Hyponatraemia in the Elderly

Transcription

1 Hyponatraemia in the Elderly Kathryn Ryan

2 Hyponatraemia

3

4

5 Patients at greater risk Post operative patients Alcoholics Malnourished patients Psychiatric polydipsic patients The Elderly Hypovolaemic patients Burns patients The risk of hyponatraemia among elderly people is compounded by chronic disease and the concurrent use of certain medications

6 Increasing risk for hyponatremia (<136 mmol/l) with age at admission and acquired at hospital. *Statistical significance. Tomas Berl CJASN 2013;8: by American Society of Nephrology

7 From: Impact of Hospital-Associated Hyponatremia on Selected Outcomes Arch Intern Med. 2010;170(3): doi: /archinternmed Figure Legend: Restrictive cubic spline depicting the unadjusted relationship between hospital admission serum sodium concentrations and inhospital mortality. Dashed lines represent the 95% confidence interval. To convert serum sodium concentration to millimoles per liter, multiply by 1.0. Date of download: 1/28/2016 Copyright 2016 American Medical Association. All rights reserved.

8 Clinical symptoms Na mmol l -1 asymptomatic Na mmol l -1 nausea, malaise Na mmol l -1 headache, disoriention As Na falls can develop seizures, coma, brain damage, respiratory arrest, death

9 Consequences Hyponatraemia Neurological Cerebral odema Osmotic demyelination

10

11

12

13 Osmotic demyelination

14 Low sodium Asymptomatic chronic hyponatraemia?? Falls/ fractures Attention deficit

15 Falls Na 126 ± 5 mmol/l 122 cases vs 244 controls Falls in Hypo Na group 21% vs 5 % in control group Attention tests Increased latency Increased errors Similar to 0.6 g/l alcohol Reeneboog et al Am J Med 2006

16 Gait pattern

17 Hyponatraemia associated with fractures in the elderly Soiza et al. J. Clin. Med. 2014

18 Osteoporosis Osteoclasts marked by red TRAP stain

19

20 Mechanism of bone injury from chronic hyponatremia in the elderly. Ayus J C, Moritz M L CJASN 2010;5: by American Society of Nephrology

21 Hyponatraemia Reduced Na concentration Occasionally pseudohyponatraemia due to increased triglycerides or protein Hyperglycaemia - Na shift into cells can result in Hyponatraemia Corrected Na = Measured Na + [Gluc 3.5] Serum osmolality to confirm hypoosmolal state

22 Hypervolemic (oedema) Heart failure Cirrhosis Nephrotic syndrome Hyponatremia Classification Dilutional Hyponatremia Total body sodium near normal Total body water increased Euvolemic (no oedema) SIADH (Hypothyroidism) Secondary adrenal insufficiency Depletional Hyponatremia Hypovolemic Sodium lost Total body water reduced Diarrhoea Vomiting Burns Trauma Pancreatitis Diuretic excess Renal salt wasting Primary adrenal insufficiency SIADH = syndrome of inappropriate antidiuretic hormone Cawley MJ. Ann Pharmacother. 2007; 41:

23 Determining the cause Assess volume status Clinical history and medication history Measure lipids, protein and glucose / serum osmolality Assess fluid balance Measure urine Na Urine osmolality Synacthen test, TFTs

24 1957

25 Diagnostic criteria for SIADH Essential features Decreased serum osmolality (<275 mosm/kg) Urinary osmolality >100 mosm/kg during hypotonicity of the serum Clinical euvolaemia Urinary sodium >40 mmol/l with normal dietary salt intake Normal thyroid and adrenal function No recent use of diuretics Adapted from Schwartz et al. [15], Janicic and Verbalis [14] and Ellison and Berl [1].

26 Diagnostic criteria for SIADH Essential features Decreased serum osmolality (<275 mosm/kg) Urinary osmolality >100 mosm/kg during hypotonicity of the serum Clinical euvolaemia Urinary sodium >40 mmol/l with normal dietary salt intake Normal thyroid and adrenal function No recent use of diuretics Supplemental features Serum uric acid <0.24 mmol/l Serum urea <3.6 mmol/l, low normal serum creatinine Fractional sodium excretion >1%, fractional urea excretion >55% Failure to correct hyponatraemia after 0.9% saline infusion Correction of hyponatraemia through fluid restriction Abnormal water loading test (excretion <80% of a 20 ml/kg water load in 4 h) Elevated vasopressin levels despite hypotonicity and clinical euvolaemia Adapted from Schwartz et al. [15], Janicic and Verbalis [14] and Ellison and Berl [1].

27

28 Copeptin C terminal of pre pro hormone Surrogate marker for AVP

29 Pulmonary Disorders Acute respiratory failure Infections Positive-pressure ventilation Miscellaneous HIV infection Idiopathic Pain Postoperative state Prolonged exercise Senile atrophy Severe nausea Upadhyay A et al. Sem Nephrol. 2009; 29: Causes of SIADH Tumours Extrathoracic Mediastinal Pulmonary SIADH Drugs Carbamazepine Chlorpropamide Clofibrate Cyclophosphamide Desmopressin MAO inhibitors Nicotine Opiates CNS Disorders Acute psychosis Stroke Hemorrhage Trauma Inflammatory and demyelinating diseases Mass lesions Oxytocin Phenothiazines Prostaglandin- synthesis inhibitors Selective serotoninreuptake inhibitors Tricyclics Vincristine

30

31 Acute 200 mls 2.7 % saline over 30 minutes

32 Formulae Change in serum Na = Change in serum Na = Total body water is 0.6 and 0.5 of body weight (kg) in non-elderly males and females and 0.5 and 0.45 in elderly males and females Infusate Na-Serum Na Total body water + 1 Infusate Na+K-Serum Na Total body water % sodium chloride= 462 mmol Na 0.9% sodium chloride= 154 mmol Na 0.45% sodium chloride=77mmol Na

33 Approaches to Management Serum sodium Sodium = Total Body Water add to the numerator (sodium chloride) Subtract from the denominator Fluid restriction Loop diuretics Demeclocycline Aquaporin receptor antagonists

34 Tolvaptan

35 Maximum suggested correction of sodium in 24 hours. R J Martin J Neurol Neurosurg Psychiatry 2004;75:iii22- iii by BMJ Publishing Group Ltd

36 Prevalence, Incidence and Etiology of Hyponatremia in Elderly Patients with Fragility Fractures Kirsten Cumming,1 Graeme E. Hoyle,1 James D. Hutchison,2 and Roy L. Soiza1,*

37 Avoiding hyponatraemia Review medication Clinical fluid status Caution with hypotonic fluids Consider 30% reduction in calculated routine maintenance fluid Monitor input/ output Check U&E