# CHAPTER 40 Care of Patients with Hematologic Problems

Red Blood Cell Disorders
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Red blood cells (RBCs), also known as erythrocytes, are the major cell in the blood. RBC disorders include problems in production, function, and destruction. Problems may result in poor function of RBCs, decreased numbers of RBCs (anemia), or an excess of RBCs (polycythemia).
Anemia is a reduction in either the number of RBCs, the amount of hemoglobin, or the hematocrit (percentage of packed RBCs per deciliter of blood). Anemia can result from dietary problems, genetic disorders, bone marrow disease, or excessive bleeding. GI bleeding is the most common reason.
Integumentary Manifestations
• Pallor, especially of the ears, the nail beds, the palmar creases, the conjunctivae, and around the mouth
• Cool to the touch
• Intolerance of cold temperatures
• Nails become brittle and become concave over time
Cardiovascular Manifestations
• Tachycardia at basal activity levels, increasing with activity and during and immediately after meals
• Murmurs and gallops heard on auscultation when anemia is severe
• Orthostatic hypotension
Respiratory Manifestations
• Dyspnea on exertion
• Decreased oxygen saturation levels
Neurologic Manifestations
• Increased somnolence and fatigue
Sickle cell disease (SCD) is a genetic disorder that results in chronic anemia, pain, disability, organ damage, increased risk for INFECTION, and early death. Normal hemoglobin (hemoglobin A [HbA]) molecule has two alpha chains and two beta chains of amino acids. Normal adult red blood cells usually contain 98% to 99% HbA, with a small percentage of a fetal form of hemoglobin (HbF).
SCD, at least 40% (and often much more) of the total hemoglobin is composed of an abnormal beta chain (hemoglobin S [(HbS]). HbS is sensitive to low oxygen content.
HbS are exposed to decreased oxygen conditions, the abnormal beta chains contract and pile together within the cell, distorting the cell into a sickle shape. Sickled cells become rigid and clump together, causing the RBCs to become "sticky" and fragile. The clumped masses of sickled RBCs block blood flow (Fig. 40-1), known as a vaso-occlusive event (VOE). VOE leads to further tissue hypoxia (reduced oxygen supply) and more sickle-shaped cells, which then leads to more blood vessel obstruction and ischemia. Cause progressive organ damage from anoxia and infarction. Conditions that cause sickling include hypoxia, dehydration, INFECTION, venous stasis, pregnancy, alcohol consumption, high altitudes, low or high environmental or body temperatures, acidosis, strenuous exercise, emotional stress, and anesthesia. Usually sickled cells go back to normal shape when the precipitating condition is removed, the blood oxygen level is normalized, and proper tissue PERFUSION resumes. Some of the hemoglobin remains twisted.
The average life span of an RBC containing 40% or more of HbS is about 10 to 20 days compared to 120. Reduced RBC life span causes hemolytic (blood cell-destroying) anemia.
CRISES have a sudden onset, which are periodic episodes of extensive cellular sickling. Damage results from tissue hypoxia, anoxia, ischemia, and cell death. Organs begin to have small infarcted areas and scar tissue formation, and eventually organ failure results. Tissues most often affected are the spleen, liver, heart, kidney, brain, joints, bones, and retina.
Sickle cell disease (SCD) is a genetic disorder with an autosomal recessive pattern of inheritance. In sickle cell disease, the patient has two HbS gene alleles, one inherited from each parent, usually resulting in 80% to100% of the hemoglobin being HbS. Because both hemoglobin alleles are S, sickle cell disease is sometimes abbreviated "SS."
If a patient with SCD has children, each child will inherit one of the two abnormal gene alleles and at least have sickle cell trait. Sickle cell trait occurs when one normal gene allele and one abnormal gene allele for hemoglobin are inherited and only half of the hemoglobin chains are abnormal. Sickle cell trait is abbreviated "AS."
Those with sickle cell trait usually have no manifestations or abnormal laboratory findings other than the presence of hemoglobin S. This person may be unaware that he or she has a hematologic problem until an acute illness is present or when anesthesia is administered.
Ask about previous crises, what led to the crises, severity, and usual management.
Review all activities and events during the past 24 hours, including food and fluid intake, exposure to temperature extremes, drugs taken, exercise, trauma, stress, recent airplane travel, and ingestion of alcohol or other recreational drugs. Ask about changes in sleep and rest patterns, ability to climb stairs, and any activity that induces shortness of breath. Determine the patient's perceived energy level using a scale
Pain is the most common manifestation of SCD crisis.
