- Email: [email protected]
SALICYLIC ACID AND ULTRAVIOLET B FOR PSORIASIS
1109
palm temperatures of the immersed hand were 9 6°C and 18’2OC, respectively. During the second minute of recovery, these temperatures rose to 102°C and 23-9°C, BP and heart rate had returned to pre-exposure levels (97/70 mm Hg, 65 beats/min). However, atypical post-exposure features became apparent about 10 min after the cold immersion. The subject complained of severe throbbing pain in the immersed hand which became bright red and oedematous while remaining cold. He became extremely agitated and collapsed after a few minutes. At emergency admission to University Hospital, he was incoherent, sweating, and hyperventilating, with BP 80/60 mm Hg and pulse rate 140 beats/min. Heart sounds were normal without symptoms of pulmonary oedema or cyanosis. The immersed hand remained red, cold, and swollen and the radial pulse was weak on the affected side. Intravenous diazepam (10 mg) was given and the affected hand was raised on a sling. After 2 hours sleep the patient behaved normally. The pain sensation and swelling in the affected hand had subsided. Sensations were intact with motor functions impaired by oedema in the affected hand. The oedema continued to subside and the subject was discharged the following day. The patient had mild pain and swelling in the hand for a further 4 days, and residual mild wrist joint pain persists 2 months after the incident. The cold water hand immersion procedure has been widely used in studies of the cutaneous1 and systemic circulation2 and of responsiveness to hand cooling in populations from temperate3 cold,4 and warms climates. Cold-induced injury has not been recorded in these investigations. Mechanisms responsible for the inflammation and oedema seen in our subject are thought to have neurogenic and autocoidic components.1 Local cooling of acral regions produces intense constriction in arterial and venous vessels via direct’ and reflex pathways.7 The local hypoxia is thought to result in the production and release of endogenous vasoactive substances, such as histamine, prostaglandins, and substance P, causing localised vasodilatation and increased capillary permeability. However, the cyclic constriction and dilatation ("hunting phenomenon") elicited by tissue injury resulting from severe cold exposure1 was not apparent in our patient. The other symptoms reported here were probably caused by pain and anxiety. Investigators should be aware of the possibility of cold injury to mild cold exposures in susceptible individuals. M. T. DUNCAN R. HUSAIN A. RAMAN V. T. JOHGALINGAM
Department of Physiology, Medical Faculty, University of Malaya, 59100 Kuala Lumpur,
Malaysia
injurious effects of cold upon the skin and underlying tissues. Br Med J 1941; 2: 795-97. 2. Hmes EA Jr, Brown GE. The cold pressor test for measuring reactivity of blood pressure: data concerning 571 normal and hypertensive subjects. Am Heart J 1936; 1. Lewis T. Observations on some normal and
11: 1-9. 3. Chen HM, Horvath SM. Cardiovascular response during cold water hand immersion. Physiologist No 4 1987; 30: 166. 4. Le Blanc J, Hildes JA, Heroux O. Tolerance of Gaspe fisherman to cold water. J Appl Physiol Resp Environ Exercise Physiol 1960; 15: 1031-35. 5. Glaser EM, Whittow GC. Retention in a warm environment of adaptation to localized 1957; 136: 98-111. cooling. Physiol J 6. Rowell LB. Human circulation regulation during physical stress. New York: Oxford
University Press, 1986. SJW, Bharali LAM. The axon reflex: an outdated idea or a valid hypothesis? News Physiol Sci 1989; 4: 45-48.
