Sanders, MclIwaine, Barrie
Contact lens related problems
As shown in Table II there were a variety of other ocular conditions .related to contact lens wear that presented in small numbers to our department. Keratoconjunctivitis sicca is usually diagnosed with a positive Schirmer's test and extensive staining of degenerate conjunctival epithelial cells with Rose Bengal. The condition is treated with artificial tears. Dendritic ulcers show a characteristic staining pattern with fluorescein and are treated with topical acyclovir ointment. All our patients with bacterial keratitis and corneal ulcers wore soft contact lenses. Other studies6 ,7 have also implicated soft contact lense users to be more at risk from serious ocular disease than other types of lens users. Soft contact lenses are generally more comfortable to wear and easier for the practitioner to fit. They have thus gained much popularity since first introduced in the 19508. In conclusion, patients should be adequately warned by the prescriber of possible contact lens related problems. They should always have, in addition to their contact lenses, a pair of spectacles and should be advised to wear the latter at the onset of ocular symptoms. It was surprising
to note the number of patients who had no alternative to their contact lens. The importance of contact lens care and personal hygiene should be emphasised and patients should be advised to seek medical advice early, should they have any ocular symptoms, in order to prevent any permanent visual loss. REFERENCES 1 Halliday BL. 100 Years of contact lenses. BMJ 1988; No: 6637, Vol 296: 1616-1617. 2 Dart JKG. Bacterial keratitis in contact lens users. BMJ 1987; No: 6604, Vol 295: 959-960. 3 Alfonso E, Mandelbawrn S, Fox MJ, Forster RK. Ulcerative keratitis associated with contact lens wear. AJO 1986; 101: 429-433. 4 Mathesus AM, Dart JKG, Sherwood M. Contact lens casualties; contact lens hygiene and related disease. JBCLA 1983; Vol 6, No 1: 36-39. 5 Easty DL. Acanthamoeba keratitis. BMJ 1988; No: 6617, Vol 296: 228. 6 Schein 0, Hibbard P, Kenyon KR. Contact lens complications: Incidental or epidemic. AJO 1986; 102: 116-117. 7 Franks WA, Adams GGW, Dart JKG, Minassian D. Relative risks of different types of contact lenses. BMJ 1988; No: 6647, Vol 297: 524-525.
0036-933019010469/1001$2.00 in USA e 1990 Scottish Medical Journal
Scot Moo J 1990; 35: 106-107
PARACETAMOL OVERDOSE IN CHILDREN
A. Kumar, K.M. Goel, M.D. Rae Departments of Medical Paediatrics and Biochemistry, Royal Hospital for Sick Children, Yorkhill, Glasgow G3
Abstract: The severity ofparacetamol poisoning varies but in general, children are considered less susceptible ~o its .toxic effects comfar~d to adults. 1 .In this r~port we describe the relatively benign ingestion ofparacetamol m children and also highlight a case of intrautenne exposure to a potentially toxic dose ofparacetamol. Patients, Methods and Results URING the period of 1974-1986, 140 children were admitted to the Royal Hospital for Sick Children, Glasgow, with paracetamol ingestion. The annual incidence of these cases did not show any significant change but the incidence of salicylate overdose did as expected have a declining trend over the same period (Fig 1). In 130 children, ingestion was accidental while in 10 it was intentional, to draw attention after a family conflict or part of an adventure. One hundred and eight children were aged between one and four years and predictably the children where the ingestion was intentional were over 10 years old. One hundred and one ingested pure paracetamol preparation either tablets or elixir while the rest consumed combined preparations containing dextropropoxyphene and codeine. Most children had access to the drugs because they were Iring freely around the house. Rumack suggested that children who ingest more than 15Omg/kg of paracetamol should be carefully observed for toxicity. In our series the ingested dose could be estimated in 94 children and of these, 31 ingested more than 15Omg/kg of paracetamol. In 19 of these plasma paracetamol was undetectable or well below the revised treatment line (Fig
D
2).2 Plasma paracetamol was measured in 133 children and in all but one it was below the revised treatment line (Fig 2). In 37 cases it was measured within four hours of ingestion, Correspondence to and requests for reprints: Dr K.M. Goel, Department of Medical Paediatrics, Royal Hospital for Sick Children, Yorkhill, GlasgowG3.
