Glossary of definitions, abbreviations, symbols and normal values See also index for definitions in the text. a useful measure of aerobic capacity for Values in [square brackets] are from the USA monitoring endurance training, but of (all values are approximate). limited value in severe COPD because peak 2,3-DPG Enzyme in red blood cells, t in exercise levels are often reached below the chronic hypoxaemia, shifting O2 dissociation anaerobic threshold. In normal subjects, curve to right and allowing easier unload­ anaerobic threshold can be increased by ing of O2 to hypoxic tissues. 25-40%. A Alveolar, e.g. P A02. Angioplasty Invasive but non-surgical dila­ a Arterial, e.g. Pa02. tation of coronary artery stenosis, using ACBT Active cycle of breathing techniques. catheter via femoral puncture, or laser. ACE inhibiters Angiotensin-converting en- Anoxia Synonymous with hypoxia, although zyme inhibiter drugs, for hypertension, implying a more complete oxygen lack. e.g. captopril, enalapril. AP Anteroposterior. ACPRC Association of Chartered Physio­ APACHE Acute Physiology And Chronic therapists in Respiratory Care. Health Evaluation (scoring system to meas­ ADL Activities of daily living. ure severity of illness). Adult respiratory distress syndrome Alterna­ Apgar score Combined measurement of heart tive name for acute respiratory distress rate, respiratory effort, muscle tone, reflex syndrome. irritability and colour (scoring system to Aerosol Suspension of particles in a gas measure birth asphyxiation). stream. Therapeutic aerosols are for Apneustic breathing Prolonged inspiration humidification and drug delivery, other usually due to brain damage. aerosols spread some lung infections and Apnoea Absence of breathing for > 10 allow damage from noxious agents. seconds. AIDS Acquired immune deficiency syndrome. ARDS Acute respiratory distress syndrome. Air trapping Retention of inspired gas in Arteriovenous oxygen difference Assess­ poorly ventilated areas of lung. ment of oxygen delivered to, and returning Airway closure Closure of small airways, from, tissue, related to metabolic rate and mostly in dependent lung regions during calculated from arterial and mixed venous expiration. blood samples. Airway resistance Normal: 0.5-2.0 cmH20/llsec. Ascites Fluid in the abdominal cavity. Albumin Plasma protein responsible for pro­ Aspiration (1) Inhalation of unwanted sub­ viding most osmotic pressure in blood. stances (e.g. gastric acid, sea water) into Normal: 40-60 gil, [4.0-6.0 g/100ml]. the lungs, or (2) therapeutic removal of ~ albumin suggests malnutrition, blood fluid or gas from a cavity such as the loss, liver failure, nephrotic syndrome. pleural space. Anaerobic threshold Highest oxygen con­ Atelectasis Alveolar collapse due to poor sumption during exercise, above which lung expansion or complete obstruction of sustained lactic acidosis occurs. Normally an airway. Glossary 313 Base deficit Negative base excess. tures outside lung that participate in breath­ Base excess (BE) Normal: from -2 to +2 ing movements. mmolll. Closing capacity Volume at which airway BB 'Blue bloater' patient. closure begins (as lung volume is reduced Bicarbonate Normal 22-26 mmoUI. towards residual volume, dependent air­ Biot's respiration Irregular cycles of deep ways begin to close); rises with age until it gasps and apnoea. equals FRC at about 66 years in standing, BiPAP Bi-Ievel positive airways pressure. 44 years in supine. Bleb Collection of air under visceral pleura, Closing volume Closing capacity minus outside alveoli (see also bulla). residual volume. Blood culture Blood taken from a pyrexial Normal: 10% of vital capacity in young patient to identify responsible micro­ people with normal lungs. organism. Age 65: 40% of Vc. bpm Beats per minute. Increases (i.e. becomes a greater propor­ Bradypnoea Slow breathing. tion of FRC) with small airways dis­ Bronchomalacia Degeneration of elastic and ease, smoking and extremes of age. connective tissue of trachea and bronchi. Clotting studies Bulla Collection of air inside distended Platelet count alveoli, over 1 em in diameter, caused by Normal: 140000-400000 mm-3 • alveolar destruction (see also bleb). Low enough to cause spontaneous bleed­ CABG Coronary artery bypass graft. ing: 20000-30000. Cachectic Emaciated. Prothrombin time (PT) CAL Chronic airflow limitation, i.e. COPD. Normal: 12-30 seconds. Calcium Normal: 2.2-2.6 mmoUI. Expressed as internalized normalized ratio CCF Congestive cardiac failure. (INR) Ca02 Arterial oxygen content. Normal: < 1-1.3. Normal: 17-20 mU100ml. If on warfarin: 4--4.5 (pulmonary em­ Cardiac enzymes Enzymes released from bolus), 2-4 (myocardial infarct), 1.8 damaged heart muscle after myocardial (postoperative ). infarction. With DIC: up to 1.5-2.2. Cardiac