Critical care is medical care for people who have life-threatening injuries and illnesses. It usually takes place in an intensive care unit (ICU). A team of specially-trained health care providers gives you 24-hour care. This includes using machines to constantly monitor your vital signs. It also usually involves giving you specialized treatments.

You need critical care if you have a life-threatening illness or injury, such as

• Severe burns
• COVID-19
• Heart attack
• Heart failure
• Kidney failure
• People recovering from certain major surgeries
• Respiratory failure
• Sepsis
• Severe bleeding
• Serious infections
• Serious injuries, such as from car crashes, falls, and shootings
• Shock
• Stroke

In a critical care unit, health care providers use lots of different equipment, including

• Catheters, flexible tubes used to get fluids into the body or to drain fluids from the body
• Dialysis machines ("artificial kidneys") for people with kidney failure
• Feeding tubes, which give you nutritional support
• Intravenous (IV) tubes to give you fluids and medicines
• Machines which check your vital signs and display them on monitors
• Oxygen therapy to give you extra oxygen to breathe in
• Tracheostomy tubes, which are breathing tubes. The tube is placed in a surgically made hole that goes through the front of the neck and into the windpipe.
• Ventilators (breathing machines), which move air in and out of your lungs. This is for people who have respiratory failure.

These machines can help keep you alive, but many of them can also raise your risk of infection.

Sometimes people in a critical care unit are not able to communicate. It's important that you have an advance directive in place. This can help your health care providers and family members make important decisions, including end-of-life decisions, if you are not able to make them.

If you get very sick or badly hurt and need help right away, you should use emergency medical services. These services use specially trained people and specially equipped facilities.

You may need care in the hospital emergency room (ER). Doctors and nurses there treat emergencies, such as heart attacks and injuries. For some emergencies, you need help where you are. Emergency medical technicians, or EMTs, do specific rescue jobs. They answer emergency calls and give basic medical care. Some EMTs are paramedics - they have training to do medical procedures on site. They usually take you to the ER for more care.

If you or someone you know needs emergency care, go to your hospital's emergency room. If you think the problem is life-threatening, call 911.

Children who have severe or life-threatening injuries need critical care. These children may be admitted to pediatric intensive care units (PICUs) in hospitals, where they receive critical care. These units are staffed by physicians with specialized training in pediatric critical care medicine ("pediatric intensivists"). Because children can experience a broad range of injury type, severity, and complexity, and because injuries can affect multiple organ systems, PICUs are staffed by and consult with many types of specialized health care providers. These include physicians, including those trained in pediatric emergency care, pediatric trauma surgeons, pediatric anesthesiologists, cardiologists, neurologists, and others. PICUs are also staffed by pediatric nurses, social workers, psychologists, and others who help guide recovery efforts for injured children and their families.

Severe cases of COVID-19 may be associated with acute respiratory distress syndrome, septic shock, cardiac dysfunction, elevations in multiple inflammatory cytokines, thromboembolic disease, and/or exacerbation of underlying comorbidities. In addition to pulmonary disease, patients with COVID-19 may also experience cardiac, hepatic, renal, and central nervous system disease. Because patients with critical illness are likely to undergo aerosol-generating procedures, they should be placed in airborne infection isolation rooms, when available.

Most of the recommendations for the management of critically ill patients with COVID-19 are extrapolated from experience with other causes of sepsis. Currently, there is limited information to suggest that the critical care management of patients with COVID-19 should differ substantially from the management of other critically ill patients, although special precaution to prevent environmental contamination by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is warranted.

As with any patient in the intensive care unit (ICU), successful clinical management of a patient with COVID-19 depends on attention to the primary process leading to the ICU admission, but also to underlying comorbidities and nosocomial complications.

Comorbid Conditions

Certain attributes and comorbidities, such as older age, cardiovascular disease, diabetes, chronic obstructive pulmonary disease, cancer, renal disease, obesity, sickle cell disease, and receipt of a solid organ transplant are associated with an increased risk of severe illness from COVID-19.

Bacterial Superinfection of COVID-19-Associated Pneumonia

Limited information exists about the frequency and microbiology of pulmonary coinfections and superinfections in patients with COVID-19, such as hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP). Some studies from China emphasize the lack of bacterial coinfections in patients with COVID-19, while other studies suggest that these patients experience frequent bacterial complications.There is appropriate concern about performing pulmonary diagnostic procedures such as bronchoscopy or other airway sampling procedures that require disruption of a closed airway circuit. Thus, while some clinicians do not routinely start empiric broad-spectrum antimicrobial therapy for patients with severe COVID-19 disease, other experienced clinicians routinely use such therapy. For the treatment of shock, however, empiric broad-spectrum antimicrobial therapy is the standard of care. Antibiotic stewardship is critical to avoid reflexive or continued courses of antibiotics.