7. Lisney
PREDICTION OF POOR OUTCOME OF CUTANEOUS SURGERY
Sm,—Most patients’ complaints after plastic surgery stem from the poor outcome of their scars. In Ehlers-Danlos syndrome poor wound healing and devastating "cigarene paper" scars are usual. A milder variant of the classic form of Ehlers-Danlos syndrome may be commoner in the general population than previously thought, and may be easily identified by a simple clinical scoring system.We have used this clinical scoring system to predict the outcome of surgical scars in the general population. 35 men and 51 women, aged nineteen to fifty-four years, were investigated. None was on any oral medication known to interfere with collagen synthesis or metabolism (anticoagulants,
corticosteroids, phenytoin, d-penicillamine, antineoplastic agents, phenylbutazone). From three months to one year before the study, patients had cutaneous surgery for naevi, dermatofibromas, cysts, and minor neoplasms. Surgery was done by the same plastic surgeon who followed Langer’s skin tension lines. The suture stitches had been removed five days after surgery to the face and seven to ten days for other regions. Scars were classified blind as barely visible, dyschromic, depressed, or atrophic, keloidal, and diastatic. The patients were also scored clinically according to Holzberg and colleagues’1 system as follows. Joint hypermobility (score 1 point for each): (a) dorsiflexion of little finger over 90° with forearm flat on the table, (b) passive apposition of thumb to flexor forearm, (c) hyperextension of elbow over 10°, (d) hyperextension of knee over 10°, and (e) forward flexion of trunk so that palms of hand rest easily on floor. Skin extensibility: skin of ventral left forearm lifted midway between the elbow and wrist (measure distance skin is stretched); (score 0 for under 4 cm,1 for 4 cm, 2 for 5 cm, 3 for 6 cm, 4 for 7 cm, 5 for 8 cm). Cigarette paper, wrinkled scarring (score for each of 5 boney points): (a) left elbow and forearm, (b) right elbow and forearm, (c) left knee, (d) right knee, and (e) forehead. Bruising (score 0 to 5): (a) 0 no history or clinical evidence, (b) 1 = positive history of mild bruising, no clinical evidence, (c) 2= positive history of moderate bruising with or without skin findings, (d) 3 = moderate bruising on physical examination, (e) 4 pronounced bruising on physical examination, and (f) 5 gross bruising on physical examination. 58 patients had a good scar (ie, barely visible or just dyschromic), whereas 28 complained of bad results: namely, hypertrophic (12), depressed or atrophic (13), and diastatic scars (3). All 58 patients with regular, barely visible, or dyschromic scars had a score of 2 or lower. 10 patients with hypertrophic scars had a score of 3 or greater and the remaining 2 had a score of 2. 12 patients with depressed or atrophic scars had a score of 3 or greater and only 1 had a score of 2. Among patients with diastasis of wound edges, 2 had a score of55 and 1 had a score of 1. The differences were significant (chi-squared test, p < 0-0005). Atrophic and diastatic scars were prevalent among patients with high scores. At score 2 or higher, scars tended to be poor and, importantly, only in 4 patients with a score below 2 was the scar acceptable. Thus the outcome of scarring is easily predictable by means of a simple scoring system based on clinical examination. =
=
=
Department of Dermatology, University of Genoa, Genoa, Italy
A. REBORA P. FIALLO G. F. MUZIO
1. Holzberg M, Hewan-Lowe KO, Olansky AJ. The Ehlers-Danlos syndrome: recognition, characterization, and importance of a milder variant of the classic form. J Am Acad Dermatol 1988; 19: 656-65.
