SA Medical - General Medicine And Imaging of Disease

Blood gases are commonly measured, and with a logical, systematic approach they may be easily interpreted. Blood gases provide information about: ventilation oxygenation and alveolar-arterial O2 gradient acid-base status Note that to convert from kiloPascals to millimetres of mercury, multiply by 7.5. The normal range for PaO2 is 11.3-13.3 kPa (82,5 to 97mmHg). A partial pressure less than 8 kPa (60mmHg) defines respiratory failure. Arterial hypoxaemia is commonly due to pulmonary disease: poor gas transfer: type I respiratory failure PaCO2 is typically low hypoventilation: type II respiratory failure PaCO2 is typically raised Arterial hypoxaemia may occur when the lungs are normal: low inspired partial pressure of oxygen e.g. altitude ventilation-perfusion mismatch right to left shunts: congenital heart disease arteriovenous malformation of the pulmonary vessels Measurement of the alveolar-arterial (A-a) gradient is useful in hypoxic patients and may help to distinguis

Auscultation of the chest should be performed in the following manner: ask patient to cough up any sputum before listening use the diaphragm of the stethoscope and consider the surface anatomy of the lungs ask the patient to breath deeply through the mouth listen at top, middle and bottom of both sides of the chest at the front and back and then in the axilla assess the character of the breath sounds assess the vocal resonance

The character of the sound produced by percussion of the chest wall is important in the examination of the respiratory system. For a right-handed examiner: the middle finger of the left hand is placed firmly on the chest wall of the patient the middle phalanx of the left middle finger is struck by the middle finger of the right hand the palm and other fingers are lifted clear of the chest to prevent any damping of the vibrations both sides of the chest should be percussed thought should given to the surface anatomy of the lungs the two sides of the chest are compared if an area of dullness is found then its limits are demarcated by percussing from a resonant to a dull area Changes in resonance are seen in the following conditions: increased resonance: emphysema pneumothorax decreased resonance: consolidation collapse abscess neoplasm fibrosis stony dull: pleural effusion

Palpation is used to determine five main clinical signs: the presence of lymphadenopathy: cervical and supraclavicular lymph nodes are particularly significant the position of the trachea: the trachea should be palpated deep in the supraclavicular notch to determine the position of the upper mediastinum the index finger is pressed deep in the suprasternal notch in the midline, if the trachea is not felt then the finger is inserted to one side or the other tracheal tug: the distance between the suprasternal notch and the cricoid cartilage is normally 2-3 fingers breadths a reduction in this distance, particularly on inspiration is a reliable sign of hyperinflation chest expansion: the examiner places the hands on either side of the chest over the upper and then lower zones observing the movement of the hands during respiration may demonstrate asymetrical expansion of the chest tactile vocal fremitus

Observe the following: evidence of respiratory distress: dyspnoea tachypnoea use of accessory muscles of respiration wheezing or stridor signs of respiratory failure: reduced level of consciousness central cyanosis asterixis chest wall: hyperexpanded in airways obstruction kyphosis or scoliosis pectus carinatum or pectus excavatum asymetric expansion surgical scars, possible tracking mesothelioma cold abscesses from underlying TB Harrison's sulcus and intercostal recession pattern of respiration lymphadenopathy, especially supraclavicular superior vena cava obstruction: puffy face engorged neck, chest and arm veins hoarse voice Horner's syndrome signs in the hands: nicotine on fingers and nails coal dust ingrained in fingers and nails clubbing wasting of small muscles yellow nails in the yellow nail syndrome

Sinusitis - Management How should I diagnose acute sinusitis? Acute sinusitis nearly always follows an upper respiratory tract infection and is diagnosed by the presence of nasal blockage (obstruction/congestion)  or  nasal discharge (anterior/posterior nasal drip)  with  facial pain (or pressure) and/or reduction of, or loss of, the sense of smell, lasting for  less  than 12 weeks. Nasal discharge — a thick, purulent, coloured discharge (especially green) is more likely to indicate bacterial involvement (unlikely with a clear discharge). Nasal blockage or congestion — usually bilateral and caused by rhinitis. Facial pain — may be described as pressure and localized over the infected sinus, or it may affect teeth, the upper jaw, or other areas (such as eye, side of face, forehead). Pain in the absence of other symptoms is unlikely to be sinusitis. In children, symptoms of rhinitis predominate, with facial pain being less prevalent. There may also be ear discomfort (Eustachian tube

About two-thirds of the patients with acute rhinosinusitis receiving placebos recovered without antibiotics. Antibiotics are superior to placebo in the treatment of rhinosinusitis. Amoxicillin/clavulanate is more effective than the cephalosporin class of antibiotics in the treatment of sinusitis only in the short-term follow up, with an absolute risk difference of about 3.5 percent. There are only a few studies that specifically examined the effect of different treatment duration on outcome efficacy; they generally found no difference between shorter and longer duration of treatment. It is not possible to compare the rates of adverse events across different antibiotic classes. Severe adverse events in general are uncommon; they occurred in up to about 3.5 percent of patients in all classes of antibiotics. As of September 2004, there have not been any published studies examining the effect of the pneumococcal vaccine on the treatment of acute sinusitis. A minority of studies were plac

Asthma, Diagnosis and Management of (Guideline) Released 06/2010 Asthma, Diagnosis and Management of (Guideline)    (PDF 2MB) + Show Additional Materials Asthma, Admission for (Order Set) Scope and Target Population: This guideline addresses the diagnosis, emergent, inpatient and outpatient management of acute and chronic asthma in all patients over five years of age who present with asthma-like symptoms or have been diagnosed with asthma. Clinical Highlights and Recommendations: Conduct interval evaluations of asthma including medical history and physical examination, assessment of asthma triggers and allergens, measurement of pulmonary function, and consideration of consultation and/or allergy testing. Assess control using objective measures and a validated asthma control tool.  Match therapy with asthma control. Provide asthma education to patients and parents of pediatric patients. Education should include basic facts about asthma, how medications work, inhaler technique,

Tetanus immunization of women of childbearing age The immunization of pregnant women with tetanus toxoid (TT) vaccine is a highly effective means of protecting the newborn child from tetanus. The optimal schedule for this vaccination depends on the immunization history of the woman. Schedule A: regions in which women were not vaccinated during infancy and childhood, or where there is insufficient documentation for previously vaccinated women to be identified, should administer a full TT 5-dose schedule for all women of childbearing age. The details of these schedules are presented in the box. The regions concerned need to determine the age group to be included in the schedule (e.g. 15–35 yrs or 15–44 yrs). Schedule B: regions in which women have documentation of previous vaccination with TT-containing vaccines during infancy or childhood can apply more selective schedules for tetanus vaccination — see box. (It is likely that more and more countries will start to

Basic immunization strategies and schedules The decision to immunize at a particular age is, for the most part, a compromise between: The desire to immunize as early as possible, thereby protecting the child before he/she becomes exposed to the infectious agent, and The requirement to wait both for the infant's immune response to mature and for the maternally-derived antibodies that crossed the placenta pre-natally to disappear, so that the immunization will be effective. Vaccines are recommended for the youngest age group at risk for developing the disease whose members are known to develop an adequate response to immunization without adverse effects from the vaccine. The basic schedule calls for all children to receive 1 dose of BCG vaccine, 3 doses of DTP vaccine, 4 doses of OPV, and 1 dose of measles vaccine before their first birthday. In countries where HBsAg carriage rates are >2%, universal infant vaccination with Hep B vaccine is recommended. Where HBsA