Oral sodium and water
9.2.1.2 Oral sodium and water
9.2.1.3 Oral bicarbonate ood
9.2 Fluids and electrolytes
bl
Sodium and potassium salts, which may be given by
and mouth to prevent deficiencies or to treat established 9.2.1 Oral preparations for fluid and n
electrolyte imbalance
deficiencies of mild or moderate degree, are discussed
9.2.2 Parenteral preparations for fluid and
in this section. Oral preparations for removing excess
electrolyte imbalance
potassium and preparations for oral rehydration therapy are also included here. Oral bicarbonate, for metabolic
Nutritio
acidosis, is also described in this section.
9 The following tables give a selection of useful electrolyte values: For reference to calcium, magnesium, and phosphate,
see section 9.5.
Electrolyte concentrations—intravenous fluids
9.2.1.1 Oral potassium
Millimoles per litre Intravenous infusion
Na + K +
Compensation for potassium loss is especially neces-
HCO
Cl
Ca sary:
Normal plasma values 142 4.5
in those taking digoxin or anti-arrhythmic drugs, Sodium Chloride 0.9%
where potassium depletion may induce arrhyth- mias;
Compound Sodium 131
in patients in whom secondary hyperaldosteronism Lactate (Hartmann’s)
occurs, e.g. renal artery stenosis, cirrhosis of the Sodium Chloride
liver, the nephrotic syndrome, and severe heart 0.18% and Glucose
in patients with excessive losses of potassium in the Potassium Chloride
faeces, e.g. chronic diarrhoea associated with intes- 0.3% and Glucose 5%
tinal malabsorption or laxative abuse. Potassium Chloride
Measures to compensate for potassium loss may also be 0.3% and Sodium
required in the elderly since they frequently take inade- Chloride 0.9%
quate amounts of potassium in the diet (but see below To correct metabolic acidosis
for warning on renal insufficiency). Measures may also be required during long-term administration of
drugs known to induce potassium loss (e.g. corticoster- 1.26%
Sodium Bicarbonate 150 —
oids). Potassium supplements are seldom required with Sodium Bicarbonate
the small doses of diuretics given to treat hypertension; 8.4% for cardiac arrest
potassium-sparing diuretics (rather than potassium Sodium Lactate (m/6)
supplements) are recommended for prevention of hypo- kalaemia due to diuretics such as furosemide (fruse-
BNF 57
9.2.1 Oral preparations for fluid and electrolyte imbalance 519
mide) or the thiazides when these are given to eliminate Modified-release preparations oedema.
Avoid unless effervescent tablets or liquid prepara- tions inappropriate
Dosage If potassium salts are used for the prevention of hypokalaemia c , then doses of potassium chloride 2 to 4 g Slow-K (Alliance) U (approx. 25 to 50 mmol) daily (in divided doses) by
Tablets , m/r, orange, s/c, potassium chloride 600 mg (8 mmol each of K mouth are suitable in patients taking a normal diet. + and Cl ). Net price 20 = 54p.
Smaller doses must be used if there is renal insufficiency Label: 25, 27, counselling, swallow whole with fluid (common in the elderly) otherwise there is danger of
during meals while sitting or standing hyperkalaemia. Potassium salts cause nausea and
vomiting therefore poor compliance is a major limita- tion to their effectiveness; where appropriate, potas- sium-sparing diuretics are preferable (see also above).
Management of hyperkalaemia
Regular monitoring of plasma-potassium concentration Acute severe hyperkalaemia (plasma-potassium concen- is essential in those receiving potassium supplements.
tration above 6.5 mmol/L or in the presence of ECG When there is established potassium depletion larger
changes) calls for urgent treatment with 10–20 mL of doses may be necessary, the quantity depending on
calcium gluconate 10% by slow intravenous injection, the severity of any continuing potassium loss (monitor-
titrated and adjusted to ECG improvement, to tempora- ing of plasma-potassium concentration and specialist
rily protect against myocardial excitability. An intra- advice would be required). Potassium depletion is fre-
venous injection of soluble insulin (5–10 units) with quently associated with chloride depletion and with
50 mL glucose 50% given over 5–15 minutes, reduces metabolic alkalosis, and these disorders require correc-
serum-potassium concentration; this is repeated if tion.
necessary or a continuous infusion instituted. The cor- rection of causal or compounding acidosis with sodium
Administration Potassium salts are preferably given bicarbonate infusion (section 9.2.2) should be consid- as a liquid (or effervescent) preparation, rather than
ered (important: preparations of sodium bicarbonate modified-release tablets; they should be given as the
and calcium salts should not be administered in the chloride (the use of effervescent potassium tablets BPC
same line—risk of precipitation). Drugs exacerbating 1968 should be restricted to hyperchloraemic states, sec-
hyperkalaemia should be reviewed and stopped as tion 9.2.1.3).
appropriate; occasionally haemodialysis is needed. Salt substitutes
A number of salt substitutes which contain Ion-exchange resins may be used to remove excess significant amounts of potassium chloride are readily available
potassium in mild hyperkalaemia or in moderate hyper- as health food products (e.g. LoSalt and Ruthmol ). These should not be used by patients with renal failure as potassium
kalaemia when there are no ECG changes. intoxication may result.