SALICYLIC ACID AND ULTRAVIOLET B FOR PSORIASIS
SIR,-After salicylic acid was synthesised in 1874 it soon became the most widely used keratolytic agent for the treatment of scaling skin disorders such as psoriasis. Today it is still used by many patients with psoriasis to remove scales, either as a sole remedy or before other external therapy. In 1925 Goeckerman described combination therapy with crude coal tar and ultraviolet light (UV), and phototherapy is now part of the standard therapeutic armamentarium for psoriasis. The advent of photochemotherapy with psoralens and LTVA (PUVA) more than a decade ago led to a resurgence of interest in UVB (280-320 nm) as monotherapy. 80-90% of psoriasis patients improve considerably or clear completely after a series of UVB exposures,l and UVB is an increasingly used treatment that is especially convenient for
outpatients. During the early days of sun protection salicylic acid derivatives such as homomenthyl and 2-ethylhexyl salicylate were commonly used in sunscreens. Growing awareness of the dangers of sun
1110 exposure has brought forth new and more effective sunscreens, and salicylates have been more or less abandoned. At our day-care centre we give some 20 000 light treatments a year. Most patients have psoriasis and their scales are removed routinely by baths, saunas, and (probably of greater significance) 2% salicylic acid in a cream base. We apply the cream a few minutes before UVB treatment because there is experimental and clinical evidence that the use of emollients before phototherapy results in a better therapeutic index, allowing more light to penetrate into the psoriatic lesions than into normal skin.2,3 One day emollient cream without salicylic acid was used, and on the following day several patients complained of red, burning skin, indicating a UV overdose. Suspecting that absence of salicylic acid was the culprit and that it had been acting as a photoprotective agent we did an open bilateral comparison in patients with stable plaque psoriasis, comparing the effect of applying the cream with or without salicylic acid before
UVB. Most patients evaluated at 4 and 6 weeks showed delayed or reduced clearing on the side where the salicylic-acid-containing cream had been applied. We know of no previous studies on this point. Since many patients with psoriasis regularly use salicylic acid preparations and, an increasing number are treated by UVB, we decided to report this influence of salicylic acid on UVB treatment. A double-blind bilateral comparative study is underway. Department of Dermatology, Central Hospital, S651 85 Karlstad, Sweden
BERIT KRISTENSEN OVE KRISTENSEN
1. Larko O. Phototherapy of psoriasis: clinical aspects and risk evaluation. Acta Dermato-Venereol 1982; suppl 103: 1-42. 2. Anderson RR, Le Vine MJ, Parrish JA. Selective modification of the optical properties of psoriatic vs normal skin. 8th International Photobiology Congress (Strasbourg, July, 1980): abstr 152. 3. Beme B. Effect of psoriasis healing of a lubricating base applied prior to phototherapy: an open study. Photodermatology 1986; 3: 188-90.
LOWER-LIMB PHLEBOGRAPHY IN RECENT PARAPLEGIA AND TETRAPLEGIA
SIR,-Pulmonary embolism (PE) is one of the leading causes of mortality in recent paraplegics,l despite the use of prophylactic anticoagulant therapy.2 Indeed in a preliminary retrospective study of 307 consecutive patients who received prophylactic anticoagulant therapy (calcium heparin 5000 U x 3), 10 patients had PE, 6 of whom died. Many patients might have had an asymptomatic deep venous thrombosis (DVT) before referral to our department. To prevent PE we examined prospectively by phlebography 147 patients with paraplegia and tetraplegia from all causes, apart from neoplasm: paralysis had occurred within 48 h and they had been referred within 90 days of the onset of paraplegia. Follow-up covered the entire hospital stay-an average of 6 months for paraplegics and 13 months for tetraplegics. There were 41 male and 106 female patients, mean age 345 (155) years. Paraplegia was attributable to trauma in 122 patients and medical conditions in 25. The upper level of the spinal cord lesion was the cervical spine in 48 patients, the thoracic spine in 78, and the lumbar spine in 21. 20 patients in whom thromboembolic disease developed between the onset of paraplegia and referral received therapeutic doses of anticoagulants and did not have phlebography. Among the other 127 patients 115 were receiving preventive anticoagulant therapy begun within a few days of onset of paraplegia. Phlebography (PHL-1) of both lower limbs was first done between the lst and 7th days (mean 5 days) after referral. When PHL-1 was normal, preventive anticoagulant therapy was maintained either with low doses of calcium heparin or with a low-molecular-weight heparin. Phlebography was also done a month later (PHL-2) (mean 35 days, range 31-38). All patients with DVT received standard anticoagulant therapy. Clinical suspicion of DVT had to be confirmed by a further phlebographic measurement.
