35.1 Assessment and Management of the Critically Ill Patient

Critical care nursing is a specialty of its own, requiring astute clinical judgement and critical thinking, due to the complexity of the patient’s medical challenges.
Patients are typically admitted to critical care settings because they have a life-threatening medical condition that requires intensive monitoring and extensive medical and nursing care. Often, they are experiencing dysfunction of multiple body systems.
Technological supports such as ventilators and continuous renal replacement, and pharmacological supports such as vasopressors and sedatives are commonly encountered in the care of the critically ill patient.
Nurses caring for critically ill patients will confront ethical and legal dilemmas such as organ donation, end-of-life support, and integration of legal documents such as living wills to assist with navigation of goals of care.

35.2 Cardiovascular Concerns

The underlying pathophysiologic mechanism of most critical cardiac conditions is a decrease in CO, which is calculated by multiplying the stroke volume by the heart rate. The three main factors that affect stroke volume are preload, afterload, and contractility.
Assessment of cardiovascular insult typically requires the insertion of arterial catheters and pulmonary artery catheters, which monitor CO, cardiac index, and other hemodynamic parameters. Other diagnostic tests and procedures used in critical care settings to evaluate the function of the cardiovascular system include chest radiography, 12-lead electrocardiograms, echocardiograms, and cardiac catheterization.
The care plan for a critically ill client with cardiovascular insult may include both pharmacological supports (typically vasoactive medications, which exert their effects on blood vessels) and technological therapies such as IABPs, ECMO, and external or transcutaneous pacing.
Cardiovascular deviations in the critically ill patient may be complicated by cardiogenic shock, which commonly results from an MI, or heart attack.
Nursing care of the critically ill patient experiencing cardiovascular dysfunction follows the Clinical Judgment Measurement Model, including frequent assessments of the cardiovascular system and close monitoring of hemodynamic parameters. The nurse is also responsible for administering and titrating medications and maintaining invasive therapies such as IABPs and ECMO.

Respiratory failure and the development of ARDS is common in critically ill patients, with the incidence increasing over the past several years due to the COVID-19 pandemic.
Pertinent assessments for critically ill patients with respiratory dysfunction include monitoring blood gases to determine CO₂ and oxygen levels, listening to lung sounds, and placing an ETT tube.
Nursing interventions for ARDS include maintenance of the mechanical ventilator, prevention of VAP, and participation in SBTs.
Effective care of the respiratory system and prevention of complications have the potential to significantly improve overall patient outcomes.

The underlying pathophysiologic mechanism behind many neurological disorders observed in critical care settings is due to increased ICP. Alterations in ICP can occur due to trauma, infection, or bleeds.
Assessments require close monitoring of neurological findings such as LOC, pupillary response, posturing, or deviations in hemodynamics (i.e., abnormal respiration)
Interventions for increased ICP include frequent neurological assessments; administration of medications, including steroids and diuretics; optimal patient positioning to promote drainage of CSF; and decreasing the body’s metabolic demands.
By intervening early and treating increased ICP, there is a better chance to prevent severe, permanent neurological disability.

The most common GI condition that results in ICU admission is the presence of acute GI bleeding, often related to ruptured stress ulcers or esophageal varices.
Providers may observe hemodynamic instability, as evidenced by low blood pressure, active bleeding in the stools, or decrease in the CBC. The patient may report dizziness, abdominal pain, poor appetite, or bloody vomitus or stools.
Interventions for acute GI bleeding include administration of medications, maintenance of hemodynamic stability, and NGT insertion.

Physiological insult to the kidneys that is commonly encountered in critical care is AKI, which can have prerenal, infrarenal or postrenal causes. AKI reduces the kidneys’ ability to filter toxins from the bloodstream and maintain fluid balance.
Diagnosing AKI involves close evaluation of serum laboratory values, especially levels of creatinine and BUN. Trends in GFR should also be monitored closely to determine the level of functioning of the kidneys.
Pharmacological interventions for AKI typically focus on maintaining optimal fluid and electrolyte balance. Hyperkalemia is a particular concern. Because many medications, most notably antibiotics, are nephrotoxic, patients should receive the lowest possible doses to prevent worsening of the kidney injury.
When caring for patients with AKI, nursing interventions center around maintaining a normal fluid and electrolyte balance and administering appropriate medications to restore kidney function. Nursing assessments include monitoring vital signs, urine output, and weight.

Integumentary pathophysiological insult results from multiple variables that place the critical care patient at risk, including nutritional problems, immobility, fluid shifts, and incontinence.
Skin breakdown in critical care settings can contribute to necrosis and the development of life-threatening infections, increasing the overall length and cost of hospitalizations. Therefore, diligent skin care should be a high priority for critical care teams.
Assessment of skin should occur every shift. Risk assessment models such as the Braden Scale help identify patients at risk, given their mobility, skin integrity, nutritional status, and skin moisture.
Interventions for the prevention of skin breakdown in critical care settings include frequent manual patient repositioning and use of specialty beds and prophylactic skin dressings.
The prevention of skin breakdown in the ICU involves an interdisciplinary care team to limit the risk of pressure injury development.

The most frequently encountered musculoskeletal problems in critically ill patients are muscle atrophy and contractures, both of which are related to prolonged immobility and bedrest.
Prevention and treatment of muscle atrophy and contractures in the ICU should be a priority of nursing care to reduce the risk of permanent physical disability after discharge.
Interventions for the prevention of muscle atrophy and contractures include frequent musculoskeletal assessments and promotion of early mobility.
Implementation of early mobility in critical care settings requires interdisciplinary collaboration and knowledge about the complexity of the patient’s medical condition and physical limitations.