Systemic and iatrogenic factors contribute to the development of severe hypernatraemia in vulnerable inpatients

OBJECTIVES

To determine all-cause in-hospital mortality associated with severe hypernatraemia and the causes, comorbidities, time to treatment, discharge destination and postdischarge mortality.

DESIGN

Retrospective observational cohort study.

PATIENTS

Severe hypernatraemia, (sodium concentration ≥ 155 mmol/L), at any time during a tertiary hospital admission in Melbourne, Australia, 1 January 2019 to 31 December 2019 (pre-COVID19).

MEASUREMENTS

Deaths, Charlson Comorbidity Index (CCI), hypernatraemia causes, time to treatment, discharge destination.

RESULTS

One hundred and one inpatients: 64 community-acquired, 37 hospital-acquired. In-hospital mortality was 38%, but cumulative mortality was 65% by 1 month after discharge, with only a minor further increase at 6 and 12 months. After adjusting for peak sodium concentration, the community acquired group had significantly reduced odds of in-hospital mortality (odds ratio 0.15, 95% confidence interval [0.04-0.54], p = .003). Iatrogenic factors were present in 57% (21/37) of the hospital-acquired group. Only 55% of all cases received active sodium directed treatment. Time to start treatment did not affect outcomes. High levels of comorbidity were present, median CCI (IQR) was 6 (5-8) in the community and 5 (4-7) in the hospital group. Dementia prevalence was higher in the community group, 66% (42/64) versus 19% (7/37) (p = .001). Infection was the most common precipitant with 52% (33/64) in the community and 32% (12/37) in the hospital group. Of the survivors, 32% who had been living independently required residential care after discharge.

CONCLUSIONS

Mortality was high and loss of independence in survivors common. To potentially improve outcomes, hypernatraemia-specific guidelines should be formulated and efforts made to reduce system and iatrogenic factors.

Challenges in using fractional excretion of sodium in the assessment of salt poisoning

AIM

Hypernatraemia typically reflects dehydration, yet in rare instances may be caused by salt poisoning. Identifying these rare cases is a difficult challenge. Making the diagnosis of salt poisoning can have severe consequences, such as the removal of the child from its home or even prison sentences for the implicated carer. It is therefore imperative to get the diagnosis right. Guidelines for the assessment of hypernatraemia emphasise the importance of the fractional excretion of sodium to distinguish between dehydration and salt poisoning, but no generally accepted cut-off value exists. Opinions about the diagnosis of salt poisoning in some cases consequently may differ. Here, we aim to highlight the challenges and stimulate discussion on how to improve the tools for the assessment of hypernatraemia.

METHODS

Report of a case of unexplained hypernatraemia in which the treating paediatrician raised the suspicion of salt poisoning.

RESULTS

Two consulted experts made opposing judgements about the aetiology of the observed hypernatraemia.

CONCLUSION

Clear diagnostic criteria for the diagnosis of salt poisoning are lacking and more data are needed for their establishment. Without this, victims may experience further harm and carers are at risk of devastating, yet potentially erroneous accusations.

Epidemiology and Outcomes of Hypernatraemia in Patients with COVID-19-A Territory-Wide Study in Hong Kong

BACKGROUND

Dysnatraemias are commonly reported in COVID-19. However, the clinical epidemiology of hypernatraemia and its impact on clinical outcomes in relation to different variants of SARS-CoV-2, especially the prevailing Omicron variant, remain unclear.

METHODS

This was a territory-wide retrospective study to investigate the clinical epidemiology and outcomes of COVID-19 patients with hypernatraemia at presentation during the period from 1 January 2020 to 31 March 2022. The primary outcome was 30-day mortality. Key secondary outcomes included rates of hospitalization and ICU admission, and costs of hospitalization.

RESULTS

In this study, 53,415 adult COVID-19 patients were included for analysis. Hypernatraemia was observed in 2688 (5.0%) patients at presentation, of which most cases (99.2%) occurred during the local "5th wave" dominated by the Omicron BA.2 variant. Risk factors for hypernatraemia at presentation included age, institutionalization, congestive heart failure, dementia, higher SARS-CoV-2 Ct value, white cell count, C-reactive protein and lower eGFR and albumin levels (p < 0.001 for all). Patients with hypernatraemia showed significantly higher 30-day mortality (32.0% vs. 5.7%, p < 0.001) and longer lengths of stay (12.9 ± 10.9 vs. 11.5 ± 12.1 days, p < 0.001) compared with those with normonatraemia. Multivariate analysis revealed hypernatraemia at presentation as an independent predictor for 30-day mortality (aHR 1.32, 95% CI 1.14-1.53, p < 0.001) and prolonged hospital stays (OR 1.55, 95% CI 1.17-2.05, p = 0.002).

CONCLUSIONS

Hypernatraemia is common among COVID-19 patients, especially among institutionalized older adults with cognitive impairment and other comorbidities during large-scale outbreaks during the Omicron era. Hypernatraemia is associated with unfavourable outcomes and increased healthcare utilization.

The incidence, hospitalisations and deaths in acutely ill children with dysnatraemias

Aim

The aim was to evaluate the incidence, hospitalisations and deaths in acutely ill children with dysnatraemias.

