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“HIDDEN DANGERS”
' 7 would have everie man write what he knozoes and no more."—MONTAIGNE
BRITISH
JOURNAL
OF
ANAESTHESIA
VOLUME 43, No. 2
FEBRUARY 1971
EDITORIAL "HIDDEN DANGERS"
antibiotic is reported to be stable in Ringer's solution for 24 hours (Jacobs, 1970). The composition of the infusing fluid influences the rate at which several commonly used antibiotics lose activity. In grave situations several drugs of very different types may be added to infusion fluids, with the object of saving life. If the activity of some ingredients is lessened or even destroyed as a result of this mixing, then the potential benefits may he lost. The extent to which these interactions are of importance in anaesthetic practice is as yet far from fully evaluated. The whole subject is complicated, confusing and sometimes controversial. No clinician can possibly be aware even of all the currently known interactions affecting his specific field. At present it would seem wise to adopt a cautious and vigilant attitude to the addition ef drugs to infusion fluids and to verify compatibilities when this information is available. Some unsuitable combinations of drugs might well be avoided if the "round-the-clock" intravenous additive service offered by a few hospitals were to be extended. It can no longer be easily assumed that the activity of each drug in a mixture infused intravenously will be identical to its activity if each is administered separately by the conventional method. REFERENCE
Jacobs, J. (1970). Drug stability and compatibility in injections and intravenous infusions. Pharmaceutical Journal, 293, 437.
It is regretted that owing to the postal workers' strike it has not been possible to include all the translated summaries. These will be published as a supplement in the earliest possible issue.
Downloaded from http://bja.oxfordjournals.org/ at Carleton University on July 17, 2015
An intravenous infusion offers a convenient route for the administration of drugs. Indeed it is not uncommon for five or six drugs of different types to be mixed together in the same infusion bottle, especially when these cannot be given orally or when superficial veins are inadequate. Repeated and painful injections can thus be avoided. This practice is not without dangers, only some of which are well recognized. Infection may be introduced or the wrong drug may be given. Immediate precipitation may follow the mining of dru^s and this should be readily apparent; but the slow formation of crystals may pass unnoticed when mixtures are enclosed in a slightly opaque container or when the solution is coloured. Filtration would remove the danger of infusion of particles, but might diminish the dose of drug actually received by the patient. The absence of visible precipitation, moreover, does not ensure that therapeutic activity is unchanged within the mixture. Other possible dangers of mining drugs in infusion fluids are less apparent and probably often unsuspected. Evidence is accumulating to indicate that some are of considerable importance to the patient. A range of infusion fluids having widely differing compositions is now available and to most of these it is common to add one or several of an increasing number of therapeutic agents. The possible permutations within the bottle are infinite and it is clearly wrong to assume that every combination is free from the possibility of interaction, with the risk of adverse effects on the therapeutic value of some of the constituents. Several factors influencing the activity of drugs when mixed with infusion fluids are now coming to light. For example, the rim? factor appears to be important in the case of ampicillin in dextrose 5 per cent, for appreciable loss of activity takes place over 4 hours. On the other hand, the same
BRITISH
JOURNAL
OF
ANAESTHESIA
VOLUME 43, No. 2
FEBRUARY 1971
EDITORIAL "HIDDEN DANGERS"
antibiotic is reported to be stable in Ringer's solution for 24 hours (Jacobs, 1970). The composition of the infusing fluid influences the rate at which several commonly used antibiotics lose activity. In grave situations several drugs of very different types may be added to infusion fluids, with the object of saving life. If the activity of some ingredients is lessened or even destroyed as a result of this mixing, then the potential benefits may he lost. The extent to which these interactions are of importance in anaesthetic practice is as yet far from fully evaluated. The whole subject is complicated, confusing and sometimes controversial. No clinician can possibly be aware even of all the currently known interactions affecting his specific field. At present it would seem wise to adopt a cautious and vigilant attitude to the addition ef drugs to infusion fluids and to verify compatibilities when this information is available. Some unsuitable combinations of drugs might well be avoided if the "round-the-clock" intravenous additive service offered by a few hospitals were to be extended. It can no longer be easily assumed that the activity of each drug in a mixture infused intravenously will be identical to its activity if each is administered separately by the conventional method. REFERENCE
Jacobs, J. (1970). Drug stability and compatibility in injections and intravenous infusions. Pharmaceutical Journal, 293, 437.
It is regretted that owing to the postal workers' strike it has not been possible to include all the translated summaries. These will be published as a supplement in the earliest possible issue.
Downloaded from http://bja.oxfordjournals.org/ at Carleton University on July 17, 2015
An intravenous infusion offers a convenient route for the administration of drugs. Indeed it is not uncommon for five or six drugs of different types to be mixed together in the same infusion bottle, especially when these cannot be given orally or when superficial veins are inadequate. Repeated and painful injections can thus be avoided. This practice is not without dangers, only some of which are well recognized. Infection may be introduced or the wrong drug may be given. Immediate precipitation may follow the mining of dru^s and this should be readily apparent; but the slow formation of crystals may pass unnoticed when mixtures are enclosed in a slightly opaque container or when the solution is coloured. Filtration would remove the danger of infusion of particles, but might diminish the dose of drug actually received by the patient. The absence of visible precipitation, moreover, does not ensure that therapeutic activity is unchanged within the mixture. Other possible dangers of mining drugs in infusion fluids are less apparent and probably often unsuspected. Evidence is accumulating to indicate that some are of considerable importance to the patient. A range of infusion fluids having widely differing compositions is now available and to most of these it is common to add one or several of an increasing number of therapeutic agents. The possible permutations within the bottle are infinite and it is clearly wrong to assume that every combination is free from the possibility of interaction, with the risk of adverse effects on the therapeutic value of some of the constituents. Several factors influencing the activity of drugs when mixed with infusion fluids are now coming to light. For example, the rim? factor appears to be important in the case of ampicillin in dextrose 5 per cent, for appreciable loss of activity takes place over 4 hours. On the other hand, the same