At PHL-1, 29 (23%) of 127 patients had a DVT, with bilateral involvement in 10. 9 of the 39 venous thromboses were in the femoral vein and 1 was in the iliac vein. Only 1 mild PE occurred in a patient 2 weeks after negative PHL-1. In this patient, PHL-2
revealed a thrombus in the right posterior tibial vein. PHL-2 could only be done in 87 of the 98 patients with a normal PHL-1. Despite preventive anticoagulant therapy DVT were found in 12 (14%) patients, bilaterally in 2. None of these 14 thromboses was above the knee. 1 patient had a mild allergic reaction at PHL-2. We have shown that despite preventive anticoagulant therapy many paraplegics had DVT at referral and most were asymptomatic. Indeed, among the 53 DVT detected in 41 patients, only 9 had clinical manifestations (1 PE and 8 with phlebitis). Systematic and repeated detection of asymptomatic DVT by phlebography could reduce the frequency of PE.
Service of Neurological Rehabilitation, and Service of Radiology, Hôpital R. Poincare, Garches, France * Present address: Service du France.
ALAIN YELNIK* OLIVIER DIZIEN BERNARD BUSSEL ELIZABETH SCHOUMAN-CLAEYS GEAORGES FRIJA STEPHANE PANNIER JEAN-PIERRE HELD
Rééducation, Hôpital F. Widal, 75010 Paris,
1. Stover
SL, Fine PR. The epidemiology and economics of spinal cord injury. Paraplegia 1987; 25: 225-28. 2. Silver JR, Moulton A. Prophylactic anticoagulant therapy against pulmonary embolism in acute paraplegia. Br Med J 1970; 2: 338-40. 3. Hachen HJ. Anticoagulant therapy in patients with spinal cord injury. Paraplegia 1974; 12: 176-87.
GREENHOUSE EFFECT AND RENAL CALCULI
SIR,-During the course of the glorious British summer of this year we noted an apparent increase in cases of renal calculi causing acute renal colic. We saw 39 such cases, confirmed by intravenous urography, during the four months May to August, 1988, while during the same period in 1989 there were 58 cases, an increase of 48%. The Meteorological Office tells us that in May to August, 1988, there were 726 hours of sunshine and daily temperatures averaged 16 1°C. During the same period in 1989 the figures were 1117 hours (an increase of 53%) and 18-2°C. Sunshine and high temperatures are well recognised factors in the aetiology of renal calculi, via hypercalciuria1.2 and dehydration,3 respectively. The studies establishing these features were from areas with very hot and sunny summers such as Israel, Australia, and the Persian Gulf. To our knowledge observations on the variations in incidence of renal calculi with climate have not previously been published from Britain. Have other radiology departments found a comparable increase in calculi this summer? If the predicted trend towards warmer weather, due to the "greenhouse effect", proves correct lessons learned in traditionally hot countries may need to be applied elsewhere. Frank and de Vries’ showed that a fluid intake sufficient to cause a urinary output of at least 1200 ml daily reduced the incidence of calculi in Israel. To prevent an increase in urolithiasis the British public should be advised to drink more fluids during the hot and sunny summers of the future. Radiology Department, Northwick Park Hospital and Clinical Research Centre, Harrow HA1 3UJ
J. CURTIN M. SAMPSON
1. Parry ES, Lister IS. Sunlight and hypercalciuria. Lancet 1975; i: 1063-65. 2. Robertson WG, Hodgkinson A, Marshall DH. Seasonal variation in the composition
of urine from normal subjects: longtitudinal study. Clin Chim Acta 1977; 80: 347-53. 3. Bateson EM. Renal tract calculi and climate. Med J Aust 1973; ii: 111-13. 4. Frank M, de Vries A. Prevention of urolithiasis. Arch Environ Hlth 1966; 13: 625.