Septic Shock and the Inflammatory Response Due to COVID-19

Patients with COVID-19 may express high levels of an array of inflammatory cytokines, often in the setting of deteriorating hemodynamic or respiratory status. This is often referred to as “cytokine release syndrome” or “cytokine storm,” although these are imprecise terms. Intensivists need to consider the full differential diagnosis of shock to exclude other treatable causes of shock (e.g., bacterial sepsis due to pulmonary or extrapulmonary sources, hypovolemic shock due to a gastrointestinal hemorrhage that is unrelated to COVID-19, cardiac dysfunction related to COVID-19 or comorbid atherosclerotic disease, stress-related adrenal insufficiency).

COVID-19-Induced Cardiac Dysfunction, Including Myocarditis

There is a growing body of literature relating COVID-19 to myocarditis and pericardial dysfunction in approximately 20% of patients. Acute cardiac injury and arrhythmias have also been described in patients with COVID-19.

Thromboembolic Events and COVID-19

Critically ill patients with COVID-19 have been observed to have a prothrombotic state, which is characterized by the elevation of certain biomarkers, and there is an apparent increase in the incidence of venous thromboembolic disease in this population. In some studies, thromboemboli have been diagnosed in patients who received chemical prophylaxis with heparinoids. Autopsy studies provide additional evidence of both thromboembolic disease and microvascular thrombosis in patients with COVID-19. Some authors have called for routine surveillance of ICU patients for venous thromboembolism. 

Renal and Hepatic Dysfunction Due to COVID-19

Although SARS-CoV-2 is primarily a pulmonary pathogen, renal and hepatic dysfunction are consistently described in patients with severe COVID-19. In one case series, continuous renal replacement therapy was needed in more than 15% of cases of critical disease. 

Considerations in Children

Several large, epidemiologic studies suggest that rates of ICU admission are substantially lower for children with COVID-19 than for adults with the disease. However, severe disease does occur in children. The risk factors for severe COVID-19 in children have not yet been established. Based on data from studies of adults and extrapolation from data on other pediatric respiratory viruses, children who are severely immunocompromised and those with underlying cardiopulmonary disease may be at higher risk for severe disease.

A new syndrome, multisystem inflammatory syndrome in children (MIS-C), which appears to be a postinfectious complication, has been described. Certain symptoms of MIS-C often require ICU-level care, including blood pressure and inotropic support. These symptoms include severe abdominal pain, multisystem inflammation, shock, cardiac dysfunction, and, rarely, coronary artery aneurysm. A minority of children with MIS-C meet criteria for typical or atypical Kawasaki disease. 

Interactions Between Drugs Used to Treat COVID-19 and Drugs Used to Treat Comorbidities

All ICU patients should be routinely monitored for drug-drug interactions. The potential for drug-drug interactions between investigational medications or medications used off-label to treat COVID-19 and concurrent drugs should be considered.

Sedation Management in Patients with COVID-19

International guidelines provide the multiprofessional ICU team with recommendations on the prevention, detection, and treatment of pain, sedation, and delirium. Sedation management strategies such as maintaining a light level of sedation, when appropriate, and minimizing sedative exposure have shortened duration of mechanical ventilation and ICU length of stay in patients without COVID-19.

The Society of Critical Care Medicine’s (SCCM’s) ICU Liberation Campaign promotes the ICU Liberation Bundle (A-F) to improve post-ICU patient outcomes. The A-F Bundle includes the following elements:

A. Assess, prevent, and manage pain;
B. Both spontaneous awakening and breathing trials;
C. Choice of analgesia and sedation;
D. Delirium: assess, prevent, and manage;
E. Early mobility and exercise; and
F. Family engagement and empowerment.

The tool also provides frontline staff with practical application strategies for each element. Incorporating the A-F Bundle using an interprofessional team model helps standardize communication among the treatment team members and improve survival and reduce long-term cognitive dysfunction of patients. Despite the known benefits of the A-F Bundle, its impact has not been directly assessed in patients with COVID-19; however, use of the Bundle should be encouraged, when appropriate, to improve ICU patient outcomes. Prolonged mechanical ventilation of COVID-19 patients, coupled with deep sedation and potentially neuromuscular blockade, increases the workload of ICU staff. Additionally, significant drug shortages may impede routine implementation of the PADIS Guidelines forcing a return to older sedatives with prolonged duration of action and active metabolites, thereby putting these patients at additional risk for ICU and post-ICU complications.

Post-Intensive Care Syndrome

Patients with COVID-19 are reported to experience prolonged delirium and/or encephalopathy associated with mechanical ventilation. Neurological complications are associated with older age and with underlying conditions, such as hypertension and diabetes mellitus. Autopsy studies demonstrate macrovascular, as well as microvascular thrombosis, with evidence of hypoxic ischemia. Adequate management requires careful attention to best sedation practices, and vigilance in stroke detection.

