CHAPTER 2 Managing the critical care environment
Bioterrorism
1. Most people are susceptible to these organisms.
3. They are fairly stable in aerosolized form.
4. Because of reason 3, they can cause disease in a large group of individuals.
Bioterrorism assessment: surveillance
Goal of surveillance
The goal is to detect a biological event as early as possible to limit the spread of the infection.
Key signs
Bioterrorism should be suspected when the following situations are seen:
• An outbreak of an illness within a short period of time; similar to one that happens in a healthy population, without a link to explain the transmission such as a similar food source
• An outbreak of an illness that occurs at an unusual time of year
• An outbreak with an unusual age distribution
• A large cluster of patients are affected by an uncommon disease, which is resulting in a higher than expected death rate.
• The severity of the disease is increased with patients having unusual routes of exposure.
• Strains of organisms seen have unusual antibiotic resistance.
• Those indoors are not as affected as or “as are those” those who have been outdoors.
• With some strains, an increased number of dead animals is noted.
• Those presenting within 48 to 72 hours of exposure have likely been exposed to a biological agent, as opposed to those exposed to a toxin, who present within a few hours.
Report
• All occurrences of these six diseases must be reported to the CDC, as they are considered Category A agents, the highest priority for monitoring.
• CDC also monitors Category B organisms (includes Brucellosis [Brucella sp.], epsilon toxin of Clostridium perfringens, food safety threats [e.g., Salmonella sp., Escherichia coli O157:H7, Shigella], Glanders [Burkholderia mallei], melioidosis [Burkholderia pseudomallei], psittacosis [Chlamydia psittaci], Q fever [Coxiella burnetii], ricin toxin from Ricinus communis [castor beans], staphylococcal enterotoxin B, typhus fever [Rickettsia prowazekii], viral encephalitis [alphaviruses, e.g., Venezuelan equine encephalitis, Eastern equine encephalitis, Western equine encephalitis], and water safety threats [e.g., Vibrio cholerae, Cryptosporidium parvum]). These organisms are the second highest priority.
Anthrax
Assessment
The symptoms (warning signs) of anthrax differ depending on the type of the disease:
• Inhalation: The most serious form with the highest mortality rate, this begins 1 to 6 days after exposure with cold or influenza (flu)-like symptoms, with sore throat, mild fever, and muscle aches. Later symptoms include cough, chest discomfort, shortness of breath, fatigue, and muscle aches. Inhalation anthrax quickly progresses to respiratory failure and shock. Chest radiograph reveals a widened mediastinum and pleural effusions.
• Cutaneous: The first symptom is a raised, itchy bump that develops into a blister, seen 1 to 7 days after exposure. The blister progresses to a skin ulcer with a blackened center. The sore, the blister, and the ulcer are painless. Fever, headache, and swollen glands may occur.
• Gastrointestinal: At 2 to 5 days after exposure, the person exhibits nausea, loss of appetite, bloody diarrhea, and fever, followed by severe stomach pain. If untreated, it can progress to generalized toxemia and sepsis.
Collaborative management
Care priorities
2. Intubation and mechanical ventilation (inhalation):
To support gas exchange and help maintain acid-base balance.
3. Intravenous fluids (inhalation and gastrointestinal):
To prevent dehydration and maintain adequate circulatory volume.
CARE PLANS: ANTHRAX
related to respiratory insufficiency from respiratory infection secondary to inhalation of anthrax.
Respiratory Status: Gas Exchange
1. Monitor rate, rhythm, and depth of respirations.
2. Note chest movement for symmetry of chest expansion and signs of increased work of breathing such as use of accessory muscles or retraction of intercostal or supraclavicular muscles.
3. Monitor for diaphragmatic muscle fatigue.
4. Ensure airway is not obstructed by tongue (snoring or choking type respirations) and monitor breathing patterns. New patterns that impair ventilation should be managed as appropriate for setting.
5. Auscultate breath sounds noting areas of decrease/absent ventilation and presence of adventitious sounds.
6. Note changes in oxygen saturation from arterial blood gases (SaO2), pulse oximetry (SpO2), and end-tidal CO2 (ETCO2) as appropriate.
7. Monitor for increased restlessness or anxiety.
8. If increased restlessness or unusual somnolence occurs, evaluate patient for hypoxemia and hypercapnia as appropriate.
9. Monitor chest x-ray reports as new films become available.
1. Administer supplemental oxygen using liter flow and device as ordered. Add humidity as appropriate.
2. Restrict patient and visitors from smoking while oxygen is in use.
3. Document pulse oximetry with oxygen liter flow in place at time of reading as ordered. Oxygen is a drug; the dose of the drug must be associated with the oxygen saturation reading or the reading is meaningless.
