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RAPID DIAGNOSIS OF MALARIA
1271 able
to detect 2 to 4 parasites per (il blood, and in 4 of 12 patients experimentally infected with malaria, we detected malaria 12-48 h before it was detected by thick blood smear. Another optical configuration may well improve the sensitivity of the technique. Division of Infectious Diseases, National Naval Medical Center, Bethesda, Maryland 20814, USA
LELAND S. RICKMAN GARY W. LONG STEPHEN L. HOFFMAN
FAT EMBOLISM AND PATENT FORAMEN OVALE
Fig 2-Ultrasonogram of biliary system of 12-year-old boy with linear echogenic structures in lumen.
fascioliasis, and Wong et al1 reported multiple hepatic filling defects the sonogram of a patient with Opisthorchis viverrini. Here we report sonographic evidence of fasciola worms in the gallbladder or bileducts. Thus sonography may serve as an additional, noninvasive technique that may help in the diagnosis of fascioliasis when serological tests are unavailable. on
Supported by Naval Medical Research and Development Command, Bethesda, Maryland, work units 3M464758D849.BH.341 and
3M162770A870.AQ.320. Divisions of Clinical Investigation and Parasitology, US Naval Medical Research Unit 3,
Cairo, Egypt
S. BASSILY M. ISKANDER F. G. YOUSSEF N. EL-MASRY M. BAWDEN
1. Wong RK, Peura DA, Mutter ML, Heit HA, Birn MT, Johnson LF. Hemobilia and liver flukes in a patient from Thailand. Gastroenterology 1985; 88: 1958-63. 2. Canquil P, Panente D, Loyer E, Lallemand D. Unusual echographic aspects of hepatic distomiasis. J Radiol 1986; 67: 715-17. 3 Karabinis A, Herson S, Brucker G, et al. Fasciolar hepatic abscesses: value of hepatic ultrasonography. Ann Méd Interne-(Paris) 1985; 136: 575-78.
RAPID DIAGNOSIS OF MALARIA
SIR—Dr White and Dr Silamut (Feb 25, p 435) state that the ’QBC’ tube technique that we described for the diagnosis of malaria will not replace the well-established procedures of Field’s stain after fixing thin smears in anhydrous methanol and actively drying thick smears, because these procedures are "... more simple, sensitive, specific, quantitative, and rapid". We agree that these techniques rapidly provide experienced microscopists with readable slides. Unfortunately inexperienced microscopists, in the tropics or elsewhere, have difficulty reading thin smears and often cannot read thick blood smears. The smear is rarely, if ever, prepared and stained with the procedures described by White and Silamut, but by standard procedures that generally require 30-60 min. Our data show that the tube technique is as sensitive as the best thick blood smear and can be done in field conditions in the tropics in less than 10 min. For many technicians it will be more simple, sensitive, specific, and rapid than a malaria smear. However, as we stated, the tube technique is not a substitute for the blood smear, but its most important role may be to facilitate the diagnosis of malaria by inexperienced microscopists. However, when the battery-operated field centrifuge and ultraviolet microscope, which Dr Spielman and Dr Perrone describe (April 1, p 727), become available, the method may prove to be useful in many clinical settings and even be preferred by experienced microscopists, because of its speed and
simplicity. Spielman and Perrone state that the optical configurations of the x lenses we used in our experimental and field studies, respectively, were suboptimal. However, in our studies the tube technique was as sensitive as an optimally processed thick blood smear read by an expert microscopist. We were consistently 50 x and 100
SIR,—The fat embolism syndrome is a rare but serious complication in patients with long-bone fractures. Usually, after an interval of 12 to 72 h, hypoxia, petechiae, and cerebral dysfunction develop. These signs indicate systemic embolisation of fat. Although the syndrome is rarely fatal by itself, it is responsible for additional mortality and long-lasting morbidity in severely injured patients.1 Bone marrow fat enters the venous circulation at fracture sites. Venous fat macroglobules can be detected in nearly all patients with long-bone fractures. Which patients will have the syndrome is unpredictable. In a retrospective study we could not identify constitutional risk factors for development of the fat embolism syndrome.2 A patent foramen ovale might allow entry of fat globules into the systemic circulation.! The presence of a patent foramen ovale is strongly associated with ischaemic stroke in young patients3°4 and decompression sickness in divers.s Might fat embolism patients have a patent foramen ovale? We selected otherwise healthy patients who had fat embolism syndrome after isolated long-bone fractures. Of all trauma patients seen at our hospital since 1978, 12 met this condition. In 6 patients
we did transoesophageal colour-coded Doppler echocardiography with a 3-75 MHz transducer (Toshiba 65A). In 5 patients no right-to-left shunt was present. 1 patient had a minute right-to-left shunt during the Valsalva manoeuvre. This shortlasting and barely detectable shunt was of no pathophysiological significance. The fact that no patients had relevant right-to-left shunting contrasts with the reported frequencies in ischaemic stroke and serious air embolism (50% and 61 %, respectively).4,5So a patent
foramen ovale can be excluded as a cause of fat embolism in these patients. Since a sensitive technique6for the detection of a patent foramen ovale was used in patients with fat embolism syndrome, we believe the negative findings imply that a patent foramen ovale is not a principal cause of systemic fat embolism in trauma patients. Traumatology Section and Cardiology Department, University Hospital Groningen, 9700 Groningen, Netherlands
M. W. N. NIJSTEN J. P. M. HAMER H. J. TEN DUIS J. L. POSMA
Gossling HR, Pellegrini VD. Fat embolism syndrome: areview ofthepathophysiology and physiological basis of treatment. Clin Orthop 1982; 165: 68-82. 2. ten Duis HJ, Nijsten MWN, Klasen HJ, Binnendijk B. Fat embolism m patients with an isolated fracture of the femoral shaft. J Trauma 1988; 28: 383-90. 3. Lechat Ph, Mas JL, Lascault G, et al. Prevalence of patent foramen ovale m patients with stroke. N Engl J Med 1988; 318: 1148-52. 4. Webster MWI, Chancellor AM, Smith HJ, et al. Patent foramen ovale in young stroke 1.
