E_Share

 Inferior vena cava The inferior vena cava has a longer course than the aorta in the abdomen. It begins opposite L5 vertebra by the confluence of the two common iliac veins behind the right common iliac artery (Fig. 5.42A). It runs upwards on the right of the aorta, grooves the bare area of the liver, and pierces the central tendon of the diaphragm on a level with the body of T8 vertebra. It lies on the bodies of the lumbar vertebrae and the right crus of the diaphragm, overlapping the right sympathetic trunk, and crossing the right renal, suprarenal and inferior phrenic arteries (Fig. 5.43). It also partly overlaps the right suprarenal gland and the coeliac ganglion. In the infracolic compartment the inferior vena cava lies behind the peritoneum of the posterior abdominal wall; it is crossed by the root of the mesentery, the right gonadal artery and the third part of the duodenum. In the supracolic compartment it lies at first behind the portal vein, head of the pancreas and bile ...

 INVASIVE TECHNIQUES If an artery is cannulated a direct measurement of blood pressure can be obtained with the help of an infusion system, transducer and recorder. Ideally, for arterial cannulation, a peripheral artery should be chosen so that the whole limb is not threatened if a clot or haematoma forms. Although some physicians use the brachial artery, the radial artery is usually the first choice but, before cannulation, a modified Allen test is carried out. The patient's hand is clenched into a fist and the doctor occludes both the radial and ulnar arteries with his fingers. Then the patient relaxes his clenched fist and the doctor releases the pressure on the ulnar artery. The patient's hand should then flush within 5 seconds. If flushing does not occur or is delayed, then this indicates that there are poor blood vessel collaterals between the radial and ulnar arteries and, therefore, another artery should be used. If the ulnar artery is to be cannulated the test is perfo...

 Heart Arterial Supply The heart has a small margin for error in its physiology and function. Therefore, it requires a dense vascular system for regulation of blood gases and nutrients. The right and left coronary arteries provide the arterial supply of the heart. These are the first branches of the aorta. They arise from the ascending aorta immediately above the aortic valve and initially pass around the opposite sides of the pulmonary trunk (Fig. 5.36A; also see Figs. 5.30 and 5.34D). The coronary arteries and their major branches are distributed over the surface of the heart and lie within subepicardial connective tissue. Table 5.3 summarizes the typical pattern of distribution of the coronary arteries in most people.  Right Coronary Artery The right coronary artery arises from the right aortic sinus of the ascending aorta, runs forward between the right side of the pulmonary trunk and the right auricle, and descends almost vertically in the right atrioventricular groove (c...

 Monitoring the brain M. Elwishi* and J. Dinsmore St Georges Hospital, London, UK *Corresponding author: a.elwishi@nhs.net Learning objectives By reading this article, you should be able to:
Describe the methods for measuring intracranial pressure (ICP) and identify the components of a normal ICP trace.
Discuss the available methods and clinical applications of cerebral tissue oxygenation monitoring.
Explain the underlying physical principles and indications for cerebral blood flow measurement. Monitoring the brain after traumatic injury, subarachnoid haemorrhage, and neurosurgery plays a crucial role in guiding management, optimising cerebral function, and prevention of secondary brain injury. This article aims to outline some of the scientific principles and clinical applications of different monitoring modalities. Monitoring intracranial pressure Intracranial pressure The cerebrospinal fluid acts as a dynamic pressure system. Pressure can be measured directly fromthe later...

 Pesticides include insecticides, herbicides, and rodenticides.1 Pesticide toxicity results from intentional, accidental, and occupational exposures. More than 150,000 pesticide poisoning deaths occur each year worldwide, with insecticides accounting for the majority of the mortality.2 Pesticides are marketed as multiple formulations, often under shared brand names. Therefore, complex clinical syndromes can result from exposure to both active and other ingredients. Human toxicity can occur from many ingredients in proprietary formulations, including solvents and surfactants. Pesticides have class-specific toxicities, with many having both local and systemic effects. Management often includes consultation with a hazardous materials and toxins database or with a poison control center. Cornerstones of management are meticulous supportive care and early identification of exposures that may benefit from administration of an antidote. The World Health Organization classifies pesticides a...

