This chapter discusses the management of surgical abdomen. It presents special circumstances, which make management of surgical abdomen difficult in some patients, including children, developmentally delayed, or obtunded individuals (from illness or drugs), patients with spinal cord injuries, pregnant patients, elderly or immunosuppressed patients, and morbid obese patients. Patients could present with referred pain, which is pain experienced at a site (or sites) distant from the initiating organ due to a shared neural origin with another body organ, such as right shoulder pain due to biliary colic or back pain due to pancreatitis. Acute-onset pain lasting longer than 6 hours in a previously healthy patient is often due to a surgical condition. As with the stable patient, a well-formulated differential diagnosis based on careful history and physical examination guides the plan of care far better than a shotgun approach of imaging and laboratory tests.

Pneumoperitoneum with CO2 gas begins the process of systemic acidification by altering the ultrastructural, metabolic, and immune functions of the peritoneum. Both direct and indirect effects of CO2 can be seen in numerous aspects of the cardiovascular system. Both obese and non-obese patients undergo laparoscopy at 15 mm Hg of CO2 gas in order to provide adequate visualization while minimizing the detrimental effects of increased intra-abdominal pressure (IAP). An overall decrease in renal perfusion and a resultant increase in hormonal activity occur with pneumoperitoneum. Patients with chronic obstructive pulmonary disease (COPD) often require lower IAP during laparoscopy. Effective preventions or control of detrimental effects of CO2 pneumoperitoneum are key to maintaining the safety profile of laparoscopy. Nevertheless, with the numerous benefits that stem from sequential compression devices (SCDs), their routine use has become widely recommended for all laparoscopic surgery.

This chapter reviews the factors involved in deciding which operation to perform for an operative candidate. Roux-en-y gastric bypass is the most common weight loss procedure performed in the United States and is a mixed restrictive and malabsorptive procedure. For many patients, government policy may also determine the operative procedure options. Patients are generally better informed and capable of deciding which bariatric operative procedure would be best for them. Past surgical history of a patient can factor into the decision making process. This information can change the surgeon's operative approach, especially if the patient has had prior gastric surgery. Patients with a history of eating high calorie liquids, such as ice cream, must change their eating habits as this is one way to fail any bariatric procedure. Some patients will have personality characteristics that may make them better candidates for one procedure over another.

Biliary ultrasound is part of any complete abdominal ultrasound and limited right upper quadrant ultrasound. It is more difficult to perform abdominal ultrasound on obese patients. This statement is particularly true with regard to the liver, gallbladder, and associated structures. The limitations of ultrasound in the right upper quadrant are few. Since ultrasound creates 2D images of 3D structures, the experience level of the sonologist is very important. It should be noted that ultrasound is not the most accurate imaging study for cholecystitis. The biliary system is made up of the gallbladder, along with the intra- and extrahepatic biliary ducts. The intrahepatic ducts form in the subsegments of the liver and course toward the porta hepatis where they form the common hepatic duct (CHD). The intrahepatic ducts are more difficult to evaluate because they are normally very narrow.