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Unit V Promoting Health in Patients With Oxygenation Disorders
Clinical Manifestations Clinical manifestations of the flu are more severe than those of a cold and have a rapid onset. They include fever, headache, sore throat, severe nasal congestion, cough, myalgia or muscle aches and pains, malaise (the general feeling of being unwell), and fatigue.
reported illnesses were 48 million, with 22 million doctors’ visits, 959,000 hospitalizations, and 79,400 deaths. A sig- nificant reduction of influenza infection was seen in both the 2019–2020 season that reported 38 million illnesses, 18 million doctors’ visits, 405,000 hospitalizations, and 22,000 deaths and the 2020–2021 season that reported 16,000 illnesses, 224 hospitalizations, and unreported number of direct influenza-related deaths. The notable decline was likely affected by mitigation strategies during the concurrent COVID-19 pandemic. Pathophysiology Human influenza viruses are divided into three types, designated as A, B, and C. Influenza A viruses are divided into subtypes based on differences in two viral proteins— hemagglutinin (H) and neuraminidase (N). Influenza B is not broken down into subtypes but can be categorized by different strains. Influenza types A and B are responsible for epidemics of respiratory illness that occur mostly during the winter months and are often associated with increased hospitalizations and deaths. The most extensive and severe outbreaks are from influenza A because of the tendency of the H and N antigens to mutate. Seasonal mutations of the viruses cause the emergence of a new and very differ- ent influenza virus and can contribute to a new pandemic. These mutations allow the viruses to escape the immune system surveillance of its host, making individuals suscepti- ble to mutated influenza infections throughout their lives. Several pathogens that have been newly identified are hanta- virus, metapneumoviruses, and coronavirus (SARS). Efforts to control the impact of influenza are focused on types A and B. Influenza C typically causes either no symptoms at all or a very mild respiratory illness. It is not associated with the occurrence of epidemics and does not have the serious public health concerns associated with influenza A and B. The primary event that initiates an influenza infection is the aerosolization of small droplets (particles less than 5 μm that settle within 3–6 feet from point of release) from an infected individual’s sneezing or coughing or by direct contact with fomites. Fomites are inanimate objects that can carry organisms and facilitate their transfer from one person to another, such as stethoscopes, scissors, or pens. The infectious agents are inhaled and become deposited on the epithelial cells of the upper respiratory tract. Over a period of approximately 4 to 6 hours, these infected cells reproduce and spread the virus to other respira- tory cells, extending the infection throughout the respi- ratory tract. The incubation period (from the time of initial droplet inhalation to symptom development) lasts approximately 18 to 72 hours. The severity of the symp- toms and subsequent illness depends on the amount of virus shed during the replication phase and the number of respiratory cells affected. Virus shedding usually ends 2 to 5 days after symptoms first appear; therefore, it is import- ant to remember that individuals are infectious for up to 7 to 10 days.
Interprofessional Management Medical Management Diagnosis
The diagnostic gold standard for identifying an influenza infection is a sampling of respiratory secretions for viral culture. The most significant drawback to this method is that viral cultures can take up to 10 days to provide con- firmation. In emergency departments and outpatient clin- ics, the most commonly used tests for influenza are called rapid influenza diagnostic tests (RIDTs) . The identifi- cation of an influenza virus infection can be made in less than 30 minutes via nasopharyngeal/throat swab or nasal washings/aspirate. The sensitivity and specificity of RIDTs can be variable depending on the manufacturer’s test used and the type of influenza virus circulating during a specific outbreak. Therefore, a negative RIDT does not necessarily mean that there is no influenza infection (a false-negative test). When using an RIDT, clinicians should not make a diagnosis solely on the basis of the test result but should also consider the patient’s symptoms and history and rely on their clinical judgment. Accepted influenza testing methods for types A and B are outlined in Table 24.2. Circulating antibodies can be detected in the blood of individuals with an influenza infection within 2 weeks after initial infection. Specific laboratory tests conducted are hemagglutination inhibition, complement-fixation, and enzyme-linked immunosorbent assay. Treatment Treatment for influenza illness is directed primarily toward prevention by annual vaccination . Inoculation by inacti- vated influenza viruses that were identified as causing out- breaks the preceding year can provide up to 80% protection from the projected upcoming year’s virus. Vaccines must be reformulated annually to match changes (mutations) in the HA protein in the viral strains predicted to circulate in the upcoming season. Side effects from vaccinations occur infrequently and consist of low-grade fever and soreness at the injection site. Individuals who have an allergy to eggs should not receive this form of the vaccine because it con- tains an inactive ingredient of an egg protein. Alternative forms of vaccine (without this protein) are available. The most appropriate time of year for vaccination is in the early fall before the “flu season” begins. Medications Medications for the treatment of mild influenza illness are directed toward the relief of symptoms. Antipyretics/ analgesics for fever and aches, adequate fluid intake to
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