Critical Care Nurse Textbook

Critical care is the discipline devoted to patients whose physiology has become so unstable, or is so threatened, that survival depends on continuous observation and immediate intervention. The patient in an intensive care unit (ICU) may have lost the ability to breathe without a machine, to maintain a blood pressure without a drug infusion, to clear metabolic waste without a filter, or to protect the brain from swelling. In each case the margin between recovery and death is measured in minutes or hours, and the person who is nearest to that margin, hour after hour, is the bedside nurse. Before any chapter on hemodynamics, ventilation, or shock can be useful, you need a clear picture of the place where that knowledge is applied and the professional identity that applies it.

1. 1.1 Evolution of Intensive Care and the Modern ICU
2. 1.2 Types of Critical Care Units and Patient Populations
3. 1.3 The Interprofessional Critical Care Team
4. 1.4 Scope of Practice and Nursing Standards at the Bedside
5. 1.5 Nurse-to-Patient Ratios, Acuity, and Workload
6. 1.6 Severity-of-Illness Scoring Systems
7. 1.7 The ICU Bedside: Equipment, Alarms, and Technology
8. 1.8 Patient Safety Culture and Handoff Communication

Assessment is the activity from which all other critical care nursing actions flow. Every infusion titration, ventilator adjustment, and call to the physician begins with an observation that something is different, better, or worse than it was an hour ago. This chapter teaches how to turn that presence into a reliable method. A systematic approach matters because critically ill patients fail in ways that are not obvious at a glance, and because human attention, under pressure, tends to fixate on whichever alarm is loudest or whichever organ is most familiar.

1. 2.1 The Rapid Primary Assessment
2. 2.2 Airway, Breathing, and Circulation Priorities
3. 2.3 Neurologic Assessment at the Bedside
4. 2.4 Cardiovascular Examination in the ICU
5. 2.5 Respiratory Examination and Work of Breathing
6. 2.6 Abdominal, Renal, and Skin Assessment
7. 2.7 Interpreting Laboratory and Diagnostic Trends
8. 2.8 Documentation, Escalation, and Early Warning Systems

Hemodynamics is the study of the forces and flows that move blood through the circulation, and it is the language in which much of critical care is spoken. When a physician asks for a mean arterial pressure, a central venous pressure, or a cardiac index, the request is for a number that summarizes how well the heart is filling, pumping, and perfusing the body. The nurse who understands where those numbers come from, what they assume, and how they can mislead is far better equipped to act on them than one who merely reads them off the screen.

1. 3.1 Determinants of Cardiac Output
2. 3.2 Preload, Afterload, and Contractility
3. 3.3 Arterial Blood Pressure Monitoring and Waveform Analysis
4. 3.4 Central Venous Pressure and Central Venous Access
5. 3.5 Pulmonary Artery Catheters and Derived Parameters
6. 3.6 Minimally Invasive and Noninvasive Cardiac Output Monitoring
7. 3.7 Dynamic Indicators of Fluid Responsiveness
8. 3.8 Troubleshooting Transducers, Damping, and Leveling

The preceding chapters built the physiologic and technical vocabulary of critical care: how to assess a failing patient, how to read a waveform, how to interpret a pressure. This chapter turns to a question that is equally central to the work and far harder to reduce to a number: what should be done, for whom, with whose permission, and in what manner. Intensive care technology can sustain breathing, circulation, and filtration long after the body would have failed on its own, and every such intervention carries a moral weight that the bedside nurse feels first and most continuously.

1. 4.1 Ethical Principles in Critical Care
2. 4.2 Informed Consent and Decision-Making Capacity
3. 4.3 Surrogate Decision-Makers and Advance Directives
4. 4.4 Code Status, Goals of Care, and Limits of Treatment
5. 4.5 Communicating With Families in Crisis
6. 4.6 Open Visitation and Family Participation in Care
7. 4.7 Moral Distress and Conflict Resolution
8. 4.8 Cultural Humility and Health Equity in the ICU

Every cardiac monitor in the intensive care unit (ICU) translates a tiny electrical signal, a few millivolts at the skin, into a line that a nurse must interpret in seconds. That line is meaningful only to a clinician who understands where it comes from: the structure of the heart, the ion currents that create each cell's action potential, and the specialized pathway that spreads depolarization from the atria to the ventricles in an orderly sequence.

