disease could have been avoided.     

Circulating immune complexes after repeated halothane anaesthesia.

A patient developed hepatitis after receiving three halothane anaesthetics in 22 days. Twenty-four hours after the onset of jaundice she developed an acute serum sickness syndrome with polyarthralgia, proteinuria, and transient impairment of renal function. Serum concentrations of complement components C1q, C4, and C3 were substantially reduced, and immune complexes capable of activating the complement system via the classical pathway were present in the serum and synovial fluid. A metabolite of halothane was associated with these complexes. Fourteen months after exposure to halothane her lymphocytes were stimulated in vitro by this metabolite. The conditions under which stimulation occurred were unusual--namely, a 7S fraction of the serum, presumably IgG, was necessary. Our results provide strong evidence that halothane may be immunogenic and that its immunogenicity is dependent on the non-covalent binding of one of its metabolites to plasma proteins.     

Molecular mimicry of trifluoroacetylated human liver protein adducts by constitutive proteins and immunochemical evidence for its impairment in halothane hepatitis.

A monospecific antibody (anti-CF3CO antibody) was obtained by affinity chromatography on a N epsilon-trifluoroacetyl-L-lysine (CF3CO-Lys) matrix of a rabbit polyclonal antiserum, directed against trifluoroacetylated protein adducts (CF3CO-proteins). The anti-CF3CO antibody recognized distinct CF3CO-proteins on immunoblots of a liver biopsy obtained from a human individual 10 h after halothane anaesthesia. Cross-reactive proteins of 52 kDa and 64 kDa were recognized on immunoblots of livers obtained from human individuals not exposed to halothane. Recognition of both CF3CO-proteins and the 52-kDa and 64-kDa cross-reactive proteins was abolished in the presence of 1 mM CF3CO-Lys. Anti-CF3CO antibody, affinity-adsorbed to the 52-kDa or the 64-kDa cross-reactive proteins of human liver, recognized the majority of target CF3CO-proteins on immunoblots of the human liver biopsy of an individual exposed to halothane. Liver biopsies of 5 out of 7 (71%) patients with halothane hepatitis exhibited an absence or low amounts of immunorecognizable 52-kDa and/or 64-kDa cross-reactive proteins. In contrast, of 22 control human individuals tested, all liver tissue samples were positive for the 52-kDa and/or the 64-kDa cross-reactive proteins. These data indicate that epitopes on the cross-reactive proteins of 52 kDa and 64 kDa of human liver bear strong immunochemical resemblance to epitopes on human liver CF3CO-proteins. Low-level expression of the cross-reactive proteins of 52 kDa and 64 kDa is discussed as one possible factor in human susceptibility to halothane hepatitis.     

Halothane hepatitis

This report describes five cases of hepatocellular injury following halothane anesthesia. Four patients had multiple exposures to the anesthetic. Three of the five died from submassive to massive liver cell necrosis. The two survivors developed jaundice and/or dark urine following each exposure to halothane; liver biopsy in one showed centrilobular and linear areas of necrosis. Fever, anorexia, nausea, vomiting, abdominal pain and jaundice were present in all cases. In the two survivors the prothrombin time was less than 20 seconds throughout the course of the disease, whereas in the three who died the prothrombin time was more than 20 seconds from the onset. The English literature to the end of 1971 is reviewed. Approximately 600 cases of halothane-related hepatitis have been reported     

The in vivo genotoxicity of cisplatin,isoflurane and halothane evaluated by alkaline comet assay in Swiss albino mice

The aim of this study was to evaluate the genotoxicity of repeated exposure to isoflurane or halothane and compare it with the genotoxicity of repeated exposure to cisplatin. We also determined the genotoxicity of combined treatment with inhalation anaesthetics and cisplatin on peripheral blood leucocytes (PBL), brain, liver and kidney cells of mice. The mice were divided into six groups as follows: control, cisplatin, isoflurane, cisplatin–isoflurane, halothane and cisplatin–halothane, and were exposed respectively for three consecutive days. The mice were treated with cisplatin or exposed to inhalation anaesthetic; the combined groups were exposed to inhalation anaesthetic after treatment with cisplatin. The alkaline comet assay was performed. All drugs had a strong genotoxicity (P < 0.05 vs. control group) in all of the observed cells. Isoflurane caused stronger DNA damage on the PBL and kidney cells, in contrast to halothane, which had stronger genotoxicity on brain and liver cells. The combination of cisplatin and isoflurane induced lower genotoxicity on PBL than isoflurane alone (P < 0.05). Halothane had the strongest effect on brain cells, but in the combined treatment with cisplatin, the effect decreased to the level of cisplatin alone. Halothane also induced the strongest DNA damage of the liver cells, while the combination with cisplatin increased its genotoxicity even more. The genotoxicity of cisplatin and isoflurane on kidney cells were nearly at the same level, but halothane caused a significantly lower effect. The combinations of inhalation anaesthetics with cisplatin had stronger effects on kidney cells than inhalation anaesthetics alone. The observed drugs and their combinations induced strong genotoxicity on all of the mentioned cells.     