index Cardiac output divided by Expressed as activated partial thrombo­ body surface area. plastin time (PIT) Normal 2.5-3.5 Uminlm2• Normal: 25-35 seconds. Cardiac output (0) Heart rate x stroke DIC: 50 seconds. volume (stroke volume depends on pre­ CMV Controlled mandatory ventilation. load, afterload and contractility), i.e. CNS Central nervous system. amount of blood ejected by left ventricle CO Cardiac output. per minute. COAD Chronic obstructive airways disease Normal; 4-6 Umin at rest, up to 25 Umin on (= COPD). exercise. Collateral ventilation Exchange of inspired Catecholamines Collective term for com­ gas between adjacent lung units. pounds having a sympathomimetic action, Colostomy Surgical creation of opening into e.g. adrenaline. large bowel. CF Cystic fibrosis. Compliance of lung Change in volume in Chest wall Rib cage, diaphragm, abdominal response to change in pressure (aV/ap). contents and abdominal wall, i.e. struc- Normal: 0.09-0.40 UcmH20. 314 Glossary Compliance of lung measured on IPPV Erythrocytosis Polycythaemia. tida.l volume _ PEEP. ETC02 End-tidal CO2• plateau aIrway pressure Normal: 4-6%. Consolidation Replacement of alveolar air by EIT Endotracheal tube. substance of greater density than air. Eucapnia Normal PaC02• COPD Chronic obstructive pulmonary dis- FBC Full blood count. ease. FEF25-75 Forced expiratory flow in middle half of CPAP Continuous positive airways pressure. expiration. CPR Cardiopulmonary resuscitation. FET Forced expiration technique. Creatinine Electrolyte in plasma or urine, FEV 1 Forced expiratory volume in one second. formed from muscle breakdown, excreted FP2 Fraction of inspired oxygen (F10 2 of 0.6 = by kidneys. 60% inspired oxygen). Normal in plasma: 50-100 fLmol/l, [0.6- 1.2 mg/100 mIl. FRC Functional residual capacity. i in hypovolaemia or kidney failure, FVC Forced vital capacity. i i in septic shock. Glottis Vocal apparatus of the larynx. CSF Cerebral spinal fluid. Glucose level in blood CT Computed tomography. Normal: 3.0-5.5 mmolll. CV02 Venous oxygen content. i in stress, i i in diabetis mellitus, ~ in Normal: 12-15 ml/100 ml. liver failure or starvation. CVP Central venous pressure. Goodpasture's syndrome Combination of lung Normal: 1-6 mmHg or 5-12 cmH20. haemorrhage and nephritis. CXR Chest X-ray. GOR Gastro-oesophageal reflux. Dehydration low blood volume (see also Haematocrit (packed cell volume) Concentra­ hypovolaemia) tion of red blood cells in blood, indicates DIC Disseminated intravascular coagulation. oxygen-carrying capacity of blood. DNA Deoxyribonucleic acid. Normal: 40-45%. DNR Do not rescusitate. ~ in anaemia, i.e. < 38%, i in poly­ D02 See oxygen delivery. cythaemia, i.e. > 55%. Duty cycle See TlfTOT• Haemoglobin (Hb) Respiratory pigment in red DVT Deep vein thrombosis. blood cells, combines reversibly with oxygen. Dysphagia Pain and/or difficulty in swallow- Normal for men: 14.0-18.0 g/100 mI. ing. Normal for women: 11.5-15.5 g/100 mI. ECC02R Extracorporeal carbon dioxide removal. ~ in anaemia, i in polycythaemia. ECG Electrocardiogram. Hb Haemoglobin, see above. ECMO Extracorporeal membrane oxygenation. -ectomy Removal. HCO-3 Bicarbonate. EIA Exercise-induced asthma. HDU High dependency unit. ER02 See oxygen extraction ratio. HFV High frequency ventilation. Left ventricular end-diastolic pressure Left HFJV High frequency jet ventilation. ventricular preload. HFO High frequency oscillation. Endotoxin Pyrogenic toxin in bacterial cell which HFPPV High frequency positive pressure vent- increases capillary permeability. ilation. Endotoxic shock Septic shock. HIV Human immunodeficiency virus. Eosinophil White blood cell associated with HLT Heart lung transplant. hypersensitivity reactions, i in allergies such H:L ratio Ratio of power in high and low as extrinsic asthma. frequency bands of electromyogram of Glossary 315 respiratory muscle, t with respiratory muscle expiratory position. fatigue. Inspiratory:expiratory ratio Numerical expres­ HME Heat moisture exchanger. sion of duration of inspiration relative to HR Heart rate. expiration. Hypematraemia i serum sodium. Inspiratory force See MIP. Hyperosmolar Containing high concentration of IMV Intermittent mandatory ventilation. osmotically active ingredients. Intrapulmonary pressure Alveolar pressure Hyperreactivity of the airways Heightened (p.4). sensitivity to a variety of stimuli, prominent in Intrathoracic pressure Pleural pressure (p. 4). asthma, sometimes present in COPD, bron­ IPPB Intermittent positive pressure breathing. chiectasis, CF, sarcoidosis, LVE IPPV Intermittent positive pressure ventila- Hyperthermia Core temperature > 4OSC. tion. Hyperventilation CO2 removal in excess of CO2 IRT Immune reactive trypsin - antibody production, producing PaC02 < 4.7 kPa identified in