patients. Lancet 1988; ii: 11-12. 5. Moon RE, Camporesi EM, Kisslo JA. Patent foramen ovale in decompression sickness m divers. Lancet 1989; i 513-14. 6. Mugge A, Daniel WG, Wenzlaff P, Lichtlan PR. Patent foramen ovale or left atrial thrombi in unexplained artenal embolism. Lancet 1989; i: 282-83.
ACUTE RENAL FAILURE AFTER NEBULISED PENTAMIDINE
SIR,-Nebulised pentamidine is now widely used for treatment prophylaxis of Pneumocystis carinii pneumonia. Side-effects, which are infrequent, include cough and bronchospasm,l bronchial bleeding,2 rash,3and hypoglycaemia.4 We report a case that suggests
and
renal failure should be added to the list of side-effects of nebulised pentamidine. A 42-year-old HIV-1positive man was admitted with a seven day history of fever, dry cough, and exertional dyspnoea. Fine, end-expiratory bibasal crackles were audible. A chest radiograph acute
to detect 2 to 4 parasites per (il blood, and in 4 of 12 patients experimentally infected with malaria, we detected malaria 12-48 h before it was detected by thick blood smear. Another optical configuration may well improve the sensitivity of the technique. Division of Infectious Diseases, National Naval Medical Center, Bethesda, Maryland 20814, USA
LELAND S. RICKMAN GARY W. LONG STEPHEN L. HOFFMAN
FAT EMBOLISM AND PATENT FORAMEN OVALE
Fig 2-Ultrasonogram of biliary system of 12-year-old boy with linear echogenic structures in lumen.
fascioliasis, and Wong et al1 reported multiple hepatic filling defects the sonogram of a patient with Opisthorchis viverrini. Here we report sonographic evidence of fasciola worms in the gallbladder or bileducts. Thus sonography may serve as an additional, noninvasive technique that may help in the diagnosis of fascioliasis when serological tests are unavailable. on
Supported by Naval Medical Research and Development Command, Bethesda, Maryland, work units 3M464758D849.BH.341 and
3M162770A870.AQ.320. Divisions of Clinical Investigation and Parasitology, US Naval Medical Research Unit 3,
Cairo, Egypt
S. BASSILY M. ISKANDER F. G. YOUSSEF N. EL-MASRY M. BAWDEN
1. Wong RK, Peura DA, Mutter ML, Heit HA, Birn MT, Johnson LF. Hemobilia and liver flukes in a patient from Thailand. Gastroenterology 1985; 88: 1958-63. 2. Canquil P, Panente D, Loyer E, Lallemand D. Unusual echographic aspects of hepatic distomiasis. J Radiol 1986; 67: 715-17. 3 Karabinis A, Herson S, Brucker G, et al. Fasciolar hepatic abscesses: value of hepatic ultrasonography. Ann Méd Interne-(Paris) 1985; 136: 575-78.