Effect of anaesthetics and dichlorodifluoromethane on the viability of the cells of Escherichia coli and the activities of some of its enzymes

Three anaesthetics (halothane, CF3CHClBr; Ethrane, F2 HCOF2CCHClF; cyclopropane) and one other halogenated, short-chain hydrocarbon (F-12, Cl2F2C) were tested under various conditions to determine their effects on the viability of cells of Escherichia coli and the activities of some of its enzymes. When any of the test chemicals were applied for 60 min at concentrations slightly in excess of saturation, the number of surviving cells decreased substantially, with halothane being the most biocidal of the four chemicals and F-12 the least. Three enzymes (malate dehydrogenase, MD; NADH dehydrogenase; glyceraldehyde-3-phosphate dehydrogenase, GPD) were tested for activity after treatment of E. coli with the test chemicals. In all instances, GPD was least resistant to inactivation and MD was most resistant. Halothane was most inhibitory followed in order by Ethrane, cyclopropane and F-12. Treatment of E. coli with halothane for 60 min at 23 degrees C and a concentration slightly in excess of saturation, resulted in nearly complete inhibition of all three enzymes.     

Effect of volatile anaesthetics on the electrical activity and the coupling coefficient of weakly electrically coupled neurones

1. The application of the volatile anaesthetics, halothane and isoflurane (1% v/v and 2% v/v), to the CNS of Lymnaea reduced the firing frequency of the small weakly coupled pedal A cluster (PeA) neurones, which eventually become quiescent. There was no change in their resting membrane potential. 2. Met-enkephalin significantly increased the coupling coefficient between PeA neurones. 3. The volatile anaesthetics decreased the coupling coefficient even in the presence of met-enkephalin. 4. These effects were dose dependent and the effects of halothane were more rapid than those of isoflurane, reflecting their different anaesthetic potencies.     

Genotoxicity of inhalation anaesthetics: DNA lesions generated by sevoflurane in vitro and in vivo

A moderate genotoxic activity of halothane and isoflurane applied as volatile anaesthetics has already been shown. The aim of this work was to estimate a potential genotoxicity of sevoflurane, introduced to clinical practice later than halothane and isoflurane. A genotoxic activity of all three compounds was estimated by using the comet assay in human peripheral blood lymphocytes (PBL) proliferating in vitro. We demonstrated that in contrast to the previously studied anaesthetics, sevoflurane did not induce any increase in DNA migration in the studied conditions. To estimate a genotoxic effect of a prolonged exposure to halogenated anaesthetics in vivo, PBL taken from operating room personnel (n = 29) were tested for DNA degradation and compared with those from a control non-exposed group (n = 20). No significant differences were detected between the groups. We conclude that sevoflurane does not have genotoxic properties, both in vitro and in vivo.     

The effects of anaesthesia and hypothermia on interstitial concentrations of acetylcholine and choline in rat striatum

The effects of the general anaesthetics pentobarbital, chloral hydrate, and halothane on interstitial concentrations of acetylcholine (ACh) in rat striatum were determined using in vivo microdialysis. All 3 anaesthetics decreased ACh. Emergence from anaesthesia coincided with a recovery of ACh to about 80% of basal values. Pentobarbital increased choline in a profile that was the mirror image of ACh. Chloral hydrate had a biphasic effect on choline, consisting of a shortlasting (20 min) initial decrease followed by an increase. When halothane anaesthetized rats were subjected to forced hypothermia by placing them on ice for 30 min, ACh release was further depressed whereas choline was greatly increased. These finding demonstrate that general anaesthetics decrease extracellular concentrations of ACh in the rat striatum and that this effect can be exacerbated by hypothermia.     

Unexplained hepatitis following halothane.