Methods

This was a register‐based cohort study of 46 518 acutely ill children aged <16 years who visited a paediatric emergency department. Risk factors were assessed using two nested case–control studies.

Results

Moderate to severe hypernatraemia occurred in 92 children (0.20%; 95% confidence interval [CI]: 0.16%–0.24%) and moderate to severe hyponatraemia in 131 children (0.28%; 95% CI: 0.24%–0.33%). Underlying medical conditions increased the risk of both moderate to severe hypernatraemia (odds ratio [OR]: 17; 95% 5.5–51) and moderate to severe hyponatraemia (OR: 3.5; 95% CI: 2.0–5.9). The use of a feeding tube (OR: 14; 95% CI: 3.2–66) and intellectual disability (OR: 7.3; 95% CI: 3.0–18) was associated with moderate to severe hypernatraemia. The risk of death was associated with moderate to severe hypernatraemia (OR: 19; 95% CI: 2.0–2564) and moderate to severe hyponatraemia (OR: 33; 95% CI: 3.7–4311).

Conclusions

Severe dysnatraemias were more prevalent in acutely ill children with underlying medical conditions and were markedly associated with the risk for death.

Diagnosis and management of hypernatraemia in children

Hypernatraemia is most commonly caused by excessive loss of solute-free water or decreased fluid intake; less often, the aetiology is salt intoxication. Especially infants, young children and individuals with a lack of access to water are at risk of developing hypernatraemia. Diagnosis is based on detailed history, physical examination and basic laboratory tests. Correction of hypernatraemia must be slow to prevent cerebral oedema and irreversible brain damage. This article reviews the aetiology, differential diagnosis and management of conditions associated with paediatric hypernatraemia. Distinguishing states with water deficiency from states with salt excess is important for proper management of hypernatraemic patients.

Pseudo-pheochromocytoma due to obstructive sleep apnea: a case report

SUMMARY

Obstructive sleep apnea (OSA) is a condition of intermittent nocturnal upper airway obstruction. OSA increases sympathetic drive which may result in clinical and biochemical features suggestive of pheochromocytoma. We present the case of a 65-year-old male with a 2.9-cm left adrenal incidentaloma on CT, hypertension, symptoms of headache, anxiety and diaphoresis, and persistently elevated 24-h urine norepinephrine (initially 818 nmol/day (89-470)) and normetanephrine (initially 11.2 µmol/day (0.6-2.7)). He was started on prazosin and underwent left adrenalectomy. Pathology revealed an adrenal corticoadenoma with no evidence of pheochromocytoma. Over the next 2 years, urine norepinephrine and normetanephrine remained significantly elevated with no MIBG avid disease. Years later, he was diagnosed with severe OSA and treated with continuous positive airway pressure. Urine testing done once OSA was well controlled revealed complete normalization of urine norepinephrine and normetanephrine with substantial symptom improvement. It was concluded that the patient never had a pheochromocytoma but rather an adrenal adenoma with biochemistry and symptoms suggestive of pheochromocytoma due to untreated severe OSA. Pseudo-pheochromocytoma is a rare presentation of OSA and should be considered on the differential of elevated urine catecholamines and metanephrines in the right clinical setting.

LEARNING POINTS

Obstructive sleep apnea (OSA) is a common condition among adults. OSA may rarely present as pseudo-pheochromocytoma with symptoms of pallor, palpitations, perspiration, headache, or anxiety. OSA should be considered on the differential of elevated urine catecholamines and metanephrines, especially in patients with negative metaiodobenzylguanidine (MIBG) scan results.

Hypernatraemia and low eGFR at hospitalization in COVID-19 patients: a deadly combination

Background

The coronavirus disease 2019 (COVID-19) pandemic has had a profound impact on the general population and the burden of pre-existing comorbidities has heavily affected the outcome of the infection. Hyponatraemia has been frequently described. Conversely, hypernatraemia has rarely been described in COVID-19.

Methods

The studied cohort encompasses all COVID-19 patients consecutively admitted to the Messina Hospital, Italy, during the first wave of the epidemic. Since healthcare structures were not overwhelmed at that time, indications for hospitalization were homogeneous throughout the study period. Serum sodium levels, kidney function [estimated glomerular filtration rate (eGFR)], demographic and clinical characteristics were recorded at admission. Correlation between mortality, sodium and eGFR was evaluated by survival curves and univariate and multivariate regression models.

Results

Baseline biochemical and clinical data at the time of admission were available for 115 COVID-19-confirmed patients. The median age at admission was 73 years (48% men), with a median Charlson Comorbidity Index of 4. A total of 23.5% of patients presented with a sodium level ≥146 mmol/L, while 7.8% had sodium <135 mmol/L. Hypernatraemic patients were older, with higher comorbidity. Age, hypernatraemia and reduced eGFR were associated with increased mortality in both univariate and multivariate regression models (P < 0.001). The combination of hypernatraemia and reduced renal function at admission had an odds ratio of 47.67 (95% confidence interval 10.08–225.43) of dying compared with patients with an eGFR ≥60 mL/min and sodium <145 mmol/L.

