Hematological Disorders in ICU PDF

# Hematological Disorders in ICU The hematologic system consists of the blood and bone marrow. Blood delivers oxygen and nutrients to all tissues, removes wastes, and transports gases, blood cells, immune cells, and hormones throughout the body. Blood consists of blood cells, suspended in fluid cal...

# Hematological Disorders in ICU The hematologic system consists of the blood and bone marrow. Blood delivers oxygen and nutrients to all tissues, removes wastes, and transports gases, blood cells, immune cells, and hormones throughout the body. Blood consists of blood cells, suspended in fluid called plasma. Blood cells include: 1. Red blood cells (RBCs), or erythrocytes 2. White blood cells (WBCs), or leukocytes 3. Platelets or thrombocytes. N.B: RBCs and platelets function entirely within blood vessels; WBCs act mainly in the (tissues outside the blood vessels. ## Reference range of CBC | | Normal Range for Men | Normal Range for Women | | -------------------------- | ---------------------- | ------------------------ | | Red Blood Cell (RBC) Count | 4–6 million cells/mcL | 4–5 million cells/mcL | | Hemocrit (HCT) | 39–50% | 35–47% | | Hemoglobin (Hgb) | 14–18 grams/dL | 12–16grams/dL | | White Blood Cell (WBC) Count | | | | - amount of white blood cells | 3.5–10.5 billion cells/L (3,500 - 10,500cells/mcL) | | | Differential (diff) | | | | - shows the percent of each different types of white cell (neutrophils, lymphocytes, monocytes, eosinophils, and basophils) | | | | - neutrophils | 55%-70% | | | - lymphocytes | 20%-40% | | | - monocytes | 2%-8% | | | - eosinophils | 1%-4% | | | - basophils | 0.5%-1% | | ## Anemia of Critical Illness Definition: A hemoglobin (Hb) level less than 13 g/dL in men and less than 12 g/dL, in women. N.B: approximately two-thirds of critical ill patients admitted to an ICU have a hemoglobin concentration of less than 12 g/dl on the day of admission, and 97% of the patients become anemic after a week in ICU that known as *(Nosocomial anemia in ICU)*. ### Etiology/Pathophysiology The cause of anemia in critical illness is complex and often multifactorial. a. Loss of red blood cells (RBCs) due to phlebotomy and bleeding from a surgical site, trauma, venous access site, or gastrointestinal bleed. b. Decreased production of RBCs due to suppression of bone marrow secondary to inflammatory cytokines, drugs, functional or absolute erythropoietin deficiency due to renal dysfunction. c. Nutritional (iron, folic acid, vitamin B12) deficiency. d. Increased destruction of RBCs (hemolysis) or RBC precursor in the bone marrow due to toxins and drugs. ### Consequences of anemia * Cardiopulmonary failure * Long term mechanical ventilation (Difficult weaning from MV) * Long term ICU stay (more hypoxic + more acid) * Complications of therapy (blood transfusion) as anaphylaxis, volume overload and acid-base disturbance. ### Management of anemia in critically ill 1. Blood Transfusions either packed red blood cells (PRBC) or whole blood. 2. Erythropoiesis-stimulating agents (ESA) as Eprex 3. Iron Therapy (restricted use in ICU due to iron sequestration and decreased absorption from the gut). ### Transfusion-related complications 1. Coagulation abnormalities as *Dilutional coagulopathy* secondary to massive transfusion of PRBC that is poor in platelets and coagulation factors present in plasma. This can be prevented by replacement of clotting factors with transfusions of fresh frozen plasma (FFP), platelets and cryoprecipitate. 2. Biochemical complications as *Hypocalcemia* due to citrate present as an anticoagulant (acts by binding to calcium). 3. *Hypothermia* form rapid blood transfusion without warming. 4. *Acid-base imbalance*: Stored blood contains citric acid as anticoagulant and lactic acid produced from stored red cells. Citric acid is metabolized by the liver into bicarbonate, which leads to metabolic alkalosis. 5. *Transfusion-related acute lung injury (TRALI)*: occurs due to the presence of leukocyte antibodies and cytokines in the plasma of the donor blood, which are directed against human leucocyte antigens (HLA) and human neutrophil alloantigen (HNA) in the recipient. This led to increased pulmonary micro vascular permeability, which is characteristic of TRALI. 6. *Transfusion-associated circulatory overload (TACO)*: Patients at high risk of volume overload (congestive heart failure, low cardiac ejection fraction, renal failure, and respiratory failure) may develop TACO on receiving massive or multiple transfusions. Signs and symptoms of TACO are like TRALI and include dyspnea, orthopnea, tachypnea, elevated jugular pressures with distended neck veins and increased blood pressure. A massive transfusion is defined as the replacement of a patient's total blood volume in less than twenty-four hours-24hrs. ### When to transfuse blood? *(Restrictive blood transfusions protocols)* 1. Critical ill patient with cardiac problem (when hemoglobin less than 9 g/dl) 2. Other critically ill patients (when hemoglobin less than 7 g/dl) ### Blood saving strategies * Minimize blood loss during various ICU procedures. * Screening high-risk patients for