1. 5.1 Cardiac Anatomy and the Coronary Circulation
2. 5.2 The Cardiac Action Potential and Conduction System
3. 5.3 Principles of Continuous ECG Monitoring
4. 5.4 A Systematic Approach to Rhythm Strip Analysis
5. 5.5 Sinus and Atrial Rhythms
6. 5.6 Junctional Rhythms and Atrioventricular Blocks
7. 5.7 Ventricular Rhythms
8. 5.8 The 12-Lead ECG in the Critically Ill Patient

Coronary artery disease remains the leading cause of death in the United States, and the acute coronary syndromes (ACS) are its most time-critical expression. The term covers a spectrum of conditions, unstable angina, non-ST-elevation myocardial infarction (NSTEMI), and ST-elevation myocardial infarction (STEMI), that share a common origin: sudden disruption of an atherosclerotic plaque, followed by thrombus formation that reduces or abolishes blood flow to a region of myocardium.

1. 6.1 Pathophysiology of Atherosclerosis and Plaque Rupture
2. 6.2 Unstable Angina and Non-ST-Elevation Myocardial Infarction
3. 6.3 ST-Elevation Myocardial Infarction and ECG Localization
4. 6.4 Cardiac Biomarkers and Diagnostic Evaluation
5. 6.5 Reperfusion Strategies: Fibrinolysis and Percutaneous Coronary Intervention
6. 6.6 Antiplatelet, Anticoagulant, and Antianginal Therapy
7. 6.7 Complications of Myocardial Infarction
8. 6.8 Nursing Management and Post-Procedure Care

The previous chapter followed the coronary arteries from plaque rupture to infarction, and it ended with the complications that arise when a large territory of myocardium is lost. This chapter follows the same story to its hemodynamic conclusion. Whether the injury comes from an infarct, from years of uncontrolled hypertension, from a viral myocarditis, from a valve that has been failing quietly for a decade, or from a toxin, the final common pathway is a ventricle that can no longer move blood forward at a rate the body requires, or can no longer fill at pressures the lungs and veins can tolerate. Heart failure is that pathway described as a chronic syndrome, and cardiogenic shock is the same pathway at its most lethal extreme, when forward flow collapses to the point that tissues begin to die.

1. 7.1 Pathophysiology of Systolic and Diastolic Dysfunction
2. 7.2 Neurohormonal Activation and Ventricular Remodeling
3. 7.3 Acute Decompensated Heart Failure: Presentation and Assessment
4. 7.4 Diuretic, Vasodilator, and Inotropic Therapy
5. 7.5 Cardiogenic Shock: Mechanisms and Recognition
6. 7.6 Hemodynamic Profiles and Management Strategies
7. 7.7 Pulmonary Edema: Pathophysiology and Emergency Care
8. 7.8 Nursing Priorities and Patient Education

Chapter 5 taught the grammar of the electrocardiogram: how an impulse arises in the sinoatrial node, travels through the atria, pauses in the atrioventricular node and spreads through the His-Purkinje system to produce a coordinated contraction. Chapter 7 showed how a failing, dilated, scarred ventricle becomes electrically unstable. This chapter takes up the consequence. A dysrhythmia is any disturbance in the rate, regularity, site of origin or conduction of the cardiac impulse, and in the intensive care unit (ICU) such disturbances are neither rare nor trivial. They arise from ischemia, electrolyte derangements, catecholamine infusions, hypoxemia, acid-base disorders, mechanical irritation from catheters, and the underlying structural disease of the heart itself.

1. 8.1 Mechanisms of Tachyarrhythmias and Bradyarrhythmias
2. 8.2 Atrial Fibrillation and Flutter in the ICU
3. 8.3 Supraventricular Tachycardias
4. 8.4 Ventricular Tachycardia and Ventricular Fibrillation
5. 8.5 Antiarrhythmic Drug Therapy
6. 8.6 Cardioversion, Defibrillation, and Transcutaneous and Transvenous Pacing
7. 8.7 Advanced Cardiac Life Support and High-Quality Resuscitation
8. 8.8 Post-Cardiac Arrest Care and Targeted Temperature Management

The preceding chapters considered the heart as an electrical and muscular organ whose failure can be treated with drugs, shocks and time. This chapter turns to the heart as a mechanical structure. The four valves must open fully and close tightly, the pericardial sac must remain a low-pressure potential space, and the aorta must contain a pulse wave of arterial pressure that repeats about a hundred thousand times each day. When any of these structures fails, the ventricle may be perfectly healthy and still unable to deliver output, and the remedy is often a procedure instead of a prescription.

