Transcript
Adult/Gerontological Health Exam 1
Chapter 11: Assessment and Care of Patients with Fluid and Electrolyte Imbalances
Homeostasis
Proper functioning of all body systems; requires fluid and electrolyte balance
Extracellular fluid (ECF)
Intracellular fluid (ICF)
Interstitial fluid
Transcellular fluids
Normal distribution of total body water in adults
Filtration
Movement of fluid through cell or blood vessel membrane because of differences in water pressure (hydrostatic pressure)
This is related to water volume pressing against confining walls
Hydrostatic Pressure: “water-pushing pressure”/ pressure between vessels
Force that pushes water outward from a confined space through a membrane
Amount of water in any body fluid space determines pressure
Example: Blood pressure
Moving whole blood from the heart to capillaries where filtration occurs to exchange water, nutrients, and waste products between the blood and tissue
Edema – water is pushed out into tissues. Develops with changes in normal hydrostatic pressure differences. Pitting edema seen in patients with heart failure
Ascites – water accumulates in the stomach
Diffusion
Free movement of particles (solute) across permeable membrane from area of higher to lower concentration
Important in transport of most electrolytes; other particles diffuse through cell membranes
Sodium pumps out of cell – water follows sodium. K+ inside cell, Na+ outside
Glucose cannot enter most cell membranes without help of insulin
Osmosis & Filtration
Act together at capillary membrane to maintain normal ECF and ICF volumes
Thirst mechanism is example of how osmosis helps maintain homeostasis (excess sodium)
Feeling of thirst caused by activation of brain cells responding to changes in ECG osmolarity
Fluid Balance
Closely linked to/affected by electrolyte concentrations
Fluid intake/ Fluid loss
Minimum urine amount needed to excrete toxic waste products = 400 to 600 mL/day
Insensible water loss – Through skin, lungs, stool
Hormonal Regulation of Fluid Balance
Aldosterone – released by kidney to reabsorb sodium (water will follow sodium and increase volume)
Antidiuretic hormone (vasopressin) blood volume is low -- will retain sodium and increase volume
Pressure is exerted on the heart and heart must work harder
Urine decreases and is more concentrated
Natriuretic peptides
Significance of Fluid Balance: Renin-Angiotensin II Pathway
Blood (plasma) volume and intracellular fluid most important to keep in balance
Kidneys are major regulator of water and sodium balance; maintain blood and perfusion pressure to all tissues/organs
When the kidneys sense a low parameter, they secrete renin
Renin-angiotensin II pathway is greatly stimulated with shock, or when stress response is stimulated
ACE Inhibitors
Disrupt renin-angiotensin II pathway by reducing amount of ACE produced
With less angiotensin II, less vasoconstriction and reduced peripheral resistance
Greater excretion of water and sodium in urine
By locking angiotensin II receptors, blood pressure lowers
Patients with hypertension often take ACE-inhibitor medications
Dehydration Collaborative Care
Fluid intake/retention does not meet body’s fluid needs; results in fluid volume deficit
Assessment
History
Physical assessment/clinical manifestations:
Cardiovascular
Respiratory
Skin
Neurologic
Renal
Fluid Overload: Collaborative Care
Assessment
Patient safety
Pulmonary edema: fluid in the lungs
Drug therapy
Nutrition therapy
Monitoring of intake and output (I&O)
1 L of water weighs 2.2 lb, equal to 1 kg
Weight change of 1 lb = fluid volume change of about 500 mL
Sodium
Normal level: 136-145 mmol/L
“Where sodium goes, water follows”
Hyponatremia (<136)
Confused
Headaches
Seizure
Coma
Intervention: 3% normal saline as an intervention
Hypernatremia: (>145)
Thirsty
Agitated
Seizures – safety is most important
Coma
Intervention: Hydration
Extracellular
Sodium imbalances manifest as neurologic issues
Potassium
Normal level: 3.5-5.0 mEq/L
Some control over intracellular osmolarity and volume
Regulate protein synthesis, glucose use and storage
Hypokalemia
Underlying metabolic disorders
Arrhythmias
Intervention: give K+ IV/PO
Hyperkalemia
Cardiac dysrhythmias
Cramping in legs
Muscle impairment
Intervention: less bananas, watch foods with K+, medications, dialysis
Heart, nerves, growth of cells
Helps with acid base balance
Potassium is regulated by the kidneys
Calcium
Normal level: 9.0-10.5 mg/dL
Absorption requires active form of vitamin D
Stored in bones
Balanced through the parathyroid hormone
Thyrocalcitonin
Hypocalcemia
Left: Palmar flexion indicating a positive Trousseau’s sign in hypocalcemia.
