Perforated Appendicitis.docx

Perforated Appendicitis Perforated appendicitis is more common in rural areas, older adults, and uninsured populations, who may have difficulty getting access to care. Patients with perforation of the appendix may be very ill and require several hours of fluid resuscitation before safe induction of general anesthesia can be achieved. Broad-spectrum antibiotics directed against gut aerobes and anaerobes are initiated early in the evaluation and resuscitation phase. In children, a laparoscopic approach to the perforated appendix appears to reduce the incidence of postoperative wound infections and ileus and is associated with shorter hospital stays and lower costs.28 Studies in adults have suggested that patients successfully treated laparoscopically realize similar benefits, albeit with a higher risk of conversion to an open procedure than for patients with simple appendicitis.29 We usually begin with a diagnostic laparoscopy and use a rolled gauze to gently sweep adherent loops of small bowel away from the cecum, thereby exposing the appendix. Depending on the ease of completing that task, a decision is made whether to convert to an open appendectomy. Extreme friability of the adjacent bowel loops may require conversion to avoid bowel injury. Any pus encountered during the dissection is aspirated and sent for Gram staining and culture. Oozing from the severely inflamed retroperitoneum is easily controlled with electrocautery or argon beam coagulation, if available. The inflamed indurated mesoappendix is divided using the LigaSure or harmonic scalpel. The taeniae of the cecum are followed onto the base of the appendix, and the stump is divided between Endoloops or with a stapler, depending on the integrity of the tissues. When the mesoappendix is densely adherent to the cecum or retroperitoneum, it may be helpful to divide the stump of the appendix with the stapler before dividing the mesoappendix. The abdomen and pelvis are irrigated and the fluid aspirated. We leave a closed suction drain in place only if a well-defined residual abscess cavity exists after reflection of the small bowel away from the appendiceal bed. Antibiotics may be altered, if necessary, based on the culture results and are continued until the patient is afebrile postoperatively. If the procedure was completed open, the wound is typically left open with nylon sutures laid into place for possible delayed primary closure after 3 to 5 days of dressing changes. Laparoscopic trocar sites are closed because the incidence of infection is low. Appendiceal Abscess Patients who present late in the course of appendicitis with a mass and fever may benefit from a period of nonoperative management, which reduces complications and overall hospital stay30 (Fig. 51-6). Imaging studies are useful for confirming the diagnosis and for evaluating the size of any abscess present (Fig. 51-7). Patients with large abscesses, larger than 4 to 6 cm, and especially those patients with abscess and high fever, benefit from abscess drainage. This may be accomplished via the transrectal or transvaginal route using ultrasound guidance if the abscess is suitably located31 or by a percutaneous image-guided approach. Patients with smaller abscesses or phlegmon and who are not sick may be successfully managed initially with antibiotics alone.

Patients who continue to have fever and leukocytosis after several days of nonoperative treatment are likely to require appendectomy during the same hospitalization, whereas those who improve promptly may be considered for interval appendectomy.32 After nonoperative treatment of suspected late appendicitis, adults who have not had one recently should undergo colonoscopy or barium enema because colon cancer is detected in an estimated 5% of cases.33 The risk for recurrent appendicitis is approximately 15% to 25% after nonoperative treatment and warrants consideration of interval appendectomy. We typically perform this procedure laparoscopically approximately 6 weeks after the initial bout of appendicitis. Interval appendectomy can frequently be done as an outpatient procedure and is associated with a low morbidity rate. The procedure is routinely performed in children. The decision about whether to proceed with interval appendectomy for adult patients includes factors such as patient age, comorbid conditions, and prior abdominal surgery. Chronic or Recurrent Appendicitis A small number of patients report episodic bouts of right lower abdominal pain in the absence of an acute febrile illness. Some are found to have appendicoliths on CT scans34 or sonographic evidence of an enlarged appendiceal diameter35; most of these will have surgical and pathologic evidence of chronic inflammation of the appendix and relief of symptoms after appendectomy. These findings support the concept that appendicitis represents a spectrum of inflammatory changes that may, in rare cases, wax and wane. The dilemma is more difficult when the report of pain is not accompanied by other clinical or radiographic findings. These patients fall into the category of those with chronic abdominal pain; pathologically confirmed appendiceal inflammation is rarely found in these patients. We have typically sought evidence of appendiceal pathology before appendectomy for chronic pain using ultrasound, CT, or both, in combination with colonoscopy, to exclude other causes of pain. Normal-Appearing Appendix If a normal-appearing appendix is identified at the time of surgery, should it be removed? This question has been raised again after the introduction of the laparoscopic approach; consensus is lacking on this point. Although it is difficult to know how many patients benefit from this practice, removal of the appendix adds little morbidity to the procedure. In some cases, pathologic abnormalities that were not apparent on visual inspection are identified.36 Our practice is to remove the appendix and perform a thorough search for other causes of the patient’s symptoms. We specifically examine the small intestine for Meckel’s diverticulum and Crohn’s disease, the mesentery for lymphadenopathy, and the pelvis for abscesses, ovarian torsion, and hernias. If findings of Crohn’s disease are observed and the base of the appendix is not involved in the inflammatory process, appendectomy is advised to prevent future confusion. If, however, the base of the appendix is involved in the inflammatory ileitis process, it may be safer to avoid appendectomy to minimize fistula formation.

