Acute renal failure (ARF) is a rapid loss of renal function due to damage to the kidneys, resulting in retention of nitrogenous (urea and creatinine) and non-nitrogenous waste products that are normally excreted by the kidney. This accumulation may be accompanied by metabolic disturbances, such as metabolic acidosis and hyperkalaemia, changes in body fluid balance and effects on many other organ systems. Metabolic acidosis and hyperkalaemia are the two most serious biochemical manifestations of acute renal failure and may require medical treatment with sodium bicarbonate administration and antihyperkalaemic measures. If not appropriately treated these can be life-threatening. ARF is diagnosed on the basis of characteristic laboratory findings, such as elevated blood urea nitrogen and creatinine, or inability of the kidneys to produce sufficient amounts of urine.

Shock is a life-threatening condition that occurs when the organs and tissues of the body are not receiving a sufficient flow of blood. Lack of blood flow, oxygen and nutrients results in the inability to function properly and damage to many organs. Shock requires immediate treatment because, if left untreated the impaired tissue perfusion and cellular hypoxia can cause irreversible tissue injury, collapse, coma or even death. There are various types of physiological shock, including: cardiogenic (due to heart damage), hypovolaemic (due to low total volume of blood or plasma), neurogenic (due to nervous system damage), septic (due to infections) and anaphylactic shock (due to allergic reactions). Hypovolaemic shock can be caused by blood loss due to trauma, internal bleeding or other fluid loss due to severe burns, prolonged diarrhoea, vomiting and sweating.

Cryptosporidium infection occurs through the faecal-oral route of transmission. It usually lasts for 5–7 days. In immunocompetent patients it is self-limiting (nitazoxanide may be used to shorten the duration). In immunocompromised patients: Antiretroviral therapy to elevate the CD4 cell count/restore the immune system is essential prior to eradication with antiparasitic drugs. Diarrhoea is the main disease. The cysts are typically identified on stool microscopy.

The peroneus brevis muscle originates from the lower two-thirds of the lateral body of the fibula and has inserts at the base of the fifth metatarsal. Fractures to this bone are common and can be due to infection, trauma, overuse and repetitive use.

Carcinoembryonic antigen (CEA) is used as a tumour marker. CEA test measures the amount of this protein that may appear in the blood of some people who have certain types of cancers especially cancer of the colon and rectal cancer. It may also be present in the pancreas, breast, ovary or lung.

Deep vein thrombosis (DVT) is the formation of a blood clot in a deep vein of the legs, thigh, or pelvis. Thrombosis is most often seen in individuals with a history of immobilization, obesity, malignancy, or hereditary thrombophilia. Vascular endothelial damage, venous stasis, and hypercoagulability, collectively referred to as the Virchow triad, are the main factors contributing to the development of DVT.
Symptoms usually occur unilaterally and include swelling, tenderness, and redness or discoloration. Pulmonary embolism (PE), a severe complication of DVT, should be suspected in patients with dizziness, dyspnoea, and fever. The diagnostic test of choice for DVT is compression ultrasound. In most cases, a negative D-dimer test allows thrombosis or PE to be ruled out, but a positive test is nonspecific.
Initial acute treatment of DVT consists of anticoagulation with heparin and, if the thrombus is large or unresponsive to anticoagulation, may also include thrombolysis or thrombectomy. Secondary prophylaxis is achieved with oral warfarin or direct factor Xa inhibitors and supportive measures such as regular exercise and compression stockings.

Spleen injuries are among the most frequent trauma-related injuries. At present, they are classified according to the anatomy of the injury. The optimal treatment strategy, however, should take into consideration the hemodynamic status, the anatomic derangement, and the associated injuries. The management of splenic trauma patients aims to restore the homeostasis and the normal physiopathology especially considering the modern tools for bleeding management.