4. Obtain arterial blood gases (ABGs) if patient experiences behavioral changes or respiratory distress, to check for hypoxemia or hypercapnia.
5. Monitor for changes in chest radiograph and breath sounds indicative of oxygen toxicity and absorption atelectasis in patients receiving higher concentrations of oxygen (more than FIO2 45%) for longer than 24 hours. The higher the oxygen concentration, the greater is the chance of toxicity.
6. Monitor for skin breakdown where oxygen devices are in contact with skin, such as nares and around edges of mask devices.
7. Provide oxygen therapy during transportation and when patient gets out of bed.
1. Monitor for conditions indicating a need for ventilation support.
2. Monitor for impending respiratory failure.
3. Consult with other health care personnel in selection of the ventilatory mode.
4. Administer muscle-paralyzing agents, sedatives, and narcotic analgesics as appropriate.
5. Monitor the effectiveness of mechanical ventilation on the patient’s physiologic and psychological status.
6. Provide patient with means of communication.
7. Monitor adverse effects of mechanical ventilation.
8. Perform routine mouth care.
9. Elevate the head of the bed (HOB) up to 45 degrees as tolerated.
Botulism
Pathophysiology
Assessment
• Foodborne: Double vision, drooping eyelids, slurred speech, dysphagia, dry mouth, and descending muscle weakness are symptoms. Weakness starts in the shoulders and upper arms, descends to the lower arms and upper thighs, and eventually spreads down to the lower legs and feet. Paralysis of the respiratory muscles leads to respiratory failure unless ventilation is supported with mechanical ventilation. Patients are generally afebrile and alert.
• Respiratory assessment: Patients who are not intubated should have their respiratory status monitored closely to detect deterioration in respiratory muscle strength. One of the best assessment tools is periodic measurement of negative inspiratory force (NIF). If the NIF falls below 20 cm H2O, the patient is likely to require intubation and mechanical ventilation.
Collaborative management
Care priorities
CARE PLANS: BOTULISM
Breathing pattern, ineffective
related to respiratory infection
Respiratory Status: Ventilation
1. Monitor rate, rhythm, depth, and effort of respirations.
2. Monitor for diaphragmatic muscle fatigue.
3. Auscultate breath sounds, noting areas of decreased/absent ventilation and presence of adventitious sounds.
4. Assess for breathing effectiveness by monitoring SaO2, SvO2, ETCO2, and changes in ABG values, as appropriate.
5. Insert oral or nasopharyngeal airway if patient cannot maintain patent airway; if severely distressed, patient may require endotracheal intubation.
1. Position patient to alleviate dyspnea and insure maximal ventilation, generally in a sitting upright position unless severe hypotension is present.
2. Assist with incentive spirometer, as appropriate.
3. Clear secretions from airway by having patient cough, or provide nasotracheal, oropharyngeal, or endotracheal tube suctioning as needed.
4. Have patient breathe slowly or manually ventilate with Ambu bag slowly and deeply between coughing or suctioning attempts.
5. Turn patient every 2 hours if immobile. Encourage patient to turn self or get out of bed as much as tolerated if able to do so.
Hemorrhagic fever viruses
Pathophysiology
Hemorrhagic fever viruses (HFVs) include many diseases separated into four families of viruses; not all are viewed as risks for bioterrorism. Those that are thought to pose a significant risk include Ebola virus disease, Marburg virus disease, Lassa fever, New World Arenaviridae, Rift Valley fever, yellow fever, Omsk hemorrhagic fever, and Kyasanur Forest disease. The pathophysiology of these diseases is not well understood. Outbreaks are sporadic and have occurred in areas with very limited health care. Infection with these viruses leads to thrombocytopenia and possibly platelet dysfunction. The effects of these viruses vary, but all lead to coagulation problems, hemorrhage, and shock. Mortality ranges range from less than 1% with Rift Valley fever to 50% to 90% with Ebola virus. Only one of the Arenaviridae viruses has been identified in the United States. Other HFVs have not emerged.
Assessment
Clinical scenarios vary depending on the virus. The most common symptom is a fever.
• Ebola and Marburg: Maculopapular rash, bleeding, disseminated intravascular coagulation, jaundice.
• Lassa fever and New World arenaviruses: Gradual onset of fever, nausea, abdominal pain, conjunctivitis, and jaundice. Severe exudative pharyngitis in Lassa fever.