POLYSTYRENE SULPHONATE RESINS POTASSIUM CHLORIDE
Indications hyperkalaemia associated with anuria or
Indications
potassium depletion (see notes above) severe oliguria, and in dialysis patients Cautions elderly, renal impairment (avoid if creatinine
children (impaction of resin with excessive clearance less than 10 mL/minute; Appendix 3);
Cautions
dosage or inadequate dilution); monitor for electrolyte
Nutrition
intestinal stricture, history of peptic ulcer, hiatus her- disturbances (stop if plasma-potassium concentration nia (for modified-release preparations); important:
below 5 mmol/litre); pregnancy and breast-feeding; special hazard if given with drugs liable to raise
sodium-containing resin in congestive heart failure, plasma-potassium concentration such as potassium-
hypertension, renal impairment, and oedema; inter-
and
sparing diuretics, ACE inhibitors, or ciclosporin, for actions: Appendix 1 (polystyrene sulphonate resins) other interactions: Appendix 1 (potassium salts)
Contra-indications obstructive bowel disease; oral
blood
Contra-indications plasma-potassium concentration administration or reduced gut motility in neonates; above 5 mmol/litre
avoid calcium-containing resin in hyperparathyroid- Side-effects nausea and vomiting (severe symptoms
ism, multiple myeloma, sarcoidosis, or metastatic may indicate obstruction), oesophageal or small
carcinoma
bowel ulceration Side-effects rectal ulceration following rectal admin- Dose
istration; colonic necrosis reported following enemas . See notes above
containing sorbitol; sodium retention, hypercal- Note Do not confuse Effervescent Potassium Tablets BPC
caemia, gastric irritation, anorexia, nausea and 1968 (section 9.2.1.3) with effervescent potassium chloride tablets. Effervescent Potassium Tablets BPC 1968 do not
vomiting, constipation (discontinue treatment—avoid contain chloride ions and their use should be restricted to
magnesium-containing laxatives), diarrhoea; calcium- hyperchloraemic states (section 9.2.1.3).
containing resin can cause hypercalcaemia (in dia- Kay-Cee-L c
lysed patients and occasionally in those with renal (Geistlich)
impairment), hypomagnesaemia Syrup , red, sugar-free, potassium chloride 7.5%
(1 mmol/mL each of K Dose + and Cl ). Net price 500 mL = £3.74. Label: 21
. By mouth , 15 g 3–4 times daily in water (not fruit squash which has a high potassium content) or as a Sando-K c (HK Pharma)
paste; CHILD 0.5–1 g/kg daily in divided doses Tablets , effervescent, potassium bicarbonate and
. By rectum , as an enema, 30 g in methylcellulose chloride equivalent to potassium 470 mg (12 mmol of K +
solution, retained for 9 hours followed by irrigation ) and chloride 285 mg (8 mmol of Cl ). Net price 20
to remove resin from colon; NEONATE and CHILD , 0.5– = £1.53. Label: 13, 21
1 g/kg daily
9.2.1 Oral preparations for fluid and electrolyte imbalance BNF 57 Calcium Resonium c (Sanofi-Synthelabo)
Rehydration should be rapid over 3 to 4 hours (except in Powder , buff, calcium polystyrene sulphonate. Net
hypernatraemic dehydration in which case rehydration price 300 g = £47.55. Label: 13
should occur more slowly over 12 hours). The patient Resonium A c (Sanofi-Synthelabo)
should be reassessed after initial rehydration and if still Powder , buff, sodium polystyrene sulphonate. Net
dehydrated rapid fluid replacement should continue. price 454 g = £70.24. Label: 13
Once rehydration is complete further dehydration is prevented by encouraging the patient to drink normal volumes of an appropriate fluid and by replacing con- tinuing losses with an oral rehydration solution; in infants, breast-feeding or formula feeds should be offered between oral rehydration drinks.