The trend in the management of splenic injury continues to favour nonoperative or conservative management. This varies from institution to institution but usually includes patients with stable hemodynamic signs, stable haemoglobin levels over 12-48 hours, minimal transfusion requirements (2 U or less), CT scan injury scale grade of 1 or 2 without a blush, and patients younger than 55 years.
Surgical therapy is usually reserved for patients with signs of ongoing bleeding or hemodynamic instability. In some institutions, CT scan–assessed grade V splenic injuries with stable vitals may be observed closely without operative intervention, but most patients with these injuries will undergo exploratory laparotomy for more precise staging, repair, or removal.

A retrospective analysis by Scarborough et al compared the effectiveness of nonoperative management with immediate splenectomy for adult patients with grade IV or V blunt splenic injury. The study found that both approaches had similar rates of in-hospital mortality (11.5% in the splenectomy group vs 10.0%), however, there was a higher incidence of infectious complications in the immediate splenectomy group. The rate of failure in the nonoperative management was 20.1% and symptoms of a bleeding disorder, the need for an early blood transfusion, and grade V injury were all early predictors of nonoperative management failure.

Mirizzi’s syndrome is a rare complication in which a gallstone becomes impacted in the cystic duct or neck of the gallbladder causing compression of the common hepatic duct, resulting in obstruction and jaundice. The obstructive jaundice can be caused by direct extrinsic compression by the stone or from fibrosis caused by chronic cholecystitis (inflammation).

Type I – No fistula present

Type IA – Presence of the cystic duct
Type IB – Obliteration of the cystic duct

Types II–IV – Fistula present

Type II – Defect smaller than 33% of the CHD diameter
Type III – Defect 33–66% of the CHD diameter
Type IV – Defect larger than 66% of the CHD diameter

Simple cholecystectomy is suitable for type I patients. This patient has type I because no fistula is present.

The inferior pancreaticoduodenal artery is a branch of the superior mesenteric artery or from the first intestinal branch of the superior mesenteric artery. Once given off, it runs to the right between the pancreatic head and the duodenum and then ascends to form an anastomosis with the superior pancreaticoduodenal artery.

The inguinal approach, with ligation of the processus vaginalis high within the internal inguinal ring, is the procedure of choice for paediatric hydroceles (typically, communicating). If a testicular tumour is identified on testicular ultrasonography, an inguinal approach with high control/ligation of the cord structures is mandated.

Approximately 10% of patients with testicular teratomas may present with a cystic mass that may transilluminate during the physical examination. Similarly, adults with testicular tumours may present with new-onset scrotal swelling. If this diagnosis is considered, measuring serum alpha-fetoprotein and human chorionic gonadotropin (hCG) levels is indicated to exclude malignant teratomas or other germ cell tumours.

Chronic cholecystitis can be a surgical challenge due to an inflammatory process that creates multiple adhesions, complicates dissection, and can hamper recognition of normal anatomical structures. In such cases cholecystostomy can be performed in order to alleviate the acute symptoms. Tube cholecystostomy allows for resolution of sepsis and delay of definitive surgery. Interval laparoscopic cholecystectomy can be safely performed once sepsis and acute infection has resolved.

Increased alkaline phosphatase is indicative of cholestasis, with a 4x or greater increase seen 1-2 days after biliary obstruction. Its level can remain elevated several days after the obstruction is resolved due to the long half life (7 days). Increase up to three times the normal level can be seen in hepatitis, cirrhosis, space-occupying lesions and infiltrative disorders. Raised alkaline phosphatase with other liver function tests being normal can occur in focal hepatic lesions like abscesses or tumours, or in partial/intermittent biliary obstruction. However, alkaline phosphatase has several isoenzymes, which originate in different organs, particularly bone. An isolated rise can also be seen in malignancies (bronchogenic carcinoma, Hodgkin’s lymphoma), post-fatty meals (from the small intestine), in pregnancy (from the placenta), in growing children (from bone growth) and in chronic renal failure (from intestine and bone). One can differentiate between hepatic and non-hepatic cause by measurement of enzymes specific to the liver e.g. gamma-glutamyl transferase (GGT).
In an elderly, asymptomatic patient, isolated rise of alkaline phosphatase usually points to bone disease (like Paget’s disease). Presence of other symptoms such as jaundice, pale stools, weight loss suggests obstructive jaundice, most probably due to pancreatic carcinoma.