Right: Facial muscle response indicating a positive Chvostek’s sign in hypocalcemia – tapping side of face
Hypercalcemia
Cancer
Problem with parathyroid hormone
Lethargic/ confused
Nausea/vomiting
Bone pain
Polyuria/dehydration
Intervention: blood work, change Ca+ diet, mobile
Helps nerve impulses, contraction of muscle
Phosphorus
Normal level: 3.0-4.5 mg/dL
Found in bones
Activates vitamins and enzymes; assists in cell growth and metabolism
Plasma levels of calcium and phosphorus exist in a balanced reciprocal relationship
Hypophosphatemia
Hyperphosphatemia
Magnesium
Normal level: 1.3 to 2.1 mg/dL
Critical for skeletal muscle contraction, carbohydrate metabolism, ATP formation (Adenosine triphosphate), vitamin activation, cell growth
Given for respiratory issues (asthma) relaxes smooth muscle of lungs, cardiac issues
Hypomagnesemia
Hypermagnesemia
Chloride
Normal level: 98 to 106 mEq/L
Imbalance occurs as a result of other electrolyte imbalances
Treat underlying electrolyte imbalance or acid-base problem
Considerations for Older Adults
At risk for most electrolyte imbalances from age-related organ changes
Have less total body water than younger adults; more at risk for fluid imbalances; more likely to be taking drugs affecting fluid or electrolyte balance
Adult/Gerontological Health Exam 1
Chapter 12: Assessment and Care of Patients with Acid-Base Imbalances
Acid-Base Balance
Fluid contains equal number of positive charges, ions with negative charges
Balance occurs by matching rate of hydrogen ion production with loss
Normal Blood pH
Balance of acids and bases in body fluids
Normal for:
Arterial blood = 7.35 to 7.45
Venous blood = 7.31 to 7.41
Changes can affect:
Shape of hormones and enzymes
Distribution of other electrolytes (fluid and electrolyte imbalance)
Excitable membranes
Effectiveness of hormones and drugs
*When measuring blood pH, use arterial blood because it is rich with oxygen, venous blood contains waste.
Acidic < 7.0
Basic > 7.5
Acid Base Chemistry
Acids – Release hydrogen ions when dissolved in water
Bases – Bind with hydrogen ions in solutions
Buffers – Critical in maintaining normal body fluid pH
Body fluid chemistry:
Bicarbonate ions (HCO3-)
Relationship between CO2 and hydrogen ions
Calculation of free hydrogen ion level
Excess Acid: incomplete breakdown of glucose, breakdown of protein and fats, destruction of cells (carbonic acid: bicarbonate = 1:20).