1. 9.1 Valvular Heart Disease: Stenosis and Regurgitation
2. 9.2 Pericardial Disease, Tamponade, and Myocarditis
3. 9.3 Aortic Dissection and Aneurysm Emergencies
4. 9.4 Immediate Postoperative Care After Cardiac Surgery
5. 9.5 Postoperative Complications: Bleeding, Tamponade, and Vasoplegia
6. 9.6 Intra-Aortic Balloon Pump Counterpulsation
7. 9.7 Ventricular Assist Devices and Impella Support
8. 9.8 Extracorporeal Membrane Oxygenation Fundamentals

The preceding chapter ended with the machines that take over the work of a failing heart and, in the case of extracorporeal membrane oxygenation, the work of failing lungs as well. The circulation is a delivery system, but what it delivers, and what it removes, is determined at the alveolar-capillary membrane, where oxygen enters the blood and carbon dioxide leaves it. When that exchange fails, every organ downstream pays the price within minutes, and the critical care nurse is frequently the first person to notice the failure and the person who will titrate the support that corrects it.

1. 10.1 Lung Anatomy and Mechanics of Breathing
2. 10.2 Ventilation, Perfusion, and Ventilation-Perfusion Matching
3. 10.3 Oxygen Transport and the Oxyhemoglobin Dissociation Curve
4. 10.4 Carbon Dioxide Transport and Control of Breathing
5. 10.5 Arterial Blood Gas Interpretation
6. 10.6 Pulse Oximetry, Capnography, and Noninvasive Monitoring
7. 10.7 Causes of Hypoxemia and Hypercapnia
8. 10.8 Oxygen Delivery Devices and High-Flow Nasal Oxygen

This chapter turns to the moment when the system fails: when the lungs can no longer keep the arterial oxygen and carbon dioxide within a range compatible with life. Acute respiratory failure is among the most common reasons for admission to an intensive care unit, and its most severe form, acute respiratory distress syndrome (ARDS), accounts for a substantial share of ventilator days and deaths. The nurse who understands the categories of failure, the sequence of injury in ARDS and the logic behind each therapy can anticipate the next step rather than react to it.

1. 11.1 Classification of Acute Respiratory Failure
2. 11.2 Pathophysiology of Acute Respiratory Distress Syndrome
3. 11.3 Diagnostic Criteria and Clinical Course
4. 11.4 Lung-Protective Ventilation Strategies
5. 11.5 Prone Positioning and Neuromuscular Blockade
6. 11.6 Rescue Therapies and Extracorporeal Support
7. 11.7 Fluid Management and Supportive Care
8. 11.8 Nursing Care and Long-Term Respiratory Outcomes

All of those strategies presuppose that someone has secured a reliable route for gas to travel between the ventilator and the alveoli, and that the person at the bedside understands the machine. They are also among the most hazardous activities in the unit, because an airway lost or a ventilator misunderstood can kill a patient within minutes. The nurse is rarely the person who places the endotracheal tube, but the nurse prepares the patient, administers the drugs, monitors the response and, afterward, owns the tube and the ventilator for twelve hours at a time.

1. 12.1 Indications for Intubation and Airway Assessment
2. 12.2 Rapid Sequence Intubation: Medications and Nursing Role
3. 12.3 Endotracheal Tube Care and Cuff Management
4. 12.4 Tracheostomy Care and Complications
5. 12.5 Noninvasive Ventilation: CPAP and BiPAP
6. 12.6 Ventilator Modes: Volume, Pressure, and Dual Control
7. 12.7 Ventilator Settings, Waveforms, and Graphics
8. 12.8 Ventilator Alarms and Troubleshooting

Positive-pressure ventilation rescues patients whose lungs or respiratory muscles can no longer sustain gas exchange, but it does so by reversing the normal physiology of breathing. A healthy person draws air in by lowering intrathoracic pressure; the ventilator pushes air in by raising it. Excess pressure and volume can tear or overstretch lung tissue, a machine that does not match the patient's own rhythm can add to the work of breathing instead of relieving it, and a tube that bypasses the upper airway gives bacteria a direct path to the lower respiratory tract. Each day on the ventilator also costs the patient diaphragm strength, muscle mass, sleep, and independence.