Excess of circulating free thyroid hormones (thyroxine and/or triiodothyronine) leads to hyperthyroidism. Common causes include Graves’ disease, toxic thyroid adenoma and toxic multinodular goitre. Grave’s disease is the most common cause and is responsible for 70-80% cases of hyperthyroidism. Other causes include excess intake of thyroid hormone, amiodarone-related. It is important that hyperthyroidism is not confused with hyperthyroxinaemia (high levels of thyroid hormone in blood), which includes causes like thyroiditis. Both the conditions lead to thyrotoxicosis (symptoms due to hyperthyroxinemia). Symptoms include weight loss associated with increased appetite, anxiety, weakness, heat intolerance, depression, increased sweating, dyspnoea, loss of libido, diarrhoea, palpitations and occasionally arrhythmias. If there is an acute increase in metabolic rate, the condition is known as ‘thyroid storm’. Elderly sometimes present only with fatigue and weight loss and this is called apathetic hyperthyroidism. Neurological symptoms are also seen in hyperthyroidism and these are tremor, chorea, myopathy and periodic paralysis. One of the most serious complications of hyperthyroidism is stroke of cardioembolic origin due to coexisting atrial fibrillation.

Sinus histiocytosis also referred to as reticular hyperplasia, refers to the enlargement, distention and prominence of the sinusoids of the lymph nodes. This is a non-specific form of hyperplasia characteristically seen in lymph nodes that drain tumours. The endothelial lining of the lymph node becomes markedly hypertrophied, along with an increase in the number of macrophages which results in the distortion, distention and enlargement of the sinus. In this scenario there is no evidence that an infection or another malignancy could account for the enlargement. Paracortical lymphoid hyperplasia is caused by an immune response.

The perineum has it’s deep boundaries in front of the pubic arch and the arcuate ligament of the pubis, behind the tip of the coccyx and on either side of the inferior rami of the pubis and ischium and the sacrotuberous ligament. It also corresponds to the outlet of the pelvis. A line drawn transversely across, in front of the ischial tuberosities divides the space into two portions, the posterior contains the termination of the anal canal and the anterior, contains the external urogenital organs.

C3b is cleaved from C3 complement with the help of the enzyme C3- convertase. It binds to the cell surface of the offending substance and opsonizes it. This makes it easy for the phagocytes to detect and eliminate them.
IgM does not act as an opsonin but igG does.
Selectins aid leukocytes to bind to the endothelial surfaces.
C5a is a chemo-attractant and histamine a vasodilator.
NADPH oxidises offending substance after phagocytosis within the macrophage.

The hoarseness of voice implies vocal cord paralysis denoting the spread of malignancy which is a contraindication to surgery.

Summary of Guidelines on the selection of patients with lung cancer for surgery (Related to this case)

PART I: FITNESS FOR SURGERY
Age:
1. Perioperative morbidity increases with advancing age. Elderly patients undergoing lung resection are more likely to require intensive perioperative support. Preoperatively, a careful assessment of co-morbidity needs to be made.
2. Surgery for clinically stage I and II disease can be as effective in patients over 70 years as in younger patients. Such patients should be considered for surgical treatment regardless of age.
3. Age over 80 alone is not a contraindication to lobectomy or wedge resection for clinical stage I disease.
4. Pneumonectomy is associated with higher mortality risk in the elderly. Age should be a factor in deciding suitability for pneumonectomy.