RAPID DIAGNOSIS OF MALARIA
SIR—Dr White and Dr Silamut (Feb 25, p 435) state that the ’QBC’ tube technique that we described for the diagnosis of malaria will not replace the well-established procedures of Field’s stain after fixing thin smears in anhydrous methanol and actively drying thick smears, because these procedures are "... more simple, sensitive, specific, quantitative, and rapid". We agree that these techniques rapidly provide experienced microscopists with readable slides. Unfortunately inexperienced microscopists, in the tropics or elsewhere, have difficulty reading thin smears and often cannot read thick blood smears. The smear is rarely, if ever, prepared and stained with the procedures described by White and Silamut, but by standard procedures that generally require 30-60 min. Our data show that the tube technique is as sensitive as the best thick blood smear and can be done in field conditions in the tropics in less than 10 min. For many technicians it will be more simple, sensitive, specific, and rapid than a malaria smear. However, as we stated, the tube technique is not a substitute for the blood smear, but its most important role may be to facilitate the diagnosis of malaria by inexperienced microscopists. However, when the battery-operated field centrifuge and ultraviolet microscope, which Dr Spielman and Dr Perrone describe (April 1, p 727), become available, the method may prove to be useful in many clinical settings and even be preferred by experienced microscopists, because of its speed and
simplicity. Spielman and Perrone state that the optical configurations of the x lenses we used in our experimental and field studies, respectively, were suboptimal. However, in our studies the tube technique was as sensitive as an optimally processed thick blood smear read by an expert microscopist. We were consistently 50 x and 100
SIR,—The fat embolism syndrome is a rare but serious complication in patients with long-bone fractures. Usually, after an interval of 12 to 72 h, hypoxia, petechiae, and cerebral dysfunction develop. These signs indicate systemic embolisation of fat. Although the syndrome is rarely fatal by itself, it is responsible for additional mortality and long-lasting morbidity in severely injured patients.1 Bone marrow fat enters the venous circulation at fracture sites. Venous fat macroglobules can be detected in nearly all patients with long-bone fractures. Which patients will have the syndrome is unpredictable. In a retrospective study we could not identify constitutional risk factors for development of the fat embolism syndrome.2 A patent foramen ovale might allow entry of fat globules into the systemic circulation.! The presence of a patent foramen ovale is strongly associated with ischaemic stroke in young patients3°4 and decompression sickness in divers.s Might fat embolism patients have a patent foramen ovale? We selected otherwise healthy patients who had fat embolism syndrome after isolated long-bone fractures. Of all trauma patients seen at our hospital since 1978, 12 met this condition. In 6 patients
we did transoesophageal colour-coded Doppler echocardiography with a 3-75 MHz transducer (Toshiba 65A). In 5 patients no right-to-left shunt was present. 1 patient had a minute right-to-left shunt during the Valsalva manoeuvre. This shortlasting and barely detectable shunt was of no pathophysiological significance. The fact that no patients had relevant right-to-left shunting contrasts with the reported frequencies in ischaemic stroke and serious air embolism (50% and 61 %, respectively).4,5So a patent
foramen ovale can be excluded as a cause of fat embolism in these patients. Since a sensitive technique6for the detection of a patent foramen ovale was used in patients with fat embolism syndrome, we believe the negative findings imply that a patent foramen ovale is not a principal cause of systemic fat embolism in trauma patients. Traumatology Section and Cardiology Department, University Hospital Groningen, 9700 Groningen, Netherlands
M. W. N. NIJSTEN J. P. M. HAMER H. J. TEN DUIS J. L. POSMA
Gossling HR, Pellegrini VD. Fat embolism syndrome: areview ofthepathophysiology and physiological basis of treatment. Clin Orthop 1982; 165: 68-82. 2. ten Duis HJ, Nijsten MWN, Klasen HJ, Binnendijk B. Fat embolism m patients with an isolated fracture of the femoral shaft. J Trauma 1988; 28: 383-90. 3. Lechat Ph, Mas JL, Lascault G, et al. Prevalence of patent foramen ovale m patients with stroke. N Engl J Med 1988; 318: 1148-52. 4. Webster MWI, Chancellor AM, Smith HJ, et al. Patent foramen ovale in young stroke 1.
patients. Lancet 1988; ii: 11-12. 5. Moon RE, Camporesi EM, Kisslo JA. Patent foramen ovale in decompression sickness m divers. Lancet 1989; i 513-14. 6. Mugge A, Daniel WG, Wenzlaff P, Lichtlan PR. Patent foramen ovale or left atrial thrombi in unexplained artenal embolism. Lancet 1989; i: 282-83.
ACUTE RENAL FAILURE AFTER NEBULISED PENTAMIDINE
SIR,-Nebulised pentamidine is now widely used for treatment prophylaxis of Pneumocystis carinii pneumonia. Side-effects, which are infrequent, include cough and bronchospasm,l bronchial bleeding,2 rash,3and hypoglycaemia.4 We report a case that suggests
and
renal failure should be added to the list of side-effects of nebulised pentamidine. A 42-year-old HIV-1positive man was admitted with a seven day history of fever, dry cough, and exertional dyspnoea. Fine, end-expiratory bibasal crackles were audible. A chest radiograph acute