How's your head?
What (3) brain components determine intracranial pressure, and under what conditions might each contribute to elevated intracranial pressure?
Blood, cerebrospinal fluid, and brain tissue determine intracranial pressure. Conditions such as stroke, trauma, tumors, and hydrocephalus contribute to elevated intracranial pressure.
What are the most common causes of burn injuries?
The most common causes of burn injuries are contact with dry heat, moist heat, electricity, chemicals, friction, or radiant and electromagnetic energy.
Why does shock have such a high mortality?
Due to the pathologic process of the shock state and the effects on other organs, organ damage can occur quickly, resulting in systemic complications, such as acute respiratory distress syndrome, disseminated intravascular coagulation, acute renal failure and multiple organ dysfunction syndrome, which are all associated with a high rate of mortality.
What is the underlying problem common among all types of shock?
a) Faulty compensatory mechanisms
b) Inadequate cellular oxygenation
c) Generalized vasodilation
d) Cardiac failure
Inadequate cellular oxygenation
Although each type of shock has specific characteristics, all are associated with a deficiency of cellular oxygen consumption. Inadequate cellular oxygenation may result from decreased cardiac output, maldistribution of blood flow, or reduced blood oxygen content. The impaired oxygen utilization by cells may lead to cell death, organ dysfunction, and stimulation of inflammatory reactions. Cardiac failure can be an outcome, but is not a common cause in all types of shock. Vasodilation occurs in only selective forms of shock. Faulty compensatory mechanisms may contribute to the seriousness of all shocks but that is not the cause of all forms of shock.
Which statement is true regarding multiple sclerosis (MS)? (Select all that apply.)
a) MS follows a predictable clinical course
b) MS is believed to be a result of a bacterial infection
c) Genetics may play a role in MS
d) The triggering process for MS is not completely understood
e) The main pathophysiology is demyelination of the nerves
C, D, E
It is believed that genetics plays a role. The triggering process is not completely understood. The main pathogenesis is demyelination. Myelin facilitates nerve conduction. The scarring slows or interrupts the conduction of nerve impulses. It is theorized that exposure to a viral infection or an environmental toxin initiates the autoimmune attack. MS is unpredictable.
Your patient comes into the ED with the following symptoms:
-severe headache
-meningismus
-n/v
-photophobia & visual disturbances
-already had a seizure in the ambulance
what might be going on here?
What are the causes and usual presentations of cerebral aneurysm and arteriovenous malformation?
Structural abnormalities of the cerebral vessels are the cause of cerebral aneurysms and arteriovenous malformations. They are often asymptomatic until the structural weakness within the vessels burst, leading to hemorrhage. Thus, the usual presentation is subarachnoid hemorrhage, with symptoms of severe headache, meningismus, nausea/vomiting, photophobia and seizure.
meningismus-mimics meningitis, but does not have actually inflammation. symptoms
Potential complications include organ dysfunction (cardiovascular, respiratory, renal), metabolic changes, cellular changes, immune depression resulting in infection, or excessive immune responses leading to burn shock.
What might we be discussing?
What are the potential complications associated with burn injuries?
How does the body try to compensate for insufficient cardiac output during shock states?
During the compensatory stage of shock, homeostatic mechanisms include sympathetic nervous system activation leading to increased heart rate and myocardial stimulation, bronchodilation, vasoconstriction, and decreased urine output. These measures maintain blood pressure even though cardiac output has fallen.
Which describes a pathologic manifestation of neurogenic shock?
a) massive immune system activation
b) increased sympathetic nervous stimulation
c) loss of sympathetic activation of arteriolar smooth muscle
d) release of vasodilatory mediators such as histamine into the circulation
Loss of sympathetic activation of arteriolar smooth muscle
Neurogenic shock results from loss of sympathetic activation of arteriolar smooth muscle. Medullary depression (brain injury, drug overdose) or lesions of sympathetic nerve fibers (spinal cord injury) are the usual causes. Release of vasodilatory mediators such as histamine into the circulation and massive immune system activation are seen in anaphylactic shock. Increased sympathetic nervous stimulation is not a characteristic of neurogenic shock.
Characteristics of a petit mal seizure include which of the following? (Select all that apply.)
a) rigid muscles
b) cessation of speaking
c) brief periods of staring
d) bladder incontinence
e) tongue biting
B, C
The patient may stop speaking or stare for a few seconds. Muscle rigidity, tongue biting, and bowel or bladder incontinence is found with tonic-clonic or grand mal seizures.