Full clinical and laboratory details of 203 patients with postoperative jaundice were submitted to a panel of hepatologists. All patients whose jaundice may have had an identifiable cause were excluded, which left 76 patients with unexplained hepatitis following halothane anaesthesia (UHFH). Hepatitis in 95% of these cases followed multiple exposure to halothane, with repeated exposure within four weeks in 55% of cases. Twenty-nine patients were obese, 52 were aged 41-70, and 53 were women. Thirteen patients died in acute hepatic failure. Rapid onset of jaundice after anaesthesia, male sex, and obesity in either sex were poor prognostic signs. Of the clinical stigmata of hypersensitivity, only eosinophilia was impressive. The UHFH group had a much greater incidence of liver kidney microsomal (LKM) and thyroid antibodies and autoimmune complement fixation than those patients whose jaundice related to identifiable factors. Thirteen of the 19 patients with LKM antibodies also had thyroid antibodies. In six patients retested two to three years later LKM antibodies had disappeared, although thyroid antibodies persisted. Rapidly repeated exposure to halothane may cause hepatitis, but such a complication is probably rare. Possibly obese women with a tendency to organ-specific autoimmunity may be more at risk. Nevertheless, the comparative risks of rapidly repeated halothane or non-halothane anaesthesia cannot be determined from the present data. If alternative satisfactory agents are available halothane should be avoided in patients with unexplained hepatitis after previous exposure, although in three to five patients with UHFH who were re-exposed to halothane jaundice did not recur.     

General and local anaesthetics perturb the fusion of phospholipid vesicles

The effects of general and local anaesthetics on Ca2+-induced fusion of negatively charged lipid vesicles have been investigated. Vesicles composed of phosphatidylcholine and phosphatidic acid (2:1 molar ratio) were induced to fuse using 5 mM free Ca2+. Fusion, assessed by an increase in size using gel filtration techniques and confirmed by electron microscopy, displayed a dependence on Ca2+ and Mg2+ concentration and on temperature. The inhalational anaesthetics halothane, methoxyflurane and diethyl ether enhanced fusion as did the uncharged local anaesthetic benzocaine. In contrast, the charged local anaesthetics lignocaine and bupivacaine inhibited the fusion process. It is suggested that the enhancement observed with the inhalational anaesthetics and benzocaine was mediated by an effect on lipid fluidity and the inhibition observed with the charged tertiary amine anaesthetics was due to an antagonism towards Ca2+.     

Effect of High-Pressure Gas Atmospheres and Anaesthetics on Chilling Injury of Plants

High pressures and anaesthetics were used to study chillinginjury in plants. Changes in membrane fluidity at low but nonfreezingtemperatures are thought to be involved in chilling injury-aphysiological disorder of many economically important plants,e.g. banana, cotton, cucumber, maize, rice, sorghum, and tomato.High-pressure helium and nitrogen atmospheres of 12 MPa increasedthe severity of chilling injury (i.e. rate of ion leakage) inexcised cucumber cotyledon discs, cucumber hypocotyl segmentsand tomato pericarp discs, and also increased the thresholdtemperature at which chilling occurred by 2° to 6°C.Exposure to vapours of the anaesthetics halothane and methoxyfluranereduced chilling injury in cucumber cotyledon discs, cucumberhypocotyl segments and tomato pericarp discs. The relative effectivenessof the two anaesthetics in reducing chilling injury was similarto their relative effectiveness in inducing anaesthesia in animalsand their relative lipid solubilities. The response of the tissuesto halothane and methoxyflurane, which increase membrane fluidity,and to high pressures, which reduce membrane fluidity, are consistentwith the hypothesis that cold-induced phase transition of membranescould be responsible for chilling injury. However, other cellularcomponents may also be affected, e.g. low temperatures, highpressures and anaesthetics can alter protein conformation, affection channels, depolymerize microtubules and cause the releaseof calcium from membrane lipids. Key words: Cucumber, Cucumis sativus, tomato, Lycopersicon esculentum, halothane, ion leakage, methoxyflurane     

Post-halothane Jaundice in Relation to Previous Administration of Halothane

The time interval since previous anaesthesia was compared in a surgical population in South Wales and in patients who developed jaundice after halothane. There was a significant difference in the pattern of time interval since previous general anaesthetics in the surgical population and in those patients who developed jaundice after halothane. In the group who developed jaundice there was an “excess” of patients who had had a previous halothane anaesthetic within four weeks. Halothane should if possible be avoided in patients who have had it before, particularly if this was within the previous four weeks. In the case of repeat halothane anaesthetics within four weeks, the risk seems to lie between 1 in 6,000 and 1 in 22,000.     

