Changes and Abnormalities in Vital Signs: NCLEX-RN
In this section of the NCLEX-RN examination, you will be expected to demonstrate your knowledge and skills of the changes and abnormailities in vital signs in order to:
- Assess and respond to changes in client vital signs
- Apply knowledge needed to perform related nursing procedures and psychomotor skills when assessing vital signs
- Apply knowledge of client pathophysiology when measuring vital signs
- Evaluate invasive monitoring data (e.g., pulmonary artery pressure, intracranial pressure)
The vital signs include the assessment of the pulse, body temperature, respirations, blood pressure and oxygen saturation, which is the newest of all the vital signs.
Vital signs are considered vital to the rapid assessment of the client when it is necessary to determine major changes in the client's basic physiological functioning. Baseline vital signs are taken prior to many procedures and treatments including upon admission to an acute care facility, prior to the administration of medications, prior to the administration of a blood transfusion, and prior to surgery and other invasive procedures These baseline vital signs are taken because they are vitally important for comparison to those vital signs that are taken during and after a treatment, a procedure or a significant change in the client. Vital signs are highly responsive to client abnormalities and changes. For example, a significant drop in blood pressure may indicate the presence of hemorrhage and bleeding, a drop in terms of a client's oxygen saturation can indicate the early stages of hypoxia, and a rise in the client's temperature can indicate the presence of infection. The sensitivity of vital signs to even subtle changes in the client's condition is so effective that vital signs are routinely taken for all acute care clients on a regular and ongoing basis.
Physiologically, the vital signs reflect the adequacy or inadequacy of basic bodily functions. For example, the blood pressure reflects the cardiac output and the systemic vascular resistance. Respirations and the respiratory rate are reflective of a number of factors including the functioning of the chemoreceptors or baroreceptors in the brain stem, the aorta and the carotid arteries; and the bodily pulses are the physiological functioning of the parasympathetic nervous system, the autonomic nervous system and the cardiovascular system functioning.
All significant changes in terms of vital signs must be reported and documented. Many facilities use a graphic flow chart for their patients' vital signs.
Applying the Knowledge Needed to Perform Related Nursing Procedures and Psychomotor Skills When Assessing Vital Signs
Bodily temperature results from the differences between heat production and heat losses. The normal bodily temperature is 98.6 degrees F, or 36.7 to 37 degrees centigrade, with some small, minor and normal variations among children, and also as impacted by stress, one's circadian rhythm, female hormonal changes and the external environment.
Temperature can be taken at a number of sites including the mouth, rectum, ear, axillae, the temporal area and the forehead depending on the type of thermometer that is used. Oral temperatures are contraindicated among neonates, infants, young children and those adult clients adversely affected with confusion, agitation and a decreased level of consciousness; and rectal temperatures are contraindicated when a client is has a seizure disorder, heart disease or a rectal disorder.
Respirations are assessed and monitored using inspection for the rise and fall of the chest or abdomen or by gently placing your hand on the chest or abdomen to monitor and assess the rate, regularity, depth and quality of the client's respirations.
A decreased respiratory rate can indicate and signal a number of disorders such as central nervous system depression secondary to opioids or central nervous system damage, a coma, planned sedation and sedation as a side effect to a medication and alkalosis; increased respiratory rates can occur secondary to a fever, pain, acidosis and anxiety.
The normal respiratory rates along the life span are as follows:
- Neonate: From 30 to 60 per minute
- Infant: From 30 to 60 per minute
- Toddler: From 20 to 40 per minute
- Pre School Child: From 22 to 30 per minute
- School Age Child: From 20 to 26 per minute
- Adolescent: The same as the adult from 16 to 22 per minute
- Adult: From 16 to 22 per minute
Pulses are assessed with both palpation and auscultation. Peripheral pulses are assessed with palpation, often bilaterally. These peripheral pulses include the radial pulse, the femoral pulse, the brachial pulse, the popliteal pulse, the dorsalis pedis pulse of the foot and the posterior tibial pulse near the ankle. During the palpation of the pulse the index finger and/or the middle finger is used to count the number of beats and to assess other characteristics of the pulse such as its regularity, fullness or volume, and other characteristics. At times, a Doppler is used for difficult to palpate and assess peripheral pulses.
The apical pulse is assessed with auscultation and the point of maximum intensity for the adult is on the left side of the chest at the fifth intercostal space. This point differs somewhat along the lifespan until adolescence and during later years secondary to an enlarged heart.