106
too early to use the nomogram, but in all cases the plasma paracetamol was very low. One hundred and ten children received gastric lavage or emetic within four hours of ingestion. One hundred and twelve children were asymptomatic. In the rest the following symptoms were observed in order of frequency; drowziness (17), vomiting (11), irritability (2), nausea (1), abdominal pain (1) and diarrhoea (1). In at least some of these children symptoms could be related to intercurrent illness or other drugs simultaneously ingested. One child of two and a half years of age in whom the paracetamollevel was in the toxic range received N-acetylcysteine and recovered uneventfully. One 13-year-old girl (not included in Fig. 2) who Number of pltlenll 40
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o
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~ SlIneyI.'.
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1976
1977
1978
1.71
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1981
L. 1982
1183
1984
1985
l
1986
Plll'lK:etamol overdose In chiIdreD
Kumar, Goel, Rae
Limit of effectiveness of Nacetylcystelne
3000 High risk cases
22000 '0
E 3'0
E :!1000 III
.. u
III
~
700
III
E
III III
•
500
ii: 300
·. 11' .• · 1
100
0
2
• .• 10
12
14
16
Time (hours)
intentionally took paracetamol developed hepatic failure, encephalopathy and raised intracranial pressure. She first presented to another hospital 24 hours after ingestion and N-acetylcysteine was not used as it was beyond the time N-acetylcysteine is considered to be effective. She recovered fully with supportive management of her liver failure and measures to reduce intracranial pressure. A pregnant mother at 38 weeks' gestation ingested 26g of paracetamol and had a four-hour plasma paracetamollevel of 1440 umol/l. She did not develop any symptoms. Emesis was induced and she was treated with N-acetylcysteine and labour induced. Seventeen hours after ingestion she delivered a boy weighing 3050gwho was mildly asphyxiated (Apgar 5 at 1 minute and 7 at 5 minutes) because of late sedation. At birth the plasma paracetamol concentration in the baby was the same as that of the mother, 85 umol/l. Six
hours later it was 40 umol/l in the baby and undetectable in the mother. The infant did not develop any evidence of paracetamol toxicity clinically or biochemically. He was discharged home on the seventh day and seven weeks later on follow up both the mother and baby were well with no biochemical or clinical sequelae. Comment The children in the age group of one to five years are most prone to accidental overdose, but we have found that serious poisoning due to paracetamol overdose, is uncommon. Only one child in the present series had a level of paracetamol which was above the treatment line. The main reason may be that the quantity actually ingested is far less than is presumed. Similar findings have been observed by others." It is encouraging to paediatricians that children are less susceptible to toxic effects of paracetamol as compared to adults'. Animal studies suggest that there is a higher rate of turnover of glutathione in young animals which may provide increased detoxification within the liver.4 Transplacental overdose of neonates presents an interesting situation. Similar levels at birth in the infant and mother suggest the transplacental transfer of paracetamol and that the baby in utero was exposed to similar toxic levels to the mother. Lederman et al 5describes a preterm neonate who was" exposed in utero to maternal plasma paracetamol levels which required treatment and where the baby underwent exchange transfusions; extrapolating from work in newborn mice they suggested that adequate glutathione stores are present in the liver before the ability to produce the toxic metabolite. It would appear that fetus is protected by treatment of the mother and by physiological mechanisms. Despite the low levels of paracetamol recorded and the good outcome in the children reported here, paracetamol is a potentially toxic drug.and all cases of suspected poisoning merit medical attention. REFERENCES 1 Rumack BH Acetaminophen overdose in young children. Am J Dis Child. 1984;138:428-433. 2 Prescott LF, Illingworth RN, Critchley JAJH et al. Intravenous N-acetylcysteine; the treatment of choice in paracetamol poisoning. Br Med J 1979;2: 1097. 3 Crome P, Vale NA, Volans GN, Widdop N. Toxicity of paracetamol in children. Br Med J 1976;2: 475. 4 Lauterberg BH, Vaishnav Y, Stillwell WG, et al. The effects of age and glutathione depletion on hepatic glutathione turnover in utero determined by acetaminophen probe analysis. J Pharmacol Ex Ther 1980; 213: 54-58. 5 Ledermann S, Fysh WJ, Tredger M, Gamsu HR. Neonatal paracetamol poisoning: treatment by exchange transfusion. Arch Dis Child 1983;58: 631-633.
