LibGuides: Care of the COVID-19 Patient: Fluid and Electrolytes and Cardiac Rhythm Interpretation (ECG)

Objectives - Fluid & Electrolytes

Upon completion of this section, you will be able to:

Describe the mechanisms which regulate fluid and electrolyte balance
Determine if an IV solution is hypotonic, isotonic or hypertonic
Identify potential fluid and electrolyte imbalances

Fluid & Electrolytes

Fluid is one essential component in determining cardiac output because preload entails volume. To competently assess a patient’s volume, it is necessary to explore the many factors that affect the status of volume within the body. Fluids move within different body compartments to help maintain a normal environment for organs and tissues. However, abnormal fluid shifts can occur due to disease processes, dehydration (decreased preload) over-hydration (increased preload) or other causes. Understanding fluids and how they move within our bodies can help the nurse recognize patients’ fluid needs. Fluids work with electrolytes to maintain health.

Electrolytes are found in various concentrations, both inside and outside the cells of the body. They work with fluids to maintain health; electrolytes are crucial for almost all cellular reactions and functions. Electrolytes are substances that separate into electrically charged particles when suspended in fluid. These particles are called ions; some ions are positively charged (cations), while others are negatively charged (anions). Although different types of electrolytes are found in varying concentrations throughout the body, total electrolytes balance out to achieve a neutral electrical charge. This means that the number of positive ions is the same as the amount of negative ions. Electrolytes also interact with hydrogen, another electrically charged substance to maintain a healthy pH, or acid-base balance in the body.

Fluid and electrolyte imbalances are potential complications of almost all disease states and medical therapies; therefore, acute care nurses must have a sound understanding to recognize and respond to these imbalances. Thorough nursing assessment and appropriate collaborative and independent interventions can minimize the effects of fluid and electrolyte imbalances or prevent them from occurring. Please complete the following readings:

I.V. fluids: What nurses need to know
Crawford, A., & Harris, H. (2011). IV fluids What nurses need to know. Nursing2011, 41(5), 30-38.

Fluid and Electrolyte Imbalances: Interpretation and Assessment
Walker, M. D. (2016). Fluid and Electrolyte Imbalances: Interpretation and Assessment. Journal of Infusion Nursing, 39(6), 382-386.

The following chart shows how the associated assessment findings your patient may exhibit if experiencing an electrolyte imbalance (CCNP, 2021)

Electrolyte Imbalances/Causes	Assessment Findings, Lab Tests, and Treatment
Hyponatremia – Caused by adrenal insufficiency, GI losses, use of diuretics, SIADH, HF, Hyperglycemia, or excessive IV D5W. Can be due to water intoxication or Na loss. Na should be replaced slowly. RISK – decrease LOC	Assessment: Dizziness, postural hypotension, abdominal cramps, nausea, vomiting, tachycardia, convulsions, coma. Lab Tests - Na < 135 mmol/L Treatment – will depend on cause. If requires IV 3% Na, note this requires cardiac monitoring, hourly neuro checks and is done slowly.
Hypernatremia – Caused by IV hypertonic saline, salt ingestion, increased aldosterone, excess corticosteroids, heatstroke, diabetes insipidis, concentrated tube feeds, Fasting-no water intake, usually secondary to water loss. RISK – seizures, coma	Assessment: Dry flushed skin, thirst, fever, agitation, restlessness, agitation, Late – convulsions. Lab Tests - High urine specific gravity; Na>145 mmol/L Treatment – will depend on cause. May add free water to enteral feeds
Hypokalemia – Caused by diuretics, diarrhea, vomiting, alkalosis, excess aldosterone, digitalis toxicity, bulimia, alkalosis, gastric suction, corticosteroids. RISK – ECG changes	Assessment: weakness, fatigue, anorexia, nausea, vomiting, muscle weakness, intestinal distension, poor peristaltic tone, irritability, ventricular dysrhythmia, irregular pulse, paresthesia, Lab Tests - <3.5 mmol/L Treatment – appropriate replacement (PO, IV, NEVER IV PUSH)
Hyperkalemia Caused by renal failure, potassium sparing diuretics, fluid volume deficit, massive cell damage, Adrenal insufficiency, acidosis especially ketoacidosis, rapid blood transfusion, rapid IV of K+ RISK –VT	Assessment: Muscle weakness, bradycardia, abdominal cramps, diarrhea, paresthesia, irritability, anxiety, ECG changes Lab Tests - >5.5 mmol/L Treatment – variety of treatments depending on cause: 1. IV insulin (HumR), D50W IV amp 2. CaCl 3. Kayexalate po/pr
Hypocalcemia - Caused by rapid blood transfusion, hypoparathyroidism, malabsorption, diuretic phase of acute renal failure, Vitamin D deficiency, pancreatitis RISK – prolonged QT, tetany, seizures	Assessment: Numbness and tingling of fingers, toes and circumoral region, seizures, + Chvostek’s sign (contraction of facial muscles when facial nerve is tapped), hyperactive deep tendon reflexes Lab Tests - <2.1 mmol/L Treatment – replacement CaCL IV, Ca gluconate IV
Hypercalcemia – Caused by hyperparathyroidism, osteoporosis, prolonged immobility, oliguric phase of renal failure, acidosis, osteometastasis, overuse of calcium supplements, digoxin toxicity RISK - ECG changes, kidney stones	Assessment: – Caused by hyperparathyroidism, osteoporosis, prolonged immobility, oliguric phase of renal failure, acidosis, osteometastasis, overuse of calcium supplements, digoxin toxicity RISK-ECG changes, kidney stones Lab Tests - >2.6 mmol/L Treatment – identify the cause; may be hydration or calcitonin
Hypomagnesemia majority of magnesium is in bones not serum so low serum Mg may reflect already depleted stores. Can be due to excessive GI losses, alcoholism, DM, renal disease, NG suctioning RISK - VT	Assessment: altered LOC, tremors, tetany, hyperactive reflexes, ECG changes, rarely low in isolation-look for other electrolytes to be abnormal as well. Lab Tests - ≤0.75mmol/l Treatment – IV Replacement
Hypermagnesemia – rare, generally due to increased intake or decreased excretion, renal failure, rhabdomylosis, drugs (lithium, laxatives etc), hyperparathyroidism RISK – altered LOC, ECG changes	Assessment: muscle depression (risk-respiratory depression), vasodilation, cardiac arrhythmias (heart blocks) Lab Tests - ≥1.25 mmol/l Treatment – IV calcium, may require dialysis
Hypophosphatemia – alcoholism, vit D deficiency, vomiting (anorexia) RISK –respiratory and cardiac failure	Assessment: weak, cardiomyopathy, decreased cardiac output, respiratory failure, bleeding Lab Tests - ≤0.9 mmol/l Treatment – replacement is with another electrolyte i.e NaPO4 or KPO4
Hyperphophastemia renal failure, hypothermia, crush injuries, respiratory or metabolic acidosis RISK - seizures	Assessment: seizures, tetany, usually co-incides with a low calcium Lab Tests - ≥1.45 mmol/l Treatment – calcium, phosphate binders (Renegal), diamox, dialysis

