Respiratory medicine

Respiratory medicine is the study of lung function. This chapter outlines the investigations in current use, including blood gas analysis, sleepiness scans, bronchoscopy, flow–volume loops, peak flow charts, needle biopsy of the pleura, spirometry, lung volume analysis, and sweat test.

Gastroenterology

This chapter summarizes key investigations to diagnose symptoms and signs in the gastrointestinal lumen, liver, and pancreas, looking at the risk and benefits of each procedure, as well as indications, special considerations, and safety concerns prior to booking. These investigations diagnose abnormal appearances, measure disordered motility, determine the presence of infection, study absorption within the intestinal lumen, and measure disordered physiology. Less invasive tests such as faecal occult blood samples are used to screen subjects to determine those at higher risk of pathology who would require more invasive investigation. Judicious use of blood tests provides a similar role in triaging before more complex tests and highlights those patients at greater risk. Finally, for practical diagnostic procedures, including ascitic tap which junior doctors are likely to complete on the wards, there are practical guides to safely completing the procedure.

Immunology and allergy

This chapter covers the role of the immunology laboratory in the diagnosis of immunological and allergic disorders, including testing for autoimmune diseases, allergic diseases, lymphocyte and neutrophil phenotype and function, and immunochemical analysis of serum proteins for the diagnosis of immune deficiency and myeloma. Information is provided on the tests, with ranges and explanation of the interpretation of abnormal results. Critical results requiring immediate action are highlighted.

Poisoning and overdose

This chapter covers the most appropriate investigations of common poisons encountered in clinical practice.

Renal medicine

This chapter reviews the investigations required for the diagnosis and classification of acute and chronic kidney diseases. Detailed guidance is provided on the choice of methods to measure or estimate the glomerular filtration rate and to quantify albuminuria/proteinuria. It offers a rational approach to the choice of blood and urine tests in the investigation of patients presenting with haematuria, proteinuria, renal tubular dysfunction, and disorders of acid–base balance. It reviews the pertinent radiological investigations used alongside specialist urine and immunology tests to aid diagnosis. There is a detailed review of the rational investigation of patients with recurrent kidney stone disease. Guidance is provided on laboratory investigation of suspected renal bone disease and on the role of renal biopsy in the investigation of kidney disease.

Symptoms and signs

Patients usually do not present with diseases, but rather with symptoms and signs. This initial chapter provides a patient-focused approach to diagnosis. By examining the signs and symptoms, the reader can then reach a working diagnosis or at least a differential diagnosis. By then reading the relevant sections of the book, the reader will then be able to come to a firm diagnosis.

Radiology

This chapter gives an overview of the role of radiological investigations in the management and work-up of common clinical conditions across a spectrum of specialties. It also provides an insight into basic interpretation skills and pitfalls when approaching common radiological tests. In addition to providing an evidence-based approach to the utilization of radiological resources, differential diagnoses are provided throughout. Where appropriate, indications and contraindications for radiological techniques are given to provide an essential bedside resource for the practising clinician. More advanced sections tackle the physics underlying each modality, as well as specialized interventional radiology and its role in minimally invasive clinical practice.

Infectious and tropical diseases

This is a brief outline of the current clinical and laboratory investigations of patients suffering from infectious diseases, including those from the tropics. It includes clinical and epidemiological assessment of the patient with fever. The appropriate investigations are discussed and cover the wide range of organisms now found in clinical practice via parasitology, mycology, bacteriology, and virology. Understanding of the laboratory techniques available is important in order to guide their rational use and understand their limitations. The techniques range from traditional methods such as microscopy and culture to newer molecular techniques such as MALDI-TOF and nucleic acid detection polymerase chain reaction. The section on clinical investigation in action outlines the approach to the patient with pyrexia of unknown origin. The increasingly important and complex clinical and laboratory assessment of antimicrobial resistance is also outlined, including how the laboratory fits in with this agenda.

Rheumatology

This chapter examines the role of investigations in diagnosis, assessing disease activity, and monitoring treatment in rheumatic disease. It reviews the relevance of haematology and biochemistry tests in clinical context, including differential diagnosis of anaemia and cytopenia which may reflect the disease process, co-morbidity, or adverse drug effects. Bone biochemistry and markers are also described. Autoantibodies are important in diagnosis and prognosis in rheumatology. Interpretation of rheumatoid factor, anti-cyclic citrullinated peptide (CCP) antibodies, antinuclear antibodies (ANA), antineutrophil cytoplasmic antibodies (ANCA), extractable nuclear antigens (ENA), antiphospholipid antibodies, and also HLA-B27 is discussed. Arthrocentesis is a technique specific to rheumatology, and neurophysiology is useful in distinguishing neurological versus inflammatory muscle disease, in addition to nerve entrapment syndromes and neuropathies. The chapter also introduces the use of diagnostic imaging and early identification of inflammatory arthritis, including X-ray, ultrasound, magnetic resonance imaging (MRI), positron emission tomography-computed tomography (PET-CT), nuclear medicine bone scintigraphy, and dual-energy X-ray absorptiometry (DXA).

Cardiology

This chapter describes and discusses commonly used investigations in the assessment of patients with cardiovascular disease. It reviews electrocardiography (ECG), including ECG monitoring, and exercise testing. It describes cardiac imaging techniques, including echocardiography, cardiac magnetic resonance imaging (MRI), and nuclear cardiology (myocardial perfusion imaging and radionuclide ventriculography). It also includes information on cardiac catheterization (including pulmonary artery catheterization) and a section on tilt table testing.