107
Contact lens related problems
As shown in Table II there were a variety of other ocular conditions .related to contact lens wear that presented in small numbers to our department. Keratoconjunctivitis sicca is usually diagnosed with a positive Schirmer's test and extensive staining of degenerate conjunctival epithelial cells with Rose Bengal. The condition is treated with artificial tears. Dendritic ulcers show a characteristic staining pattern with fluorescein and are treated with topical acyclovir ointment. All our patients with bacterial keratitis and corneal ulcers wore soft contact lenses. Other studies6 ,7 have also implicated soft contact lense users to be more at risk from serious ocular disease than other types of lens users. Soft contact lenses are generally more comfortable to wear and easier for the practitioner to fit. They have thus gained much popularity since first introduced in the 19508. In conclusion, patients should be adequately warned by the prescriber of possible contact lens related problems. They should always have, in addition to their contact lenses, a pair of spectacles and should be advised to wear the latter at the onset of ocular symptoms. It was surprising
to note the number of patients who had no alternative to their contact lens. The importance of contact lens care and personal hygiene should be emphasised and patients should be advised to seek medical advice early, should they have any ocular symptoms, in order to prevent any permanent visual loss. REFERENCES 1 Halliday BL. 100 Years of contact lenses. BMJ 1988; No: 6637, Vol 296: 1616-1617. 2 Dart JKG. Bacterial keratitis in contact lens users. BMJ 1987; No: 6604, Vol 295: 959-960. 3 Alfonso E, Mandelbawrn S, Fox MJ, Forster RK. Ulcerative keratitis associated with contact lens wear. AJO 1986; 101: 429-433. 4 Mathesus AM, Dart JKG, Sherwood M. Contact lens casualties; contact lens hygiene and related disease. JBCLA 1983; Vol 6, No 1: 36-39. 5 Easty DL. Acanthamoeba keratitis. BMJ 1988; No: 6617, Vol 296: 228. 6 Schein 0, Hibbard P, Kenyon KR. Contact lens complications: Incidental or epidemic. AJO 1986; 102: 116-117. 7 Franks WA, Adams GGW, Dart JKG, Minassian D. Relative risks of different types of contact lenses. BMJ 1988; No: 6647, Vol 297: 524-525.
0036-933019010469/1001$2.00 in USA e 1990 Scottish Medical Journal
Scot Moo J 1990; 35: 106-107
PARACETAMOL OVERDOSE IN CHILDREN
A. Kumar, K.M. Goel, M.D. Rae Departments of Medical Paediatrics and Biochemistry, Royal Hospital for Sick Children, Yorkhill, Glasgow G3
Abstract: The severity ofparacetamol poisoning varies but in general, children are considered less susceptible ~o its .toxic effects comfar~d to adults. 1 .In this r~port we describe the relatively benign ingestion ofparacetamol m children and also highlight a case of intrautenne exposure to a potentially toxic dose ofparacetamol. Patients, Methods and Results URING the period of 1974-1986, 140 children were admitted to the Royal Hospital for Sick Children, Glasgow, with paracetamol ingestion. The annual incidence of these cases did not show any significant change but the incidence of salicylate overdose did as expected have a declining trend over the same period (Fig 1). In 130 children, ingestion was accidental while in 10 it was intentional, to draw attention after a family conflict or part of an adventure. One hundred and eight children were aged between one and four years and predictably the children where the ingestion was intentional were over 10 years old. One hundred and one ingested pure paracetamol preparation either tablets or elixir while the rest consumed combined preparations containing dextropropoxyphene and codeine. Most children had access to the drugs because they were Iring freely around the house. Rumack suggested that children who ingest more than 15Omg/kg of paracetamol should be carefully observed for toxicity. In our series the ingested dose could be estimated in 94 children and of these, 31 ingested more than 15Omg/kg of paracetamol. In 19 of these plasma paracetamol was undetectable or well below the revised treatment line (Fig
D
2).2 Plasma paracetamol was measured in 133 children and in all but one it was below the revised treatment line (Fig 2). In 37 cases it was measured within four hours of ingestion, Correspondence to and requests for reprints: Dr K.M. Goel, Department of Medical Paediatrics, Royal Hospital for Sick Children, Yorkhill, GlasgowG3.