nosocomial blood loss. * Using of honinvasive monitoring devices instead of invasive devices as pulse oximetry instead of arterial puncture for ABG analysis. * Reviewing the appropriateness of tests to minimize unnecessary blood drawings. * Documenting the cumulative nosocomial blood loss as part of daily intake and output records can assist in detecting patients who are experiencing excessive losses. * Use ultrasound in inserting invasive devices as central venous catheters. * Using point-of care testing (POCT) at the bedside with micro analyzers, which require 1 ml or less of blood. * Adequate control of bleeding after venipuncture by direct pressure. * Avoid trauma to the skin, teeth, and nose for risky patients. * Assess for sings of bleeding in gums, skin, urine, stool, and vomitus. * Review all drugs that cause anemia as thrombolyties, NSAIDs, antibiotics, chemotherapeutic agents, antiplatelets and anticoagulants * Monitor laboratory data as CBC, coagulation profile, urine analysis, serum iron, stool analysis * Use of *blood-saving bundle* (BSB); 1. Blood conservation devices for arterial lines. 2. Reduction of the size of the blood collection tubes. 3. Policy to use non-invasive methods, such as pulse oximetry and capnography as often as possible to adjust mechanical ventilation in order to reduce the frequency of invasive arterial blood gas analyses. * Support RBCs production: nutritional using iron, folic acid, vitamin B and protein. * Control sepsis and metabolic stress. * Maximize oxygen delivery and minimize oxygen demand as administration of fluids to increase preload, positive inotropic agents to improve cardiac contractility or vasodilating agents to decrease afterload and peripheral resistance. ## Disseminated intravascular coagulation (DIC) DIC is a coagulopathy that accelerates clotting causes small blood vessel occlusion organ necrosis, depletion of circulating clotting factors and platelets, and activation of the fibrinolytic system that cause bleeding. Cloting in the microcirculation usually affects the kidneys and extremities, but may occur the brain, lungs, and Gl mucosa. ### Causes * Infection, Obstetric complications * Neoplastic disease, Shock * Disorders that produce necrosis, such as extensive burns * Trauma, brain tissue destruction, transplant rejection, and hepatic * Poisonous snakebite * Cirrhosis, Fat embolism * Incompatible blood transfusion * Cardiac arrest, Surgery necessitating cardiopulmonary bypass * Severe venous thrombosis, Heat stroke ### Blood Product | Blood product | Uses | Special consideration | |---------------|---------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------| | Factor Viii | - To treat hemophilia A | - Be aware that patients with hemophilia A or von Willebrand's disease should only be treated with cryoprecipitate when appropriate factor VIII concentrates are not available. | | | - To treat von Willebrand's disease | - Administer by I.V. injection using a filter needle or use the administration set supplied by the manufacturer. | | Fresh frozen | - To correct coagulation deficiency or a specific factor | - Use a blood administration set. | | plasma (FFP) | - To replace a specific factor when that factor is not available | - Monitor patient for signs and symptoms of hypocalcemia because the citric acid in FFP may bind to calcium. | | | - To reverse warfarin | - Remember that FFP must be infused within 6 hours of being thawed. | | | - To treat thrombotic thrombocytopenic purpura | | | Cryoprecipitate | - To treat factor VIII deficiency and fibrinogen disorders | - Add normal saline solution to each bag of cryoprecipitate, as necessary, to facilitate transfusion. | | | - To treat significant factor XIII deficiency | - Keep in mind that cryoprecipitate must be administered within 6 hours of thawing | | | | - Before administering, check lab studies to confirm a deficiency of one of the specific clotting factors present in cryoprecipitate. | | Platelets | - To treat bleeding caused by decreased circulating platelets or functionally abnormal | - Use a filtered component drip administration set to infuse. | | | | - If ordered, administer prophylactic medications, such as pretransfusion. | | Packed Red | - To restore or maintain oxygen-carrying capacity | - Use a blood administration set to infuse blood within 4 hours. | | blood cells | - To correct anemia and surgical blood loss | - Administer only with normal saline solution. | | (RBCs) | - To increase RBC mass | - Keep in mind that an RBC transfusion is not appropriate for anemias treatable by nutritional or drug therapies. | | whole blood but | | | | with most of the | | | | plasma removed | | | | Leukocyte-poor | - To improve RBC exchange | - Use blood administration tubing. | | RBCs | - Same as packed RBCs | - It may require a 40-micron filter suitable for hard-spun, leukocyte-poor RBCs. | | | - To prevent febrile reactions from leukocyte antibodies | - Use only with normal saline solution. | | | - To treat immunocompromised patients | - Keep in mind that cells expire 24 hours after washing. | | | - To restore RBCs to patients who have had two or more non-hemolytic febrile reactions | |