How are level of consciousness and cranial nerve reflexes used to assess changes in neurologic status in the brain-injured patient?
Level of consciousness provides a general measure of brain function and injury severity and is commonly measured by using the Glasgow Coma Scale (GCS). Sudden or progressive changes in level of consciousness can be detected by a decreasing GCS score. Assessment of the integrity of brain stem function is performed by assessing cranial nerve reflexes. Deficits or progressive worsening of cranial nerve function can be detected to determine worsening neurological function. Both assessments are used to guide therapy.
Which statement is true regarding amyotrophic lateral sclerosis?
a) early symptoms include speech abnormalities and respiratory failure
b) hands or upper extremities are affected first
c) most patients die w/in 1 year from cardiac failure
d) most patients lose their sensory and cognitive functions
The earliest symptoms include muscle twitching, cramping, and stiffness. The hands or upper extremities are affected first. The weakness is progressive and eventually affects the muscles that control speech, swallowing, and breathing. These symptoms occur later in the progression of this disease. Despite the marked physical disability, most patients maintain their sensory and cognitive functions. Most people die from respiratory failure within 3 to 5 years from the onset of symptoms.
What are the similarities and differences between multiple sclerosis and amyotrophic lateral sclerosis?
Multiple sclerosis is a demyelinating disease of the central nervous system (CNS), whereas ALS is a progressive disease affecting the upper- and lower-motor neurons. In most cases of MS, symptoms are slowly progressive, and the disease is marked by periods of exacerbations and remissions. In contrast, the mean survival in ALS is about 3 years from the time of diagnosis. The main similarities between MS and ALS is that an exact etiology remains unknown, and the primary symptom presentation of both diseases is muscle weakness.
Early compensation for hypovolemic shock includes which alteration?
a) shunting blood from the brain to the extremities
b) decreased systemic vascular resistance
c) release of epinephrine from adrenal glands
d) decreased heart rate
Release of epinephrine from adrenal glands
In the early stage of shock, the adrenal medulla is stimulated to release increased amounts of the catecholamines epinephrine and norepinephrine (NE), which circulate to the heart and stimulate β-1 receptors, thus increasing cardiac output. Heart rate initially increases. Systemic vascular resistance is not decreased in early hypovolemic shock. Blood is shunted to the brain in cases of shock.
Which of the following are principles to guide the management of burn injuries?
a) meticulous wound management
b) adequate nutritional support
c) early excision and grafting of full-thickness wounds
d) flushing wounds with hydrogen peroxide to ensure wound healing
A, B, C
hydrogen peroxide can actually be damaging to the healing process and is no longer considered EBP acceptable.
What are the common manifestations of types of traumatic brain injury and hemorrhage?
* Bonus points if you can name the types of traumatic brain injuries and hemorrhages*
types of traumatic brain injury: focal, polar, diffuse
types of hemorrhage: epidural, subdural, subarachnoid
Common manifestations of the various types of traumatic brain injury and hemorrhage include a decreased level of consciousness, cranial nerve dysfunction, muscle weakness, increased intracranial pressure (headache, nausea, vomiting), and coma.
Which finding is consistent with Guillain-Barré syndrome?
a) patients often experience paresthesia or dysesthesia
b) there is a progressive descending paralysis
c) sensory nerves are affected more than motor nerves
d) the symptoms usually begin in the arms and face
Patients often experience paresthesia or dysesthesia.
Patients often experience paresthesia or dysesthesia. Neuropathic pain may also be present. They generally have progressive ascending weakness or paralysis. It usually begins in the legs, spreading often to the arms and face. The respiratory muscles may also be affected. Sensory nerves may be affected, but to a lesser extent than motor neurons.
How is shock managed?
Shock is managed by treating the underlying etiology and using strategies to improve cardiac output and perfusion. Specifically, cardiogenic shock is treated with inotropic agents, afterload-reducing agents, preload-reducing agents, intra-aortic balloon counterpulsation, and ventricular assist devices; hypovolemic shock is treated with fluid replacement with crystalloids, colloids, and blood products; distributive shock may be treated with vasopressors and fluids; and septic shock is treated with fluids and antibiotics.