Post-intensive care syndrome (PICS) is a spectrum of cognitive, psychiatric, and/or physical disability that affects survivors of critical illness and persists after a patient leaves the ICU. Patients with PICS may present with varying levels of impairment including profound muscle weakness (ICU-acquired weakness), problems with thinking and judgment (cognitive dysfunction), and mental health problems, such as problems sleeping, post-traumatic stress disorder (PTSD), depression, and anxiety. ICU-acquired weakness affects 33% of all patients who receive mechanical ventilation, 50% of patients with sepsis, and ≤50% of patients who remain in the ICU for ≥1 week. Cognitive dysfunction affects 30% to 80% of patients discharged from the ICU. About 50% of ICU survivors do not return to work within 1 year after discharge. Although no single risk factor has been associated with PICS, there are opportunities to minimize the risk of PICS through medication management (A-F Bundle), physical rehabilitation, follow-up clinics, family support, and improved education about the syndrome. PICS also affects family members who participate in the care of their loved ones. In one study, a third of family members who had main decision-making roles experienced mental health problems, such as depression, anxiety, and PTSD. Early reports suggest that some patients with COVID-19 who have been treated in the ICU express manifestations of PICS. Although specific therapies for COVID-19-induced PICS are not yet available, physicians should maintain a high index of suspicion for cognitive impairment and other related problems in survivors of severe or critical COVID-19 illness.

Other Intensive Care Unit-Related Complications

Patients who are critically ill with COVID-19 are at risk for nosocomial infections and other complications of critical illness care, such as VAP, HAP, catheter-related bloodstream infections, and venous thromboembolism. When treating patients with COVID-19, clinicians also need to minimize the risk of conventional ICU complications in order to optimize the likelihood of a successful ICU outcome.

Advance Care Planning and Goals of Care

The advance care plans and the goals of care for all critically ill patients must be assessed at hospital admission and regularly thereafter. This is an essential element of care for all patients. 

To guide shared decision-making in cases of serious illness, advance care planning should include identifying existing advance directives that outline a patient’s preferences and values. Values and care preferences should be discussed, documented, and revisited regularly for patients with or without prior directives. Specialty palliative care teams can facilitate communication between clinicians and surrogate decision makers, support front-line clinicians, and provide direct patient-care services when needed.

Surrogate decision makers should be identified for all critically ill patients with COVID-19 at hospital admission. Infection-control policies for COVID-19 often present barriers to communication with surrogate decision makers, and most surrogates will not be physically present when discussing treatment options with clinicians. Many decision-making discussions will occur via telecommunication.

Acknowledgements

The Surviving Sepsis Campaign (SSC), an initiative supported by the SCCM and the European Society of Intensive Care Medicine, issued Guidelines on the Management of Critically Ill Adults with Coronavirus Disease 2019 (COVID-19) in March 2020. The COVID-19 Treatment Guidelines Panel (the Panel) has based the recommendations in this section on the SSC COVID-19 Guidelines with permission, and the Panel gratefully acknowledges the work of the SSC COVID-19 Guidelines Panel. The Panel also acknowledges the contributions and expertise of Andrew Rhodes, MBBS, MD, of St. George’s University Hospitals in London, England, and Waleed Alhazzani, MBBS, MSc, of McMaster University in Hamilton, Canada.

What is physical trauma?

Physical trauma is a serious injury to the body. Two main types of physical trauma are:

• Blunt force trauma—when an object or force strikes the body, often causing concussions, deep cuts, or broken bones.
• Penetrating trauma—when an object pierces the skin or body, usually creating an open wound.

Surgery can also cause physical trauma, sometimes called a controlled injury.

Psychological trauma is an emotional or psychological injury. It usually results from an extremely stressful or life-threatening situation.

How has basic research improved trauma patient care?

Research on how the body responds to trauma has led to advances in the following areas:

• Fluid replacement, such as saline solution for dehydration, and blood or blood substitutes for blood loss
• Wound cleaning
• Infection control
• Nutrition support, such as vitamins that support wound healing

This means people who might have died from infection or blood loss before these advances have a better chance at survival today.

What are researchers learning about how the body responds to major trauma?

Researchers are making important discoveries about how the body responds to trauma. For example:

• Research reveals that inflammation plays critical and complex roles after injury. It is needed for healing. But it can also lead to many life-threatening complications.
• Studies of gene activity show that severe injury alters a large number of genes. By taking a close look at these changes, scientists can better understand how the body responds to trauma in the short and long term. It might also point to new treatment strategies.
• Scientists have found links between the brain and the system that controls inflammation throughout the body. This work is leading to new treatments, including a way to stimulate the left vagus nerve—part of a pair of nerves that run from the brainstem through the neck and down to each side of the chest and abdomen—to control inflammation.
• Internal organs often suffer damage after a serious injury. When faced with a life-threatening injury, the body redirects blood to try to save the brain and heart. This may rob the intestines and lungs of oxygen and other vital substances. Doctors can give the patient blood and other fluids to prevent damage to other organs.
• Increasingly, researchers and doctors exchange ideas on new ways to treat severely injured patients.

What is on the horizon for trauma research supported by the National Institute of General Medical Sciences (NIGMS)?

NIGMS-funded research is directed toward an improved understanding of immediate as well as prolonged total body response to injury. This includes the following areas:

• Researchers hope to find specific genes or proteins that they could measure to better predict outcomes and guide doctors to the best treatments for each patient.
• Advances in wound care, including lab-grown cells, promise to speed healing. They may also allow a greater return to function and less scarring.
• Continued testing of experimental approaches will bring new treatments. This means patients will have fewer complications, and more of them will survive.