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Biochemical Analysis of Electrolytes and Their Role in Paediatric Patients admitted in Intensive Care Unit (PICU)

Date : 07 Apr, 2020

Biochemical Analysis of Electrolytes and their role in Paediatric patients admitted in Intensive Care Unit (PICU)

  1. Introduction:

Electrolytes in the body are electrically charged minerals—such as sodium, potassium, calcium, phosphorous, and magnesium which are critical for nerve and muscle cell function. They are found in the body fluids. Dehydration disturbs the delicate balance of electrolytes in the individuals; children are especially vulnerable to dehydration due to their small size and fast metabolism, which causes them to replace water and electrolytes at a faster rate than adults. An illness that causes severe vomiting, diarrhoea and a high fever increases the risk of a fluid and electrolyte disturbance, as does taking medication which results in excessive urination. Profuse sweating from physical exertion can also increase the risk of dehydration. Fluid and electrolyte disturbances are common in children with a serious underlying medical condition. For instance, children with chronic kidney disease, a condition that affects the ability of these organs to maintain proper fluid and electrolyte levels, are at risk. Conditions that affect the production of thyroid hormones and parathyroid hormones, which help regulate calcium and other electrolytes, can also make a child susceptible to a fluid and electrolyte imbalance. Children with heart disease may retain sodium and water, and develop abnormal electrolyte levels.

Dehydration makes the patient urine appear darker than usual. Other electrolyte disorders cause confusion, weakness, cramping, and muscle spasms. Some can cause difficulty breathing, dizziness, and a rapid heart rate. Parents who notice any of these symptoms, especially if a child has an underlying medical condition or a fever, rush their child to PICU units to get evaluated by the Critical care experts. Rapid diagnosis and treatment are utmost important at this stage. Severe dehydration and the accompanying electrolyte disturbances can reduce blood and mineral flow to vital organs, including the brain, heart, and liver. In rare instances, this can make brain tissue swell or shrink, causing seizures, or life-threatening disturbances in heart rhythm, known as arrhythmia. Hence electrolyte balance plays key role in maintaining ‘homeostasis’ along with other body fluids in critically ill paediatric patients in PICU unit of the hospital.The higher and lower value of critical electrolytes like sodium, potassium and chloride can affect cellular processes drastically as it may result in cardiac and neurological complications altering the patient`s status in terms of morbidity and mortality. Electrolyte imbalance significantly affects the quality of life of the patient.1, 2

        Paediatric Intensive Care Unit (PICU) is an essential component of in any tertiary hospital. The main function of PICU is to keep check on mortality of the critically ill paediatric patients. The paediatric patients with high risk of mortality need to be monitored intensively and treated with expert clinical services and advance lifesaving equipments. It is also important to estimate risk of mortality by assessing patient’s provisional diagnosis, PICU resources utilization, evaluating therapies, and matching severity of illness in clinical studies. Critical care provision through PICU is aimed at maintaining homeostasis in the body which is vital for the organ’s support and optimal function. Fluid and electrolyte balance plays important role in this. It has been observed that mortality rate is high in patients with sepsis and hypocalcaemia as compared with patients with normocalcemia. Same is true for patients with hypernatremia and hyperkalaemia which are commonly found in PICU patients.3, 4

Major electrolytes important in this regard are sodium, potassium and chloride.5 Their imbalance in either direction i.e. lower or higher than normal can affect cellular processes, which can significantly affect morbidity and mortality.6 These imbalances also result in longer stay in hospitals7, thus adding significantly to the costs of stay and medical management in the hospital. Thus early recognition and intervention to correct these imbalances is essential to avoid poor outcome.4The precise information about exact level of essential electrolyte has great significance in treatment of patients in PICU.

Five possible mechanisms for the occurrence of electrolyte imbalance are:

  • Underlying disease process,
  • End organ injury,
  • Fluid & electrolyte interventions,
  • Use of medications with potential electrolyte derangements
  • Application of critical care technology i.e. positive pressure ventilation.8

If these critical electrolytes are compromised then, it may result in life-threatening conditions such as cardiac arrhythmias, respiratory failure, muscular paralysis and paralytic ileus.9 The purpose of our study was to analyse the level of sodium, potassium and chloride in critically ill PICU patients. These electrolytes were studied and evaluated for various electrolyte disorders in relation to the underlying illness and their association with the morbidity and mortality in these critically ill patients in PICU.

  1. Aims and objectives: To study the Biochemical analysis of Electrolytes like sodium, potassium & chloride and their respective role in Paediatric patients admitted in Intensive Care Unit.