1. 13.1 Barotrauma, Volutrauma, and Ventilator-Induced Lung Injury
2. 13.2 Patient-Ventilator Asynchrony and Auto-PEEP
3. 13.3 Ventilator-Associated Pneumonia and Prevention Bundles
4. 13.4 Readiness Testing and Spontaneous Breathing Trials
5. 13.5 Weaning Protocols and Failed Weaning
6. 13.6 Extubation Planning and Post-Extubation Care
7. 13.7 Prolonged Mechanical Ventilation and Tracheostomy Timing
8. 13.8 Early Mobility and Rehabilitation on the Ventilator

Some respiratory diseases evolve over days and give the nurse time to observe and adapt. A clot lodges in the pulmonary artery and the right ventricle strains against a sudden wall of resistance. An asthmatic airway narrows so tightly that the chest falls silent. A collapsed lung presses the heart and great veins aside. In each case the physiology moves quickly, the margin between compensation and arrest is narrow, and the nurse's recognition of the first changes, often before a diagnosis is established, shapes the outcome.

1. 14.1 Pulmonary Embolism: Pathophysiology and Diagnosis
2. 14.2 Anticoagulation, Thrombolysis, and Embolectomy
3. 14.3 Status Asthmaticus
4. 14.4 Acute Exacerbation of Chronic Obstructive Pulmonary Disease
5. 14.5 Pneumonia and Severe Community-Acquired Infection
6. 14.6 Pneumothorax, Hemothorax, and Chest Tube Management
7. 14.7 Pleural Effusion and Thoracentesis
8. 14.8 Pulmonary Hypertension and Right Heart Failure

Shock is the state in which the circulation fails to deliver enough oxygen and nutrients to meet the metabolic needs of the tissues. A patient can be in shock with a normal blood pressure, and a young athlete can have a low blood pressure without being in shock. What defines the condition is the imbalance between oxygen delivery and oxygen demand at the cellular level, and what makes it lethal is that the imbalance, if uncorrected, progresses from reversible dysfunction to irreversible cell death and multisystem failure. The bedside nurse often meets shock in its earliest stage, when a restless patient has a slightly fast heart rate and cool hands, and the actions taken in that first hour influence the outcome as much as any later therapy.

1. 15.1 Cellular Pathophysiology of Shock
2. 15.2 Stages of Shock and Compensatory Mechanisms
3. 15.3 Hypovolemic Shock and Hemorrhage Control
4. 15.4 Distributive Shock: Anaphylactic and Neurogenic
5. 15.5 Obstructive Shock
6. 15.6 Crystalloids, Colloids, and Blood Products
7. 15.7 Lactate, Perfusion Markers, and Resuscitation Endpoints
8. 15.8 Massive Transfusion Protocols and Damage Control Resuscitation

Sepsis is the final common pathway by which an ordinary infection becomes a threat to life. A urinary tract infection, a perforated diverticulum, a pneumonia, an infected central line: each begins as a local contest between microbe and host, and in most people that contest is won quietly. In a minority it is not. The host's own defenses, designed to wall off and destroy the invader, spill over into the circulation and begin to injure the very organs they exist to protect. Sepsis remains one of the most common reasons for admission to intensive care and one of the leading causes of in-hospital death in the United States, and it is the clinical syndrome in which critical care nursing vigilance most directly changes outcome.