Pulmonary function:
There should be a formal liaison in borderline cases between the referring chest physician and the thoracic surgical team.
2.No further respiratory function tests are required for a lobectomy if the post-bronchodilator FEV1 is >1.5 litres and for a pneumonectomy, if the post-bronchodilator FEV1 is >2.0 litres, provided that there is no evidence of interstitial lung disease or unexpected disability due to shortness of breath.
STEP 1
3.All patients not clearly operable on the basis of spirometry should have: (a) full pulmonary function tests including estimation of transfer factor (TLCO); (b) measurement of oxygen saturation on air at rest; and (c) a quantitative isotope perfusion scan if a pneumonectomy is being considered.
4.These data should be used to calculate estimated postoperative FEV1 expressed as % predicted and the estimated postoperative TLCO expressed as % predicted, using either the lung scan for pneumonectomy or an anatomical equation for lobectomy, taking account of whether the segments to be removed are ventilated or obstructed.
STEP 2
5.(a) Estimated postoperative FEV1 >40% predicted and estimated postoperative TLCO >40% predicted and oxygen saturation (SaO 2) >90% on air: average risk.
(b)Estimated postoperative FEV1 <40% predicted and estimated postoperative TLCO <40% predicted: high risk.
(c)All other combinations: consider exercise testing.
6.Patients for whom the risk of resection is still unclear after step 2 tests should be referred for exercise testing.
STEP 3
7.(a) The best distance on two shuttle walk tests of <25 shuttles (250 m) or desaturation during the test of more than 4% SaO 2 indicates a patient is a high risk for surgery.
(b)Other patients should be referred for a formal cardiopulmonary exercise test. For cardiopulmonary exercise testing peak oxygen consumption (V˙O 2peak) of more than 15 ml/kg/min indicates that a patient is an average risk for surgery.
(c)A V˙O 2peak of <15 ml/kg/min indicates that a patient is a high risk for surgery. PART II: OPERABILITY
Diagnosis and staging
1.All patients being considered for surgery should have a plain chest radiograph and a computed tomographic (CT) scan of the thorax including the liver and adrenal glands.
2.Confirmatory diagnostic percutaneous needle biopsy in patients presenting with peripheral lesions is not mandatory in patients who are otherwise fit, particularly if there are previous chest radiographs showing no evidence of a lesion.
3.Patients with mediastinal nodes greater than 1 cm in short-axis diameter on the CT scan should undergo biopsy by staging mediastinoscopy, anterior mediastinotomy, or needle biopsy as appropriate.
Operability and adjuvant therapy
1.The proportion of patients found to be inoperable at operation should be 5–10%.
2.Patients with stage I (cT1N0 and cT2N0) and stage II (cT1N1, cT2N1 and cT3N0) tumours should be considered operable.
3.Patients with stage I tumours have a high chance and those with stage II tumours a reasonable chance of being cured by surgery alone.
4.Patients who are known preoperatively to have stage IIIA (cT3N1 and cT1–3N2) tumours have a low chance of being cured by surgery alone but might be considered operable in the context of a trial of surgery and adjuvant chemotherapy.
5.Participation in prospective trials of multimodality treatment for locally advanced disease is strongly recommended.
6.Some small individual studies indicate a place for surgery in T4N0 and T4N1 tumours within stage IIIB, few long term data are available. Generally, stage IIIB tumours with node involvement and stage IV tumours should be considered inoperable.
7.There is no place for postoperative radiotherapy following complete primary tumour resection.

Chronic hypocalcaemia is mostly seen in patients with hypoparathyroidism as a result of accidental removal or damage to parathyroid glands during thyroidectomy.

There is strong evidence to support haemostatic resuscitation in the setting of massive haemorrhage due to trauma. This advocates the use of 1:1:1 ratio.

Uncontrolled haemorrhage accounts for up to 39% of all trauma-related deaths. In the UK, approximately 2% of all trauma patients need massive transfusion. Massive transfusion is defined as the replacement of a patient’s total blood volume in less than 24 hours or the acute administration of more than half the patient’s estimated blood volume per hour. During acute bleeding, the practice of haemostatic resuscitation has been shown to reduce mortality rates. It is based on the principle of transfusion of blood components in fixed ratios. For example, packed red cells, FFP, and platelets are administered in a ratio of 1:1:1.

Tuberous sclerosis is a genetic disorder characterized by the growth of numerous noncancerous (benign) tumours in many parts of the body. These tumours can occur in the skin, brain, kidneys, and other organs, in some cases leading to significant health problems. Tuberous sclerosis also causes developmental problems, and the signs and symptoms of the condition vary from person to person.