  1. Materials and methods
  • Inclusion criteria: 180 paediatric patients (97 Males and 83 Females, in the age group 2-15 years with various critical illnesses admitted in PICU of Rajiv Gandhi Medical College & Hospital , Kalwa , Thane , Maharashtra, during the time period of 6 months from September 2019 to February 2020. The PICU patients were regularly monitored for the electrolyte imbalance. Demographics of patients and their detailed medical history were documented for the study. The parents or the guardian of these patients have signed information consent for this study. Serum samples were collected for sodium, potassium and chloride for electrolyte analysis on Fully Automated Biochemistry Analyzer XL-640 manufactured by Transasia Biomedicals (Erba Mannheim) which has Ion Selective Electrode (ISE-Na/K/Cl/Li) and diffraction grating for high resolution measurement. The statistical analysis was done by using SPSS analysis version 16. Descriptive statistics were applied to describe the results in terms of percentages and frequencies. Chi-square was applied for association of electrolyte imbalance with the outcome, P-value < 0.05 was considered significant. The patient values matched with values mentioned in table no. 1 and any value less than or higher than the cut off values was considered abnormal.

Table 1: Electrolyte Normal Range



Normal range



135- 145 mEq/L



3.3-4.6 mEq/L



95-105 mEq/L

The patients were admitted in PICU for critical illnesses related to respiratory, central nervous system (CNS), sepsis, cyclic vomiting syndrome (CVS), etc. Various outcomes for these patients were - discharged with proper clinical treatment, or discharged against medical advice (DAMA) or expired. The discharge outcome has been documented along with length of stay in PICU.

  • Exclusion criteria: Patients who underwent electrolyte therapy before admission were excluded from the study.

  1. Results: During the study, 180 paediatric patients admitted in PICU were enrolled for the analysis. Amongst these patients, 83 patients (46%) were females and 97 patients (54%) were males. 69 patients (38%) were under five years of age, 73 patients (41%) were between 5 and 10 years of age and 38 patients (21%) were above 10 years of age. There were 62 patients (34%) whose hospital stay was 2 days, 45 patients (25%) stayed for more than 2 days but less than 5 days, and 41 patients (23%) stayed for more than 5 days but less than 10 days and 19 patients stayed for more than 10 days and 13 patients (7%) who expired due to critical illnesses (Figure 1). During admission, 72 patients (40%) had respiratory diseases, 24 patients (14%) had sepsis/infection, 36 patients (20%) had neurological diseases, and 18 patients (10%) had cardiovascular illnesses, 12 patients (6%) had gastrointestinal illnesses and 18 patients (10%) had endocrinal diseases (Figure 2). Hypernatremia was observed in 63 patients (35%) while hyponatremia in 56 patients (31%). Hyperkalemia in 49 patients (27%) while hypokalemia in 26 patients (14%). Hyperchloremia was observed in 44 patients (24%) while hypochloremia in 10 patients (5%) (Figure 3).

                Figure 1: Patient Hospital Stay Duration

Title: Patient Stay Duration



 Figure 2: Patient Diagnosis during admission

                Figure 3: Level of Electrolytes observed

  1. Discussion: It is critical to identify clinical state of paediatric patient, as it may result in cardiac and neurological complications. Bhadoria and Bhagwat (2008) has included a lot of criteria of patients admitting to PICU like conscious level (Glasgow coma scale), heart rate, blood pressure, respiratory rate, ABG, bleeding tendency, bilirubin level and blood sugar10.In this study, we have analysed three electrolytes sodium, potassium and chloride. Laville et al, has reported hyponatremia is most commonly results from an abnormality in the handling of water and the common cause of hyponatremia is Syndrome of inappropriate antidiuretic hormone secretion (SIADH) 11.

        Singhi et al., has very well documented the renal capacity of excreting 15-20 litres of free water per day. Hence, hyponatremia can occur when a clinical condition impairs normal free water excretion. The incidence of hyponatremia depends largely on the patient population and the criteria used to establish the diagnosis. Amongst the hospitalized patients, 15-20% have a serum sodium level of <135 mEq/L, while only 1-4% have a serum sodium level of less than 130 mEq/L. The prevalence of hyponatremia is lower in the ambulatory setting & severe hyponatremia (< 125 mEq/L) has a high mortality rate. In instances when the serum sodium level is less than 105 mEq/L, the mortality is over 50%12.In our study Hypernatremia cases are more than hyponatremia in children; they were about 63 patients out of 180 admitted in PICU, associated with metabolic disorder, sepsis, gastroenteritis & renal tubular acidosis. 12 cases out of these developed convulsion.