1. 16.1 Definitions: Infection, Sepsis, and Septic Shock
2. 16.2 Host Response, Inflammation, and Immune Dysregulation
3. 16.3 Early Recognition and Screening Tools
4. 16.4 The Hour-1 Bundle: Cultures, Antibiotics, Fluids, and Vasopressors
5. 16.5 Source Control and Antimicrobial Stewardship
6. 16.6 Corticosteroids and Adjunctive Therapies
7. 16.7 Multiple Organ Dysfunction Syndrome
8. 16.8 Nursing Management and Sepsis Survivorship

Few tasks in critical care nursing combine as much physiology, arithmetic and responsibility as managing a vasoactive infusion. The drugs in this chapter act within seconds, are titrated minute by minute, have half-lives measured in minutes, and can cause harm in either direction: too little and the patient remains in shock, too much and the patient develops arrhythmia, ischemia, or tissue necrosis. The nurse is the clinician who stands at the pump, turns the dose up and down, and sees what happens, so the nurse must understand why the drug works, what else it does, and how to calculate what the pump is delivering.

1. 17.1 Adrenergic Receptors and Signal Transduction
2. 17.2 Norepinephrine, Epinephrine, and Vasopressin
3. 17.3 Dopamine, Dobutamine, and Phenylephrine
4. 17.4 Milrinone, Levosimendan, and Other Inotropes
5. 17.5 Vasodilators: Nitroglycerin, Nitroprusside, and Nicardipine
6. 17.6 Titration, Dose Calculations, and Weight-Based Dosing
7. 17.7 Peripheral Versus Central Administration and Extravasation
8. 17.8 High-Alert Medication Safety and Smart Pump Practice

The brain is the organ the critical care nurse can least afford to lose track of. It makes up about two percent of body weight yet receives roughly fifteen to twenty percent of cardiac output and consumes about twenty percent of the body's oxygen, it stores almost no energy, and it is enclosed in a rigid box that allows no room for swelling. A heart can fail and be supported by a pump, a kidney can fail and be replaced by dialysis, but a brain that is deprived of perfusion for minutes suffers injury that no device can reverse. Neurologic assessment is therefore not a specialty skill reserved for the neuro unit; it is a core competence of every ICU nurse, because delirium in sepsis, a stroke in a cardiac patient, anoxic injury after arrest, and sedation-related coma all present as changes in the neurologic examination, and the nurse at the bedside is the first to see them.

1. 18.1 Neuroanatomy and Cerebral Blood Flow Regulation
2. 18.2 The Glasgow Coma Scale and Advanced Neurologic Scales
3. 18.3 Pupillary, Cranial Nerve, and Motor Examination
4. 18.4 The Monro-Kellie Doctrine and Intracranial Hypertension
5. 18.5 ICP Monitoring, External Ventricular Drains, and Waveforms
6. 18.6 Cerebral Perfusion Pressure Management
7. 18.7 Osmotherapy, Sedation, and Hyperventilation
8. 18.8 Brain Death Evaluation and Determination

The previous chapter gave you the language and the physiology of the injured brain: the Monro-Kellie doctrine, the relationship between intracranial pressure (ICP) and cerebral perfusion pressure (CPP), the Glasgow Coma Scale, and the pupillary and motor examination that lets you detect deterioration before a monitor does. This chapter applies those principles to the diseases that most often bring a patient to the neurologic intensive care unit or make a patient in any ICU suddenly neurologically unstable. Ischemic and hemorrhagic stroke, traumatic brain injury (TBI), spinal cord injury, status epilepticus, central nervous system infection, and neuromuscular emergencies look different at the bedside, yet they share a single organizing idea: the brain and spinal cord have almost no metabolic reserve, so the quality of your nursing in the first minutes and hours determines how much tissue survives.

1. 19.1 Ischemic Stroke: Pathophysiology and Time-Sensitive Care
2. 19.2 Thrombolysis and Mechanical Thrombectomy
3. 19.3 Intracerebral and Subarachnoid Hemorrhage
4. 19.4 Traumatic Brain Injury: Primary and Secondary Injury
5. 19.5 Spinal Cord Injury and Autonomic Dysreflexia
6. 19.6 Status Epilepticus and Antiseizure Therapy
7. 19.7 Meningitis, Encephalitis, and Neuromuscular Emergencies
8. 19.8 Neurocritical Care Nursing and Rehabilitation Planning

The kidney fails more quietly. A patient may look much the same while urine output falls, creatinine rises, potassium creeps upward, and fluid accumulates in the lungs and tissues, and by the time these changes are unmistakable the injury may already be well established. Acute kidney injury (AKI) occurs in a large proportion of critically ill adults, and it is both a marker and a cause of poor outcome: it prolongs ventilation and hospital stay, alters the clearance of nearly every drug on the medication record, and, when severe enough to require dialysis, carries a substantial mortality.

