Hypophosphatemia in surgical patients.
Explore the source record for details and available documents.
Adenosine Triphosphate↗
Biomedical subjects
D B Morgan
Publications and source records attributed to D B Morgan.
Hypertension and hyperkalaemia responding to bendrofluazide.
A 33-year-old man is described with hyperkalaemia, hypertension and acidosis. The blood pressure was 160 to 200 mmHg systolic and 90 to 110 mmHg diastolic and the plasma potassium was between 6.0 and 7.0 mmole per litre. There was no renal disease and creatinine clearance was 103 ml per minute. Plasma renin activity was low and plasma aldosterone was at the lower limit of normal. Sodium deprivation or oral frusemide had little effect on blood pressure, plasma potassium, renin, aldosterone or arginine vasopressin. However, bendrofluazide caused a rapid fall of blood pressure and plasma potassium, and rise of plasma renin, aldosterone and plasma arginine vasopressin. Hypertension and hyperkalaemia is rare in the absence of renal failure. Four similar patients reported previously are reviewed. We suggest that our patient, and perhaps some of those reported earlier had primary abnormality of renal tubular function with impaired secretion of potassium and excessive tubular reabsorption of sodium. The plasma renin activity could be due to volume expansion and the low plasma aldosterone was probably caused by the antagonistic effects of low renin depressing synthesis and hyperkalaemia increasing it. A minor similar tubular abnormality might be the explanation in some of the patients with essential hypertension who have low plasma renin activity.
Adult↗
Severe hyponatraemia. A study of 17 patients.
17 patients with severe hyponatraemia (none had cardiac failure or had lately had an operation) all had excessively high plasma-antidiuretic hormone (A.D.H.). Only 13 had features typical of the syndrome of inappropriate secretion of A.D.H. (S.I.A.D.H.). Plasma-A.D.H. was not related to either plasma-sodium or diagnosis. There were as many patients with chest infection as with carcinoma of the lung. Plasma-sodium and plasma-A.D.H. returned rapidly towards normal in the patients with chest infection or volume depletion but these concentrations corrected much more slowly in patients with carcinoma of the lung. The increase in plasma-sodium in patients with chest infection was too rapid to be produced by water-deprivation treatment and was due to return of plasma-A.D.H. to normal. The term S.I.A.D.H. implies an understanding of pathophysiology that does not exist. As a diagnosis it does not help in management or prognosis. A simpler, more descriptive terminology such as "hyponatraemia with carcinoma of the lung" would be more useful and less confusing in the clinical situation.
Aged↗
Muscle chemistry of critically ill surgical patients and the effects of a course of intravenous nutrition.
The water, electrolyte and nitrogen contents of muscle were measured in 15 critically ill surgical patients before and after a course (approximately 2 weeks) of intravenous nutrition and in 8 normal individuals. The muscle from the surgical patients contained a significantly increased ratio of water to fat-free dry weight (P less than 0.01) due to an increase in the proportion of extracellular to intracellular water, and this was not corrected by intravenous nutrition. These changes could be due to an accumulation of extracellular fluid alone or to a loss of cell cytoplasm or a loss of whole muscle fibres. Intracellular chemistry was normal in the ill surgical patients and was not changed by intravenous nutrition.
Adult↗
Blood lactate and pyruvate levels in diabetic patients treated with biguanides with and without sulphonylureas.
Blood lactate and pyruvate were measured two to three hours after breakfast in 153 patients with maturity-onset (type 2) diabetes. Blood lactate was raised in 56% of all patients taking phenformin and in 35% of all patients taking metformin, while 75% and 35% respectively had raised pyruvate. Mean blood lactate level was raised at 2.2 mmol/1 (range 0.2-4.4 mmol/1) in the patients on phenformin and 1.7 mmol/1 (range 0.2-4.3 mmol/1) in those on metformin, with mean blood pyruvate levels of 0.122 mmol/1 (range 0.050-0.215 mmol/1) and 0.111 mmol/1 (range 0.038-0.259 mmol/1) respectively. In patients treated with a sulphonylurea drug alone mean blood lactate and pyruvate levels were not increased and were no different in those receiving sulphonylurea therapy in addition to a biguanide from those receiving a biguanide alone. Blood lactate did not correlate with any clinical or biochemical measurement in any of the treatment groups except for a correlation with serum creatinine in those patients taking metformin alone. The finding of raised blood lactate levels in diabetic patients treated with metformin suggests that this drug should be prescribed with caution.