Electrolyte Imbalances/Causes

Assessment Findings, Lab Tests, and Treatment

Hyponatremia – Caused by adrenal insufficiency, GI losses, use of diuretics, SIADH, HF, Hyperglycemia, or excessive IV D5W. Can be due to water intoxication or Na loss. Na should be replaced slowly.

RISK – decrease LOC

Assessment: Dizziness, postural hypotension, abdominal cramps, nausea, vomiting, tachycardia, convulsions, coma.

Lab Tests - Na < 135 mmol/L

Treatment – will depend on cause. If requires IV 3% Na, note this requires cardiac monitoring, hourly neuro checks and is done slowly.

Hypernatremia – Caused by IV hypertonic saline, salt ingestion, increased aldosterone, excess corticosteroids, heatstroke, diabetes insipidis, concentrated tube feeds, Fasting-no water intake, usually secondary to water loss.

RISK – seizures, coma

Assessment: Dry flushed skin, thirst, fever, agitation, restlessness, agitation, Late – convulsions.

Lab Tests - High urine specific gravity; Na>145 mmol/L

Treatment – will depend on cause. May add free water to enteral feeds

Hypokalemia – Caused by diuretics, diarrhea, vomiting, alkalosis, excess aldosterone, digitalis toxicity, bulimia, alkalosis, gastric suction, corticosteroids.

RISK – ECG changes

Assessment: weakness, fatigue, anorexia, nausea, vomiting, muscle weakness, intestinal distension, poor peristaltic tone, irritability, ventricular dysrhythmia, irregular pulse, paresthesia,

Lab Tests - <3.5 mmol/L

Treatment – appropriate replacement (PO, IV, NEVER IV PUSH)

Hyperkalemia Caused by renal failure, potassium sparing diuretics, fluid volume deficit, massive cell damage, Adrenal insufficiency, acidosis especially ketoacidosis, rapid blood transfusion, rapid IV of K+

RISK –VT

Assessment: Muscle weakness, bradycardia, abdominal cramps, diarrhea, paresthesia, irritability, anxiety, ECG changes

Lab Tests - >5.5 mmol/L

Treatment – variety of treatments depending on cause: 1. IV insulin (HumR), D50W IV amp 2. CaCl 3. Kayexalate po/pr

Hypocalcemia - Caused by rapid blood transfusion, hypoparathyroidism, malabsorption, diuretic phase of acute renal failure, Vitamin D deficiency, pancreatitis

RISK – prolonged QT, tetany, seizures

Assessment: Numbness and tingling of fingers, toes and circumoral region, seizures, + Chvostek’s sign (contraction of facial muscles when facial nerve is tapped), hyperactive deep tendon reflexes

Lab Tests - <2.1 mmol/L

Treatment – replacement CaCL IV, Ca gluconate IV

Hypercalcemia – Caused by hyperparathyroidism, osteoporosis, prolonged immobility, oliguric phase of renal failure, acidosis, osteometastasis, overuse of calcium supplements, digoxin toxicity

