A 61-year-old housewife was brought to the hospital with progressive breathlessness of three weeks duration. The candidate asked whether she got more breathless on lying down and how many pillows she took. She said she was comfortable resting in bed and took only one pillow. Her care giver, a daughter, said the she only took one pillow but became breathless soon after lying down and spent most of the night sitting up in bed.
Is she orthopneic? Does she have paroxysmal nocturnal dyspnoea? Asked if she spent the night lying down; she said no I am more comfortable sitting in an armchair. Yes she has orthopnoea and not PND. Some patients like to downplay their symptoms, some have not realised what is happening to them or are in denial. Listen to what they say and interpret the disability.
She had a cough, which was dry. The candidate did not ask about wheezing. She said the she was so breathless that she found it difficult to walk to the bathroom. The candidate interpreted this as grade 4 dyspnoea AHA classification. She was not asked when she was able to carry out her usual activity and what her usual level of activity was. When asked by the tutor the patient said that 3 weeks ago she had been able to go to the market about 200 yards from her home to buy vegetables and fruit for daily consumption. She cooked the food assisted by her daughter, washed the pots and pans and washed her own clothes and hung them out to dry. She had not been able to get out of bed for three weeks or perform any of these tasks. This suggests sudden onset of breathlessness not progressive breathlessness as is listed in the cardiac causes of breathlessness in the various classifications used.
She said she had no chest pain even on deep breathing. The patient denied that she had fever but the caregiver said “Yes there was fever, very high for a day or two and then it had settled to “normal” but had not been checked with a thermometer” By “normal” she meant that the fever had settled to a lower degree. The candidate immediately asked if she had chills and had rigors repeatedly. When asked “Is this question appropriate?” the candidate said yes because she may have had malaria. The question was justified but this answer was not. Malaria does not present with the sudden onset of breathlessness and a dry cough. Chest pain occurs in 30 percent of cases of pneumonia, chills in 40 to 50 percent, and rigors in 15 percent. Rigors are not recurrent as the fever does not rise and fall rapidly. If a patient with pneumonia has shaking chills the illness is severe. Because of the rapid onset of symptoms, most individuals seek medical care within the first few days.
What was the right answer? “I am thinking of community acquired pneumonia. Chills are felt at the onset by 40% of patients and 15% may have a rigor at the onset.”
Common clinical features of CAP include cough, fever, pleuritic chest pain, dyspnea, and sputum production. Mucopurulent sputum production is most frequently found in association with bacterial pneumonia, while scant or watery sputum production is more suggestive of an atypical pathogen. Although there are classic descriptions of certain types of sputum production and particular pathogens (eg, pneumococcal pneumonia and rust-colored sputum), these clinical descriptions do not help in clinical decision-making regarding treatment because they are rarely seen. Other common features are gastrointestinal symptoms (nausea, vomiting, diarrhea) and mental status changes. Chest pain occurs in 30 percent of cases. Fever may not be seen in 20% of patients specially the elderly. An evening rise in the body temperature is part of the diurnal variation in body temperature and is not significant clinically. This lady was afebrile at the time of examination. She had no GI symptoms or mental status changes, had not had swollen ankles.
She had no previous history of diabetes, hypertension or heart disease. She had not needed to consult a doctor before this illness.
On examination she was not toxic or flushed. She had no audible wheeze. Her temperature was 98.8 degrees F, pulse was 110/min, BP 110/70 mmHg, respiratory rate was 28/min. She was not cyanosed and was breathing comfortably sitting up.
What importance should be given to the breathlessness? Does it fit in with CAP? If large areas of the lung are affected there will be significant breathlessness with a low PaO2. Look for an associated pathology like a pleural effusion or collapse consolidation. What will you look for in the clinical examination of the chest? Check the trachea and apex beat. If they are displaced towards the side of the rest of the abnormal signs then think of collapse and if they have moved away from the side of the lesion think of a massive effusion. A neutral position may make you think again. Check the vocal fremitus, dulness to percussion, bronchial or decreased breath sounds, vocal resonance and maybe try to detect whispering pectoriloqy. The vocal fremitus is considered obsolete in the West but remember in the under privileged countries where an X-ray may not be affordable and sometimes the health professional is not even provided with a stethoscope it can be a useful sign with which 3rd world physicians should be familiar.