Conclusions

Our study suggests that the association between hypernatraemia and reduced eGFR at referral is a highly relevant prognostic marker for death during hospitalization. The role of this association should be further tested in larger, multicentre cohorts.

Prognostic impact of hyponatraemia and hypernatraemia at admission and discharge in heart failure patients with preserved, mid-range and reduced ejection fraction

BACKGROUND

Hyponatraemia is common in patients with acute heart failure (HF).

AIMS

To determine the impact of sodium disturbances on mortality and readmissions in HF with reduced left ventricular ejection fraction (HFrEF), preserved ejection fraction (HFpEF) and mid-range ejection fraction (HFmrEF).

METHODS

This study was a prospective multicentre consecutive registry in 20 hospitals, including patients admitted due to acute HF in cardiology departments. Sodium <135 mmol/L was considered hyponatraemia, >145 mmol/L hypernatraemia and 135-145 mmol/L normal.

RESULTS

A total of 1309 patients was included. Mean age was 72.0 ± 11.9 years, and 810 (61.9%) were male. Mean serum sodium level was 138.6 ± 4.7 mmol/L at hospital admission and 138.1 ± 4.1 mmol/L at discharge. The evolution of sodium levels was: normal-at-admission/normal-at-discharge 941 (71.9%), abnormal-at-admission/normal-at-discharge 127 (9.7%), normal-at-admission/abnormal-at-discharge 155 (11.8%) and abnormal-at-admission/abnormal-at-discharge 86 (6.6%). Hyponatraemia at discharge was more common in HFrEF (109 (20.7%)) than in HFpEF (79 (13.9%)) and HFmrEF (27 (12%)), P = 0.003. The prevalence of hypernatraemia at discharge was similar in the three groups: HFrEF (10 (1.9%)), HFpEF (12 (2.1%)) and HFmrEF (4 (1.9%)), P = 0.96. In multivariate analysis, abnormal sodium concentrations at hospital admission (hazard ratio (HR) 1.42, 95% confidence interval (CI) 1.15-1.76, P = 0.001) and discharge (HR 1.33, 95% CI 1.08-1.64, P = 0.007) were both independently associated with increased mortality and readmissions at 12 months.

CONCLUSIONS

Hyponatraemia and hypernatraemia at admission and discharge predict a poor outcome in patients with acute HF regardless of left ventricular ejection fraction. Hyponatraemia at discharge is more frequent in HFrEF than in the other groups.

Effectiveness of dietary diabetes insipidus bundle on the severity of postoperative fluid imbalance in pituitary region tumours: A randomized controlled trial

AIM

To test the effectiveness of nurse-led dietary diabetes insipidus (DI) bundle on the severity of postoperative fluid imbalance in pituitary region tumours.

DESIGN

Blinded randomized controlled trial.

METHODS

Patients aged 18-65 operated for sellar-suprasellar tumours in an Indian tertiary care centre were enrolled through total enumeration sampling and underwent randomization with allocation concealment during Sep 2018-Feb 2019. Pre-operative DI, postoperative ventilation, renal failure or decompensated diabetes mellitus were excluded. Patients in the intervention group received a nurse-led DI bundle (validated by three Delphi rounds) with four dietary components: intake of only water during thirst and avoidance of the following-added salt, high-protein foods and caffeinated drinks. Treating clinicians and the investigator assessing outcome were blinded about enrolment. Urine output, serum sodium, vasopressin requirement and hospital stay were assessed as primary outcomes. The outcome measures were monitored daily till the 6th postoperative day. Analyses were performed on 'intention-to-treat' basis, irrespective of compliance. Independent t-test and Chi-square test were used.

RESULTS

Of the initial 63 patients, 50 fulfilling criteria were randomized to two groups and assessed over six days yielding 150 patient-days per group. There were no significant baseline differences between groups. The mean daily urine output was significantly lower in the DI bundle group than in control, both overall and among endonasal operated pituitary adenomas [3000.09(462.7) vs. 4095.71(896.4)ml & 2987.14(419.5) vs. 4064.73(1051)ml], with the greatest difference on the second postoperative day. Though hypernatraemia in controls became most prominent during days 2-3 and resolved in a week, it was significantly lower in the intervention group (12.7% vs. 30.7% overall, 11.4% vs. 29.4% endonasal adenomas). The need for vasopressin analogues and hospital stay were also significantly lower with DI bundle (p < 0.001).

CONCLUSION

This is probably the first ever report of dietary DI bundle among operated pituitary patients, which seem to flatten the DI trend with significant benefits in polyuria, hypernatraemia, vasopressin requirement and hospital stay.

TRIAL REGISTRATION

CTRI/2018/07/015127 of ICMR.

IMPACT

The nurse-led dietary DI bundle has effectively reduced the severity of DI among operated pituitary patients with significant benefits in polyuria, hypernatraemia, vasopressin requirement and hospital stay. Its implementation is simple and easy to carry out, especially in resource-constrained institutions, where continuous monitoring and repeated serum sodium estimation are difficult.