        Darmon & Funk et al., reported higher prevalence of hypernatremia, 9–26% in critically ill patients. The mortality rates 30–48% have been reported by this study in ICU patients with serum sodium levels exceeding 150 mEql/L13. According to Cummings et al, Potassium abnormalities are common in critically ill patients, who found that one-third had abnormal values. Hypokalemia affected 40% of the admitted cases14.In our study Hyperkalemia affected 49 patients out of 180. Unlike our study, hyperkalemia is a life threatening condition that is most often seen in the PICU patients. Hyperkalemia cases are more in numbers that hypokalemia cases. The hypokalemia is commonly associated with CNS- Central Nervous System infection, chest infection with gastroenteritis, sepsis with gastroenteritis, sepsis with renal tubular acidosis, diabetic ketoacidosis, diabetes insipidus & haemolytic uremic syndrome.

In 2018, Stenson et al., have reported 93% moralities in hyperchloremia cases. A minimum chloride greater than or equal to 110 mEq/L was associated with increased odds of complicated course (odds ratio, 1.9; 95% CI, 1.1-3.2; p = 0.023) and mortality (odds ratio, 3.7; 95% CI, 2.0-6.8; p < 0.001). A mean chloride greater than or equal to 110 mEq/L was also associated with increased odds of mortality (odds ratio, 2.1; 95% CI, 1.3-3.5; p = 0.002). The secondary analysis yielded similar results. In our study we have reported more hyperchloremia cases as compare to hypochloremia with less mortality rates with cardiac and neurological complications.

  1. Conclusion: The electrolyte balance plays a key role in the treatment of critically ill patients. Also the presence & accurate measurement of the electrolyte imbalance at the time of admission in critically ill children irrespective of the primary disease process is an important prognostic indicator in PICU patients where greater attention and proper analysis of electrolytes is recommended.

  1. References
  1. Naseem F, Saleem A, Mahar IA, Arif F. Electrolyte imbalance in critically ill paediatric patients. Pak J Med Sci. 2019; 35(4):1093-1098.
  2. Rao SSD, Thomas B. Electrolyte abnormalities in children admitted to paediatric intensive care unit. Indian Pediatr.2000; 37:1348-1353.
  3. Sadeghi-Bojd S, Noori N M, Damani E, Teimouri A. Electrolyte Disturbances in PICU: A Cross Sectional Study, Nephro-Urol Mon. 2019 ; 11(2):e87925
  4. Panda I, Save S. Study of association of mortality with electrolyte abnormalities in children admitted in pediatric intensive care unit. International Journal of Contemporary Pediatrics, 2018;5(3):1097-1103.
  5. Agarwal N, Rao Y, Saxena R, Acharya R. Profile of serum electrolytes in critically ill children: A prospective study. Indian J child Health. 2018; 5(2):128-132.
  6. Rukesh CC, Shalini B. Correlation between serum electrolytes and clinical outcome in children admitted to PICU. IOSR J Dent Med Sci. 2017; 16:11:24-27.
  7. Reddy A, Thapar RK, Gupta RK. Electrolyte disturbances in critically ill children admitted to pediatric tertiary care centre. J Evol Med Dent Sci. 2017; 6:3269-3273.
  8. Hauser GJ, Kulick AF. Electrolyte disorders in the PICU. In: Wheeler DS et al, eds. Pediatric critical care medicine. London: Springer-Verlag. 2014;13:147-161.
  9. Agarwal N, Saxena R, Acharya R. Profile of serum electrolytes in critically Ill children: A prospective study. Indian J Child Health. 2018; 5(2):128-132.
  10. Bhadoria P and Bhagwat AG. Severity Scoring Systems in Paediatric Intensive Care Units. Indian Journal of Anaesthesia. 2008;52(5):663-75.
  11. Laville M, Burst V, Peri A, Verbalis JG. Hyponatremia secondary to the syndrome of inappropriate secretion of antidiuretic hormone (SIADH): therapeutic decision-making in real-life cases. Clin Kidney J. 2013;6 (Suppl 1):i1–i20.
  12. Singhi S and Jayashre M. Free water excess is not the main cause for hyponatremia in critically ill children receiving conventional maintenance fluids. Indian Pediatr. 2009;46(7):577-83.
  13. Darmon M, Timsit JF, Francais A, Nguile-Makao M, Adrie C, Cohen Y. Association between hypernatraemia acquired in the ICU and mortality: a cohort study. Nephrol Dial Transplant. 2010;25(8):2510-5.
  14. Cummings BM, Macklin EA, Yager PH, Sharma A, Noviski N. Potassium abnormalities in a pediatric intensive care unit: frequency and severity. J Intensive Care Med. 2014;29(5):269-74.