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Abdominal Assessment and Anatomy

A proper abdominal assessment must follow a specific sequence consisting of inspection, followed by auscultation, then percussion, and finally palpation. It is essential to identify organ locations across the four quadrants accurately. The right upper quadrant contains the pylorus, duodenum, gallbladder, liver, and right kidney, while the left upper quadrant houses the stomach, pancreas, spleen, and left kidney. The appendix and cecum are found in the right lower quadrant, and the sigmoid colon is located in the left lower quadrant. The small intestine, which measures approximately $18-20$ feet, is primary for digestion and absorption through the duodenum, jejunum, and ileum. The large intestine, spanning $5-6$ feet, focuses on water and electrolyte absorption, waste elimination, and the synthesis of vitamins like Vitamin $K$ and $B_{12}$.

Nutritional Guidelines

The American Society for Parenteral and Enteral Nutrition (ASPEN) recommends providing nutrition as early as possible in the clinical course. Enteral nutrition is preferred over parenteral routes whenever the patient can tolerate it. General caloric needs for most patients are approximately $25$ calories per kilogram per day, with a significant emphasis on providing at least $1$ gram of protein per kilo per day. Standard labs such as albumin and pre-albumin are considered unreliable for assessing acute nutritional status in hospitalized patients as they often drop during acute illness.

Bowel Infarction

Small bowel infarctions typically present with abdominal pain and leukocytosis, which is a general elevation in white blood cell counts. These infarctions are split into occlusive types, caused by clots in the mesenteric artery, and non-occlusive types, resulting from low cardiac output and poor perfusion. Pathophysiological progression follows a path of ischemia and edema leading to potential necrosis and perforation. Labs often reveal elevated lactate, $LDH$, amylase, and metabolic acidosis. Management includes fluid resuscitation, gastric decompression, and surgical resection of dead bowel to anastomose healthy segments.

Bowel Obstruction

Bowel obstructions can be caused by various factors including adhesions, ileus, opiates, tumors, or volvulus. Proximal small bowel obstructions usually manifest as vomiting and crampy epigastric pain, whereas distal or large bowel obstructions present with constipation, vague pain, and late-stage feculent vomiting. Early assessment reveals hyperactive bowel sounds, which eventually become hypoactive or absent as the condition progresses. Treatment focuses on fluid and electrolyte replacement, particularly for potassium and magnesium, along with pain management and potential surgical intervention.

Perforation

Although rare, perforations in the GI tract can be fatal due to the leakage of intestinal contents into the peritoneum, which causes rapid and severe infection. Patients often present with a rigid or board-like abdomen, tachycardia, and fever. Diagnostic measures include CT scans or exploratory laparotomy to identify the source. Management requires aggressive fluid resuscitation, broad-spectrum antibiotics, gastric decompression, and an abdominal washout in the operating room to mitigate septic complications.

Gastrointestinal Bleeding

Upper GI bleeds are more common and carry a higher mortality rate than lower GI bleeds. Common causes include peptic ulcers, esophageal varices, and tumors. Bright red blood in the stool might indicate a lower bleed or a rapid upper bleed causing dumping syndrome. Management focuses on hemodynamic stabilization using blood transfusions and clotting factors, along with the administration of proton pump inhibitors or H2 blockers. Pharmacological interventions such as vasopressin or octreotide may also be used to reduce portal pressure in variceal cases.

Acute Pancreatitis

Acute pancreatitis is an enzymatic auto-digestion of the pancreas often caused by gallstones or chronic alcohol use. Patients experience severe upper abdominal pain radiating to the back, along with signs like Cullen's sign, which is periumbilical ecchymosis, or Grey Turner's sign, appearing as flank ecchymosis. Key lab findings include hyperglycemia, hypocalcemia, and elevated amylase and lipase levels. Treatment is largely supportive, focusing on pancreatic rest, fluid resuscitation, and monitoring for pulmonary complications like ARDS. Ranson’s criteria are often used to predict mortality based on clinical and laboratory values upon admission and during the first $48$ hours.

Hepatic Failure

Hepatic failure involves the loss of $75\%-90\%$ of hepatocytes, leading to a failure to filter ammonia and synthesize plasma proteins. Acute hepatic failure is often drug-induced (DILLY), with acetaminophen being the primary cause. Chronic failure involves scarring and fibrosis, commonly from alcoholism, leading to portal hypertension. Patients may present with jaundice, encephalopathy, and asterixis involving hand flapping. The MELD score is used clinically to determine the three-month mortality risk and transplant priority based on creatinine, bilirubin, $INR$, and sodium levels.

Cirrhosis and Ascites Management

Advanced cirrhosis leads to ascites due to low albumin and portal hypertension. Management strategies include a low-sodium diet, fluid restriction to $1.5$ liters per day, and the use of diuretics like spironolactone and furosemide. Large-volume paracentesis may be required for respiratory relief, though the fluid often reaccumulates quickly. Nursing care must focus on monitoring renal function to identify hepatorenal syndrome and assessing for spontaneous bacterial peritonitis through fluid analysis.

Esophageal Varices

Esophageal varices are engorged veins in the distal esophagus caused by portal hypertension, carrying a high risk of life-threatening hemorrhage. Treatment includes airway protection, endoscopic banded ligation, and pharmacological control via octreotide or vasopressin. A TIPS procedure stands for transjugular intrahepatic portosystemic shunt and may be performed to shunt blood and relieve portal pressure. In emergent cases, balloon tamponade using a Minnesota or Blakemore tube is used, though it requires constant monitoring to prevent airway obstruction and tissue erosion.

Gastrointestinal Trauma

Abdominal trauma is classified as blunt or penetrating, with the spleen and liver being the most frequently injured organs. The FAST exam is used for rapid internal assessment of bleeding. The "Death Triad" of trauma consisting of acidosis, hypothermia, and coagulopathy indicates a significantly high risk of mortality. Modern resuscitation favors a $1:1:1$ ratio of blood, FFP, and platelets over high-volume crystalloid use to avoid dilutional coagulopathy and improve survival outcomes.

Intra-abdominal Hypertension and Compartment Syndrome

Intra-abdominal hypertension occurs when internal pressures rise due to inflammation or massive fluid resuscitation. This can lead to abdominal compartment syndrome, characterized by decreased urine output, respiratory distress, and systemic hypotension. Bladder pressure reflects intra-abdominal pressure, with normal values usually being $5-10$ $mmHg$. An abdominal perfusion pressure calculated as $APP = MAP - IAP$ that falls below $50$ $mmHg$ is associated with poor outcomes. Treatment for severe cases involves a decompressive laparotomy to relieve pressure immediately.

Bariatric Surgery

Bariatric procedures like the gastric sleeve and Roux-en-Y gastric bypass are used to treat morbid obesity and related conditions like type $2$ diabetes. The sleeve restricts stomach volume by removing a large portion, while the Roux-en-Y combines restriction with components of malabsorption. Post-operative complications include leaking at anastomosis sites, bleeding, and deep vein thrombosis. Nursing staff must never blindly insert gastric tubes into these patients to avoid pouch perforation. Long-term concerns include dumping syndrome, B-vitamin deficiencies, and episodes of hypoglycemia.