Suboptimal management of hypernatraemia in acute medical admissions

BACKGROUND

Hypernatraemia arises commonly in acute general medical admissions. Affected patients have a guarded prognosis with high rates of morbidity and mortality. Age-related physiology and physical/cognitive barriers to accessing water predispose older patients to developing hypernatraemia. This study sought to perform a descriptive retrospective review of hypernatraemic patients admitted under acute general medicine teams.

METHODS

A retrospective cross-sectional study of a sample of acute medical in-patients with serum[sodium]>145 mmol/L was conducted. Patients were exclusively older(>69 years) and admitted from Nursing homes (NH)(41%) and non-NH pathways(59%). A comparison of management of NH /non-NH patients including clinical presentation, comorbidities, laboratory values, [sodium] monitoring, intravenous fluid regimes and patient outcomes was performed.

RESULTS

In total, 102 consecutive patients (males, n=69(67.6%)) were included. Dementia and reduced mobility were more common in NH residents and admission serum [Sodium] higher (148 vs 142 mmol/L/p=0.003). Monitoring was inadequate: no routine bloods within the first 12h in >80% of patients in both groups. No patient had calculated free water deficit documented. More NH patients received correct fluid management (60% vs 33%/p%0.015). Incorrect fluid regimes occurred in both groups (38% vs 58%/p=0.070). Length of stay in discharged patients was lower in NH, (8(4-20) vs 20.5(9.8-49.3 days)/p=0.003). Time to death for NH residents was shorter (9(5.5-11.5) vs 16 (10.25-23.5) days/p=0.011).

CONCLUSION

This study highlights suboptimal management of hypernatraemia. Implementation of hypernatraemia guidelines for general medical older inpatients are clearly required with mechanisms to confirm adherence. Health care workers require further education on diagnostic challenges of dehydration in older people and the importance of maintaining adequate hydration.

Literature review on congenital glucose-galactose malabsorption from 2001 to 2019

AIM

Congenital glucose-galactose malabsorption (CGGM) is a rare disease characterised by severe diarrhoea, dehydration and weight loss. To better understand CGGM, we investigated all the case reports and series of CGGM from 2001 to 2019.

METHODS

A review of reports of CGGM published from 2001 to 2019 was undertaken, using PubMed, Ovid Medline, Springer, Wanfang Database, CBMD database and CKNI database. The clinical features, diagnosis, treatment and prognosis of CGGM in these reports were obtained and analysed.

RESULTS

We reviewed 107 cases for this study. Out of 55 cases from Saudi Arabia and Turkey, 43 cases (78.2%) were from consanguineous marriage. Forty-nine cases (73.1%) were infants. Dehydration, diarrhoea and weight loss occurred in almost all cases. Half of the cases presented hypernatremia and abdominal distension. Vomiting, polyuria/haematuria and fever were reported in 11, 7 and 3 cases, respectively. Twenty cases (18.7%) showed hypercalcaemia or nephrolithiasis. Stool pH was tested in 43 cases (40.2%). Fifty-five cases (51.4%) were diagnosed for more than 1 month after the onset of symptoms. Two cases (1.9%) died, one needed amputation, and the other 104 cases (97.2%) recovered with fructose formula. Seventy-three cases (68.2%) underwent gene testing, 30 SLC5A1 gene mutations were detected, with 23 cases homozygous, and seven heterozygous mutation.

CONCLUSION

The clinical characteristics of CGGM are nonspecific, and the diagnosis method is not conventionally applied. Fasting and gene testing are the two most important diagnostic methods. The best treatment of CGGM is supplementation with fructose-based formula.

Anticancer Medications and Sodium Dysmetabolism

Therapeutic advances have revolutionised cancer treatment over the last two decades, but despite improved survival and outcomes, adverse effects to anticancer therapy such as dyselectrolytaemias do occur and need to be managed appropriately. This review explores essential aspects of sodium homeostasis in cancer with a focus on alterations arising from anticancer medications. Sodium and water balance are tightly regulated by close interplay of stimuli arising from hypothalamic osmoreceptors, arterial and atrial baroreceptors and the renal juxtaglomerular apparatus. This delicate balance can be disrupted by cancer itself, as well as the medications used to treat it. Some of the conventional chemotherapeutics, such as alkylating agents and platinum-based drugs, can cause hyponatraemia and, on rare occasions, hypernatraemia. Other conventional agents such as vinca alkaloids, as well as newer targeted cancer therapies including small molecule inhibitors and monoclonal antibodies, can cause hyponatraemia, usually as a result of inappropriate antidiuretic hormone secretion. Hyponatraemia can also sometimes occur secondarily to drug-induced hypocortisolism or salt-wasting syndromes. Another atypical but distinct mechanism for hyponatraemia is via pituitary dysfunction induced by immune checkpoint inhibitors. Hypernatraemia is uncommon and occasionally ensues as a result of drug-induced nephrogenic diabetes insipidus. Identification of the aetiology and appropriate management of these conditions, in addition to averting treatment-related problems, can be lifesaving in critical situations.