1. 20.1 Renal Anatomy and the Regulation of Filtration
2. 20.2 Prerenal, Intrinsic, and Postrenal Injury
3. 20.3 Staging Criteria and Diagnostic Evaluation
4. 20.4 Nephrotoxins and Contrast-Associated Injury
5. 20.5 Indications for Renal Replacement Therapy
6. 20.6 Continuous Renal Replacement Therapy Modalities and Circuits
7. 20.7 Anticoagulation, Dosing, and Complications of Dialysis
8. 20.8 Nursing Care and Recovery of Renal Function

That environment, the volume and composition of body water, its dissolved electrolytes, and the hydrogen ion concentration of blood, is so tightly regulated in health that most people never think about it. In the ICU the regulation is constantly disturbed, by hemorrhage and resuscitation, by diuretics and diarrhea, by insulin and catecholamines, by kidney and liver failure, by mechanical ventilation, and by the intravenous fluids that nurses hang. Many of the emergencies that nurses recognize first, such as a wide QRS complex from hyperkalemia, a seizure from severe hyponatremia, or tetany after a massive transfusion, are electrolyte problems that were detectable earlier in the laboratory trend or the monitor.

1. 21.1 Body Fluid Compartments and Osmolality
2. 21.2 Sodium Disorders: Hyponatremia and Hypernatremia
3. 21.3 Potassium Disorders and Cardiac Consequences
4. 21.4 Calcium, Magnesium, and Phosphate Disorders
5. 21.5 A Stepwise Approach to Acid-Base Interpretation
6. 21.6 Metabolic Acidosis and Alkalosis
7. 21.7 Respiratory Acidosis and Alkalosis
8. 21.8 Mixed Disorders and Compensation

The gastrointestinal tract is often described as the motor of critical illness. It is the largest immune organ in the body, it houses trillions of microorganisms, it absorbs nutrients and drugs, and through the portal circulation it feeds the liver, which in turn synthesizes clotting factors, detoxifies ammonia, clears drugs and manufactures the proteins that hold fluid inside the vasculature. When any part of this system fails, the effects spread outward: blood is lost into the lumen, bacteria and endotoxin cross a damaged mucosal barrier, pressure builds inside a distended abdomen and squeezes the kidneys and lungs, and a failing liver permits ammonia to reach the brain. The patient who arrives with what looks like a belly problem can, within hours, be in hemorrhagic or septic shock with several organs failing.

1. 22.1 Upper Gastrointestinal Bleeding and Stress Ulcer Prophylaxis
2. 22.2 Lower Gastrointestinal Bleeding and Mesenteric Ischemia
3. 22.3 Bowel Obstruction, Perforation, and Abdominal Compartment Syndrome
4. 22.4 Acute Pancreatitis
5. 22.5 Acute Liver Failure and Hepatic Encephalopathy
6. 22.6 Cirrhosis, Variceal Bleeding, and Hepatorenal Syndrome
7. 22.7 Acute Cholangitis and Biliary Emergencies
8. 22.8 Nursing Management of Gastrointestinal Critical Illness

Feeding a critically ill patient is not the same as feeding a healthy person who happens to be in bed. A well person who stops eating adapts by lowering metabolic rate, burning fat and sparing protein. A patient in septic shock, burn injury or major trauma does the opposite: the stress response drives hypermetabolism, mobilizes protein from skeletal muscle, and makes tissues resistant to insulin, so that substrate is consumed or wasted at a rate that no ordinary diet could match. Within a week a patient can lose a substantial fraction of lean body mass, and that loss shows up later as ventilator dependence, weakness, delayed wound healing, infection and prolonged recovery. Nutrition therapy is therefore a clinical intervention with doses, routes, complications and monitoring, rather than a comfort measure delegated to the end of the care plan.