The normal parameters for pulse rates along the life span are:
- Neonate: From 80 to 180 beats per minute
- Infant: From 100 to 160 beats per minute
- Toddler: From 90 to 140 beats per minute
- Pre School Child: From 80 to 110 beats per minute
- School Age Child: From 70 to 100 beats per minute
- Adolescent: From 60 to 100 beats per minute
- Adult: From 60 to 100 beats per minute
Blood pressure results from the pressure of the blood flow as it moves through the arteries. The blood pressure is what it is as the result of a combination of the blood volume, the peripheral vascular resistance, the pumping action of the heart and the thickness, or viscosity, of the blood.
Systolic blood pressures reflect the pressure that occurs with the heart's contraction and diastolic blood pressure reflects the pressure that is exerted when the heart is at rest. Blood pressures are measured most commonly over the brachial artery just above the client's antecubital space.
The normal blood pressures along the life span are:
- Neonate: Diastolic from 40 to 50 mm Hg and systolic from 60 to 80 mm Hg
- Infant: Diastolic from 50 to 70 mm Hg and systolic from 74 to 100 mm Hg
- Toddler: Diastolic from 50 to 80 mm Hg and systolic from 80 to 112 mm Hg
- Preschool child: Diastolic from 50 to 78 mm Hg and systolic from 82 to 110 mm Hg
- School age child: Diastolic from 54 to 80 mm Hg and systolic from 84 to 120 mm Hg
- Adolescent: < 120/80
- Adult: < 120/80
Nurses apply a knowledge of the client's pathophysiology when they are assessing vital signs.
As stated above, temperatures are a function of bodily heat losses and bodily heat production. Among other things, bodily temperatures gains and abnormal body temperatures can result from pathophysiological changes of the brain, the central nervous system, pathologies of the hypothalamus, the inflammatory process, endocrine hormones, and external environmental temperatures such as extremes of hot or cold which can cause hyperthermia and hypothermia, respectively.
Pathophysiologically, alterations and abnormalities of the cardiovascular system, the parasympathetic nervous system and the autonomic nervous system can lead to an abnormal pulse in terms of number of beats per minute, the regularity of the pulse, the volume of the pulse, and other characteristics of the pulse.
Pathophysiological alterations affecting the brain stem and the baroreceptors in the carotid arteries, and the aorta, as well as pathophysiology of the respiratory system can lead to alterations in terms of the client's respirations.
Similarly, pathophysiological changes in terms of cardiac rate, systemic vascular resistance, and venous return can lead to alterations in terms of the client's blood pressure.
In addition to monitoring noninvasive data like vital signs, registered nurses also monitor and evaluate invasive monitoring data such as increased intracranial pressure, pulmonary artery pressure and other hemodynamic monitoring data.
Increased Intracranial Pressure
The pressure within the cranial cavity or skull is known as intracranial pressure (ICP). The normal contents of the skull include the brain, cerebrospinal fluid and blood. Because the skull, after infancy, is a boney and rigid structure without any ability to expand and contract when necessary, increased intracranial pressure in the skull will lead to impaired cerebral perfusion, hypoxia, and the compression of the cerebral arteries. Increased intracranial pressure can be a life threatening situation when it is not treated and reversed.
Increased intracranial pressure can increase when many neurological insults including a closed head injury, a cerebral tumor, an epidural hematoma, a subdural hematoma, a subarachnoid hematoma, spina bifida, infections and abscesses, hydrocephalus, a cerebral infarct, and status epilepticus.
The normal range for intracranial pressure ranges from 5 to 15 mmHg. Increased ICP occurs when the volume of the cranial cavity increases. Under normal circumstances, the pressure that is necessary to adequately perfuse the brain is known as cerebral perfusion pressure which can be mathematically calculated by subtracting the actual intracranial pressure from the mean arterial blood pressure, as shown below.
Cerebral perfusion pressure = The mean arterial pressure – The intracranial pressure
The normal cerebral perfusion pressure, under normal circumstances, should range from 60 to 100 mm Hg.
Brain herniation occurs when intracranial pressure increases to the point where the boney, rigid skull can no longer accommodate for this increased pressure without successful treatment. The types of brain herniation that can occur are a downward, lateral, and medial displacements, which are referred to as central transtentorial, transtentorial, and cingulated herniation, respectively.
Some of the signs and symptoms of increased intracranial pressure include:
- A widening pulse pressure
- Decreased level of consciousness
- A headache
- Decorticate or decerebrate posturing
- Dilated and sluggish pupils
- Neurological sensory and motor losses
- Visual disturbances
- Cheyne-Stokes respirations: Cheyne-Stokes respirations are signaled with the classical signs of rapid, deep breathing with periods of apnea and abnormal posturing.