RISK - ECG changes, kidney stones

Assessment: – Caused by hyperparathyroidism, osteoporosis, prolonged immobility, oliguric phase of renal failure, acidosis, osteometastasis, overuse of calcium supplements, digoxin toxicity RISK-ECG changes, kidney stones

Lab Tests - >2.6 mmol/L

Treatment – identify the cause; may be hydration or calcitonin

Hypomagnesemia majority of magnesium is in bones not serum so low serum Mg may reflect already depleted stores. Can be due to excessive GI losses, alcoholism, DM, renal disease, NG suctioning

RISK - VT

Assessment: altered LOC, tremors, tetany, hyperactive reflexes, ECG changes, rarely low in isolation-look for other electrolytes to be abnormal as well.

Lab Tests - ≤0.75mmol/l

Treatment – IV Replacement

Hypermagnesemia – rare, generally due to increased intake or decreased excretion, renal failure, rhabdomylosis, drugs (lithium, laxatives etc), hyperparathyroidism

RISK – altered LOC, ECG changes

Assessment: muscle depression (risk-respiratory depression), vasodilation, cardiac arrhythmias (heart blocks)

Lab Tests - ≥1.25 mmol/l

Treatment – IV calcium, may require dialysis

Hypophosphatemia – alcoholism, vit D deficiency, vomiting (anorexia)

RISK –respiratory and cardiac failure

Assessment: weak, cardiomyopathy, decreased cardiac output, respiratory failure, bleeding

Lab Tests - ≤0.9 mmol/l

Treatment – replacement is with another electrolyte i.e NaPO4 or KPO4

Hyperphophastemia renal failure, hypothermia, crush injuries, respiratory or metabolic acidosis

RISK - seizures

Assessment: seizures, tetany, usually co-incides with a low calcium

Lab Tests - ≥1.45 mmol/l

Treatment – calcium, phosphate binders (Renegal), diamox, dialysis

Specific COVID-19 Considerations for high acuity patients include:

Fluid administration

Acute respiratory distress syndrome (ARDS) is common and may be exacerbated by excessive fluid resuscitation. Keep fluid resuscitation to a minimum (Yang et al., 2020).

Objectives - Cardiac Rhythm Interpretation

Upon completion of this section, you will be able to:

Identify correct skin preparation and lead placement
Associate the normal pacemakers of the heart with their corresponding rates
Identify normal components of the ECG waveform
Demonstrate a systematic approach for interpreting a cardiac rhythm
Recognize common and lethal arrhythmias
Discuss treatment options for common and lethal arrhythmias

Cardiac Rhythm Interpretation

These courses are available on the Nova Scotia Health Learning Management System (LMS):

ECG 1 Basic Electrocardiography
- First module in a series of five. Recommended as the prerequisite for the remaining modules.
ECG 2 Interpretation Cardiac Rhythm
- Second in the series of five. Recommended as the prerequisite for the remaining modules.
ECG 3 Sinus Dysrhythmia Interpretation
ECG 4 Atrial and Junctional Dysrhythmia Interpretation
ECG 5 Blocks and Ventricular Dysrhythmia Interpretation
ECG 6 Dysrhythmia Interpretation Exam

Nova Scotia Health Learning Management System (LMS)
You must sign in to LMS to search for courses. To sign in, enter your domain\username (e.g. cdha\doej) and password. Once signed in, select Catalogue tab. Copy course title or code, paste it in the Keywords search box and select Search.

NOTE Microsoft Edge is the optimal browser for LMS. For more information: https://intra.nshealth.ca/UCS/BPS/SitePages/LMS.aspx

View the following ECG Waveform:

ECG Waveform

8-Step Method – Systematic Rhythm Interpretation

Utilize this 8-step method for ECG rhythm interpretation. Do this every time with a rhythm, you will become highly proficient in rhythm interpretation:

Step 1: Rhythm (atrial and ventricular)

Step 2: Rate (atrial and ventricular)

Step 3: P Wave, P:QRS ratio

Step 4: PR Interval

Step 5: QRS Complex

Step 6: ST segment and T wave

Step7: QT interval

Step 8: Rhythm interpretation

Remember these key concepts as you integrate this 8-step process (CCNP, 2021):

The electrocardiogram records electrical activity in the heart. Each complex recorded on the ECG is a picture of the electrical impulse as it travels down the normal pathway of the conduction system. The impulse begins at the sinus node, travels along the internodal tracts to the atrioventricular node, down the Bundle of His, into the right and left bundle branches and finally into the Purkinje fibres. The normal complex consists of a P-wave, which represents atrial depolarization; a QRS complex, which represents ventricular depolarization; and a T-wave, sometimes with a U-wave, which represents ventricular repolarization.
The heart is an electrical field in which current flows in repetitive patterns with each cardiac cycle. The arms and legs are linear extensions of this electrical field. Therefore, electrical activity of the heart can be detected in the extremities by placing electrodes on the skin.
An electrode is a contact for the detection of electrical activity that is placed on the skin.

Review the following: