Laboratory interpretative comments and guidance: clinical and operative outcomes on moderate to severe hyponatraemia patient management

AimsHyponatraemia is the most common body fluid disorders but often goes unnoticed. Our laboratory incorporated a standardised procedure to help clinicians detect moderate/severe hyponatraemia. The study aims were to evaluate the outcomes on patient care and clinicians’ satisfaction.MethodsThe study, observational and retrospective, included 1839 cases, adult and paediatric patients, with sodium concentration <130 mmol/L. The procedure consisted of interpretative comments in the emergency and core laboratories report and the point-of-care testing blood gas network report. We evaluated hyponatraemia length in two equal periods: before and after the implementation. We conducted a survey addressed to the staff of the clinical settings involved to know their satisfaction.ResultsThe median hyponatraemia length decreased significantly from 4.95 hours (2.08–16.57) in the first period to 2.17 hours (1.06–5.39) in the second period. The lack of hyponatraemia patients follow-up was significantly less after the procedure implementation. The survey was answered by 92 (60 senior specialists and 32 residents) out of 110 clinicians surveyed. Ninety of them (98%) answered positively.ConclusionsWe have demonstrated the reduction in the time for diagnosing and management by physicians, the higher uniformity in the time required to solve hyponatraemia episodes following our laboratory procedure and the clinicians’ satisfaction.

233 Blood Tests and Radiographs After Hip and Knee Arthroplasty – We May Not Always Need Them

Aim Routine blood tests and radiographs are routinely performed after total joint arthroplasty as a pre-discharge requirement. This study aims to explore whether there might be sub-group of patients undergoing arthroplasty for whom post-operative blood tests and radiographs might not be mandated in the absence of clinical concern. Method A retrospective study of 612 ASA 1 and 2 patients underwent total hip or knee arthroplasty at a single orthopaedic centre. Variables purported to be of interest were sodium and Potassium levels, Haemoglobin concentration and eGFR. Return to theatre and alterations of the routine Physiotherapy rehabilitation were matched to post-operative radiographs. Results 42 (6.9%) patients had post-operative haemoglobin below 10 g/L. Of these 4 were symptomatic, which required treatment. Acute kidney injury was identified in 13 patients (2.1%); 11 had pre-existing renal disease. The other two had both suffered pro-longed post-operative hypotension. Two patients had severe hyponatraemia and one of whom had pre-existing renal disease. Two patients had hypokalaemia and one of whom had metabolic syndrome but normalised within 24 hours after oral supplement. No patient had abnormal post-operative radiography that altered management. Conclusions Our study indicates that routine post-operative blood tests and radiographs may not be necessary in ASA 1 and 2 patients with normal pre-existing blood tests. Where patient is clinically symptomatic or there is evidence of pre-operative renal dysfunction, metabolic syndrome, electrolyte imbalance or anaemia, we would suggest blood tests are necessary. If there is no surgical concern, it is safe to delay check radiography until their first post-operative follow up.

Severe metabolic derangement: a case of concomitant diabetic ketoacidosis and beer potomania

Diabetic ketoacidosis (DKA) and hyponatraemia associated with beer potomania are severe diagnoses warranting intensive care level management. Our patient, a middle-aged man, with a history of chronic alcohol abuse and insulin non-compliance, presents with severe DKA and severe hyponatraemia. Correcting sodium and metabolic derangements in each disorder require significant attention to fluid and electrolyte levels. Combined they prove challenging and require an individualised approach to prevent the overcorrection of sodium. Furthermore, management of these conditions lends to the importance of understanding the pathophysiology behind their hormonal and osmotic basis.

Cyclical haematological changes in a case of hypopituitarism

A 40-year-old woman presented to our emergency department in an altered state following a generalised tonic-clonic seizure. On regaining consciousness, she gave a history of bleeding tendencies and menorrhagia, fatigue, nausea, vomiting and appetite loss for a long time. She had received multiple blood transfusions in the last 10 years. Investigations revealed severe hyponatraemia, transaminitis and pancytopenia, which showed cyclical fluctuations in the hospital. Hyponatraemia was attributed to a central cause owing to secondary hypothyroidism and hypocortisolism on evaluation. A diagnosis of cyclical thrombocytopenia was made by logging the trends of blood cell lines and applying the Lomb-Scargle test. Liver biopsy showed features of transfusion hemosiderosis explaining transaminitis. All of the haematological abnormalities and clinical symptoms resolved on thyroxine and corticosteroid replacement, suggesting causal association hypopituitarism with cyclical thrombocytopenia

Pituitary microadenoma with hypopituitarism presenting as hyponatremia

The incidence of pituitary adenoma has been increasing these days. Majority of the cases are incidental findings on imaging; and these patients may be asymptomatic without any laboratory abnormalities. However, a non-functional sellar mass can initially present with hypopituitarism. The patient being described is an elderly female who presented with severe hyponatraemia. She has history of recurrent admissions for hyponatraemia in the past. Her biochemical evaluation revealed hypopituitarism and magnetic resonance imaging of brain showed pituitary microadenoma. Hyponatraemia as a presenting feature of hypopituitarism due to pituitary microadenoma is an uncommon scenario.