Cardiovascular changes, including the risk for high-output heart failure, occur because of the anemia. Assess the patient for shortness of breath and general fatigue or weakness. Other problems may include murmurs, the presence of an S3 heart sound, and increased jugular-venous pulsation or distention. Compare peripheral pulses, temperature, and capillary refill in all extremities. Extremities distal to blood vessel occlusion are cool to the touch with slow capillary refill and may have reduced or absent pulses. Heart rate may be rapid and blood pressure may be low to average.
Priapism is a prolonged erection that can occur in men who have SCD. The cause is excessive vascular engorgement in erectile tissue. Urinary retention!
Skin changes include pallor or cyanosis because of poor GAS EXCHANGE from decreased PERFUSION. Examine the lips, tongue, nail beds, conjunctivae, palms, and soles of the feet for color. With cyanosis, the lips and tongue are gray and the palms, soles, conjunctivae, and nail beds have a bluish tinge. Jaundice results from RBC destruction and release of bilirubin. To assess for jaundice in patients with darker skin, inspect the roof of the mouth for a yellow appearance. Examine the sclera closest to the cornea. Jaundice equals itching. Inspect the legs and feet for ulcers or darkened areas that may indicate necrotic tissue.
Abdominal changes include damage to the spleen and liver. In crisis, abdominal pain is diffuse and steady, involving the back and legs. The liver or spleen may feel firm and enlarged with a nodular or "lumpy" texture in late stage.
Kidney and urinary changes are common. Chronic kidney disease occurs as a result of anoxic damage to the kidney nephrons. The urine contains protein, and the patient may not concentrate urine. Eventually, the kidneys fail, resulting in little or no urine.
Musculoskeletal changes occur because arms and legs are often sites of blood vessel occlusion. Joints may be damaged from hypoxic episodes and have necrotic degeneration. Inspect the arms and legs, and record any areas of swelling, temperature, or color difference. Ask patients to move all joints. Record the range of motion and any pain.
Central nervous system (CNS) changes may occur. With crises, patients may have a low-grade fever. If the CNS has infarcts or repeated episodes of hypoxia, patients may have seizures or manifestations of a stroke. Assess for the presence of "pronator drift," bilateral hand grasp strength, gait, and coordination.
Diagnosis of SCD is based on the percentage of hemoglobin S (HbS) on electrophoresis. A person who has AS usually has less than 40% HbS, and the patient with SCD may have 80% to 100% HbS. This percentage does not change during crises. Another indicator of SCD is the number of RBCs with permanent sickling. This value is less than 1% among people with no hemoglobin disease, is 5% to 50% among people with AS, and may be 90% among patients with SCD.
The hematocrit of patients with SCD is low (between 20% and 30%) because of RBC shortened life span/destruction.
This value decreases even more during crises or during stress (aplastic crisis). The reticulocyte count is high, indicating anemia of long duration. The total bilirubin level may be high because damaged RBCs release iron and bilirubin.
The total white blood cell (WBC) count is usually high in patients with SCD. This elevation is related to chronic inflammation caused by tissue hypoxia and ischemia.
The skull may show changes on x-ray as a result of bone surface cell destruction and new growth, giving the skull a "crew cut" appearance on x-ray. X-rays of joints may show necrosis and destruction. Ultrasonography, CT, positron emission tomography (PET), and MRI may show soft-tissue and organ changes from poor PERFUSION and chronic inflammation.
OTHER: Electrocardiographic (ECG) changes document cardiac infarcts and tissue damage. Specific ECG changes are related to the area of the heart damaged. Echocardiograms may show cardiomyopathy and decreased cardiac output (low ejection fraction).
The pain with sickle cell crisis is the result of tissue injury. Acute pain episodes have a sudden onset, usually involving the chest, back, abdomen, and extremities. Complications of SCD can cause severe, chronic pain, requiring large doses of opioids.
Opioid addiction is rare, occurring in only 2% to 5% of patients with SCD. Addicted patients in acute pain crisis still need opioids.
Drug therapy for patients in acute sickle cell crisis often starts with at least 48 hours of IV analgesics. Morphine and hydromorphone (Dilaudid) are given IV on a routine or PCA. Avoid "as needed" (PRN) schedules because they do not provide adequate relief. Moderate pain may be managed with oral opioids/NSAIDs.
Hydroxyurea (Droxia) may reduce the number of sickling and pain episodes by stimulating fetal hemoglobin (HbF) production. Increasing the level of HbF reduces sickling of red blood cells . This drug is associated with an increased incidence of leukemia. Hydroxyurea also suppresses bone marrow function including IMMUNITY, and require follow-up to monitor CBCs.
Hydration by the oral or IV route helps reduce the duration of pain episodes. Patient is often dehydrated and his or her blood is hypertonic, hypotonic fluids are usually infused at 250 mL/hr for 4 hours. Once the patient's blood osmolarity is down to the normal range of 270 to 300 mOsm, the IV rate is reduced to 125 mL/hr if more needed.