The actions of three volatile general anaesthetics on withdrawal responses of the pond-snail Lymnaea stagnalis (L.)

1. The gastropod mollusc Lymnaea stagnalis (L.) is an ideal model system for studies on anaesthesia. It is reversibly anaesthetized by the general anaesthetics halothane, enflurane and isoflurane. 2. Criteria for "anaesthesia" in Lymnaea were established. The reflex used in ED50 trials was the whole animal withdrawal reflex. 3. ED50 values for halothane, enflurane and isoflurane were, 0.83% v.v. (volume for volume), 1.01% v.v. and 1.09% v.v. respectively. 4. Relationships between anaesthetic concentrations, weights of animals and mortality rates are reported.     

Do clinical levels of general anaesthetics affect lipid bilayers? Evidence from Raman scattering

We have used Raman spectroscopy to investigate the effects of the general anaesthetics halothane and chloroform on lipid bilayer order. Clinical concentrations of these anaesthetics had no significant effect on the hydrocarbon chain conformation in multilamellar vesicles of dimyristoylphosphatidylcholine/cholesterol. This result was obtained with a technique sufficiently precise to monitor changes in the acyl chain trans-gauche population ratio associated with a 1–2 K alteration in temperature. Very high levels of anaesthetics caused a marked disordering of the hydrocarbon chains. The danger of inferring an effect at clinical concentrations from data obtained at much higher levels is illustrated by a statistical analysis of our dose-response curves.     

The effects of halothane on hepatic microsomal electron transfer.

1. The effects of halothane (CF3CHBrCl), a volatile anaesthetic agent, on electron transfer in isolated rat liver microsomal preparations were examined. 2. At halothane concentrations achieved in tissues during clinical anaesthesia (1-2mM), halothane shifts the redox equilibrium of microsomal cytochrome b5 in the presence of NADPH towards the oxidized form. Halothane accelerates stoicheiometric consumption of NADPH and O2, increases the rate of reoxidation of NADH-reduced microsomal ferrocytochrom b5, but does not affect NADPH- or NADH-cytochrome c reductase activity. The enhanced microsomal electron flow seen in the presence of halothane is not diminished by CO nor is it increased by pretreatment of the animals with phenobarbital. 3. The effects of halothane are maximum in microsomal preparations isolated from animals fed on a high-carbohydrate diet to induce stearate desaturase activity. Changes in microsomal electron transfer caused by halothane are in all cases abolished by low concentrations (1-2mM) of cyanide. Microsomal stearate desaturase activity is unaffected by halothane. 4. The first-order rate constant for oxidation of membrane-bound ferrocytochrome b5 in the absence of added substrate (k1 equals 1.5 times 10(-3)A-1) is similar to that for autoxidation of purified ferrocytochrome b5(k1 equals 7 times 10(-3)S-1) the rate of autoxidation of soluble ferrocytochrome b5 is unaffected by halothane. 5. It is concluded that the effects of halothane on microsomal electron transfer are not related to cytochrome P-450 linked metabolism but rather arise from the interaction of halothane with the cyanide-sensitive factor of the stearate desaturase pathway.     

Inhibition of rat liver cholesterol esterase by local anaesthetics.

1. A number of local anaesthetics was shown to inhibit rat liver cholesterol esterase activity towards radioactively labelled cholesterol oleate. The anaesthetics inhibited in the order dibucaine greater than chlorpromazine greater than tetracaine greater than benzocaine greater than procaine greater than lidocaine greater than cocaine. 2. The mode of inhibition was seen to be non-competitive with respect to the substrate and is probably independent of any involvement of Ca2+. 3. The inhibition by tetracaine is partially reversed by sodium deoxycholate. However, all ionic and non-ionic detergents studied, sodium deoxycholate, sodium taurocholate, Triton X-100, and cetyltrimethylammonium bromide are capable of inhibiting the rat liver cholesterol esterase in a concentration dependent manner. Only sodium taurocholate stimulates enzymic activity.     

The kidney as a novel target tissue for protein adduct formation associated with metabolism of halothane and the candidate chlorofluorocarbon replacement 2,2-dichloro-1,1,1-trifluoroethane.

