BMJ  2006;333:551 (9 September), doi:10.1136/bmj.333.7567.551

Letter

Early intervention in acute renal failure

Assessing fluid status is important

EDITOR—Bennett-Jones suggests that doctors take a pragmatic and prompt approach to intravenous fluid replacement, based on the patient's blood pressure, capillary refill time, and venous filling.¹ Assessment of fluid status needs to be much broader and incorporate a full history of any fluid gains and losses from the patient, relatives, nurses, fluid balance charts, prescription charts, anaesthetic records, and daily weights. The patient should be assessed for symptoms of hypovolaemia, which can include postural dizziness, thirst, dry mouth, reduced urine output, feeling cold, shivering, shortness of breath, and altered mental state.

Furthermore, in examining the patient, of central importance are blood pressure, a postural fall in blood pressure, tachycardia (or rarely bradycardia with severe hypovolaemia) and postural changes in pulse rate, whereas capillary refill time is not of proved diagnostic value in adults.² Other signs that should be sought are jugular venous pressure, pallor, peripheral perfusion, the dryness of mucous membranes, and the presence of pulmonary and peripheral oedema. If doubt about volume status remains, central venous pressure monitoring should be considered.

This careful assessment of fluid status is crucial before the instruction to give intravenous fluids, not loop diuretics to avoid patients developing dangerous pulmonary oedema, particularly since in some studies fluid loading in intensive care has been associated with a higher incidence of acute renal failure.³

Oxford Kidney Unit, Oxford OX3 7LJ jgleadle{at}well.ox.ac.uk

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Competing interests: None declared.

References

1. Bennett-Jones DN. Early intervention in acute renal failure. BMJ 2006;333: 406-7. (26 August.)[Free Full Text]
2. McGee S, Abernethy WB, Simel DL. Is this patient hypovolemic? JAMA 1999;281: 1022-9.[Abstract/Free Full Text]
3. Van Biesen W, Yegenaga I, Vanholder R, Verbeke F, Hoste E, Colardyn F, et al. Relationship between fluid status and its management on acute renal failure (ARF) in intensive care unit (ICU) patients with sepsis: a prospective analysis. J Nephrol 2005 18: 54-60.[ISI][Medline]

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Early intervention in acute renal failure

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