Adolescent↗
Potassium depletion in heart failure and its relation to long-term treatment with diuretics: a review of the literature.
There have been many studies which suggest that patients with heart failure were potassium depleted. This depletion has been attributed to the use of potent diuretics, and these are now given with either potassium supplements or potassium-retaining diuretics. A detailed examination of the studies suggests that the reported decrease in body potassium compared with the results in healthy persons is not due to the diuretics. It can be partly explained by a failure to match patients and controls in terms of age, and the remaining difference can be explained by muscle wasting. There is therefore no evidence of a potassium depletion in these patients with heart failure.
Adult↗
The assessment of glomerular function: creatinine clearance or plasma creatinine?
Plasma creatinine concentration is superior to creatinine clearance for the detection of abnormal glomerular function, of changes of glomerular function in patients with chronic renal disease. Creatinine clearance should be abandoned as the routine assessment of glomerular function.
Adult↗
The effects of potassium supplements, spironolactone of amiloride on the potassium status of patients with heart failure.
Extra potassium supplements, spironolactone or amiloride were given for 5 months to forty-nine patients with heart failure who were taking furosemide and were in a steady state. Plasma potassium increased with all three treatments but there was no significant increase in total body potassium or red cell potassium. These findings together with other studies suggest that patients with heart failure taking diuretics do not have a significant depletion of body potassium.
Adult↗
Intraperson variability. Magnitude, source, and influence on interpretation and diagnosis.
In a person in a steady state the set of values obtained for a test carried out on a series of samples will show fluctuation about a value (the setting). In practice a single test value is usually taken as an estimate of the setting. The general consequences of this approximation are discussed in relation to the various uses of data in diagnosis, and illustrated for the common measurements of clinical chemistry. The magnitude of these consequences depends on the proportion of the total variation in a group of persons which is caused by these fluctuations in the person--within-person variation (VarWP). When the proportion is high the aim should be to reduce VarWP. When VarWP is high because of analytical error, then improved analytical technique or replicate analysis is required. Otherwise standardised techniques and conditions for venepuncture or, as a last resort, repeated samplings are necessary. These problems are discussed in relation to the detection of hypokalaemia.
Chemistry, Clinical↗
Sodium losing renal disease: Two cases and a review of the literature.
Two patients with sodium-losing renal disease were studied in detail. Both presented with shock and hypotension which was attributed at first to other causes, as was the recurrent hyponatraemia in one of them. In both patients the cause of the sodium loss was probably unrelieved urinary obstruction which has been reported previously to cause water loss but not sodium loss. Both patients had severe hyponatraemia when they were sodium depleted, which has previously been attributed to water retention from excessive secretion of antidiuretic hormone. Plasma arginine vasopressin concentrations were raised in one patient but not in the other. The cause of the water retention in the other patient is not known. One of the patients, like others described in the literature, was only able to vary his sodium excretion within narrow limits. He became sodium depleted on a normal intake and oedematous when he was given saline intravenously. We suggest that the term sodium-losing renal disease should be replaced by the term 'fixed sodium' excretion renal disease.
Adult↗
The potassium status of patients prior to open-heart surgery.
The dysrhythmia that happens after open-heart surgery has at times been attributed to potassium depletion. Therefore, in some centers, patients scheduled for open-heart surgery are routinely given potassium supplements. We have assessed the potassium status of 32 patients prior to cardiac surgery (1) by measurements of plasma, red cell, and leukocyte potassium levels and total body potassium before and after administration of potassium supplements (144 mmoles daily for 3 days) and (2) by the changes in urine potassium during the supplementation. On admission none of the patients showed evidence of a large potassium deficit, and none of them retained much of the supplemental potassium. The observations that have previously been taken as evidence of potassium depletion in such patients are discussed, and alternative explanations are suggested for all these observations.
Body Weight↗
Urinary excretion of calcium in late pregnancy and its relation to creatinine clearance.