1. 23.1 The Metabolic Response to Stress and Injury
2. 23.2 Nutritional Screening and Assessment
3. 23.3 Estimating Energy and Protein Requirements
4. 23.4 Enteral Nutrition: Access, Initiation, and Tolerance
5. 23.5 Parenteral Nutrition Indications and Complications
6. 23.6 Refeeding Syndrome
7. 23.7 Glycemic Control in the ICU
8. 23.8 Nutrition in Special Populations

Hormones are the body's slow messengers, yet when they fail, the consequences can unfold within hours. Insulin, cortisol, thyroid hormone, antidiuretic hormone and the catecholamines together set the pace of metabolism, the tone of blood vessels, the distribution of water and the availability of fuel. In critical illness the system is pushed to its limits: stress raises cortisol and glucose, inflammation alters thyroid hormone handling, and the pituitary and adrenal glands may be injured by shock, hemorrhage, infection or drugs. An endocrine emergency may be the reason a patient comes to the ICU, as in diabetic ketoacidosis, or it may be the hidden explanation for shock that does not respond to fluids and vasopressors.

1. 24.1 Pancreatic Physiology and Insulin Action
2. 24.2 Diabetic Ketoacidosis: Pathophysiology and Presentation
3. 24.3 DKA Management: Fluids, Insulin, and Electrolytes
4. 24.4 Hyperosmolar Hyperglycemic State
5. 24.5 Adrenal Crisis and Critical Illness-Related Corticosteroid Insufficiency
6. 24.6 Thyroid Storm and Myxedema Coma
7. 24.7 Diabetes Insipidus and SIADH
8. 24.8 Hypoglycemia and Insulin Infusion Safety

Blood is the only organ that must remain liquid to do its work and yet solidify within seconds when a vessel is breached. That paradox sits at the center of hematologic critical care. Every patient in the intensive care unit (ICU) lives somewhere on a spectrum between bleeding and clotting, and the critically ill drift along that spectrum for reasons that have little to do with any inherited tendency: sepsis activates coagulation, major surgery and trauma consume clotting factors, liver failure stops their manufacture, dilution from resuscitation thins them, and the medications that keep catheters patent, stents open and veins free of thrombus can themselves precipitate hemorrhage. The nurse at the bedside is usually the first person to see the early signs, whether that is oozing at a line site, a falling platelet count on the morning laboratory panel, or a leg that has quietly become swollen and warm.

1. 25.1 Hemostasis and the Coagulation Cascade
2. 25.2 Anemia and Transfusion Thresholds
3. 25.3 Transfusion Reactions and Blood Product Administration
4. 25.4 Disseminated Intravascular Coagulation
5. 25.5 Heparin-Induced Thrombocytopenia and Thrombocytopenic Syndromes
6. 25.6 Anticoagulation Management and Reversal Agents
7. 25.7 Venous Thromboembolism Prophylaxis
8. 25.8 Oncologic Emergencies and Neutropenic Sepsis

Injury is the leading cause of death among Americans under the age of 45, and its victims arrive in the intensive care unit (ICU) at every hour with problems that are rarely confined to a single organ. A driver ejected from a vehicle may have a pulmonary contusion, a lacerated spleen, an unstable pelvis and a femur fracture simultaneously, and the sequence in which these are found and treated determines whether he lives. A burn patient may look deceptively well in the first hour, then lose liters of plasma into injured tissue over the next day. A heat stroke victim and a hypothermic hiker present with opposite temperatures but the same threat: failure of the systems that hold the body’s internal environment steady.

1. 26.1 Mechanisms of Injury and the Trauma Primary Survey
2. 26.2 Thoracic and Abdominal Trauma
3. 26.3 Pelvic and Orthopedic Trauma and Fat Embolism
4. 26.4 Rhabdomyolysis and Crush Injury
5. 26.5 Burn Pathophysiology and Fluid Resuscitation
6. 26.6 Inhalation Injury and Burn Wound Care
7. 26.7 Hypothermia, Hyperthermia, and Heat Stroke
8. 26.8 Drowning and Electrical Injury

For much of the history of intensive care, deep sedation was considered a kindness. The patient on the ventilator who lay motionless, unaware and untroubled by the tube in the throat seemed to be spared suffering, and the nurse’s workload was lighter. Experience has taught the opposite. Deep and prolonged sedation lengthens ventilation, increases delirium, hides neurologic change, promotes weakness and leaves survivors with memories of fear or no memory at all of the weeks that changed their lives. Pain, meanwhile, was undertreated precisely in the patients least able to report it. The modern approach reverses the old order: treat pain first, sedate only as much as needed, protect sleep, look actively for delirium, and get the patient awake, breathing and moving as early as safety allows.