Fatal case of hospital-acquired hypernatraemia in a neonate: lessons learned from a tragic error

A 3-week-old boy with viral gastroenteritis was by error given 200 mL 1 mmol/mL hypertonic saline intravenously instead of isotonic saline. His plasma sodium concentration (PNa) increased from 136 to 206 mmol/L. Extreme brain shrinkage and universal hypoperfusion despite arterial hypertension resulted. Treatment with glucose infusion induced severe hyperglycaemia. Acute haemodialysis decreased the PNa to 160 mmol/L with an episode of hypoperfusion. The infant developed intractable seizures, severe brain injury on magnetic resonance imaging and died. The most important lesson is to avoid recurrence of this tragic error. The case is unique because a known amount of sodium was given intravenously to a well-monitored infant. Therefore the findings give us valuable data on the effect of fluid shifts on the PNa, the circulation and the brain’s response to salt intoxication and the role of dialysis in managing it. The acute salt intoxication increased PNa to a level predicted by the Edelman equation with no evidence of osmotic inactivation of sodium. Treatment with glucose in water caused severe hypervolaemia and hyperglycaemia; the resulting increase in urine volume exacerbated hypernatraemia despite the high urine sodium concentration, because electrolyte-free water clearance was positive. When applying dialysis, caution regarding circulatory instability is imperative and a treatment algorithm is proposed.

Lithium treatment, nephrogenic diabetes insipidus and the risk of hypernatraemia: a retrospective cohort study

BACKGROUND

Hypernatraemia is a serious condition that can potentially become life threatening. It is known that lithium is associated with polyuria and nephrogenic diabetes insipidus, risk factors for hypernatraemia. In this study, we tested the hypothesis that lithium treatment was a risk factor for hypernatraemia.

METHODS

We performed a retrospective cohort study in the Swedish region of Norrbotten into the effects and potential adverse effects of lithium treatment and other mood stabilizers (LiSIE). For this particular study, we included all patients who had experienced at least one episode with a sodium concentration ⩾150 mmol/L between 1997 and 2013. Medical records were reviewed regarding past or current lithium exposure, diabetes insipidus and other potential risk factors for hypernatraemia.

RESULTS

Of 2463 patients included, 185 (7.5%) had experienced 204 episodes of hypernatraemia within the 17-year review period. In patients 65 years or older, infections dominated as the cause with 51%. In patients younger than 65 years, intoxications, particularly with alcohol, dominated as the cause with 35%. In the whole sample, dehydration accounted for 12% of episodes, 25% of which in the context of suspected or confirmed nephrogenic diabetes insipidus. Of all episodes, 25% resulted in death, with infection being the most common cause of death in 62% of cases.

CONCLUSIONS

In our sample, infections and harmful use of substances including alcohol were the most common causes of hypernatraemia. Both current and past use of lithium also led to episodes of hypernatraemia, when associated with nephrogenic diabetes insipidus. Clinicians should remain vigilant, have a low threshold for checking sodium concentrations and consider even risk factors for hypernatraemia beyond lithium.

Hypernatraemia in 39 hospitalised foals: clinical findings, primary diagnosis and outcome

OBJECTIVE

To evaluate hypernatraemia in foals presenting as medical emergencies to an intensive care unit (ICU) to determine the prevalence, clinical findings, primary diagnosis and outcome.

METHODS

Retrospective case study of records from Thoroughbred foals aged less than 3 months that presented to an ICU as medical emergencies in 2002-12. Data retrieved included signalment, clinical findings, laboratory results, primary diagnosis and outcome. Foals with hypernatraemia (serum sodium > 145 mmol/L) on admission laboratory data were identified and further evaluated.

RESULTS

A total of 39 of 1718 foals (2.3%) were diagnosed with hypernatraemia; all foals were less than 7 days of age. The most common primary diagnoses in the foals with hypernatraemia were neonatal syndrome (19/39, 48.7%) and sepsis (15/39, 38.5%). Foals with hypernatraemia at presentation were more likely to die or be euthanased during their hospitalisation than foals with a normal serum sodium concentration on ICU admission (33.3% vs 16.1%; odds ratio, 2.3; 95% confidence interval, 1.2-4.6; P = 0.02).

CONCLUSION

Admission hypernatraemia was an uncommon but important electrolyte abnormality in this population of hospitalised foals. Although the short-term outcome in survivors was most likely dependent on the underlying disease process, hypernatraemia was negatively associated with outcome in hospitalised foals.

MRI of lobar holoprosencephaly in a cat with hypodipsic hypernatraemia

Case summary

A 2-year-old neutered female domestic shorthair cat presented with a history of hypodipsia, recurrent hypernatraemia, pelvic limb ataxia and tremor. The serum arginine vasopressin level was low for the serum osmolality. MRI of the brain revealed a failure of separation of the cerebrum, which manifested as absence of the rostral part of the corpus callosum, fornix and septum pellucidum, thus resulting in a single fused ventricle. The diagnosis was lobar holoprosencephaly with hypodipsic hypernatraemia.

Relevance and novel information

To our knowledge, this is the first description of the MRI characteristics of lobar holoprosencephaly in a cat. This report suggests that MRI examination should be considered for precise diagnosis of hypodipsic hypernatraemia in young cats.

