Asymptomatic hyponatremia in pulmonary tuberculosis

Diagnosis of Mycobacterium tuberculosis Septic Shock in Patients With Anti-synthetase Syndrome Based on Next-Generation Sequencing: A Case Report and Literature Review

A 51-year-old woman was transferred to the intensive care unit with such symptoms as fever, swollen left knee joint, pain and hypotension. After preliminary evaluation, she was diagnosed as suffering acute suppurative arthritis and septic shock. Then, she was rescued and prescribed to receive treatment with broad-spectrum antibiotics. However, there was no source of infection identified except for the knee joint. The bacterial and fungal cultures of blood samples and articular effusion were shown to be negative, while the results obtained from the next-generation sequencing of blood and articular effusion revealed that Mycobacterium tuberculosis was positive. The patient was then put on five combinations of anti-tuberculosis therapeutic treatment. Nevertheless, despite the active anti-tuberculosis treatment put in place, her general condition still deteriorated progressively. As the level of her bilirubin continued to rise, further treatment was affected, which prompted the change made to the anti-tuberculosis treatment program. Her clinical condition continued to deteriorate, which led to the development of unstable vital signs and the multiple organ dysfunction syndrome. In spite of our best efforts to save her life, the patient still ended up with death.

The Echo of Pulmonary Tuberculosis: Mechanisms of Clinical Symptoms and Other Disease-Induced Systemic Complications

Clinical symptoms of active tuberculosis (TB) can range from a simple cough to more severe reactions, such as irreversible lung damage and, eventually, death, depending on disease progression. In addition to its clinical presentation, TB has been associated with several other disease-induced systemic complications, such as hyponatremia and glucose intolerance. Here, we provide an overview of the known, although ill-described, underlying biochemical mechanisms responsible for the clinical and systemic presentations associated with this disease and discuss novel hypotheses recently generated by various omics technologies. This summative update can assist clinicians to improve the tentative diagnosis of TB based on a patient's clinical presentation and aid in the development of improved treatment protocols specifically aimed at restoring the disease-induced imbalance for overall homeostasis while simultaneously eradicating the pathogen. Furthermore, future applications of this knowledge could be applied to personalized diagnostic and therapeutic options, bettering the treatment outcome and quality of life of TB patients.

The syndrome of inappropriate antidiuresis is associated with excess long-term mortality: a retrospective cohort analyses

Introduction

The syndrome of inappropriate antidiuresis (SIAD) is the commonest cause of euvolaemic hyponatraemia in patients admitted to hospital. The mortality after discharge from hospital has not been previously studied in patients with SIAD.

Aims

To compare mortality in patients with SIAD and those with kidney injury (KI). To identify underlying diagnoses associated with deaths due to SIAD.

Methods

Single-centre retrospective cohort analyses of 804 patients with severe hyponatraemia over a 3-year period. Five-year survival data in patients with SIAD and those with KI were compared. The underlying diagnoses that contributed to SIAD in this cohort were analysed using ICD-10 codes.

Results

202 patients had SIAD using biochemical cut-off parameters; 248 patients had KI. Patient with KI had a statistically significant (log-rank p<0.0001) shorter median survival time (2.24 months (95% CI 1.3 to 4.3)) compared with those with SIAD (31.0 months (95% CI 21.6 to 54.8)). 53.8% (n=78) of patients with hyponatraemia due to SIAD died within the first year after admission; the corresponding figure for those presenting with KI was 74.1% (n=166). Five years after admission, 80.8% (n=117) of those with SIAD had died; the corresponding figure for those with KI was 88.4% (n=200). In those patients with SIAD that died within the first year, malignancy appeared to be the most common cause (25.4%) followed by infection (23.8%).

Conclusions

Severe hyponatraemia in SIAD carries a high mortality after discharge, and although this seems often to be attributable to the underlying cause, the extent to which treatment with V2-recptor antagonists may help to correct the hyponatraemia associated with SIAD and influence the medium-to-long-term outcome in such patients is worthy of further study.

Radiologic predictors of hyponatremia in children hospitalized with community-acquired pneumonia

BACKGROUND

Hyponatremia (HNa) is the most common electrolyte imbalance seen in clinical practice and a common laboratory finding in children with community-acquired pneumonia (CAP). This study investigated whether there is a link between the radiological pattern seen in patients with CAP and the occurrence of HNa, hypothesizing that children with moderate and severe HNa would have a lobar-segmental pattern on chest radiograph.

METHODS

The medical files and chest radiographs of 54 children with moderate to severe HNa (sodium <130 mmol/L) admitted with CAP over a 2-year period at our institution were retrospectively studied. Community-acquired pneumonia was defined as either lobar-segmental or interstitial by a radiologist blinded to laboratory results.

RESULTS

Hyponatremia was seen more frequently in children with lobar-segmental pneumonia: 40 (74%) compared with 14 (26%) with interstitial pneumonia (P = 0.004). There was no relationship between the pattern of pneumonia seen on chest radiograph and severity of HNa; however, all 6 cases of severe HNa had lobar-segmental CAP, and all patients with complicated CAP were from the lobar-segmental group.

CONCLUSIONS

We found an association between lobar-segmental CAP and moderate or severe HNa. In addition, all cases of severe HNa occurred in patients with lobar-segmental CAP. The presence of a lobar-segmental pattern on chest radiography in CAP suggests the need for assessment of electrolyte status even in patients with adequate respiratory status.