NEAR-DEATH EXPERIENCES
SIR,-It intrigues me, as a biologist, how the near-death illusion of travelling down a tunnel towards-and, presumably, in actual death fusing with-a light evolved. We know it is a limbic system mechanism, and it has probably kept the dying happy and’ quiet since Neanderthal times. The blissful final joining is the promise of
palm temperatures of the immersed hand were 9 6°C and 18’2OC, respectively. During the second minute of recovery, these temperatures rose to 102°C and 23-9°C, BP and heart rate had returned to pre-exposure levels (97/70 mm Hg, 65 beats/min). However, atypical post-exposure features became apparent about 10 min after the cold immersion. The subject complained of severe throbbing pain in the immersed hand which became bright red and oedematous while remaining cold. He became extremely agitated and collapsed after a few minutes. At emergency admission to University Hospital, he was incoherent, sweating, and hyperventilating, with BP 80/60 mm Hg and pulse rate 140 beats/min. Heart sounds were normal without symptoms of pulmonary oedema or cyanosis. The immersed hand remained red, cold, and swollen and the radial pulse was weak on the affected side. Intravenous diazepam (10 mg) was given and the affected hand was raised on a sling. After 2 hours sleep the patient behaved normally. The pain sensation and swelling in the affected hand had subsided. Sensations were intact with motor functions impaired by oedema in the affected hand. The oedema continued to subside and the subject was discharged the following day. The patient had mild pain and swelling in the hand for a further 4 days, and residual mild wrist joint pain persists 2 months after the incident. The cold water hand immersion procedure has been widely used in studies of the cutaneous1 and systemic circulation2 and of responsiveness to hand cooling in populations from temperate3 cold,4 and warms climates. Cold-induced injury has not been recorded in these investigations. Mechanisms responsible for the inflammation and oedema seen in our subject are thought to have neurogenic and autocoidic components.1 Local cooling of acral regions produces intense constriction in arterial and venous vessels via direct’ and reflex pathways.7 The local hypoxia is thought to result in the production and release of endogenous vasoactive substances, such as histamine, prostaglandins, and substance P, causing localised vasodilatation and increased capillary permeability. However, the cyclic constriction and dilatation ("hunting phenomenon") elicited by tissue injury resulting from severe cold exposure1 was not apparent in our patient. The other symptoms reported here were probably caused by pain and anxiety. Investigators should be aware of the possibility of cold injury to mild cold exposures in susceptible individuals. M. T. DUNCAN R. HUSAIN A. RAMAN V. T. JOHGALINGAM
Department of Physiology, Medical Faculty, University of Malaya, 59100 Kuala Lumpur,
Malaysia
injurious effects of cold upon the skin and underlying tissues. Br Med J 1941; 2: 795-97. 2. Hmes EA Jr, Brown GE. The cold pressor test for measuring reactivity of blood pressure: data concerning 571 normal and hypertensive subjects. Am Heart J 1936; 1. Lewis T. Observations on some normal and
11: 1-9. 3. Chen HM, Horvath SM. Cardiovascular response during cold water hand immersion. Physiologist No 4 1987; 30: 166. 4. Le Blanc J, Hildes JA, Heroux O. Tolerance of Gaspe fisherman to cold water. J Appl Physiol Resp Environ Exercise Physiol 1960; 15: 1031-35. 5. Glaser EM, Whittow GC. Retention in a warm environment of adaptation to localized 1957; 136: 98-111. cooling. Physiol J 6. Rowell LB. Human circulation regulation during physical stress. New York: Oxford
University Press, 1986. SJW, Bharali LAM. The axon reflex: an outdated idea or a valid hypothesis? News Physiol Sci 1989; 4: 45-48.