scwkzt early in presentation, vital signs may be minimally altered. The body temperature and pulse rate may be normal or slightly elevated. Changes of greater magnitude may indicate that a complication has occurred or that another diagnosis should be considered.35 Physical findings are determined by the presence of peritoneal irritation and are influenced by whether the organ has already ruptured when the patient is first examined. Patients with appendicitis usually move slowly and prefer to lie supine due to the peritoneal irritation. On abdominal palpation, there is tenderness with a maximum at or near McBurney’s point (Fig. 30-1).5 On deep palpation, one can often feel a muscular resistance (guarding) in the right iliac fossa, which may be more evident when compared to the left side. When the pressure of the examining hand is quickly relieved, the patient feels a sudden pain, the so-called rebound tenderness. Indirect tenderness (Rovsing’s sign) and indirect rebound tenderness (i.e., pain in the right lower quadrant when the left lower quadrant is palpated) are strong indicators of peritoneal irritation. Rebound tenderness can be very sharp and uncomfortable for the patient. It is therefore recommended to start with testing for indirect rebound tenderness and direct percussion tenderness. Anatomic variations in the position of the inflamed appendix lead to deviations in the usual physical findings. With a retrocecal appendix, the abdominal findings are less striking, and tenderness may be most marked in the flank. When the appendix hangs into the pelvis, abdominal findings may be entirely absent, and the diagnosis may be missed. Right-sided rectal tenderness is said to help in this situation, but the diagnostic value is low. Pain with extension of the right leg (psoas sign) indicates a focus of irritation in the proximity of the right psoas muscle. Similarly, stretching of the obturator internus through internal rotation of a flexed thigh (obturator sign) suggests inflammation near the muscle

Give some causes of hyperkalaemia. haemolysis in the blood bottle

Artefact: e.g. Iatrogenic: excess

external administration Following internal redistribution: Between intracellular fluid (ICF) and ECF due to injury, e.g. crush injury, burns, intravascular haemolysis Reduced cellular uptake: diabetes mellitus, acidosis Decreased excretion: Renal: renal failure, potassium-sparing diuretics Adrenal origin: Addison’s disease Mineralocorticoid resistance: systemic lupus erythematosus (SLE), chronic interstitial nephritis 5. Which ECG changes may you see with hyperkalaemia? Tall and tented T-waves Small P-waves QRS complex

Wide

6. Give some causes of hypokalaemia. Artefact: e.g. drip-arm sampling Decreased oral intake Internal re-distribution: Between ECF and ICF: alkalosis, excess insulin (iatrogenic, insulinoma) Loss from the body: GIT losses: vomiting, diarrhoea, mucin-secreting colonic adenoma, enterocutaneous fistula Renal loses: Conn’s syndrome, use of loop and thiazide diuretics 7. Which ECG changes might you see? T-waves Prolonged PR-interval S–T segment depression

Small or inverted

Peritonitis Peritonitis is inflammation of the peritoneum and peritoneal cavity, usually caused by a localized or generalized infection. Primary peritonitis results from bacterial, chlamydial, fungal, or mycobacterial infection in the absence of perforation of the GI tract, whereas secondary peritonitis occurs in the setting of GI perforation. Frequent causes of secondary bacterial peritonitis include peptic ulcer disease, acute appendicitis, colonic diverticulitis, and pelvic inflammatory disease. Spontaneous Bacterial Peritonitis Spontaneous bacterial peritonitis (SBP) is defined as a bacterial infection of ascitic fluid in the absence of an intra-abdominal, surgically treatable source of infection. Although usually associated with cirrhosis, SBP may also occur in patients with nephrotic syndrome and, less commonly, congestive heart failure. It is extremely rare for patients with ascitic fluid containing a high protein concentration to develop SBP, such as those with peritoneal carcinomatosis. The most common pathogens in adults with SBP are the aerobic enteric flora Escherichia coli and Klebsiella pneumoniae. In children with nephrogenic or hepatogenic ascites, group A streptococcus, Staphylococcus aureus, and Streptococcus pneumoniae are common isolates. Bacterial translocation from the GI tract is thought to be an important step in the pathogenesis of SBP. Impaired GI motility in cirrhotics is thought to alter normal gut microflora and impaired local and systemic immune function prevents the effective clearance of translocated bacteria from the mesenteric lymphatics and bloodstream. A