 ORGANOPHOSPHATES Organophosphate poisoning accounts for nearly one third of hospital admissions from poisoning in Sri Lanka. Organophosphorus insecticides inhibit the enzyme acetyl cholinesterase (AChE) at nerve endings by phosphorylation, 40resulting in accumulation of acetyl choline at receptor sites. This occurs at the neuro-effector junctions, skeletal neuro-muscular junctions, autonomic ganglia and in the brain. After ingestion, symptoms can occur almost immediately. However, symptoms following occupational exposure may be delayed for a few hours or days. Certain organophosphates (e.g. methamidophos) can damage the axons of peripheral nerves, causing weakness or paralysis and paraesthesia of the extremities. Clinical features appear a few weeks after the poisoning episode and persist for several months. No useful therapeutic measures, apart from physiotherapy, are available for this condition. CLINICAL FEATURES Ingestion Clinical features observed after ingestion can be divid...

 SCALP The scalp extends from the superciliary arches anteriorly to the external occipital protuberance and superior nuchal lines posteriorly and to the temporal lines laterally. It consists of five layers (see Fig. 12.2). Conveniently, the first letters of each layer together spell SCALP, making recall easier. The first three layers are intimately bound together and move as a unit. Skin. This is thick and hair bearing and contains numerous sebaceous glands. Connective tissue beneath the skin. This is a dense fibrofatty layer containing fibrous septa that unite the skin to the underlying epicranialaponeurosis. This layer contains numerous blood vessels. The arteries are derived from both the external and internal carotid arteries, and free anastomoses occur between them. Aponeurosis (epicranial). This is a thin, tendinous sheet that unites the occipital and frontal bellies of the occipitofrontalis muscle (see below and Fig. 12.14). The lateral margins of the aponeurosis are attache...

Guidelines for the Administration of Blood and Blood Components District General Hospital Trincomalee SUMMARY OF KEY RECOMMENDATIONS Decision of transfusions. The rationale for transfusion should be based on clinical and laboratory assessment and the specific components to be transfused should be documented in the patient's clinical record. Patient Consent Informed consent, either verbal or written, should be obtained (wherever possible) and documented in the patient's clinical note Prescriptions Decision of transfusion with justification and expected outcome should be legibly written in BHT/Clinic note with type of blood component, volume / number of units to be transfused, date of transfusion, special transfusion requirements and any special instruction Requests for transfusions REQUEST FORMS FOR RED CELL PRODUCTS and REQUEST FOR PLATELETS AND PLASMA COMPONENTS issued by National Blood Transfusion service should be filled completely and legible Pre-transfusion patient Identif...

 SCALP The scalp extends from the superciliary arches anteriorly to the external occipital protuberance and superior nuchal lines posteriorly and to the temporal lines laterally. It consists of five layers (see Fig. 12.2). Conveniently, the first letters of each layer together spell SCALP, making recall easier. The first three layers are intimately bound together and move as a unit. Skin. This is thick and hair bearing and contains numerous sebaceous glands. Connective tissue beneath the skin. This is a dense fibrofatty layer containing fibrous septa that unite the skin to the underlying epicranialaponeurosis. This layer contains numerous blood vessels. The arteries are derived from both the external and internal carotid arteries, and free anastomoses occur between them. Aponeurosis (epicranial). This is a thin, tendinous sheet that unites the occipital and frontal bellies of the occipitofrontalis muscle (see below and Fig. 12.14). The lateral margins of the aponeurosis are attache...

 Blood supply of the midgut Superior mesenteric artery This is the artery of the midgut and supplies the gut from the entrance of the bile duct to a level just short of the splenic flexure of the colon. The artery arises from the front of the aorta a centimetre below the coeliac trunk, at the level of the lower border of L1 vertebra. It is directed steeply downwards behind the splenic vein and the body of the pancreas, with the superior mesenteric vein on its right side. It lies anterior to the left renal vein, the uncinate process of the pancreas and the third part of the duodenum, in that order from above downwards (Fig. 5.26). With its vein it enters the upper end of the mesentery of the small intestine and passes down to the right along the root of the mesentery (Fig. 5.23). Pressure of the superior mesenteric artery on the left renal vein may produce left-sided varicocele, and pressure on the duodenum may give symptoms of chronic duodenal ileus, particularly when the angle bet...