Bicarbonate: weak base
Major buffer of extracellular fluid (ECF)
From intestinal absorption of ingested bicarbonate into ECF, kidney absorption and breakdown of carbonic acid
Level is typically 20 times greater than that of carbonic acid (1:20)
Excess absorption of bicarbonate = alkaline
Acid-Base Control Actions & Mechanisms: Respiratory
When chemical buffers alone cannot prevent blood pH changes, respiratory system is second line of defense:
Hyperventilation
Hypoventilation
Lungs compensate for acid-base imbalances of metabolic origin
Acid-Base Control Actions & Mechanisms: Kidneys
Third line of defense against pH changes
Stronger for regulating acid-base balance; take longer than chemical and respiratory
Kidney movement of bicarbonate
Formation of acids and ammonium
Kidneys can correct/compensate for pH changes when respiratory system is overwhelmed or unhealthy
Bicarbonate is released with acidosis to balance it out and reach equilibrium – bicarb released by kidney
Mechanism does not work in kidney failure
Compensation
Body attempts to correct blood pH changes
pH <6.9 or >7.8 usually fatal
Respiratory system more sensitive to acid-base changes; can begin compensating in seconds to minutes
Kidneys more powerful; result in rapid changes in ECF composition; fully triggered for imbalance of several hours to days
Normal CO2: 35-45
Normal O2: 80-100
Pulse ox above 90%, measures peripheral
Arterial Blood Gas 80+ ( @ 80 you are functioning at 60% of your bodily function) Respiratory state, metabolic will compensate
Metabolic state, respiratory will compensate
R: Respiratory:
O: Opposite: pH and CO2 are always opposite
increase pH, decrease CO2 – respiratory alkalosis
decrease pH, increase CO2 – respiratory acidosis – COPD patients, hyperventilating and retaining CO2
M: Metabolic:
E: Equal: if pH and CO2 are equal = metabolic condition
increase pH, decrease CO2 – metabolic alkalosis
decrease pH, increase CO2 – metabolic acidosis
Acidosis: Patient-Centered Collaborative Care
CNS changes
Neuromuscular changes
? Muscle tone, deep tendon reflexes
Cardiovascular changes
Early: ? Heart rate, cardiac output changes
Worsening: Hyperkalemia; ? heart rate; T wave peaked and QRS widened; weak peripheral pulses; hypotension
Respiratory changes
Kussmaul respiration – fast and rapid breathing
Skin changes (metabolic and respiratory acidosis)
Warm, dry, and pink (vasodilation)
Psychosocial assessment
Metabolic Acidosis
Hydrogen ions
Overproduction
Under-elimination
Bicarbonate ions
Under-production
Over-elimination
Laboratory Assessment:
pH <7.35 – acidotic
Bicarbonate <21 mEq/L
Normal: 21-28 mEq/L
Pao2 normal
Paco2 normal or slightly decreased
Serum potassium high
Interventions:
Hydration
Drug therapy: insulin to treat DKA, antidiarrheals, bicarbonate (only with low serum level)
Respiratory Acidosis
Respiratory function is impaired, causing problems with O2 and CO2
Retention of CO:
Respiratory depression
Inadequate chest expansion
Airway obstruction
Reduced alveolar-capillary diffusion
Hallmark of respiratory acidosis:
Decreased Pao2 with rising Paco2
Laboratory Assessment:
pH <7.35
Pao2 low
Paco2 high
Serum bicarbonate variable
Serum potassium levels elevated (if acute acidosis)
Serum potassium levels normal or low (if renal compensation present)
Interventions:
Focus is on improving ventilation and oxygenation, maintaining patent airway
Drug therapy
Bronchodilators
Anti-inflammatories
Mucolytics
Oxygen therapy
Pulmonary hygiene
Ventilation support
Prevention of complications
Alkalosis: Patient-Centered Collaborative Care
Assessment (same for metabolic and respiratory alkalosis)
Hypocalcemia
Hypokalemia
CNS changes – Positive Chvostek’s and Trousseau’s signs
Neuromuscular changes – Tetany
Cardiovascular changes
Respiratory changes
Metabolic Alkalosis
Base excess – Excessive intake bicarbonates, carbonates, acetates, citrates
Acid deficit – Prolonged vomiting, excess cortisol, hyperaldosteronism, thiazide diuretics, prolonged NG suction
Hallmark of base excess acidosis:
ABG result with ? pH and ? bicarbonate level with normal O2 and CO2 levels
Respiratory Alkalosis
Hyperventilation – Anxiety, fear, improper vent settings, stimulation of central respiratory center due to fever, CNS lesion, salicylates
Hallmark of respiratory alkalosis:
ABG result with ? pH coupled with low CO2 level
O2 and bicarbonate usually normal
Interventions: Alkalosis
Prevent further losses of hydrogen, potassium, calcium, chloride ions
Restore fluid balance
Monitor changes, provide safety
Modify or stop gastric suctioning, IV solutions with base, drugs that promote hydrogen ion excretion
Adult/Gerontological Health Exam 1
Chapter 68: Care of Patients with Acute Kidney Injury and Chronic Kidney Disease
Acute Kidney Injury (AKI)
Rapid reduction in kidney function resulting in a failure to maintain fluid and electrolyte balance and acid base balance.