Pseudohyponatraemia caused by acute pancreatitis–derived hypertriglyceridaemia

We report a case of pseudohyponatraemia due to severe hypertriglyceridaemia-induced acute pancreatitis, stemming from unknown diabetes. A woman in her late 30s was admitted to the local hospital by her general practitioner due to severe hyponatraemia (116 mmol/L) and upper abdominal pain. At admission to the hospital, there was a discrepancy of 19 mmol/L between arterial and venous sodium, along with severe hypertriglyceridaemia and hypercholesterolaemia. Pancreatitis was diagnosed using a CT scan. The patient received plasmapheresis which significantly reduced triglycerides, and venous plasma sodium was normalised indicating pseudohyponatraemia at admission. Finally, a haemoglobin A1c of 83 mmol/mol was found. Diabetes was diagnosed, and insulin was initiated.

Clinical experience of the efficacy and safety of low dose tolvaptan therapy in a UK tertiary oncology setting

Background In patients with cancer, hyponatraemia is associated with increased morbidity and mortality and can delay systemic therapy. Methods The safety and efficacy of low-dose tolvaptan (7.5 mg) for hospitalized, adult patients with hyponatraemia due to Syndrome of Inappropriate Antidiuresis (SIAD), and co-existing malignancy were retrospectively evaluated in a tertiary cancer centre. Results Fifty-five patients with mean baseline serum sodium (sNa) 117.9±4.6 mmol/L were included. 90.9% had severe hyponatraemia (sNa&lt;125 mmol/L). Mean age was 65.1±9.3 years. Following an initial dose of tolvaptan 7.5 mg, median (range) increase in sNa observed at 24 hours was 9(1-19) mmol/L. Within one week, 39 patients (70.9%) reached sNa≥130 mmol/L and 48 (87.3%) had sNa rise of ≥5 mmol/L within 48 hours. No severe adverse events were reported. Thirty-three (60%) and seventeen (30.9%) patients experienced sNa rise of ≥8 and ≥12 mmol/L/24hrs, respectively. The rate of sNa correction in the first 24 hours was significantly higher among participants that continued fluid restriction after tolvaptan administration (median[quantiles]: 14[9-16] versus 8[5-11] mmol/L, p=0.036). Moreover, in the over-rapid correction cohort (≥12 mmol/L/24hrs) demeclocycline was appropriately discontinued only in 60% compared to 91.7% of the remaining participants (P=0.047). Lower creatinine was predictive of higher sNa correction rate within 24 hours (p=0.01). Conclusion In the largest series to date, although low-dose tolvaptan was demonstrated to be effective in correcting hyponatraemia due to SIAD in cancer patients, a significant proportion experienced over-rapid correction. Concurrent administration of demeclocycline and/or fluid restriction must be avoided due to the increased risk of over-rapid correction.

Active management of severe hyponatraemia is associated with improved mortality

Objective Severe hyponatraemia (plasma sodium concentration, pNa <120 mmol/L) is reported to be associated with mortality rates as high as 50%. Although there are several international guidelines for the management of severe hyponatraemia, there are few data on the impact of treatment. Design and methods We have longitudinally reviewed rates of specialist input, active management of hyponatraemia, treatment outcomes and mortality rates in patients with severe hyponatraemia (pNa <120 mmol/L) in 2005, 2010 and 2015, and compared the recent mortality rate with that of patients with pNa 120–125 mmol/L. Results Between 2005 and 2010 there was a doubling in the rate of specialist referral (32 to 68%, P = 0.003) and an increase in the use of active management of hyponatraemia in patients with pNa <120 mmol/L (63 to 88%, P = 0.02), associated with a reduction in mortality from 51 to 15% (P < 0.001). The improved rates of intervention were maintained between 2010 and 2015, but there was no further reduction in mortality. When data from all three reviews were pooled, specialist consultation in patients with pNa <120 mmol/L was associated with a 91% reduction in mortality risk, RR 0.09 (95% CI: 0.03–0.26), P < 0.001. Log-rank testing on in-hospital survival in 2015 found no significant difference between patients with pNa <120 mmol/L and pNa 120–125 mmol/L (P = 0.56). Conclusion Dedicated specialist input and active management of severe hyponatraemia are associated with a reduction in mortality, to rates comparable with moderate hyponatraemia.

Pre-eclampsia complicated by severe hyponatraemia

A 41-year-old woman was diagnosed with pre-eclampsia at 35 weeks gestation. She was treated with antihypertensives but, unfortunately, her condition became complicated by severe hyponatraemia. Her sodium levels rapidly dropped to 125 mmol/L. The cause for the hyponatraemia was the syndrome of inappropriate antidiuretic hormone secretion. She was initially managed with fluid restriction, but an emergency caesarean section was necessary in view of fetal distress. Her sodium levels returned to normal within 48 hours of delivery.Pre-eclampsia is rarely associated with hyponatraemia. A low maternal sodium level further increases the mother’s risk for seizures during this state. Additionally, the fetal sodium rapidly equilibrates to the mother’s and may result in fetal tachycardia, jaundice and polyhdraminios. All these factors may necessitate an emergency fetal delivery.