SOCIETY FOR ENDOCRINOLOGY CLINICAL GUIDANCE: Inpatient management of cranial diabetes insipidus

Cranial diabetes insipidus (CDI) is a treatable chronic condition that can potentially develop into a life-threatening medical emergency. CDI is due to the relative or absolute lack of the posterior pituitary hormone vasopressin (AVP), also known as anti-diuretic hormone. AVP deficiency results in uncontrolled diuresis. Complete deficiency can lead to polyuria exceeding 10 L/24 h. Given a functioning thirst mechanism and free access to water, patients with CDI can normally maintain adequate fluid balance through increased drinking. Desmopressin (DDAVP, a synthetic AVP analogue) reduces uncontrolled water excretion in CDI and is commonly used in treatment. Critically, loss of thirst perception (through primary pathology or reduced consciousness) or limited access to water (through non-availability, disability or inter-current illness) in a patient with CDI can lead to life-threatening dehydration. This position can be further exacerbated through the omission of DDAVP. Recent data have highlighted serious adverse events (including deaths) in patients with CDI. These adverse outcomes and deaths have occurred through a combination of lack of knowledge and treatment failures by health professionals. Here, with our guideline, we recommend treatment pathways for patients with known CDI admitted to hospital. Following these guidelines is essential for the safe management of patients with CDI.

Long-term outcome in inherited nephrogenic diabetes insipidus

Background

Inherited nephrogenic diabetes insipidus (NDI) is a rare disorder characterized by impaired urinary concentrating ability. Little clinical data on long-term outcome exists.

Method

This was a single-centre retrospective medical record review of patients with a diagnosis of NDI followed between 1985 and 2017. We collected available data on growth, weight, school performance, complications and comorbidities.

Results

We identified 36 patients with available data and a clinical diagnosis of NDI, which was genetically confirmed in 33 of them. Patients presented at a median age of 0.6 years and median length of follow-up was 9.5 years. Chief symptoms at presentation were faltering growth, vomiting/feeding concerns, polyuria/polydipsia, febrile illness and hypernatraemic dehydration. Median weight standard deviation scores (SDS) improved from −2.1 at presentation to 0.2 at last follow-up. In contrast, height SDS remained essentially unchanged at −1.1 at presentation and −0.9 at last follow-up. Most patients were treated with prostaglandin synthesis inhibitors and thiazides, yet weaned off during school age without an obvious change in urine output. Median estimated glomerular filtration rate at last follow-up was 81 mL/min/1.73 m². Urological complications were noted in 15 patients, constipation in 11 and learning difficulties in 5. Median age at resolution of nocturnal enuresis was 11 years. Estimated median daily fluid intake at median age of 13 years was 3800 mL/m².

Conclusion

The overall prognosis in inherited NDI is favourable with regular treatment. As expected, most complications were related to polyuria. There is an apparent loss of efficacy of medications during school age. Our data inform the prognosis and management of patients with NDI.

Management of Diarrhoeal Dehydration in Childhood: A Review for Clinicians in Developing Countries

The survival of a child with severe volume depletion at the emergency department depends on the competency of the first responder to recognize and promptly treat hypovolemic shock. Although the basic principles on fluid and electrolytes therapy have been investigated for decades, the topic remains a challenge, as consensus on clinical management protocol is difficult to reach, and more adverse events are reported from fluid administration than for any other drug. While the old principles proposed by Holliday and Segar, and Finberg have stood the test of time, recent systematic reviews and meta-analyses have highlighted the risk of hyponatraemia, and hyponatraemic encephalopathy in some children treated with hypotonic fluids. In the midst of conflicting literature on fluid and electrolytes therapy, it would appear that isotonic fluids are best suitable for the correction of hypotonic, isonatraemic, and hypernatraemic dehydration. Although oral rehydration therapy is adequate to correct mild to moderate isonatraemic dehydration, parenteral fluid therapy is safer for the child with severe dehydration and those with changes in serum sodium. The article reviews the pathophysiology of water and sodium metabolism and, it uses the clinical case examples to illustrate the bed-side approach to the management of three different types of dehydration using a pre-mixed isotonic fluid solution (with 20 or 40 mmol/L of potassium chloride added depending on the absence or presence of hypokalemia, respectively). When 3% sodium chloride is unavailable to treat hyponatraemic encephalopathy, 0.9% sodium chloride becomes inevitable, albeit, a closer monitoring of serum sodium is required. The importance of a keen and regular clinical and laboratory monitoring of a child being rehydrated is emphasized. The article would be valuable to clinicians in less-developed countries, who must use pre-mixed fluids, and who often cannot get some suitable rehydrating solutions.

The association between intensive care unit-acquired hypernatraemia and mortality in critically ill patients with cerebrovascular diseases: a single-centre cohort study in Japan

OBJECTIVES

Hypernatraemia is one of the major electrolyte disorders associated with mortality among critically ill patients in intensive care units (ICUs). It is unclear whether this applies to patients with cerebrovascular diseases in whom high sodium concentrations may be allowed in order to prevent cerebral oedema. This study aimed to examine the association between ICU-acquired hypernatraemia and the prognosis of patients with cerebrovascular diseases.