Types
Prerenal failure: caused by reduced perfusion
Intrarenal failure: damage to kidney tissue and reflects injury to the glomeruli, nephrons, or tubules
Postrenal failure: obstruction of urine flow
**With prerenal or postrenal pathology, the kidney compensates by the three responses of constricting kidney blood vessels, activating RAA pathway, and releasing ADH (these increase blood volume and improve kidney perfusion)**
Prerenal azotemia: the retention and buildup of nitrogenous wastes in the blood
Causes
Reduced perfusion to the kidneys, damage to kidney tissue, and obstruction
Hypovolemic shock
Heart failure
Phases of AKI
Rapid decrease in kidney function leads to collection of metabolic wastes in the body
Phases
Onset
Oliguric: urine output less than 400mL/day
Diuretic
Recovery
Acute syndrome may be reversible with prompt intervention
Hypovolemic Shock
Nursing interventions for: nutritional considerations, electrolyte imbalances, dosing implications
Chronic Kidney Disease (CKD)
Progressive, irreversible kidney injury; kidney function does not recover
End-stage kidney disease (ESKD)
Azotemia: the retention and buildup of nitrogenous wastes in the blood
Uremia
Uremic syndrome
Stages of CKD
Reduced renal reserve
Reduced glomerular filtration rate (GFR)
ESKD
Stages of CKD Changes
(1) Kidney changes
(2) Metabolic changes - urea and creatinine
(3) Electrolyte changes - sodium, potassium, acid-base imbalance, calcium and phosphorus
(4) Cardiac changes – hypertension, hyperlipidemia, heart failure, pericarditis
(5) Hematologic changes
(6) GI changes
Priority Nursing Care
Dietary restrictions
Uremic frost
Muscle strength, energy
Family members
Excess fluid volume
Decreased cardiac output
Recombinant human erythropoietin
Interdisciplinary team
Hemodialysis
Patient selection
Dialysis settings
Procedure
Anticoagulation
Complications: dialysis disequilibrium syndrome, infectious disease, Hep B and C, HIV
Subclavian Dialysis Catheters:
These catheters are radiopaque tubes that can be used for hemodialysis access. The Y-shaped tubing allows arterial outflow and venous return through a single catheter.
Mahurkar catheters: made of polyurethane and used for short-term access.
PermCath catheter: made of silicone and used for long-term access.
Vascular Access
Arteriovenous fistula or graft for long-term permanent access
Hemodialysis catheter dual or triple lumen, or AV shunt for temporary access
Precautions
Complications: thrombosis or stenosis, infection, aneurysm formation, ischemia, heart failure
Peritoneal Dialysis: involves siliconized rubber catheter placed into abdominal cavity for infusion of dialysate
Peritoneal dialysis exchange for control of fluids, electrolytes, nitrogenous wastes, blood pressure, and acid-base balance.
Types:
Continuous ambulatory (CAPD)
Automated
Intermittent
Continuous-cycle
Complications
Peritonitis, pain
Exit site/tunnel infections
Poor dialysate flow
Dialysate leakage
Nursing Care for Peritoneal Dialysis
Before treatment: Evaluate baseline vital signs, weight, laboratory tests
Continually monitor patient for respiratory distress, pain, discomfort
Monitor prescribed dwell time, initiate outflow
Observe outflow amount and pattern of fluid
Kidney Transplantation
Candidate selection criteria
Donors
Preoperative care
Immunological studies
Surgical team
Operative procedure
Postoperative Care
Urologic management
Assessment of hourly urine output x 48hrs
Complications:
Rejection
Acute tubular necrosis
Renal artery stenosis
Immunosuppressive drug therapy
Psychological preparation
A patient with diabetes who has chronic kidney disease (CKD) often requires reduced doses of insulin and/or antidiabetic drugs because the failing kidneys do not excrete or metabolize these drugs well. Thus the drugs are effective longer, increasing the risk for hypoglycemia.
A patient’s temperature is elevated after dialysis because the dialysis machine warms the blood slightly. Weight and blood pressure should be decreased because excess fluid is removed during dialysis. Heparin is required during hemodialysis and increases clotting time. All invasive procedures should be avoided for 4 to 6 hours after dialysis.