7. Lisney
PREDICTION OF POOR OUTCOME OF CUTANEOUS SURGERY
Sm,—Most patients’ complaints after plastic surgery stem from the poor outcome of their scars. In Ehlers-Danlos syndrome poor wound healing and devastating "cigarene paper" scars are usual. A milder variant of the classic form of Ehlers-Danlos syndrome may be commoner in the general population than previously thought, and may be easily identified by a simple clinical scoring system.We have used this clinical scoring system to predict the outcome of surgical scars in the general population. 35 men and 51 women, aged nineteen to fifty-four years, were investigated. None was on any oral medication known to interfere with collagen synthesis or metabolism (anticoagulants,
corticosteroids, phenytoin, d-penicillamine, antineoplastic agents, phenylbutazone). From three months to one year before the study, patients had cutaneous surgery for naevi, dermatofibromas, cysts, and minor neoplasms. Surgery was done by the same plastic surgeon who followed Langer’s skin tension lines. The suture stitches had been removed five days after surgery to the face and seven to ten days for other regions. Scars were classified blind as barely visible, dyschromic, depressed, or atrophic, keloidal, and diastatic. The patients were also scored clinically according to Holzberg and colleagues’1 system as follows. Joint hypermobility (score 1 point for each): (a) dorsiflexion of little finger over 90° with forearm flat on the table, (b) passive apposition of thumb to flexor forearm, (c) hyperextension of elbow over 10°, (d) hyperextension of knee over 10°, and (e) forward flexion of trunk so that palms of hand rest easily on floor. Skin extensibility: skin of ventral left forearm lifted midway between the elbow and wrist (measure distance skin is stretched); (score 0 for under 4 cm,1 for 4 cm, 2 for 5 cm, 3 for 6 cm, 4 for 7 cm, 5 for 8 cm). Cigarette paper, wrinkled scarring (score for each of 5 boney points): (a) left elbow and forearm, (b) right elbow and forearm, (c) left knee, (d) right knee, and (e) forehead. Bruising (score 0 to 5): (a) 0 no history or clinical evidence, (b) 1 = positive history of mild bruising, no clinical evidence, (c) 2= positive history of moderate bruising with or without skin findings, (d) 3 = moderate bruising on physical examination, (e) 4 pronounced bruising on physical examination, and (f) 5 gross bruising on physical examination. 58 patients had a good scar (ie, barely visible or just dyschromic), whereas 28 complained of bad results: namely, hypertrophic (12), depressed or atrophic (13), and diastatic scars (3). All 58 patients with regular, barely visible, or dyschromic scars had a score of 2 or lower. 10 patients with hypertrophic scars had a score of 3 or greater and the remaining 2 had a score of 2. 12 patients with depressed or atrophic scars had a score of 3 or greater and only 1 had a score of 2. Among patients with diastasis of wound edges, 2 had a score of55 and 1 had a score of 1. The differences were significant (chi-squared test, p < 0-0005). Atrophic and diastatic scars were prevalent among patients with high scores. At score 2 or higher, scars tended to be poor and, importantly, only in 4 patients with a score below 2 was the scar acceptable. Thus the outcome of scarring is easily predictable by means of a simple scoring system based on clinical examination. =
=
=
Department of Dermatology, University of Genoa, Genoa, Italy
A. REBORA P. FIALLO G. F. MUZIO
1. Holzberg M, Hewan-Lowe KO, Olansky AJ. The Ehlers-Danlos syndrome: recognition, characterization, and importance of a milder variant of the classic form. J Am Acad Dermatol 1988; 19: 656-65.