For the client in hypovolemic shock, what compensatory mechanism will help preserve adequate circulation?
a) decreased secretion of ADH
b) vasodilation
c) the renin-angiotensin-aldosterone cascade
d) increased activity of the parasympathetic nervous system
The renin-angiotensin-aldosterone cascade
The sympathetic nervous system stimulates cells in the kidney to release renin, which triggers the renin-angiotensin-aldosterone cascade. The sympathetic and not the parasympathetic nervous system is involved in the compensatory mechanisms of hypovolemic shock. Antidiuretic hormone (ADH, vasopressin) is secreted from the posterior pituitary gland in response to reduced blood volume. ADH stimulates the kidney tubules to reabsorb water and improves the vascular response to catecholamines. Renin triggers the formation of angiotensin II, which is a potent vasoconstrictor, and also stimulates the kidney nephrons to conserve sodium and water.
A patient with a spinal cord injury at T4 diagnosed with autonomic dysreflexia is likely to develop which of the following? (Select all that apply.)
a) Headache
b) Sudden HTN
c) diaphoresis
d) tachycardia
e) upper body flushing
A, B, C, E
Autonomic dysreflexia is characterized by a sudden episode of hypertension, body flushing, sweating, and headache. Autonomic dysreflexia is characterized by a sudden episode of bradycardia, not tachycardia.
How do meningitis and encephalitis differ with regard to usual infective organisms, cerebrospinal fluid analysis findings, clinical manifestations, and treatment?
Meningitis is usually caused by a bacterial pathogen (Streptococcus pneumoniae, Neisseria meningitides, or Haemophilus influenzae type B) while encephalitis is typically associated with a viral pathogen. In bacterial meningitis, the CSF findings typically reveal a WBC count with a predominance of neutrophils, low a glucose level, and elevated protein. The combination of headache, fever, stiff neck, and signs of cerebral dysfunction is the classic presentation of meningitis, with rapid and progressive deterioration in the level of consciousness. Treatment includes general supportive care, intravenous antibacterial drug therapy targeting the specific pathogen, and management of complications. In viral encephalitis, the CSF will typically have a normal or mildly elevated white blood cell count, a small increase in protein, and normal glucose. Encephalitis typically presents with rapid onset of general malaise, mild headache, nausea, vomiting, and a moderately elevated temperature. The general treatment is supportive and symptomatic.
How are burn degree and severity determined?
Burn degree is determined by depth of burn injury, which is divided into four classifications: first-degree (superficial), second-degree (superficial and deep partial thickness), third-degree (full thickness), and fourth-degree (full thickness with bone or muscle involvement). Severity is determined by the extent to which the physiologic functions of the skin are disrupted beyond the body’s normal ability to respond with compensatory mechanisms, and is classified as minor, moderate, or major.
What are the roles of the immune mechanisms in Guillain-Barré syndrome, amyotrophic lateral sclerosis, and multiple sclerosis?
Guillain-Barré syndrome is associated with postinfectious immunologic mechanisms.
Amyotrophic lateral sclerosis involves multiple intracellular enzymatic pathways that cause premature programmed cell death.
Both humoral and cellular immune factors have been implicated in the demyelination process of multiple sclerosis, including the formation of antibodies to specific myelin proteins and T-cell lymphocyte-mediated damage to the myelin.
What is the result of the shift to anaerobic metabolism in shock?
*hint-we might draw a lab to check this*
Increased lactate production
When the citric acid cycle is inhibited, pyruvate accumulates in the cytoplasm. Pyruvate accumulation would quickly inhibit further glycolysis and shut down ATP production entirely except that it can be converted to a substance called lactate, which diffuses from the cell and into the extracellular fluid. A shift to anaerobic metabolism in shock does not result in metabolic alkalosis, decreased oxygen utilization, or decreased hydrogen ion production.
Which type of shock is characterized by generalized vasodilation and peripheral pooling of blood? (Select all that apply.)
a) neurogenic
b) hypovolemic
c) anaphylactic
d) septic
e) cardiogenic
A,C, D
Septic shock, neurogenic shock, and anaphylactic shock are characterized by excessive vasodilation and peripheral pooling of blood. Cardiac output is inadequate because of reduced preload. Cardiogenic shock occurs primarily as a result of severe dysfunction of the left or right ventricles, or both, that results in inadequate cardiac pumping. Hypovolemic shock is a result of excessive blood loss; vasoconstriction is initially seen in this form of shock.