The distribution of the values for the daily urinary excretion of calcium during the last trimester of pregnancy was skewed toward high values in 1,034 women in Bradford, England. The logarithms of the values had a Gaussian distribution. The 95% range of this log-Gaussian distribution was 0.75 to 15.5 mmoles (30 to 620 mg.) per day. Nearly 20% of the values exceeded 8.75 mmoles (350 mg.) per day, which is the reported upper limit of the 95% range for nonpregnant women. Creatinine clearance is known to increase during pregnancy, and a prospective investigation in 112 pregnant Caucasian women in a hospital showed a highly significant correlation between calcium excretion and creatinine clearance. It is suggested that the increase in calcium excretion during pregnancy is due to the increase in glomerular filtration rate.
Absorption↗
Plasma creatinine and urea: creatinine ratio in patients with raised plasma urea.
We examined the plasma urea and creatinine concentrations and the ratio between them according to diagnosis in 100 unselected and 31 selected adult hospital patients with a plasma urea concentration greater than or equal to 10 mmol/l (60mg/100ml). We also examined plasma urea and creatinine concentrations in 350 unselected consecutive patients, but found no useful relation between the two values. Congestive heart failure was the most common identifiable cause of a raised plasma urea concentration in the 100 unselected patients (36%). Among these 100 patinets the plasma creatinine concentration was a more useful discriminant between prerenal uraemia and intrinsic renal failure than was the urea:creatinine ratio or the plasma urea concentration. A plasma creatinine concentration greater than 250 mumol/1 (2-8 mg/100ml) indicated intrinsic renal failure with a 90% probability.
Acute Kidney Injury↗
Malnutrition in surgical patients. An unrecognised problem.
Indices of nutritional state were measured in 105 surgical patients. The indices were chosen to give information on protein-calorie malnutrition, anaemia, vitamin deficiency. Abnormal values for the various indices were common in the group as a whole and most frequent (50%) in patients who were still in hospital more than a week after major surgery. These patients had a high frequency of anaemia, vitamin deficiency, weight-loss, loss of arm-muscle bulk, and low plasma levels of transferrin and albumin. These abnormalities had gone almost entirely unrecognised, even in patients with sepsis after major surgery, who would benefit from improvement in nutritional state.
Adolescent↗
Sodium, water and acid-base balance: teaching transient and steady states.
We suggest that medical teaching should give greater emphasis to the interpretation of measurements in patients with chronic disturbances of homeostatic mechanisms, and some principles are outlined. The single principle which is most useful in reducing confusion is that in the steady state excretion rate is equal to intake or metabolic production rate, and rarely helps to decide the nature of a homeostatic disturbance.
Acid-Base Equilibrium↗
Water intoxication and oxytocin infusion.
The case reports are presented of two patients who developed water intoxication after high-dose oxytocin infusions. Plasma sodium and urine flow were studied in two further patients given high-dose oxytocin infusions. The findings are related to previously published observations.
Adult↗
Red-blood-cell composition in thyroid disease.
Eight red-blood-cell (R.B.C.) consitituents were measured in ten patients with hyperthyroidism and in ten healthy subjects. Only R.B.C. sodium ([Na]) and zinc ([Zn]) differed much between the groups. Therefore, only these variables were measured in a larger group of untreated hyperthyroid patients. The increase in. R.B.C. [Na] and decrease in R.B.C. [Zn] were confirmed. The R.B.C. [Na] and [Zn] were related to each other and to the plasma-thyroid-hormone concentration. However, more patients had low R.B.C. [Zn] (91%) than had raised R.B.C. [Na] (50%). Further studies suggest that the R.B.C. [Zn] lags behind the clinical response when these patients are treated. These results suggest that the measurement of R.B.C. [Zn] may have a role in the diagnosis of hyperthyroidism.
Adult↗
Effect of long-term diuretic treatment on body-potassium in heart-disease.
Plasma and total body potassium have been measured in 151 patients with chronic heart-disease, 83 of whom were taking diuretics and potassium supplements. After allowance for age and body-size, the deficit in total body-potassium was only 3-5% (100-150 mmol) in the diuretic group. 13 of the 83 patients taking diuretic had hypokalaemia (less than 3-5 mmol/1) but the potassium deficit was no greater than in the patients with normal plasma-potassium. There was no relation between the dose of potassium supplements and either the plasma-potassium or the total body-potasium. It is suggested that potassium depletion is not a major problem in patients with heart-failure treated with diuretics. The dose of potassium supplements should therefore be determined entirely by the plasma-potassium.
Adult↗