Hydrochlorofluorocarbons (HCFCs) have been identified as chemical replacements of the widely used chlorofluorocarbons (CFCs) that are implicated in stratospheric ozone depletion. Many HCFCs are structural analogues of the anesthetic agent halothane and may follow a common pathway of biotransformation and formation of adducts to protein-centered and other cellular nucleophiles. Exposure of rats to a single dose of halothane (2-bromo-2-chloro-1,1,1-trifluoroethane) or of the candidate CFC substitute HCFC 123 (2,2-dichloro-1,1,1-trifluoroethane) led to the formation of trifluoroacetylated protein adducts (CF3CO-proteins) not only in the liver, but also in the kidney as a novel target tissue for protein trifluoroacetylation. CF3CO-proteins in the kidney amounted to about 5% of those formed in the liver of the same animal. The amount of CF3CO-proteins formed within the kidney was roughly reflected by the capacity of metabolism of halothane or HCFC 123 by rat kidney microsomes in vitro which amounted to about 10% of that observed with liver microsomes. By immunohistochemistry, CF3CO-proteins in the kidney were mainly localized in the tubular segments of the cortex. In the liver, the density of CF3CO-proteins decreased from the central vein towards the portal triad. In vitro incubation of rat liver microsomes with halothane or HCFC 123 resulted in extensive formation of CF3CO-proteins and reproduced faithfully the pattern of liver CF3CO-proteins obtained in vivo. CF3CO-proteins generated in vitro were immunochemically not discernible from those generated in vivo. Glutathione (5 mM) and cysteine (5 mM) virtually abolished CF3CO-protein formation; the release of Br- from halothane and Cl- from HCFC 123 was reduced to much lesser a degree. S-Methyl-glutathione, N-acetyl-cysteine, methionine, and N-acetyl-methionine only slightly affected the formation of CF3CO-proteins or metabolism of either substrate. The data suggest that metabolism and concomitant CF3CO-protein formation of halothane or of candidate CFC replacements like HCFC 123 is not restricted to the liver but also takes place in the kidney. Furthermore, an in vitro system for CF3CO-protein formation has been developed and used to show that protein-centered and glutathione-centered nucleophilic sites compete for intermediates of metabolism of halothane or of HCFC 123.     

Respiratory compliance during sedation, anesthesia, and paralysis in infants and young children

Although total respiratory compliance (Crs) has been shown to fall in adults on induction of halothane anesthesia, no successful paired studies have been reported in children. The multiple occlusion technique was used to measure Crs in 17 infants and young children during sedated sleep (CrsS) and shortly after, following induction of halothane anesthesia (CrsA). Crs fell in all but one infant after induction of anesthesia, with a mean fall of 34.7% (range 0-58%). This was accompanied by a reduction in tidal volume and increase in frequency in every case. In 7 of the 17 children, who were to be paralyzed for surgical purposes, Crs was also measured in this anesthetized-paralyzed state. When tidal volume administered during manual ventilation was similar to that observed during measurement of CrsA, Crs during this low-volume ventilation was similar to CrsA. When tidal volume was increased and Crs remeasured, there was a significant increase in every case, with the high-volume Crs within 10% of CrsS in all but one child, in whom there was a 31.4% increase with respect to CrsS. Changes in tidal volume accounted for approximately 50% of the variability in each state. These results demonstrate a highly significant fall in Crs in infants and young children after induction of halothane anesthesia. In addition it appears that this reduction in Crs can be reversed by paralyzing the child and manually ventilating with tidal volumes approximating those seen during sedation.     

Effects of halothane, pentobarbital and ketamine on serum melatonin levels in the early scotophase in New Zealand white rabbits

In mammals, the nocturnal rise in pineal melatonin is regulated by signals from the endogenous clock, the hypothalamic suprachiasmatic nuclei. There have been few reports on whether anaesthetics which modulate multisynaptic neuronal functions affect melatonin secretion. We studied the effects of three commonly used anaesthetics, halothane, pentobarbital and ketamine, on serum melatonin levels in male New Zealand white rabbits. Seven blood samples were collected, 30-60 min apart, before, during and after anaesthesia. Experiments were performed in the late light and early dark period, so that changes in melatonin secretion would be reflected in the onset and/or level of nocturnal serum melatonin. Serum melatonin levels were determined by radioimmunoassay. Our results indicated that halothane attenuated the release of melatonin and pentobarbital had no apparent effect, whereas ketamine potentiated the release of melatonin. These findings suggest that melatonin levels may be affected in patients anaesthetized with halothane or ketamine, resulting in disturbed biological rhythms, especially the sleep-wake cycle following recovery.