Adult/Gerontological Health Exam 1
Chapter 65: Assessment of the Renal/Urinary System
Kidney/Urinary System Changes Associated with Aging
Reduced blood flow to kidneys
Thickened glomerular and tubular basement membranes
Decreased tubule length
Decreased GFR
Nocturnal polyuria
Risk for dehydration
Laboratory Assessment: Serum creatinine, BUN, BUN to serum creatinine ration, blood osmolarity
Urinalysis
Color, odor, turbidity
Specific gravity
pH, glucose, ketone bodies, protein
leukoeserase, nitrites
cells, casts, crystals, bacteria
Other Urine Tests
Urine for culture and sensitivity
Composite urine collections
Creatinine clearance- best indication of overall kidney function
Urine electrolytes and osmolarity
Other Studies
Bedside sonography/bladder scanners
Imagine assessment
Retrograde procedures
Urodynamic studies
Kidney biopsy
Patients with kidney failure are anemic because they cannot produce the hormone erythropoietin. A high oxygen saturation in an anemic patient who is showing signs of respiratory distress may still be hypoxemic. Clients who have decreased hemoglobin could have a high percentage of the hemoglobin saturated with oxygen, but because they have a decreased hemoglobin level, not enough oxygen is provided. Administering oxygen is necessary
Adult/Gerontological Health Exam 1
Chapter 66: Care of Patients with Urinary Problems
Cystitis: inflammation of bladder
Most commonly caused by bacteria moving up urinary tract from external urethra to bladder
Catheters: high risk factor in developing nosocomial cystitis
Frequent urge to urinate
Dysuria/urgency
Urinalysis needed when testing for leukocyte esterase
Organism type confirmed by urine culture
Urethritis: inflammation of urethra causing symptoms similar to UTI
Role of estrogen in treating estrogen-depletion urethritis
Urethral Structures
Narrowed areas of urethra
Most common symptom: obstruction of urine flow
Surgical treatment by urethroplasty: best chance of long term cure
Dilation of urethra (temporary)
Stress Incontinence
Involuntary loss of urine during activities that increase abdominal and detrusor muscle pressure. It is often caused by weakening of the bladder neck support associated with childbirth. Urine loss occurs with physical exertion such as coughing, sneezing, or exercise.
Interventions: kegal exercises, drug therapy (estrogen), vaginal cone therapy, surgery
Urge Incontinence
Interventions: Anticholinergics, antihistamines, avoid caffeine and alcohol
Overflow Incontinence (reflex incontinence)
Interventions: Surgery to relieve obstruction, intermittent catheterization, bladder compression
Functional Incontinence
Interventions: treatment of reversible causes, urinary habit training, urinary catheterization, containment of urine/protection of skin
Urolithiasis
Presence of calculi (stones) in urinary tract
Pain relief measures: drug therapy, complementary/alternative med, lithotripsy
Lithotripsy: uses sound, laser, or dry shock wave energy to break up stones into small fragments. Patient undergoes conscious sedation; topical anesthetic cream applied, and continuous ECG monitoring.
Urothelial Cancer
Malignant tumors or urothelium, lining of transitional cells in kidney, renal pelvis, ureters, urinary bladder, and urethra
Bladder Trauma
Causes may be from injury to lower abdomen or stabbing/GSW
Surgical intervention required
Fractures should be stabilized before bladder repair
Nursing interventions prior to surgical interventions
Pyelonephritis
Bacterial infection in kidney and renal pelvis (upper urinary tract)
Acute symptoms:
Fever, chills, tachycardia, tachypnea
Flank, back, or loin pain
Abdominal discomfort
Turning, nausea and vomiting, urgency, frequency, nocturia
General malaise or fatigue
Key features of chronic pyelonephritis
Hypertension
Inability to conserve sodium
Decreased ability to concentrate urine
Development of hyperkalemia and acidosis
Renal Cell Carcinoma
Adenocarcinoma of kidney
Paraneoplastic syndromes
Anemia, erythrocytosis, hypercalcemia, liver dysfunction, increased sedimentation rate, and hypertension
Kidney Trauma
Minor injuries – Contusions, small lacerations
Major injuries – Lacerations to cortex, medulla, or branches of renal artery
Collaborative management
Nonsurgical management – Drug therapy, fluid therapy
Surgical management – Nephrectomy or partial nephrectomy