DESIGN

A retrospective cohort study.

SETTING

The incidence of ICU-acquired hypernatraemia was assessed retrospectively in a single tertiary care facility in Japan.

PARTICIPANTS

Adult patients (≥18 years old) whose length of stay in ICU was >2 days and those whose serum sodium concentrations were 130-149 mEq/L on admission to ICU were included.

OUTCOME MEASURES

28-day in-hospital mortality risk was assessed by Cox regression analysis. Hypernatraemia was defined as serum sodium concentration ≥150 mEq/L. Using multivariate analysis, we examined whether ICU-acquired hypernatraemia and the main symptom present at ICU admission were associated with time to death among ICU patients. We also evaluated how the maximum and minimum sodium concentrations during ICU stay were associated with mortality, using restricted cubic splines.

RESULTS

Of 1756 patients, 121 developed ICU-acquired hypernatraemia. Multivariate Cox proportional hazard analysis revealed an association between ICU-acquired hypernatraemia and 28-day mortality (adjusted HR, 3.07 (95% CI 2.12 to 4.44)). The interaction between ICU-acquired hypernatraemia and cerebrovascular disease was significantly associated with 28-day mortality (HR, 3.03 (95% CI 1.29 to 7.15)). The restricted cubic splines analysis of maximum serum sodium concentration in ICU patients determined a threshold maximum of 147 mEq/L. There was no significant association between minimum sodium concentration and mortality.

CONCLUSIONS

ICU-acquired hypernatraemia was associated with an increased mortality rate among critically ill patients with cerebrovascular diseases; the threshold maximum serum sodium concentration associated with mortality was 147 mEq/L.

Management of severe dehydration

The presented case is one of severe dehydration and acute kidney injury with significant resultant complications that required considerable fluid and electrolyte replacement. Approaches to fluid resuscitation in the context of hypernatraemia and the hyperosmolar state were considered and then judiciously combined to manage a complex case with a successful outcome. Conflicting guidance in this domain is discussed with recommendations for a future management strategy that is tailored to individual patients.

Preoperative abnormalities in serum sodium concentrations are associated with higher in-hospital mortality in patients undergoing major surgery

BACKGROUND

Abnormal serum sodium concentrations are common in patients presenting for surgery. It remains unclear whether these abnormalities are independent risk factors for postoperative mortality.

METHODS

This is a secondary analysis of the European Surgical Outcome Study (EuSOS) that provided data describing 46 539 patients undergoing inpatient non-cardiac surgery. Patients were included in this study if they had a recorded value of preoperative serum sodium within the 28 days immediately before surgery. Data describing preoperative risk factors and serum sodium concentrations were analysed to investigate the relationship with in-hospital mortality using univariate and multivariate logistic regression techniques.

RESULTS

Of 35 816 (77.0%) patients from the EuSOS database, 21 943 (61.3%) had normal values of serum sodium (138-142 mmol litre(-1)) before surgery, 8538 (23.8%) had hyponatraemia (serum sodium ≤137 mmol litre(-1)) and 5335 (14.9%) had hypernatraemia (serum sodium ≥143 mmol litre(-1)). After adjustment for potential confounding factors, moderate to severe hypernatraemia (serum sodium concentration ≥150 mmol litre(-1)) was independently associated with mortality [odds ratio 3.4 (95% confidence interval 2.0-6.0), P<0.0001]. Hyponatraemia was not associated with mortality.

CONCLUSIONS

Preoperative abnormalities in serum sodium concentrations are common, and hypernatraemia is associated with increased mortality after surgery. Abnormalities of serum sodium concentration may be an important biomarker of perioperative risk resulting from co-morbid disease.

Polyuria in relation to dysnatraemias in neurocritical care

INTRODUCTION

Polyuria has the potential to cause severe water and sodium imbalance. We studied the epidemiology of polyuria in association with dysnatraemias and whether polyuria is an independent risk factor for higher mortality and poorer outcome in neurocritical care.

METHODS

We performed an analysis of a 3-year prospective database containing 902 neurocritical care patients. Polyuria was defined as diuresis above 4000 ml/day, hyponatraemia as a serum sodium (SeNa) < 135 mmol/l and hypernatraemia as SeNa > 150 mmol/l.

RESULTS

We identified polyuria in 236 (26.2%) patients (639 days). Polyuric patients stayed in the neurointensive care unit (NICU) longer than those without polyuria (mean: 10.7 vs. 3.5 days, p < 0.001). These patients also had more frequent cerebral complications (p < 0.001) and a poorer outcome upon discharge from the NICU (p = 0.032). NICU mortality had borderline significance in relation to whether the patients were polyuric (p = 0.055). There were only 49 (20.8%) patients with dysnatraemia who were shown to have a significantly higher NICU mortality (p = 0.006). There were no differences in frequency between hyponatraemic and hypernatraemic polyuric patients (p = 0.127). Polyuric patients with hypernatraemia suffered poorer outcomes (p = 0.009) and higher NICU mortality (p < 0.001), but they had a lower Glasgow Coma Scale or GCS recorded at the onset of polyuria (p < 0.001). Cerebral salt wasting (CSW) was thought to be the cause of polyuria in 7 (3.0%) patients and central diabetes insipidus (CDI) in another 5 (2.1%) patients. Univariate models showed polyuria to be a risk factor for poor outcome (odds ratio [OR] = 1.39, p = 0.032) and had a borderline significance for mortality during their NICU stay (OR = 1.83, p = 0.055). These factors did not appear as significant following multivariate logistic regression analysis.