This lady had dulness to percussion on the left lower chest with absent breath sounds in the lower chest and bronchial breath sounds above that, The VR and VF were increased in the mid chest on the left and absent below that. The candidate had only examined in the front and interpreted this as a consolidation in the lingula, The signs were more marked at the back indicating a lower lobe pathology; the pleural effusion was missed clinically. On what should you base your diagnosis? Tachypnoea, tachycardia, fever, chest pain, cough, sputum, breathlessness and clinical findings keeping in mind that not all of these will be present plus the interpretation of the clinical signs you have detected.
What is the next step? Check for signs of congestive heart failure: JVP, peripheral edema, a palpable liver. An ECG done at the bedside will help rule out a recent cardiac event. Atrial fibrillation and right BBB or right ventricular strain pattern may be seen in extensive pneumonia. An X-ray of the chest is the most useful investigation. In consolidation with organisms such as pneumococci a dense opacity with an air bronchogram is usually seen. A pleural effusion shows as a dense, homogenous opacity in the costophrenic angle with a curving concave surface at the top caused by movement of the fluid by capillary action. A horizontal fluid line will be seen if there is air in the pleural cavity i.e. hydropneumothorax. A fluid line will also be seen in a fluid filled cavity or wherever there is a fluid air interphase. An X-ray cannot reliably differentiate between a bacterial typical or atypical pneumonia or a viral pneumonia.
Co-morbidities which affect the type of pneumonia or severity of pneumonia can be medical ( diabetes, ischemic heart disease, organ transplant, neoplasia either hematopoetic or solid organ, liver failure or renal failure, diseases requiring immunosuppresion) or respiratory (chronic bronchitis, asthma, emphysema, bronchiectasis, previous tuberculosis or interstitial fibrosis). Do remember this when taking the history. If you prepare a list of questions to ask you will not have to scratch your head in front of the examiner. However do learn to modify your list of questions depending on the type of patient you have and the clinical situation.
What if the X-ray chest is clear? If the X-ray is done too early the consolidation may not be visible. Repeat it after an interval of 24 hours and after hydrating the patient. Do a high-resolution CT scan. This will show infiltrates, cavities and hilar lymph nodes better. CT scanning is not generally recommended for routine use because the data for its use in CAP are limited, the cost is high, and there is no evidence that it improves the outcome. Thus, a chest radiograph is the preferred method for initial imaging, with CT scan or magnetic resonance imaging (MRI) reserved for further anatomical definition (eg, detecting cavitation, adenopathy, or mass lesions).
Other laboratory tests that are needed: leucocyte count, hemoglobin, platelet count, (it is preferable to say these individually rather than a blood CP or CBC. Also give reasons for why you need them i.e. for determining the severity of the infection or to help decide if antibiotics are needed), serum creatinine, arterial blood gases and pH of blood, BUN and electrolytes specially sodium and potasium, check out the serum bilirubin (hemolysis can occur in DIC and severe pneumonia), liver enzymes, blood sugar. Think of any thing else that is appropriate to the clinical situation. Urine analysis, specially ketones.
Determine the severity of the illness. This will help you determine the appropriateness of care i.e. whether you can treat the patient as an outpatient, in the ward or in the ICU. Severity of illness is the most critical factor in making this determination, but other factors should also be taken into account. These include the ability to maintain oral intake, likelihood of medication adherence, history of active substance abuse, mental illness, cognitive or functional impairment, and living or social circumstances (eg, homelessness, the family support system’s ability to provide adequate care, residence too far from a healthcare facility that precludes timely return to care in the event of clinical worsening). All this should be included in the socio-economic history.
How do you determine the severity of the pneumonia? Clinical judgment is the best or use the Pneumonia Severity Index (PSI). Determine if there is septic shock or respiratory failure. If there is they go to the ICU preferably one with facilities for ventilatory support. An early transfer to such a facility is recommended.
The PSI stratified adults with radiographic evidence of pneumonia into five classes for risk of death from all causes within 30 days of presentation. Predictor variables were based upon the medical history, physical examination, and selected laboratory and radiographic findings readily available at the time of patient presentation. In contrast with previous prediction rules, the PSI application uses two steps that parallel decision-making processes the physician usually follows during a patient encounter.
Step 1 of the rule identifies patients in the lowest risk class (risk class I) without using laboratory tests based upon the absence of 11 demographic, comorbid conditions, and physical examination findings.
These factors consist of:
a) Age >50 years.
b)The presence of coexisting conditions: Neoplastic disease. Heart failure. Cerebrovascular disease. Renal disease. Liver disease
c) The presence of physical examination abnormalities: Altered mental status. Pulse ≥125/minute. respiratory rate ≥30/minute. Systolic blood pressure <90 mmHg. Temperature <35°C or ≥40°C.
