Introduction:

Intensive care unit (ICU) services require expensive technology, and account for as much as 10 percent of all health care costs. The outcome of critically ill patients is therefore of importance not only to the patients and their families, but also to the society. After admission to the ICU, the outcome is dependent upon both the diagnosis and management of the primary illness and, in many cases, the presence or absence of multi-organ involvement.¹

On the other hand, electrolytes such as potassium, sodium, chloride, magnesium, calcium and phosphate play important roles in cellular metabolism and energy transformation, and in the regulation of cell membrane potentials, especially those of muscle and nerve cells, which demonstrate their important role in the outcome of critically ill patients. Depletion of these electrolytes can induce a wide range of clinical disorders, including neuromuscular dysfunction and severe arrhythmias. The risk for these disorders increases significantly when more than one electrolyte is deficient.²

It is well known that hypokalemia can induce cardiac arrhythmias (especially in patients with ischemic heart disease and left ventricular hypertrophy), and that it is associated with other adverse effects such as muscle weakness, rhabdomyolysis, renal failure and hyperglycemia. Additionally, hyperkalemia may cause symptoms such as severe muscle weakness or paralysis and cardiac conduction abnormality which may lead to adverse outcomes in ill ICU patients.^3-6

Moreover, hyponatremia is a common electrolyte abnormality in critically ill patients.^6-9The risk of hyponatremia among hospitalized patients is influenced by the underlying disease state and clinical circumstances. Another sodium disturbance, hypernatremia, is basically a mirror image of hyponatremia^6,10-12and can cause rupture of the cerebral veins, leading to focal intracerebral and subarachnoid hemorrhages and possible irreversible neurologic damage. The clinical manifestations of this disorder begin with lethargy, weakness, and irritability, and can progress to twitching, seizures, and coma

The importance of regulating potassium and sodium levels is well recognized in most intensive care units (ICUs) and the development of many electrolyte disturbances in the ICU can be prevented by attention to the usual intravenous fluids and nutrition. On the other hand, chloride levels have not been studied extensively. Chloride is the most abundant anion in the extracellular fluid and constitutes approximately one-third of the extracellular fluid tonicity.¹³Chloride plays a pivotal role in many body functions including acid-base balance, muscular activity, osmosis, and immunomodulation.¹⁴Despite its physiological importance, chloride has captured little attention by the scientific community until recently¹⁵when chloride-rich solutions were associated with hyperchloremic metabolic acidosis^16,17and short-term mortality after non-cardiac surgery.^18,19

The most common chloride-rich solution utilized in clinical practice is 0.9% saline²⁰, particularly in critical illness and perioperatively. 0.9% saline is in reality a non-neutral solution²¹and has a supraphysiologic amount of chloride when compared to plasma (154 vs ~100 mEq/L, respectively).^22,23The consequent hyperchloremic metabolic acidosis derived from the liberal use of chloride-rich solutions has been described as a common but poorly recognized disorder in critically ill patients^24,25, with numerous detrimental consequences^26,27, particularly in those with severe sepsis and septic shock.²⁸

The purpose of our study was to determine whether there was an independent association of serum and urinary electrolyte levels at 2 different time points of ICU stay with hospital mortality in critically ill septic patients. The 2 evaluated time points were ICU admission (t0) and at 48-72 h of ICU stay (t72). 

Objectives

·     To evaluate the profile of serum and urinary electrolytes in critically ill patients.

·     To study the association of serum and urinary electrolytes with short-term mortality in critically ill patients

·     To evaluate any association between serum and urinary electrolytes and Acute Kidney Injury in critically ill patients.

Methodology:

All critically ill patients admitting in the Medical ICU of Dr. Pinnamaneni Siddhartha Institute of Medical Sciences & RF will be screened for inclusion in the study.  Participants/Attendants if willing for the study, and who have reports of serum electrolytes performed within three hours of admission to the ICU will be enrolled.

The baseline characteristics such as Age, Gender, history of Diabetes Mellitus, Hypertension, Cardiac disease, kidney disease, smoking and alcohol history will be obtained. The patient’s diagnosis will be noted from the medical records. The subjects blood pressure (BP) will be recorded from the medical records. 

The reports of the following investigations done within 3 hours of ICU admission will be collected: Hemoglobin (Hb), Random blood sugar (RBS), serum creatinine, serum electrolytes (sodium, potassium, chloride), Calcium, Phosphorous, Total Bilirubin, serum Albumin and Arterial Blood Gas analysis. Patients with incomplete reports will be excluded from the study. The patients spot urinary electrolytes and urinary creatinine will be measured (t0). Serum and urinary electrolytes will be repeated again between 48-72 hours after admission (t72). Biochemical investigations will be done as per the standard hospital methodology. eGFR will be calculated using CKD-EPI equation. Lower levels of laboratory reference values will be used as the cutoff points for clinically significant electrolyte depletion, and the upper levels as cutoff points for significant increase in electrolyte concentration. 

The patients will be followed up and the development of AKI, cumulative fluid balance in ICU, in-ICU mortality, in-hospital mortality, duration of ICU stay and duration of hospital stay will be recorded. The patients will be contacted and followed up at three months to identify mortality upto three months.

References:

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