For intravenous rehydration see section 9.2.2. Sodium chloride is indicated in states of sodium deple-
9.2.1.2 Oral sodium and water
tion and usually needs to be given intravenously (sec- tion 9.2.2). In chronic conditions associated with mild or moderate degrees of sodium depletion, e.g. in salt-losing
ORAL REHYDRATION SALTS (ORS)
bowel or renal disease, oral supplements of sodium Indications fluid and electrolyte loss in diarrhoea, see chloride or sodium bicarbonate (section 9.2.1.3),
notes above
according to the acid-base status of the patient, may
Dose
be sufficient. . According to fluid loss, usually 200–400 mL solution after every loose motion; INFANT 1–1½ times usual
feed volume; CHILD 200 mL after every loose motion Indications sodium depletion—see also 9.2.2.1;
SODIUM CHLORIDE
nebuliser diluent (section 3.1.5); eye (section 11.8.1); UK formulations oral hygiene (section 12.3.4); wound irrigation (sec-
Note After reconstitution any unused solution should be dis- tion 13.11.1)
carded no later than 1 hour after preparation unless stored in a refrigerator when it may be kept for up to 24 hours
Slow Sodium c (HK Pharma) Dioralyte c (Sanofi-Aventis)
ood
Tablets , m/r, sodium chloride 600 mg (approx. Oral powder bl , sodium chloride 470 mg, potassium 10 mmol each of Na + and Cl ). Net price 100-tab pack = £6.05. Label: 25
chloride 300 mg, disodium hydrogen citrate 530 mg, Dose prophylaxis of sodium chloride deficiency 4–8 tablets daily
and glucose 3.56 g/sachet, net price 6-sachet pack = n
with water (in severe depletion up to max. 20 tablets daily) £2.11, 20-sachet pack (black currant- or citrus-fla- Chronic renal salt wasting, up to 20 tablets daily with appropriate
voured or natural) = £6.99 fluid intake
Note Reconstitute 1 sachet with 200 mL of water (freshly boiled CHILD see BNF for Children
and cooled for infants); 5 sachets reconstituted with 1 litre of water
Nutritio
provide Na 60 mmol, K 20 mmol, Cl 60 mmol, citrate 10 mmol,
9 and glucose 90 mmol Oral rehydration therapy (ORT)
Dioralyte c Relief (Sanofi-Aventis) As a worldwide problem diarrhoea is by far the most
Oral powder , sodium chloride 350 mg, potassium important indication for fluid and electrolyte replace-
chloride 300 mg, sodium citrate 580 mg, cooked rice ment. Intestinal absorption of sodium and water is
powder 6 g/sachet, net price 6-sachet pack (apricot-, enhanced by glucose (and other carbohydrates). Repla-
black currant- or raspberry-flavoured) = £2.35, 20- cement of fluid and electrolytes lost through diarrhoea
sachet pack (apricot-flavoured) = £7.42 can therefore be achieved by giving solutions containing
Note Reconstitute 1 sachet with 200 mL of water (freshly boiled sodium, potassium, and glucose or another carbohy- and cooled for infants); 5 sachets when reconstituted with 1 litre of water provide Na 60 mmol, K 20 mmol, Cl 50 mmol and citrate drate such as rice starch.
10 mmol; contains aspartame (section 9.4.1) Oral rehydration solutions should:
Electrolade c (Actavis) .
enhance the absorption of water and electrolytes; Oral powder , sodium chloride 236 mg, potassium .
replace the electrolyte deficit adequately and safely; chloride 300 mg, sodium bicarbonate 500 mg, anhy- .
contain an alkalinising agent to counter acidosis; drous glucose 4 g/sachet (banana-, black currant-, lemon and lime-, or orange-flavoured). Net price 6-
be slightly hypo-osmolar (about 250 mmol/litre) to sachet (plain or multiflavoured) pack = £1.33, 20- prevent the possible induction of osmotic diarrhoea;
sachet (single- or multiflavoured) pack = £4.99 .
be simple to use in hospital and at home; Note Reconstitute 1 sachet with 200 mL of water (freshly boiled . and cooled for infants); 5 sachets when reconstituted with 1 litre of be palatable and acceptable, especially to children; water provide Na 50 mmol, K 20 mmol, Cl 40 mmol, HCO
be readily available. 30 mmol, and glucose 111 mmol It is the policy of the World Health Organization (WHO)
Rapolyte c (KoGEN) to promote a single oral rehydration solution but to use
Oral powder , sodium chloride 350 mg, potassium it flexibly (e.g. by giving extra water between drinks of
chloride 300 mg, sodium citrate 600 mg, anhydrous oral rehydration solution to moderately dehydrated
glucose 4 g, net price 20-sachet pack (black currant- infants).
or raspberry-flavoured) = £4.28 Oral rehydration solutions used in the UK are lower in
Note Reconstitute 1 sachet with 200 mL of water (freshly boiled sodium (50–60 mmol/litre) than the WHO formulation
and cooled for infants); 5 sachets when reconstituted with 1 litre of since, in general, patients suffer less severe sodium loss. water provide Na 60 mmol, K 20 mmol, Cl 50 mmol, citrate 10 mmol, and glucose 110 mmol
WHO formulation Oral Rehydration Salts (Non-proprietary) Oral powder , sodium chloride 2.6 g, potassium chloride 1.5 g, sodium citrate 2.9 g, anhydrous glucose
13.5 g. To be dissolved in sufficient water to produce
1 litre (providing Na +
75 mmol, K +
20 mmol, Cl
65 mmol, citrate 10 mmol, glucose 75 mmol/litre) Note Recommended by the WHO and the United Nations Chil- dren’s Fund but not commonly used in the UK.