Virtually all affected people have skin abnormalities, including patches of unusually light-coloured skin, areas of raised and thickened skin, and growths under the nails. Tumours on the face called facial angiofibromas are also common beginning in childhood.

Tuberous sclerosis often affects the brain, causing seizures, behavioural problems such as hyperactivity and aggression, and intellectual disability or learning problems. Some affected children have the characteristic features of autism, a developmental disorder that affects communication and social interaction. Benign brain tumours can also develop and these tumours can cause serious or life-threatening complications.

Kidney tumours are common in people with tuberous sclerosis; these growths can cause severe problems with kidney function and may be life-threatening in some cases. Additionally, tumours can develop in the heart, lungs, and the retina.

Spermatic or testicular veins arise from the posterior aspect of the testis and receive tributaries from the epididymis. Upon uniting, they form the pampiniform plexus that makes up the greater mass of the spermatic cord. The vessels that make up this plexus rise up the spermatic cord in front of the ductus deferens. They then unite, below the superficial ring, to form three or four veins that traverse the inguinal canal and enter the abdomen through the deep inguinal ring. They further unite to form 2 veins that ascend up the psoas major muscle behind the peritoneum each lying on either side of the testicular artery. These further unite to form one vein that empties on the right side of the inferior vena cava at an acute angle and on the left side into the renal vein, at a right angle. The left testicular vein courses behind the iliac colon and is thus exposed to pressure from the contents of this part of the bowel. The ovarian vein is the equivalent of the testicular vein in women. They form a plexus in the broad ligament near the ovary and uterine tube and communicate with the uterine plexus. They drain into similar vessels as in a man.

Pleural fluid is a serous fluid produced by the serous membrane covering normal pleurae. Most fluid is produced by the parietal circulation (intercostal arteries) via bulk flow and reabsorbed by the lymphatic system. The total volume of fluid present in the intrapleural space is estimated to be only 2–10 ml. A small amount of protein is present in intrapleural fluid. Normally, the rate of reabsorption increases as a physiological response to accumulating fluid.

The maxillary sinuses usually develop symmetrically. The maxillary sinus ostium drains into the infundibulum which joins the hiatus semilunaris and drains into the middle meatus.

The definitive treatment for appendicitis is appendectomy. An appendectomy, also spelled appendicectomy, is a surgical operation in which the vermiform appendix is removed. Appendectomy is normally performed as an urgent or emergency procedure to treat acute appendicitis.

Appendectomy may be performed laparoscopically (as minimally invasive surgery) or as an open operation. Laparoscopy is often used if the diagnosis is in doubt, or in order to leave a less visible surgical scar.
The classic history of anorexia and vague periumbilical pain, followed by migration of pain to the right lower quadrant (RLQ) and onset of fever and vomiting, is observed in fewer than 60% of patients. Children with appendicitis do not localize in the same way as adults and often the diagnosis is difficult and all too often made late. If the appendix perforates, an interval of pain relief is followed by development of generalized abdominal pain and peritonitis.

Laboratory findings may increase suspicion of appendicitis but are not diagnostic. The minimum laboratory workup for a patient with possible appendicitis includes a white blood cell (WBC) count with differential and urinalysis. Liver function tests and amylase and lipase assessments are helpful when the aetiology is unclear. Baseline blood urea nitrogen and creatinine are needed prior to intravenous contrast CT scanning. The WBC count becomes elevated in approximately 70-90% of patients with acute appendicitis.

Astrocytomas are primary intracranial tumours derived from astrocyte cells of the brain. They can arise in the cerebral hemispheres, in the posterior fossa, in the optic nerve and, rarely, in the spinal cord. These tumours express glial fibrillary acidic protein (GFAP). In almost half of cases, the first symptom of an astrocytoma is the onset of a focal or generalised seizure. Between 60% and 75% of patients will have recurrent seizures during the course of their illness. Secondary clinical sequelae may be caused by elevated intracranial pressure (ICP) cause by the direct mass effect, increased blood volume, or increased cerebrospinal fluid (CSF) volume. CT will usually show distortion of the third and lateral ventricles, with displacement of the anterior and middle cerebral arteries. Histological diagnosis with tissue biopsy will normally reveal an infiltrative character suggestive of the slow growing nature of the tumour.