SALICYLIC ACID AND ULTRAVIOLET B FOR PSORIASIS
SIR,-After salicylic acid was synthesised in 1874 it soon became the most widely used keratolytic agent for the treatment of scaling skin disorders such as psoriasis. Today it is still used by many patients with psoriasis to remove scales, either as a sole remedy or before other external therapy. In 1925 Goeckerman described combination therapy with crude coal tar and ultraviolet light (UV), and phototherapy is now part of the standard therapeutic armamentarium for psoriasis. The advent of photochemotherapy with psoralens and LTVA (PUVA) more than a decade ago led to a resurgence of interest in UVB (280-320 nm) as monotherapy. 80-90% of psoriasis patients improve considerably or clear completely after a series of UVB exposures,l and UVB is an increasingly used treatment that is especially convenient for
outpatients. During the early days of sun protection salicylic acid derivatives such as homomenthyl and 2-ethylhexyl salicylate were commonly used in sunscreens. Growing awareness of the dangers of sun
1110 exposure has brought forth new and more effective sunscreens, and salicylates have been more or less abandoned. At our day-care centre we give some 20 000 light treatments a year. Most patients have psoriasis and their scales are removed routinely by baths, saunas, and (probably of greater significance) 2% salicylic acid in a cream base. We apply the cream a few minutes before UVB treatment because there is experimental and clinical evidence that the use of emollients before phototherapy results in a better therapeutic index, allowing more light to penetrate into the psoriatic lesions than into normal skin.2,3 One day emollient cream without salicylic acid was used, and on the following day several patients complained of red, burning skin, indicating a UV overdose. Suspecting that absence of salicylic acid was the culprit and that it had been acting as a photoprotective agent we did an open bilateral comparison in patients with stable plaque psoriasis, comparing the effect of applying the cream with or without salicylic acid before
UVB. Most patients evaluated at 4 and 6 weeks showed delayed or reduced clearing on the side where the salicylic-acid-containing cream had been applied. We know of no previous studies on this point. Since many patients with psoriasis regularly use salicylic acid preparations and, an increasing number are treated by UVB, we decided to report this influence of salicylic acid on UVB treatment. A double-blind bilateral comparative study is underway. Department of Dermatology, Central Hospital, S651 85 Karlstad, Sweden
BERIT KRISTENSEN OVE KRISTENSEN
1. Larko O. Phototherapy of psoriasis: clinical aspects and risk evaluation. Acta Dermato-Venereol 1982; suppl 103: 1-42. 2. Anderson RR, Le Vine MJ, Parrish JA. Selective modification of the optical properties of psoriatic vs normal skin. 8th International Photobiology Congress (Strasbourg, July, 1980): abstr 152. 3. Beme B. Effect of psoriasis healing of a lubricating base applied prior to phototherapy: an open study. Photodermatology 1986; 3: 188-90.
LOWER-LIMB PHLEBOGRAPHY IN RECENT PARAPLEGIA AND TETRAPLEGIA
SIR,-Pulmonary embolism (PE) is one of the leading causes of mortality in recent paraplegics,l despite the use of prophylactic anticoagulant therapy.2 Indeed in a preliminary retrospective study of 307 consecutive patients who received prophylactic anticoagulant therapy (calcium heparin 5000 U x 3), 10 patients had PE, 6 of whom died. Many patients might have had an asymptomatic deep venous thrombosis (DVT) before referral to our department. To prevent PE we examined prospectively by phlebography 147 patients with paraplegia and tetraplegia from all causes, apart from neoplasm: paralysis had occurred within 48 h and they had been referred within 90 days of the onset of paraplegia. Follow-up covered the entire hospital stay-an average of 6 months for paraplegics and 13 months for tetraplegics. There were 41 male and 106 female patients, mean age 345 (155) years. Paraplegia was attributable to trauma in 122 patients and medical conditions in 25. The upper level of the spinal cord lesion was the cervical spine in 48 patients, the thoracic spine in 78, and the lumbar spine in 21. 20 patients in whom thromboembolic disease developed between the onset of paraplegia and referral received therapeutic doses of anticoagulants and did not have phlebography. Among the other 127 patients 115 were receiving preventive anticoagulant therapy begun within a few days of onset of paraplegia. Phlebography (PHL-1) of both lower limbs was first done between the lst and 7th days (mean 5 days) after referral. When PHL-1 was normal, preventive anticoagulant therapy was maintained either with low doses of calcium heparin or with a low-molecular-weight heparin. Phlebography was also done a month later (PHL-2) (mean 35 days, range 31-38). All patients with DVT received standard anticoagulant therapy. Clinical suspicion of DVT had to be confirmed by a further phlebographic measurement.