The distribution of body fluids in congestive heart failure. III. Exchanges in patients during diuresis

The balance technic was applied in six studies of patients with congestive heart failure during the diuresis of their edema fluid. From the data so obtained changes in the extra- and intracellular phases of the body fluids were calculated, as well as transfers of sodium and potassium between the several phases and between the body and external environment. The results indicate that abnormalities of intracellular fluid exist in this condition.

John P. Peters and Nephrology

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Altered water metabolism in tuberculosis: role of vasopressin

PURPOSE

Patients with hyponatremia due to tuberculosis have shown variable responses to water loading in previous small studies, ranging from persistent antidiuresis to a normal diuresis. Although tuberculosis is considered a cause of the syndrome of inappropriate antidiuretic hormone secretion (SIADH), circulating vasopressin has been documented in only a few cases. We studied a larger group of patients to determine whether it can be suppressed by a short-term reduction in osmolality.

PATIENTS AND METHODS

Twenty-eight hyponatremic patients (mean age +/- SD: 40 +/- 10 years) with pulmonary or miliary tuberculosis underwent a clinical evaluation, measurement of blood and urine chemistry values, and (in 22) a water load of 20 mL/kg. Volume status was evaluated by urine sodium concentration, blood and urine urea nitrogen, and plasma renin activity. Endocrine, renal, and other recognized causes of SIADH were excluded.

RESULTS

All 22 patients exhibited a decline in urine osmolality and an increase in free water clearance after water loading. Water excretion was fully normal in seven of 22, with the remainder showing variable impairment of diluting ability and/or volume excreted. Plasma vasopressin, measured in 11 of 22 patients as well as in six others not subjected to water loading, was detectable despite hypo-osmolality in 16 of 17. Vasopressin levels declined after water loading, from 1.85 +/- 1.32 to 0.77 +/- 0.25 pg/mL (p less than 0.05). The majority of patients had the euthyroid sick syndrome but normal adrenal responses to cosyntropin. Although several patients had mild volume depletion when studied, this factor did not appear to explain the defect in water excretion. Hyponatremia resolved predictably within days to weeks of antituberculous therapy.

CONCLUSIONS

Circulating vasopressin remains detectable in hyponatremic patients with tuberculosis and is responsive to changes in osmolality. A downsetting of osmoregulation induced by active tuberculosis ("reset osmostat") could explain this abnormality, but we cannot exclude an unidentified non-osmotic stimulus that can be counteracted by water loading.

Factors that limit brain volume changes in response to acute and sustained hyper- and hyponatremia

Rats were made acutely hyper- or hyponatremic by infusion of hypertonic saline or water, respectively. Other rats were maintained in these states from 1 to 7 days to observe the effects of time. Brain tissue water, Na, Cl, and K were compared with serum Na and Cl concentration (Na(E) and Cl(E)). The following observations are noted: Brain Cl content varies directly with Cl(E) and brain Na content in the Cl space (Na(e)) varies directly with Na(E), indicating little or no restraint on the inward or outward movement of Na or Cl from the Cl space of brain. The intracellular volume of brain fluid (V(i)) derived as the difference between total water and Cl space, decreases with hypernatremia and increases with hyponatremia. The changes in V(i) in the acute studies are not accompanied by any change in brain K content, or calculated intracellular Na content, and are approximately 0.6 the changes predicted from osmotic behavior of cells, which apply four assumptions: (a) Na(E) is proportional to osmolality; (b) brain osmolality remains equal to plasma osmolality; (c) V(i) is osmotically active; and (d) there is no net gain or loss of solute from V(i). The validity of these assumptions is considered. When changes in osmolality are sustained, V(i) is much closer to control values than when in the acute phase. K content increases in hypernatremia and decreases in hyponatremia. The changes in K content can account for some of the adjustment in V(i) observed over the extended period of hyper- or hyponatremia. The regression of (Na + K)/v upon Na(E) describes a slope less than 1.0 and an intercept of (Na + K)/v equal to 40% of the control (Na + K)/v. These characteristics are interpreted to mean that significant quantities of Na and K in brain are osmotically inactive. The brain protects itself from acute volume changes in response to change in Na(E) by the freedom for Na and Cl to move from the Cl space, by V(i) not changing acutely to the degree predicted from osmotic properties of cells in general, and by significant quantities of Na + K in V(i) being osmotically inactive. With sustained changes in osmolality, V(i) approaches normal values and brain K changes to account for part of this later adjustment.

The Genesis of Hyponatremia Associated with Marked Overhydration and Water Intoxication

Prolonged overhydration and hyponatremia have been produced in 10 patients with use of Pitressin Tannate in Oil. Balance studies have shown that in patients who developed moderate hyponatremia, the drop in serum sodium could be explained by water retention. In patients who developed severe water intoxication, the very low levels of serum sodium (100-114 mEq./L.) could not be entirely accounted for by changes in salt and water balance.

Certain patients failed to develop severe water intoxication although an equivalent degree of overhydration was achieved. In these subjects, further overhydration was limited by intermittent episodes of low solute diuresis. This diuretic escape from Pitressin effect has been evaluated by measurement of U/P osmolar ratio on 24-hour urine specimens as well as T c H 2 O during hypertonic mannitol infusion. Defects in both aspects of renal concentration were observed, although they were not necessarily coexistent.