Cerebrospinal Fluid Analysis.

Cerebrospinal fluid (CSF) analysis is a diagnostic tool for many conditions affecting the central nervous system. Urgent indications for lumbar puncture include suspected central nervous system infection or subarachnoid hemorrhage. CSF analysis is not necessarily diagnostic but can be useful in the evaluation of other neurologic conditions, such as spontaneous intracranial hypotension, idiopathic intracranial hypertension, multiple sclerosis, Guillain-Barré syndrome, and malignancy. Bacterial meningitis has a high mortality rate and characteristic effects on CSF white blood cell counts, CSF protein levels, and the CSF:serum glucose ratio. CSF culture can identify causative organisms and antibiotic sensitivities. Viral meningitis can present similarly to bacterial meningitis but usually has a low mortality rate. Adjunctive tests such as CSF lactate measurement, latex agglutination, and polymerase chain reaction testing can help differentiate between bacterial and viral causes of meningitis. Immunocompromised patients may have meningitis caused by tuberculosis, neurosyphilis, or fungal or parasitic infections. Subarachnoid hemorrhage has a high mortality rate, and rapid diagnosis is key to improve outcomes. Computed tomography of the head is nearly 100% sensitive for subarachnoid hemorrhage in the first six hours after symptom onset, but CSF analysis may be required if there is a delay in presentation or if imaging findings are equivocal. Xanthochromia and an elevated red blood cell count are characteristic CSF findings in patients with subarachnoid hemorrhage. Leptomeningeal carcinomatosis can mimic central nervous system infection. It has a poor prognosis, and large-volume CSF cytology is diagnostic.

Otolaryngeal and Oropharyngeal Conditions: Common Ear Conditions.

Ear pain (otalgia) is a common reason for visits to family physician offices and emergency departments. Otalgia is primary when the pathology originates from the ear, and is secondary for disease processes associated with otalgia and an ear examination with normal findings. The most common diagnosis related to otalgia in children and adults is acute otitis media (AOM). It is characterized by an erythematous, bulging, and cloudy tympanic membrane. Otitis media with effusion is the presence of fluid behind the tympanic membrane without signs of inflammation. Chronic middle ear effusion is managed definitively with myringotomy and tympanostomy tube placement. Tympanic membrane rupture is a common complication after AOM or trauma. Tympanic membranes that do not heal develop chronic infection, leading to chronic suppurative otitis media. Initial management is cleaning and drying of the ear and application of topical antibiotics. Otitis externa is a painful cellulitis of the external auditory canal associated with erythema, edema, and occasional drainage. Cerumen impaction is managed with cerumenolytics, irrigation, or manual extraction. Foreign bodies in the ear are common in children younger than 6 years. Many foreign bodies can be removed with irrigation or forceps.

Respiratory Conditions: Upper Respiratory Tract Infections.

Upper respiratory tract infections (URTIs) include the common cold, rhinosinusitis, pharyngitis, and acute otitis media (AOM). URTIs account for billions of dollars in annual health care costs; acute respiratory tract infections are the most common reason for acute care appointments. Although URTIs typically are viral, these infections are the most common reason for prescription of antibiotics in adults. Recommended therapy for the common cold involves symptom management with over-the-counter drugs, though the Food and Drug Administration advises against use of these drugs in children younger than 6 years. Acute rhinosinusitis also typically is viral. A bacterial etiology is more likely if symptoms last longer than 10 days, the temperature is greater than 39°C (102.2°F), or if symptoms worsen after initial improvement. Antibiotics are not recommended unless symptoms worsen or do not improve after an additional 7 days. Acute pharyngitis also typically is of viral origin. Antibiotics for streptococcal pharyngitis should be prescribed only if test or culture results are positive. AOM can be managed without antibiotics except in children younger than 6 months, children ages 6 to 23 months with bilateral AOM, children older than 2 years with bilateral AOM and otorrhea, and certain high-risk patients.

Respiratory Conditions: Lower Respiratory Tract Infections.

Acute bronchitis and pneumonia are conditions commonly diagnosed in inpatient and outpatient settings. Acute bronchitis is a lower respiratory tract infection characterized by cough, with or without sputum production, lasting 1 to 3 weeks. It typically is viral. Testing for influenza should be obtained in patients at high risk of influenza complications. Antibiotics are not indicated in patients without chronic lung disease unless Bordetella pertussis infection is suspected. If pertussis is confirmed, macrolide antibiotics should be prescribed. Otherwise, symptom control and patient education are key to management. Community-acquired pneumonia (CAP) is a leading cause of death in children and adults. Diagnosis is based on symptoms and imaging study results. Ultrasonography is more accurate than chest x-rays. Severity scoring systems are used to aid clinical judgement in selecting inpatient versus outpatient management. Antibiotics should be administered according to current guidelines. Hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP) are nosocomial infections with high mortality rates. Microorganisms responsible for HAP and VAP have high rates of resistance and vary based on geographic regions. Implementation of prevention protocols has decreased rates of VAP.

Respiratory Conditions: Interstitial Lung Disease.

Interstitial lung disease (ILD) includes approximately 100 separate conditions that fall into four main categories: conditions with known etiologies (eg, connective tissue disease), granulomatous diseases, idiopathic interstitial pneumonias, and miscellaneous conditions. Most patients report unexplained exertional dyspnea that develops insidiously over a variable period. Cough also is common. Because the clinical manifestations of ILD mimic those of other lung diseases, comprehensive testing almost always is required. Testing typically includes chest imaging, pulmonary function testing, and basic laboratory tests. If findings are not consistent with common diagnoses, such as chronic obstructive pulmonary disease, additional testing with high-resolution computed tomography scan and bronchoscopy or surgical lung biopsy can help confirm the diagnosis and type of ILD. Depending on the type, therapy can involve management of the underlying disease (eg, management of an autoimmune condition) or symptomatic treatment. Several drugs and interventions are available to help alleviate symptoms, slow progression, and, in some cases, reverse the condition. In cases of refractory disease, lung transplantation may be required. For patients with progressive disease and contraindications to transplantation, palliative care measures should be considered.

Evaluating Medical Decision-Making Capacity in Practice.

Medical decision-making capacity is the ability of a patient to understand the benefits and risks of, and the alternatives to, a proposed treatment or intervention (including no treatment). Capacity is the basis of informed consent. Patients have medical decision-making capacity if they can demonstrate understanding of the situation, appreciation of the consequences of their decision, and reasoning in their thought process, and if they can communicate their wishes. Capacity is assessed intuitively at every medical encounter and is usually readily apparent. However, a more formal capacity evaluation should be considered if there is reason to question a patient's decision-making abilities. Such reasons include an acute change in mental status, refusal of a clearly beneficial recommended treatment, risk factors for impaired decision making, or readily agreeing to an invasive or risky procedure without adequately considering the risks and benefits. Any physician can evaluate capacity, and a structured approach is best. Several formal assessment tools are available to help with the capacity evaluation. Consultation with a psychiatrist may be helpful in some cases, but the final determination on capacity is made by the treating physician. If a patient is found not to have capacity, a surrogate decision maker should be identified and consulted. If the patient is unable to give consent and identifying a surrogate decision maker will result in a delay that might increase the risk of death or serious harm, physicians can provide emergency care without formal consent.