- Cushing's reflex: Cushing's reflex is a late sign of increased intracranial pressure. It is characterized with bradycardia, hypertension and a widening pulse pressure, which is the mathematical difference between the systolic and diastolic blood pressure. For example, the pulse pressure is 40 when a client's blood pressure is 120/80 (120-80= 40) and the pulse pressure will rise to 90 when the client's blood pressure changes to 160/70 (160-70=90). This rise is referred to as a widening pulse pressure.
Intracranial pressure is assessed and monitored with invasive and noninvasive tests. A CT scan can diagnose and monitor intracranial pressure and invasive direct monitoring of the intracranial pressure can be done with a intraventricular catheter, also referred to as a ventriculostomy, which is placed into the lateral ventricle of the brain, a subarachnoid bolt and an epidural bolt. Some of these devices also drain excess intracranial fluid to relieve the pressure.
The treatments of increased intracranial pressure are often dependent on the cause of the increase and the severity of the increased intracranial pressure. In addition to the identification and treatment of an underlying disorder when possible, some of the medications that are used include intravenous osmotic diuretics, like mannitol, to remove fluid, corticosteroids to reduce edema, and anticonvulsant medications to prevent seizures. At times, a barbiturate coma may be induced to preserve brain functioning by decreasing the metabolic demands of the brain. Life saving measures, including cardiopulmonary resuscitation and mechanical ventilation may be indicated.
Decorticate posturing is abnormal rigid bodily posturing that is characterized with the tight clenching of the fists on the chest while the arms are turned inward; and decerebrate posturing is rigid and abnormal bodily posturing that is characterized with the extension and arching backward of the client's head while the arms and the legs are extended and the toes are point upward. These abnormal posturings can be unilateral or bilateral.
Hemodynamic monitoring provides health care providers with current data and information relating to the client's blood pressure, pulmonary artery pressures, pulmonary artery wedge pressure, central venous pressure, cardiac output, intra-arterial pressure, mixed venous oxygen saturation and other data.
The normal values for hemodynamic monitoring measurements are as below:
- Pulmonary Artery Systolic Pressure: 15 to 26 mm Hg
- Pulmonary Artery Diastolic Pressure: 5 to 15 mm Hg
- Pulmonary Artery Wedge Pressure: 4 to 12 mm Hg
- Central Venous Pressure: 1 to 8 mm Hg
- Cardiac Output: 4 to 7 L/min
- Mixed Venous Oxygen Saturation: 60% to 80%
- Right Atrium Pressure: 0 to 8 mm Hg
- Right Ventricle Peak Systolic: 15 to 30 mm Hg
- Right Ventricle End Diastolic: 0 to 8 mm Hg
- Pulmonary Artery Mean: 9 to 16 mm Hg
- Pulmonary Artery Peak Systolic: 15 to 30 mm Hg
- Pulmonary Artery End Diastolic: 4 to 14 mm Hg
- Pulmonary Artery Occlusion Mean: 2 to 12 mm Hg
- Left Atrium Mean: 2 to 12 mm Hg
- Left Atrium A Wave: 4 to 16 mm Hg
- Left Atrium V Wave: 6 to 12 mm Hg
- Left Ventricle Peak Systolic: 90 to 140 mm Hg
- Left Ventricle End Diastolic: 5 to 12 mm Hg
- Brachial Artery Mean: 70 to 150 mm Hg
- Brachial Artery Peak Systolic: 90 to 140 mm Hg
- Brachial Artery End Diastolic: 60 to 90 mm Hg
Invasive hemodynamic monitoring systems include a pressure transducer, a monitor, pressure tubing, a pressure bag and a flush device. Some even permit access to draw arterial blood gases. For example, a pulmonary artery catheter consists of a proximal lumen which measures the central venous pressure and it can also be used for the administration of intravenous fluids and to draw venous blood samples, a distal lumen that measures the pulmonary wedge, the pulmonary artery systolic, and the pulmonary artery diastolic pressures, a thermistor that measures the cardiac output, and a balloon inflation port that measures the pulmonary artery wedge pressure when it is briefly inflated.
- Changes/Abnormalities in Vital Signs (Currently here)
- Diagnostic Tests
- Laboratory Values
- Potential For Alterations in Body Systems
- Potential for Complications of Diagnostic Tests/Treatments/ Procedures
- Potential for Complications from Surgical Procedures and Health Alterations
- System Specific Assessments
- Therapeutic Procedures