Anterior cruciate ligament (ACL) injuries are most often a result of low-velocity, noncontact, deceleration injuries and contact injuries with a rotational component. Contact sports also may produce injury to the ACL secondary to twisting, valgus stress, or hyperextension all directly related to contact or collision.

Symptoms of an acute ACL injury may include the following:
– Feeling or hearing a “pop” sound in the knee
– Pain and inability to continue the activity
– Swelling and instability of the knee
– Development of a large hemarthrosis

Differential Diagnoses
A- Medial Collateral Knee Ligament Injury
Contact, noncontact, and overuse mechanisms are involved in causing MCL injuries.
Contact injuries involve a direct valgus load to the knee. This is the usual mechanism in a complete tear.
Noncontact, or indirect, injuries are observed with deceleration, cutting, and pivoting motions. These mechanisms tend to cause partial tears.
Overuse injuries of the MCL have been described in swimmers. The whip-kick technique of the breaststroke has been implicated. This technique involves repetitive valgus loads across the knee.

B- Posterior Cruciate Ligament Injury
Knowledge of the mechanism of injury is helpful. The following 4 mechanisms of PCL injury are recognized:
– A posteriorly directed force on a flexed knee, e.g., the anterior aspect of the flexed knee striking a dashboard, may cause PCL injury.
– A fall onto a flexed knee with the foot in plantar flexion and the tibial tubercle striking the ground first, directing a posterior force to the proximal tibia, may result in injury to the PCL.
– Hyperextension alone may lead to an avulsion injury of the PCL from the origin. This kind of injury may be amenable to repair.
– An anterior force to the anterior tibia in a hyperextended knee with the foot planted results in combined injury to the knee ligaments along with knee dislocation.

In chronic PCL tears, discomfort may be experienced with the following positions or activities:
– A semi flexed position, as with ascending or descending stairs or an incline
– Starting a run
– Lifting a load
– Walking longer distances
– Retro patellar pain symptoms may be reported as a result of posterior tibial sagging.
– Swelling and stiffness may be reported in cases of chondral damage.
– Individuals may describe a sensation of instability when walking on uneven ground
– Medial joint line pain may be reported.

Rapid eye movement (REM) sleep is also known as paradoxical sleep, as the summed activity of the brain’s neurons is quite similar to that during waking hours. Characterised by rapid movements of the eyes, most of the vividly recalled dreams occur during this stage of sleep. The total time of REM sleep for an adult is about 90–120 min per night.
Certain neurones in the brainstem, known as REM sleep-on cells, which are located in the pontine tegmentum, are particularly active during REM sleep and are probably responsible for its occurrence. The eye movements associated with REM are generated by the pontine nucleus with projections to the superior colliculus and are associated with PGO (pons, geniculate, occipital) waves.

Sputum culture is used to detect and identify the organism that are infecting the lungs or breathing passages.

Papillary carcinoma accounts for 70-80% of all thyroid cancers and is seen commonly in people aged 30-60 years. It is more aggressive in elderly patients. 10-20% cases may have recurrence or persistent disease. More common in females with a female to male ratio of 3:1. Papillary carcinomas can also contain follicular carcinomas. The common route of spread is through lymphatics to regional nodes in one-third cases and pulmonary metastasis can also occur. Papillary carcinomas of the thyroid have the best prognosis, especially in patients less than 45 years of age with small tumours confined to the thyroid gland.

Multiple endocrine neoplasia type 2 (MEN2) is a hereditary condition associated with 3 primary types of tumours: medullary thyroid cancer, parathyroid tumours, and pheochromocytoma. MEN2 is classified into subtypes based on clinical features. Virtually all patients with classical MEN2A develop medullary thyroid carcinoma (MTC), which is often the first manifestation of the disease and usually occurs early in life. Pheochromocytomas (PHEOs) tend to be diagnosed several years later or simultaneously with the MTC.