1. 27.1 Pain Physiology and Assessment in Nonverbal Patients
2. 27.2 Opioid and Multimodal Analgesia
3. 27.3 Sedative Agents: Propofol, Dexmedetomidine, and Benzodiazepines
4. 27.4 Light Sedation Targets and Sedation Scales
5. 27.5 Daily Awakening and Spontaneous Breathing Coordination
6. 27.6 Delirium: Pathophysiology, Screening, and Prevention
7. 27.7 Management of Agitation, Withdrawal, and Neuromuscular Blockade
8. 27.8 The ABCDEF Liberation Bundle

In the poisoned patient the cause of organ failure is a specific molecule, often unknown at the moment of arrival, and the skill of the critical care nurse lies in supporting physiology while the identity and the dose of that molecule are pieced together from fragments: an empty pill bottle, a paramedic's report, a pupil size, a heart rate, a blood gas. Poisoning is common, accounting for a large share of emergency department visits and intensive care unit (ICU) admissions in the United States, and it ranges from the intentional overdose of a despondent adolescent to the accidental opioid exposure of a person who believed a counterfeit tablet was a legitimate prescription.

1. 28.1 Initial Approach to the Poisoned Patient
2. 28.2 Toxidromes and Recognition Patterns
3. 28.3 Acetaminophen and Salicylate Toxicity
4. 28.4 Opioid, Sedative, and Stimulant Overdose
5. 28.5 Alcohol Withdrawal and Toxic Alcohols
6. 28.6 Cardiotoxic Ingestions: Beta Blockers, Calcium Channel Blockers, and Digoxin
7. 28.7 Antidotes, Decontamination, and Enhanced Elimination
8. 28.8 Carbon Monoxide and Cyanide Poisoning

Every preceding chapter has taught you to rescue: to restore perfusion, to reopen an airway, to reverse a poison. Yet the intensive care unit (ICU) is also a place where many people die. A substantial fraction of patients in American hospitals who die do so after a stay in intensive care, and in many ICUs death follows a deliberate decision to stop treatments that can no longer achieve what the patient would have wanted. Learning to care well for the dying is therefore not a separate specialty that begins when critical care ends. It is a core competency of the critical care nurse, as essential as interpreting a waveform or titrating a vasopressor, and it draws on the same attention to physiology, the same precision, and the same advocacy.

1. 29.1 Principles of Palliative Care in the ICU
2. 29.2 Symptom Management at the End of Life
3. 29.3 Withdrawal of Life-Sustaining Therapy
4. 29.4 Supporting Families Through Dying and Death
5. 29.5 Brain Death, Circulatory Death, and Donation Pathways
6. 29.6 Donor Management and the Nurse's Role
7. 29.7 Organ Transplant Recovery in the ICU
8. 29.8 Grief, Bereavement, and Caregiver Support

Everything in this book so far has described what happens to a patient: the physiology that fails, the monitoring that reveals it, and the treatments that restore it. The patient, however, lives inside a system, and much of what determines whether a critically ill person leaves the hospital alive, and in what condition, is decided not by any single dramatic intervention but by the reliability of ordinary care. A central line that is inserted with every barrier precaution, a turn that is performed every two hours, a medication that is checked against the order by two people, and a nurse who speaks up when something looks wrong are less glamorous than a thrombectomy or an extracorporeal circuit, yet they prevent a large share of the harm that hospitalized patients suffer.

1. 30.1 Infection Prevention: CLABSI, CAUTI, and Isolation Practice
2. 30.2 Pressure Injury Prevention and Skin Integrity
3. 30.3 Falls, Medication Errors, and Just Culture
4. 30.4 Post-Intensive Care Syndrome and ICU Survivorship
5. 30.5 Telehealth and Tele-ICU
6. 30.6 Evidence-Based Practice and Quality Improvement
7. 30.7 Burnout, Compassion Fatigue, and Resilience
8. 30.8 Career Pathways, Certification, and Lifelong Learning