The principal function of the gastrointestinal (GI) tract is to provide the body with a supply of water, nutrients, and electrolytes. Each division of the GI tract—esophagus, stomach, small and large intestines—is adapted for specific functions such as passage, storage,…
Epidemiology Nearly 4.5 million people in the United States are living with chronic liver disease, while more than 40,000 deaths annually are attributed to chronic liver disease. Liver dysfunction affects multiple organ systems and increases the risk of perioperative morbidity…
Introduction The peripheral nervous system consists of nerve elements outside the brain and spinal cord. It contains both peripheral nerves and elements of the autonomic nervous system. Disorders of the autonomic nervous system can result in significant hemodynamic changes as…
Anatomy of the vertebral column and spinal cord The vertebral column consists of 24 individual vertebrae (7 cervical, 12 thoracic, and 5 lumbar), in addition to the sacrum and coccyx. Basic anatomy of individual vertebrae and the vertebral column is…
Cerebral physiology Cerebral blood flow, blood volume, and metabolism Cerebral blood flow (CBF) is modulated by cerebral metabolic rate, cerebral perfusion pressure (CPP, the difference between the mean arterial pressure [MAP] and intracranial pressure [ICP]), and arterial blood carbon dioxide…
Diseases of the thoracic and abdominal aorta Aneurysms, dissections, and occlusive disease are the main pathologies that can affect arterial vessels. Whereas occlusive disease is more likely to occur in peripheral arteries, the aorta and its major branches are affected…
Introduction Pericardial diseases have a varied clinical presentation, ranging from chronic or subacute to acute and potentially life threatening. These pathologies often present urgently to the operating room, and their perioperative management poses unique challenges for the anesthesiologist. The hemodynamic…
Heart failure Definition The ability of the left ventricle to function as one of the body’s two main pumping chambers depends on how efficiently it ejects and subsequently fills with oxygenated blood. This implicit duality indicates that heart failure may…
Systemic hypertension In 2017, the American College of Cardiology/American Heart Association (ACC/AHA) redefined hypertension as a sustained systolic blood pressure above 130 mm Hg and/or a diastolic pressure above 80 mm Hg. This new definition arose in response to the…
Introduction The development of the modern-day electrocardiogram (ECG) started with the recognition by scientists that the electric currents regulating the heart could be detected at the surface of the skin. In the late 1800s Willem Einthoven built a machine called…