• Rift Valley fever: Fever, headache, photophobia, and jaundice.
Plague
Pathophysiology
Plague is an infectious disease caused by the bacterium Yersinia pestis that is found in rodents and their fleas. Several forms of plague can occur individually or in combination: bubonic, pneumonic, and septicemic plague. Bubonic plague is the most common, occurring when an infected flea bites a human or when infectious materials enter through a break in the skin. Pneumonic plague occurs when Y. pestis infects lungs through direct or close contact with a person who has pneumonic plague or in untreated patients with bubonic or septicemic plague, allowing bacterial spread to lungs. Septicemic plague can occur as a complication of either of the previous types of plague or alone. The bacteria enter the bloodstream and multiply, prompting the systemic effects of sepsis.
Assessment
• Pneumonic plague: Fever, headache, weakness, and rapidly developing pneumonia with shortness of breath, chest pain, cough, and sometimes bloody or watery sputum. The pneumonia progresses and in 2 to 4 days can cause respiratory failure and shock. Without treatment, patients with pneumonic plague will die.
• Bubonic plague: Swollen, tender lymph glands (called buboes), fever, headache, chills, and weakness.
• Septicemic plague: Fever and chills, abdominal pain, and shock with bleeding (due to DIC).
Smallpox (variola)
Pathophysiology
Smallpox is an excellent agent for bioterrorism because it is easy to both transport and store, because it is very stable and markedly virulent when aerosolized.
Assessment
• Clinical case definition: An illness with acute onset of fever ≥101°F (38.3°C), followed by a rash characterized by firm, deep-seated vesicles or pustules in the same stage of development without other apparent cause. These characteristics help differentiate the smallpox from chickenpox. Smallpox may be easily missed in the early stage by health care providers.
• Incubation period: Usually 12 to 14 days but can range from 7 to 17 days. During this time, the patient feels fine and is not contagious.
• Prodromal period: Begins with a high fever (101° to 104°F), malaise, headache, and backache. The patient may exhibit severe abdominal pains, vomiting, and delirium. This period lasts for 2 to 4 days before a rash develops. The rash begins with small red spots on the tongue and mouth. During this phase, the person is most contagious.
• Rash development: Progresses in the mouth and develops on the skin, starting on the face and moving to the arms and legs and then to the feet and hands. It usually spreads to all parts within 24 hours. When rash appears, the patient’s fever subsides and the patient starts to feel better. On day 3, the rash consists of raised bumps. On day 4, the bumps fill with thick, cloudy fluid with a possible indent in the center. Indentation is the classic sign of smallpox rash. The bumps become pustules and eventually scab over. During the pustule stage, the patient is again febrile. After 2 weeks, most of the sores have scabs, which begin to fall off, leaving marks that will become pitted scars on the skin.
Initial confirmation of a smallpox outbreak requires additional testing at the CDC.Collaborative management
Care priorities
A key is to identify smallpox exposure and administer vaccine within 3 days, to prevent or significantly lessen the severity of the disease process. Vaccine administered within 4 to 7 days after exposure may provide some protection and lessen the disease severity.
• Provide hydration: Intravenous fluids to prevent dehydration
• Provide nutrition: To help strengthen the immune system
• Initiate mechanical ventilation: If patient experiences respiratory failure
• Hemodynamic monitoring: If management of fluid balance and blood pressure is difficult
• Control fever: Antipyretics to reduce body temperature if greater than 103°F
• Reduce pain and anxiety: Analgesics and sedatives as indicated
CARE PLANS: SMALLPOX
related to numerous skin lesions resulting from infection with smallpox
Patient will acknowledge change in physical appearance and express a positive self-worth.
Body Image, Self-Esteem1. Use anticipatory guidance to prepare patient for predictable changes in body image.
2. Assist patient to discuss changes caused by illness.
3. Assist patient to separate physical appearance from feelings of personal self-worth.
4. Identify the effects of the patient’s culture, religion, race, sex, and age in terms of body image.
Tularemia
Assessment
• Disease presentation: May vary depending on the infecting organism, dose, and site of inoculation. It usually starts abruptly with a fever of 100.1° to 104°F (38° to 40°C), headache, chills, generalized body aches, rhinitis, and a sore throat. Some patients have dry cough, substernal pain, skin or mouth ulcers, swollen painful lymph glands, and swollen and painful eyes.
• Illness progression: Progressive weakness, malaise, anorexia, and weight loss. If untreated, symptoms may persist for several weeks to months. Secondary sepsis, pleuropneumonia, and, rarely, meningitis may develop.