If no Step 1 factors exist, patients are assigned to the lowest severity risk class I; if one or more risk factors are present, the evaluation of illness severity proceeds to Step 2.
Step 2 considers laboratory and radiographic information and stratifies the remaining patients into risk classes II, III, IV, or V based upon the total number of points assigned to each risk factor identified.
A total point score is computed by adding the patient age in years (years minus 10 for females) and the points for each applicable risk factor. Total scores of 70 or under correspond to class II, 71 to 90 to class III, 91 to 130 to class IV, and over 130 to class V (calculator 1). In the derivation and validation of the PSI, any variables with missing information were considered to be normal. There are limitations to the PSI so consider the following factors also:
- Female sex.
- Presentation at a specific inner city hospital (this represents people from overcrowded and inadequate housing, poor financial circumstances and prevalent infections)
- Diminished premorbid functional status
- Comorbidities (eg, chronic obstructive pulmonary disease [COPD], asthma, heart disease, inflammatory bowel disease)
- Active substance abuse
- Psychiatric illness
- Respiratory rate ≥28 breaths/min
- Shaking chills, shortness of breath, nausea, or diarrhea.
- Which hospital did this patient report to first? If she was transferred to another hospital what was the reason for referral.
- Has she had recurrent shaking chills? (For heavens sake do not think of malaria and malaria and malaria only).
- Substance abuse can be cigarettes, niswar, alcohol or hard drugs. Subtler forms are long-term use of sleeping tablets or pills to reduce “tension”. These are either overprescribed or are available over the counter in most third world countries. Lexatonil, Xanax and its variants, diazepam are special favorites as are pain medication which contain opioids. What medicines does the patient take for sleep or to reduce mental tension and how long has she been taking them?
- Does she have asthma, chronic cough and does she take steroids for either disease?
- Has she had a heart attack or stroke in the past?
- Was she bed ridden before the start of her current symptoms?
- Will the family be able to afford domiciliary oxygen, a visiting nurse.
- How have you determined the severity of the pneumonia?
- What are the limitations of this system?
CURB-65 and CRB-65 scores — The CURB-65 score is based upon five easily measurable factors from which its name is derived
- Confusion (based upon a specific mental test or new disorientation to person, place, or time)
- Urea (blood urea nitrogen in the United States) >7 mmol/L (20 mg/dL)
- Rrespiratory rate ≥30 breaths/minute
- Blood pressure (BP; systolic <90 mmHg or diastolic ≤60 mmHg.
- Age ≥65 years
Viva questions. What is the benefit of checking the mental status in a patient with pneumonia? Why should you check the respiratory rate frequently if the patient is not on machine monitoring? How does renal function affect the prognosis of pneumonia? When will you say the patient has multiorgan failure?
Another scoring system can be used for patients who are admitted to a hospital.
SCAP — The severe community-acquired pneumonia (SCAP) score was developed as a simplified method for predicting in-hospital mortality, need for mechanical ventilation, and risk for septic shock. The following criteria were independently associated with severe CAP:
- Major criteria:
- Arterial pH <7.30 – 13 points
- Systolic blood pressure <90 mmHg – 11 points
- Minor criteria:
- Respiratory rate >30 breaths/minute – 9 points
- PaO2/FiO2 <250 mmHg – 6 points
- Blood urea nitrogen >30 mg/dL (10.7 mmol/L) – 5 points
- Altered mental status – 5 points
- Age ≥80 years – 5 points
- Multilobar/bilateral infiltrates on radiograph – 5 points
Other scoring systems in addition use arterial oxygen saturation, leucocyte count and platelet count as well.
DSA/ATS severity criteria — The 2007 Infectious Diseases Society of America (IDSA)/American Thoracic Society (ATS) consensus guidelines identified two major criteria for requiring admission to an intensive care unit (ICU): septic shock requiring vasopressor support and requirement for mechanical ventilation.
I am putting down some information that I find most candidates have ignored in their preparation for the examination.
Most candidates come to a stop after saying “Viruses” in response to the question what pathogens other than bacteria can cause pneumonia? Please take time to read and remember the “usual” viruses that can cause pneumonia and also remember to be current with viruses being reported in the news.
What are the viruses which can cause pneumonia?
Influenza A and B, avian influenza H5N1 and H7N9, swine influenza H1N1, parainfluenza; Middle East respiratory syndrome coronavirus (MERS) a novel coronavirus, Middle East respiratory syndrome coronavirus, causing severe respiratory illness, emerged in 2012. Severe acute respiratory syndrome (SARS) another corona virus emerged from the Huangduo province in China transmitted from civet cats to humans. In the USA the Hanta virus caused an epidemic, it was transmitted by rats. Other rhino, adeno viruses can be the cause. In the Netherlands an outbreak was caused by metapneumonia virus in the community. The respiratory syncitial virus usually affects children but can affect adults also.