At PHL-1, 29 (23%) of 127 patients had a DVT, with bilateral involvement in 10. 9 of the 39 venous thromboses were in the femoral vein and 1 was in the iliac vein. Only 1 mild PE occurred in a patient 2 weeks after negative PHL-1. In this patient, PHL-2
revealed a thrombus in the right posterior tibial vein. PHL-2 could only be done in 87 of the 98 patients with a normal PHL-1. Despite preventive anticoagulant therapy DVT were found in 12 (14%) patients, bilaterally in 2. None of these 14 thromboses was above the knee. 1 patient had a mild allergic reaction at PHL-2. We have shown that despite preventive anticoagulant therapy many paraplegics had DVT at referral and most were asymptomatic. Indeed, among the 53 DVT detected in 41 patients, only 9 had clinical manifestations (1 PE and 8 with phlebitis). Systematic and repeated detection of asymptomatic DVT by phlebography could reduce the frequency of PE.
Service of Neurological Rehabilitation, and Service of Radiology, Hôpital R. Poincare, Garches, France * Present address: Service du France.
ALAIN YELNIK* OLIVIER DIZIEN BERNARD BUSSEL ELIZABETH SCHOUMAN-CLAEYS GEAORGES FRIJA STEPHANE PANNIER JEAN-PIERRE HELD
Rééducation, Hôpital F. Widal, 75010 Paris,
1. Stover
SL, Fine PR. The epidemiology and economics of spinal cord injury. Paraplegia 1987; 25: 225-28. 2. Silver JR, Moulton A. Prophylactic anticoagulant therapy against pulmonary embolism in acute paraplegia. Br Med J 1970; 2: 338-40. 3. Hachen HJ. Anticoagulant therapy in patients with spinal cord injury. Paraplegia 1974; 12: 176-87.
GREENHOUSE EFFECT AND RENAL CALCULI
SIR,-During the course of the glorious British summer of this year we noted an apparent increase in cases of renal calculi causing acute renal colic. We saw 39 such cases, confirmed by intravenous urography, during the four months May to August, 1988, while during the same period in 1989 there were 58 cases, an increase of 48%. The Meteorological Office tells us that in May to August, 1988, there were 726 hours of sunshine and daily temperatures averaged 16 1°C. During the same period in 1989 the figures were 1117 hours (an increase of 53%) and 18-2°C. Sunshine and high temperatures are well recognised factors in the aetiology of renal calculi, via hypercalciuria1.2 and dehydration,3 respectively. The studies establishing these features were from areas with very hot and sunny summers such as Israel, Australia, and the Persian Gulf. To our knowledge observations on the variations in incidence of renal calculi with climate have not previously been published from Britain. Have other radiology departments found a comparable increase in calculi this summer? If the predicted trend towards warmer weather, due to the "greenhouse effect", proves correct lessons learned in traditionally hot countries may need to be applied elsewhere. Frank and de Vries’ showed that a fluid intake sufficient to cause a urinary output of at least 1200 ml daily reduced the incidence of calculi in Israel. To prevent an increase in urolithiasis the British public should be advised to drink more fluids during the hot and sunny summers of the future. Radiology Department, Northwick Park Hospital and Clinical Research Centre, Harrow HA1 3UJ
J. CURTIN M. SAMPSON
1. Parry ES, Lister IS. Sunlight and hypercalciuria. Lancet 1975; i: 1063-65. 2. Robertson WG, Hodgkinson A, Marshall DH. Seasonal variation in the composition
of urine from normal subjects: longtitudinal study. Clin Chim Acta 1977; 80: 347-53. 3. Bateson EM. Renal tract calculi and climate. Med J Aust 1973; ii: 111-13. 4. Frank M, de Vries A. Prevention of urolithiasis. Arch Environ Hlth 1966; 13: 625.
NEAR-DEATH EXPERIENCES
SIR,-It intrigues me, as a biologist, how the near-death illusion of travelling down a tunnel towards-and, presumably, in actual death fusing with-a light evolved. We know it is a limbic system mechanism, and it has probably kept the dying happy and’ quiet since Neanderthal times. The blissful final joining is the promise of