CONCLUSION

Polyuria often occurred in neurocritical care patients, but was not usually associated with sodium imbalance, CSW or CDI. We did not find that polyuria was a significant predictor of increased mortality or poorer outcome in NICU patients.

Are patients admitted to hospitals from care homes dehydrated? A retrospective analysis of hypernatraemia and in-hospital mortality

OBJECTIVES

To compare risks of hypernatraemia on admission to hospital in persons who were with those who were not identified as care home residents and evaluate the association of hypernatraemia with in-hospital mortality.

DESIGN

Retrospective observational study.

SETTING

A National Health Service Trust in London.

PARTICIPANTS

A total of 21,610 patients aged over 65 years whose first admission to the Trust was between 1 January 2011 and 31 December 2013.

MAIN OUTCOME MEASURES

Hypernatraemia on admission (plasma Na > 145 mmol/L) and in-hospital death.

RESULTS

Patients admitted from care homes had 10-fold higher prevalence of hypernatraemia than those from their own homes (12.0% versus 1.3%, respectively; odds ratio [OR]: 10.5, 95% confidence interval [CI]: 8.43-13.0). Of those with hypernatraemia, nine in 10 cases were associated with nursing home ECOHOST residency (attributable fraction exposure: 90.5%), and the population attributable fraction of hypernatraemia on admission associated with care homes was 36.0%. After correcting for age, gender, mode of admission and dementia, care home residents were significantly more likely to be admitted with hypernatraemia than were own-home residents (adjusted odds ratio [AOR]: 5.32, 95% CI: 3.85-7.37). Compared with own-home residents, care home residents were also at about a two-fold higher risk of in-hospital mortality compared with non-care home residents (AOR: 1.97, 95% CI: 1.59-2.45). Consistent with evidence that hypernatraemia is implicated in higher mortality, the association of nursing homes with in-hospital mortality was attenuated after adjustment for it (AOR: 1.61, 95% CI: 1.26-2.06).

CONCLUSIONS

Patients admitted to hospital from care homes are commonly dehydrated on admission and, as a result, appear to experience significantly greater risks of in-hospital mortality.

Intravenous infusion of sterile water for the treatment of hypernatraemia

Little research has been carried out into the infusion of intravenous sterile water for the treatment of hypernatraemia, and it remains a contentious issue. We conducted a review of the literature and extract results following an extensive search of Medline 1946, Embase 1974, ProQuest, evidence-based practice resources, national and international guideline sites and the publications of various professional bodies. The review is presented on the infusion of sterile water (hypotonic fluid) to lower serum sodium level in those circumstances when enteral supplementation of water is not possible, such as in postoperative patients or when other isotonic fluids (such as 5% dextrose in water infusion) are less than ideal-for example, hyperglycaemic patients on an insulin infusion. Absence of guidelines has limited the use of sterile water, even as an off-label drug when it can be administered relatively safely via a central line.

Use of only oral rehydration salt solution for successful management of a young infant with serum sodium of 201 mmol/L in an urban diarrhoeal diseases hospital, Bangladesh

A boy aged 4 months 7 days was admitted to the Intensive Care Unit (ICU) of the Dhaka Hospital of icddr,b, Dhaka, Bangladesh, with the problems of acute watery diarrhoea with some dehydration, pneumonia, lethargy, and hypernatraemia (serum sodium of 201 mmol/L). Correction for hypernatraemia was tried by using only oral rehydration salt (ORS) solution. Seizures occurred during correction of the hypernatraemia. These were difficult to control and required three doses of injection lorazepam, a loading dose of injection phenobarbitone, followed by injection phenytoin and finally two doses of injection mannitol (even though there was no clinical or imaging evidence by ultrasonography or computed tomography of cerebral oedema). The correction was continued with ORS, and all the anticonvulsants were successfully weaned without any further seizures, and the patient recovered without any overt neurological sequelae. We present a case report of extreme hypernatraemia, which was successfully managed using only ORS.

A review of drug-induced hypernatraemia

Drug-induced electrolyte abnormalities have been increasingly reported and may be associated with considerable morbidity and/or mortality. In clinical practice, hypernatraemia (serum sodium higher than 145 mmol/L) is usually of multifactorial aetiology and drug therapy not infrequently is disregarded as a contributing factor for increased serum sodium concentration. Strategies to prevent this adverse drug effect involve careful consideration of risk factors and clinical and laboratory evaluation in the course of treatment. Herein, we review evidence-based information via PubMed and EMBASE and the relevant literature implicating pharmacologic treatment as an established cause of hypernatraemia and discuss its incidence and the underlying pathophysiologic mechanisms.