These are potential agents of bioterrorism that can cause respiratory symptoms. These include B. anthracis (inhalation anthrax), Yersinia pestis (pneumonic plague), F. tularensis (tularemia), C. burnetii (Q fever), Legionella spp, influenza virus, hantavirus, and ricin. It is important to remember them in areas of warfare.
Viva question: What pathogens will you look for if you are dealing with a group of refugees with severe respiratory symptoms who have recently been the target of enemy bombing? Which gases released by an enemy faction or by an industrial accident can cause respiratory symptoms?
Fungi causing pneumonia.
Fungal infection is an unusual cause of CAP in immunocompetent patients, but certain fungi (eg, Histoplasma capsulatum, Coccidioides spp, Blastomyces dermatitidis) can cause pneumonia in immunocompetent or immunocompromised patients who reside in or have visited endemic areas. The specific epidemiology of some fungal infections is therefore important as a diagnostic clue. Fungal infection is more common in immunocompromised patients, particularly those with neutropenia, those receiving chronic immunosuppressive therapy (eg, organ transplant recipients), and those infected with HIV.
How will you select an antibiotic for a patient with pneumonia?
In patients in Class 1 PSI for CAP infiltrates in the x-ray chest and a raised white cell count may be sufficient to start an antibiotic on an outpatient basis. Pathogen identification of the pathogen is required. Sputum for Gram staining, sputum culture may be sufficient for these patients, and blood cultures for more critically ill patients who require admission. Polymerase chain reaction (PCR) for detecting Chlamydia pneumoniae and Mycoplasma pneumoniae as well as 14 respiratory tract viruses are recommended. These tests are rapid (one to two hours), sensitive, and specific.
Urinary antigen — Alternative or complementary methods to detect S. pneumoniae and Legionella are urinary antigen assays. There are several advantages like the results are available within 2 hours, can be used to select the appropriate antibiotic at once, are not altered by the prior use of antibiotics, as commercial kits are available no microbiology laboratory is required but a trained technician is required and disadvantages to urine antigen testing are that they will be negative if there is no bacteremia nd no antibiotic sensitivity can be done. These tests are more specific when compared with sputum and blood culture.
PROCALCITONIN AND CRP — Procalcitonin is a serum biomarker that rises in response to bacterial infections. Because the diagnostic accuracy of procalcitonin is only moderate, it is not done routinely but can be used to aid in the diagnosis of CAP. However, some resea.rchers do typically obtain a procalcitonin level at the time of CAP diagnosis, and serially thereafter, to help determine the appropriate duration of antibiotics. CRP has more limited use.
Medical ward — In patients who require hospitalization but not admission to an intensive care unit (ICU), the most frequently isolated pathogens are S. pneumoniae, respiratory viruses (eg, influenza, parainfluenza, respiratory syncytial virus, rhinovirus), and, less often, M. pneumoniae, H. influenzae, and Legionella spp.
Intensive care unit — The distribution is different in patients with CAP who require admission to an ICU. S. pneumoniae is most common, but Legionella, gram-negative bacilli, Staphylococcus aureus, and influenza are also important.
Community-associated methicillin-resistant S. aureus (MRSA) typically produces a necrotizing pneumonia with high morbidity and mortality.
Viva question: When will you suspect gram negative pathogens causing pneumonia?
Gram-negative bacilli (including Pseudomonas) — Risk factors for CAP due to gram-negative bacilli include previous antibiotic therapy, recent hospitalization, immunosuppression, pulmonary comorbidity (eg, cystic fibrosis, bronchiectasis, or repeated exacerbations of chronic obstructive pulmonary disease that require frequent glucocorticoid and/or antibiotic use), probable aspiration, and multiple medical comorbidities (eg, diabetes mellitus, alcoholism).
Principals of antibiotic therapy.
The antibiotic should have a spectrum of effectiveness which covers the likely pathogen. For CAP being treated in the outpatients the usual choice is mono-therapy with a beta lactam (penicillin, ampicillin, cephalosporins, carbapenems) or a macrolide (clarithromucin, azithromycin, roxithromycin, erythromycin) or a combination of a betalactam and macrolide or monotherapy with a respiratory quinolone (moxifloxacin and levofloxacin). You should know the routes of administration and the dosage and duration of therapy.