low protein concentration in ascitic fluid prevents effective opsonization of bacteria and hence clearance by macrophages and neutrophils. The diagnosis of SBP is made initially by demonstrating more than 250 neutrophils/mm3 of ascitic fluid in a clinical setting consistent with this diagnosis—that is, abdominal pain, fever, or leukocytosis in a patient with low-protein ascites. It is unusual to document bacterascites on Gram staining of ascitic fluid, and delay of appropriate antibiotic management until the ascitic fluid cultures grow bacterial isolates risks the development of overwhelming infection and death. Bedside screening of ascitic fluid for leukocyte esterase, using colorimetric leukocyte esterase reagent strips, has been used to shorten the time from paracentesis to treatment, although its widespread use remains controversial.20,21 Broad-spectrum antibiotics, such as a third-generation cephalosporin, are started immediately in patients suspected of having ascitic fluid infection. These agents cover approximately 95% of the flora most commonly associated with SBP and are the antibiotics of choice for patients suspected to have SBP.22,23 The spectrum of the antibiotic coverage may be narrowed once the results of antibiotic sensitivity tests are known. Repeat paracentesis with ascitic fluid analysis is not needed in the usual case, in which there is rapid improvement in response to antibiotic therapy. If the setting, symptoms, ascitic fluid analysis, or response to therapy are atypical, repeat paracentesis may be helpful for detecting secondary peritonitis. Multiple bacterial isolates, particularly of gram-negative enteric organisms, combined with a poor response to antibiotic therapy, suggest the presence of secondary peritonitis. The immediate mortality risk caused by SBP is low, particularly if recognized and treated expeditiously. However, the development of other complications of hepatic failure, including GI hemorrhage or hepatorenal syndrome, contributes to the death of many of these patients during the hospitalization in which SBP is detected. The occurrence of SBP is an important landmark in the natural history of cirrhosis, with 1- and 2-year survival rates of approximately 30% and 20%, respectively. Several studies, including a randomized controlled trial, have shown that plasma expansion with albumin improves circulatory function and reduces the risk for hepatorenal syndrome and hospital mortality in patients with SBP.24 Tuberculous Peritonitis Tuberculosis is common in impoverished areas of the world and is encountered with increasing frequency in the United States and other developed countries. Since 1985, the number of cases of tuberculosis in the United States and European nations has increased dramatically as the number of immigrants, refugees, and individuals with acquired immunodeficiency syndrome (AIDS) has increased. Others have described an association between peritoneal tuberculosis and alcoholic cirrhosis and chronic renal failure.25 Peritoneal tuberculosis is the sixth most common site of extrapulmonary tuberculosis, after lymphatic, genitourinary, bone and joint, miliary, and meningeal. Most cases result from reactivation of latent peritoneal disease that had been previously established hematogenously from a primary pulmonary focus. Only approximately 17% of cases are associated with active pulmonary disease. The illness often presents insidiously, with patients having had symptoms for several weeks to months at the time of presentation. Abdominal swelling caused by ascites formation is

the most common symptom, occurring in more that 80% of cases. Similarly, most patients complain of a nonlocalized, vague abdominal pain. Constitutional symptoms such as low-grade fever and night sweats, weight loss, anorexia, and malaise are reported in approximately 60% of patients. The concomitant presence of other chronic conditions such as uremia, cirrhosis, and AIDS makes these symptoms difficult to interpret. Abdominal tenderness is present on palpation in approximately 50% of patients with peritoneal tuberculosis.25 A positive tuberculin skin test is present in most cases, whereas only approximately 50% of these patients will have an abnormal chest radiograph. The ascitic fluid SAAG is less than 1.1 g/dL, consistent with a high protein concentration in the ascitic fluid. Microscopic examination of the ascites shows erythrocytes and an increased number of leukocytes, most of which are lymphocytes. Recently, measurement of ascitic fluid adenosine deaminase activity and polymerase chain reaction assays have been used as noninvasive and rapid tests for tuberculous peritonitis. Ascitic fluid adenosine deaminase activity, in particular, appears to be highly sensitive and specific for tuberculous peritonitis. Abdominal imaging with ultrasound or CT may suggest the diagnosis but lacks the sensitivity and specificity to be diagnostic. Ultrasound may demonstrate the presence of echogenic material in the ascitic fluid, seen as fine mobile strands or particulate matter. CT will demonstrate the thickened and nodular mesentery with mesenteric lymphadenopathy and omental thickening. The diagnosis is made by laparoscopy with directed biopsy of the peritoneum. In more than 90% of cases, laparoscopy demonstrates a number of whitish nodules (<5 mm) scattered over the visceral and parietal peritoneum; histologic examination demonstrates caseating granulomas. Multiple adhesions are commonly present between the abdominal organs and parietal peritoneum. The gross appearance of the peritoneal cavity is similar to that of peritoneal carcinomatosis, sarcoidosis, and Crohn’s disease, thus reiterating the importance of biopsy. Blind percutaneous peritoneal biopsy has a much lower yield than directed biopsy, and laparotomy with peritoneal biopsy is reserved for cases in which laparoscopy has been nondiagnostic or cannot be safely performed. Microscopic examination of