Australian and New Zealand journal of medicine
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Comparative Study
Comparison of methods of assessment of renal function in patients with cancer treated with cisplatin, carboplatin or methotrexate.
In patients with cancer treated with cisplatin, carboplatin or methotrexate creatinine clearance calculated using the Cockcroft-Gault formula was compared with measured clearance and with the glomerular filtration rate. In 106 patients the average squared difference for calculated and 24 hour urine creatinine clearance was 0.288, n = 606; and for calculated creatinine clearance and glomerular filtration rate (measured using diethylenetriaminepenta-acetic acid, DTPA), 0.212, n = 34. On 35 of 606 occasions (6%) in 18 patients (17%), the calculated clearance overestimated the 24-hour urine creatinine clearance when it was less than 1 mL/s. ⋯ Derivation of an equation to predict creatinine clearance showed a linear association with plasma creatinine concentration, patient age, weight and gender. Variability in cancer patients was similar to that in the original Cockcroft-Gault study. Calculation of creatinine clearance can be used in cancer patients to monitor treatment with renally-eliminated chemotherapy agents.
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We describe in six men, recurrent episodes recurring over months or years, of sudden, brief complete obstruction to respiration followed by dyspnoea with loud inspiratory stridor lasting two to five minutes. Attacks occurred during wakefulness and/or sleep. In one patient an episode was witnessed endoscopically: the initial obstruction was seen to be caused by complete laryngeal closure. ⋯ Although stimulation of laryngeal receptors is known to produce reflex laryngeal closure, cough is the usual response during wakefulness. Treatment aimed at reducing upper airway irritation and voluntary inhibition of coughing appeared successful in reducing the incidence and severity of the episodes. Recognition of the condition is important as it may be confused with other causes of acute dyspnoea and it appears to respond to specific management.