106
too early to use the nomogram, but in all cases the plasma paracetamol was very low. One hundred and ten children received gastric lavage or emetic within four hours of ingestion. One hundred and twelve children were asymptomatic. In the rest the following symptoms were observed in order of frequency; drowziness (17), vomiting (11), irritability (2), nausea (1), abdominal pain (1) and diarrhoea (1). In at least some of these children symptoms could be related to intercurrent illness or other drugs simultaneously ingested. One child of two and a half years of age in whom the paracetamollevel was in the toxic range received N-acetylcysteine and recovered uneventfully. One 13-year-old girl (not included in Fig. 2) who Number of pltlenll 40
j
o
35
Per.eel.mot
~ SlIneyI.'.
30
25
20
15 r10
:'~ Ir Ir lei 1974
1975
1976
1977
1978
1.71
llJaO V•• r
1981
L. 1982
1183
1984
1985
l
1986
Plll'lK:etamol overdose In chiIdreD
Kumar, Goel, Rae
Limit of effectiveness of Nacetylcystelne
3000 High risk cases
22000 '0
E 3'0
E :!1000 III
.. u
III
~
700
III
E
III III
•
500
ii: 300
·. 11' .• · 1
100
0
2
• .• 10
12
14
16
Time (hours)
intentionally took paracetamol developed hepatic failure, encephalopathy and raised intracranial pressure. She first presented to another hospital 24 hours after ingestion and N-acetylcysteine was not used as it was beyond the time N-acetylcysteine is considered to be effective. She recovered fully with supportive management of her liver failure and measures to reduce intracranial pressure. A pregnant mother at 38 weeks' gestation ingested 26g of paracetamol and had a four-hour plasma paracetamollevel of 1440 umol/l. She did not develop any symptoms. Emesis was induced and she was treated with N-acetylcysteine and labour induced. Seventeen hours after ingestion she delivered a boy weighing 3050gwho was mildly asphyxiated (Apgar 5 at 1 minute and 7 at 5 minutes) because of late sedation. At birth the plasma paracetamol concentration in the baby was the same as that of the mother, 85 umol/l. Six
hours later it was 40 umol/l in the baby and undetectable in the mother. The infant did not develop any evidence of paracetamol toxicity clinically or biochemically. He was discharged home on the seventh day and seven weeks later on follow up both the mother and baby were well with no biochemical or clinical sequelae. Comment The children in the age group of one to five years are most prone to accidental overdose, but we have found that serious poisoning due to paracetamol overdose, is uncommon. Only one child in the present series had a level of paracetamol which was above the treatment line. The main reason may be that the quantity actually ingested is far less than is presumed. Similar findings have been observed by others." It is encouraging to paediatricians that children are less susceptible to toxic effects of paracetamol as compared to adults'. Animal studies suggest that there is a higher rate of turnover of glutathione in young animals which may provide increased detoxification within the liver.4 Transplacental overdose of neonates presents an interesting situation. Similar levels at birth in the infant and mother suggest the transplacental transfer of paracetamol and that the baby in utero was exposed to similar toxic levels to the mother. Lederman et al 5describes a preterm neonate who was" exposed in utero to maternal plasma paracetamol levels which required treatment and where the baby underwent exchange transfusions; extrapolating from work in newborn mice they suggested that adequate glutathione stores are present in the liver before the ability to produce the toxic metabolite. It would appear that fetus is protected by treatment of the mother and by physiological mechanisms. Despite the low levels of paracetamol recorded and the good outcome in the children reported here, paracetamol is a potentially toxic drug.and all cases of suspected poisoning merit medical attention. REFERENCES 1 Rumack BH Acetaminophen overdose in young children. Am J Dis Child. 1984;138:428-433. 2 Prescott LF, Illingworth RN, Critchley JAJH et al. Intravenous N-acetylcysteine; the treatment of choice in paracetamol poisoning. Br Med J 1979;2: 1097. 3 Crome P, Vale NA, Volans GN, Widdop N. Toxicity of paracetamol in children. Br Med J 1976;2: 475. 4 Lauterberg BH, Vaishnav Y, Stillwell WG, et al. The effects of age and glutathione depletion on hepatic glutathione turnover in utero determined by acetaminophen probe analysis. J Pharmacol Ex Ther 1980; 213: 54-58. 5 Ledermann S, Fysh WJ, Tredger M, Gamsu HR. Neonatal paracetamol poisoning: treatment by exchange transfusion. Arch Dis Child 1983;58: 631-633.
107
