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Summary The haemiglobincyanide (HiCN) method for measuring haemoglobin is used extensively worldwide; its advantage is the ready availability of a stable and internationally accepted reference standard/calibrator. However, its use may create a problem, especially in automated analysers, as the waste disposal of large volumes of reagent containing cyanide may constitute a potential toxic hazard. As an alternative, conversion of haemoglobin to a sulphate derivative by non‐toxic sodium lauryl sulphate has been proposed and is available as a commercial product from Toa Medical Electronics Co. Ltd., Japan. This evaluation has shown it to be as reliable and reproducible as HiCN for measuring haemoglobin at all concentrations, by both spectrophotometry and automated analyser. Maximum absorbance is at 534 nm. Total conversion occurs almost instantaneously, and includes methaemoglobin but not sulphaemoglobin. HbF is also measured. The only disadvantage is that solutions of haemoglobin‐sulphate are stable for only a few hours at room temperature and up to three weeks at 4°C. Thus, for standardization and calibration of instruments it is necessary to use a sample of blood or lysate the haemoglobin value of which has been assigned initially by the HiCN method.

We studied 16 patients with long-standing irritable bowel syndrome of moderate severity using a controlled, double-blind crossover method. Five sedative-anticholinergic drug combinations and a placebo were tested. The subjective response was assessed with four subjective methods to include an increasing number of response variables. The patients preferred 30 mg phenobarbital plus 8 mg belladonna (P & B) to placebo (P = 0.02). Five of ten patients were helped "some" or "a lot" with placebo, while ten of 15 were helped "some" or "a lot" with P & B (P = 0.07). The ten prominent-symptoms method revealed that subjective symptoms such as nervousness, sleep difficulties, and tiredness were experienced as greater problems than diarrhea. The factor analysis method documented a strong placebo response. Simpler evaluation methods such as drug preference and a five-choice method appear more likely to show a positive drug effect, while the inclusion of a larger number of variables appears to emphasize the placebo portion of the response. These observations may help explain some of the apparent discrepancies between the conclusions of some controlled clinical trials and subsequent clinical experience.

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