Surgical Intensive Care Unit

INTRODUCTION

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Surgical procedures constitute a sudden insult to the body, which can result in a myriad of life-threatening complications.¹ While most postoperative complications occur 1 to 3 days after surgery, others can take weeks to present.²

Some complications may occur after any type of operation and have predictable time courses (Table 27-1). Others are more specific to the operation performed and the patient’s medical history (Table 27-2). Postoperative fever is one of the most common complications encountered after any type of operation and requires a systematic approach to identify the etiology (Table 27-3).

TABLE 27-1General Postoperative Complications

Immediate (hours to days)
- Complications of anesthesia: malignant hyperthermia, allergic reaction, arrhythmia, hypotension, hypertension
- Hemorrhage: primary (cut ends of vasculature), secondary (congenital bleeding diathesis, consumptive coagulopathy, anticoagulant-related)
- Hypoxia: aspiration pneumonitis, atelectasis, pulmonary edema, transfusion reaction
- Oliguria: inadequate fluid replacement, bladder atony secondary to anesthetics, acute tubular necrosis secondary to medications, hypotension, or rhabdomyolysis
- Shock: hypovolemic (blood or fluid loss), distributive (sepsis, side effect of anesthesia), cardiogenic (post-surgical MI), obstructive (acute PE)
- Thromboembolic events: cerebrovascular accident, MI, PE
Early (days)
- Acute kidney injury: prerenal, intrinsic, obstructive
- Anastomotic breakdown/wound dehiscence
- Dehydration
- Delirium
- Electrolyte imbalance
- Hypoxic respiratory insufficiency: acute respiratory distress syndrome, pneumonia, PE
- Ileus/Ogilvie syndrome
- Infection: local wound infection or systemic infection (pneumonia, urinary, intravascular catheters, abscess)
- Thromboembolic events: deep venous thrombosis, PE
- Urinary retention
- Transfusion-associated reactions
Late (weeks to months)
- Abscess
- Fistula
- Hernia: incisional, internal

TABLE 27-2Procedure-Specific Complications

Type of Procedure	Specific Complications
Gastrointestinal surgery	Bowel operations Anastomotic complications/leak Bowel obstruction Fluid collections Ileus/Ogilvie syndrome Nerve damage (presacral plexus) Gallbladder operations Common bile duct injury/leak Pancreatitis
Thoracic surgery	Air leak, pneumothorax, and bronchopleural fistula Lobar torsion Pleural effusions and hemothorax Postpneumonectomy syndrome Postpneumonectomy pulmonary edema
Cardiac surgery	Arrhythmias (bradycardia, supraventricular, ventricular) Myocardial ischemia Shock (blood loss, vasodilation due to warming, cardiopulmonary bypass–induced inflammation and capillary leak, decrease in ventricular compliance due to ischemia-reperfusion injury)
Vascular surgery	Cerebrovascular accident Compartment syndrome due to Bleeding Reperfusion edema Cranial nerve injuries Graft-related complications Fistula formation Hemorrhage Infection Ischemia Rethrombosis Multisystem organ failure
Urological surgeries	Bleeding/hematuria Electrolyte abnormalities (most commonly hyponatremia) Retrograde ejaculation Sphincter damage/incontinence Urinary tract infections (urethritis, cystitis, pyelonephritis, prostatitis)
Neck surgeries	Airway obstruction secondary to compression from hematoma Electrolyte abnormalities (most commonly hypocalcemia due to parathyroid gland damage/removal) Facial or recurrent laryngeal nerve damage

TABLE 27-3Etiologies of Postoperative Fever

Immediate
- Drug fever
- Malignant hyperthermia (rare)
- Transfusion reaction
Acute
- Catheter-associated infections
- Skin and soft tissue infections
- Urinary tract infection
- Ventilator-associated pneumonia/aspiration pneumonia/pneumonitis
Subacute
- Antibiotic-associated fever
- Catheter-associated infections/thrombophlebitis
- Clostridium difficile colitis
- Skin and soft tissue infections, wound-related complications
- Urinary tract infection
- Ventilator-associated pneumonia/aspiration pneumonia/pneumonitis
Delayed
- Blood-product-related infections (parasitic, viral)
- Chylothorax, chyloperitoneum, lymphedema
- Late wound-related complications (fistulae/leaks)
- Postpericardiotomy syndromes

In this chapter, we will first outline the main postoperative complications that a critical care provider is likely to encounter in the intensive care unit (ICU), followed by a more in-depth discussion of particularly common or serious complications.

MAJOR GASTROINTESTINAL SURGERY

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Abdominal Compartment Syndrome

Abdominal compartment syndrome (ACS) is a life-threatening complication defined as sustained intra-abdominal pressure (IAP) greater than 20 mmHg with new organ dysfunction.³ Risk factors for ACS include (1) decreased abdominal wall compliance due to abdominal surgery, major trauma, burns, or prone positioning; (2) increased volume of intraluminal bowel contents due to gastroparesis, ileus, pseudo-obstruction, or volvulus; (3) increased volume of peritoneal free fluid due to hemoperitoneum, infection, carcinomatosis, or ascites; and (4) capillary leak due to massive fluid resuscitation or transfusion therapy, acidosis, hypothermia, or acute pancreatitis.^2–4

The frequency of ACS is estimated at 5% of critically ill patients.³ This diagnosis requires a high level of suspicion and is easily missed. Unfortunately, untreated ACS carries an extremely high mortality rate. The 3 hallmark signs of ACS are (1) a sudden increase in plateau pressures on the ventilator due to extrinsic compression from the abdomen, (2) hypotension due to impaired venous return, and (3) oliguria/anuria due to hypotension and compression of the renal vessels.⁴ The physical exam will reveal a distended and tense abdomen, hypotension, tachycardia, jugular venous distension, peripheral edema, and evidence of hypoperfusion. Bladder pressure, which is an estimation of the IAP, will be greater than 20 mmHg.³

Treatment includes supportive care (nasogastric and rectal tube decompression, pain control, supine position, and chemical paralysis) and/or abdominal decompression via laparotomy.⁵

Pancreatitis

One to three percent of patients undergoing a peripancreatic operation will develop pancreatitis. Of all cases of acute pancreatitis, postoperative pancreatitis accounts for approximately 10%.⁶ Secondary infection and pancreatic necrosis are 3-fold more common in the setting of postoperative pancreatitis than biliary or alcoholic pancreatitis. Both infection and necrosis are associated with a high mortality rate (30–40%). Diagnosis of postoperative pancreatitis requires a high index of suspicion, as the clinical exam is nonspecific and amylase/lipase levels may be normal.⁷ Abdominal computed tomography (CT) showing pancreatic edema and peripancreatic fluid collections may help to establish the diagnosis. Close monitoring and management in the ICU are recommended for patients with end-organ dysfunction, and early enteral nutrition may limit injury and decrease the rate of infection. The use of prophylactic antibiotics is not recommended in patients with pancreatic necrosis without evidence of infection. Severe cases of pancreatitis may result in fluid collections that require percutaneous drainage or endoscopic transgastric necrosectomy.

Cholecystitis

Postoperative cholecystitis is mostly acalculous (70–80%) and occurs more commonly in males (75%).⁶ Risk factors include critical illness, endoscopic sphincterotomy, and parenteral nutrition.⁶ Postoperative cholecystitis progresses rapidly to necrosis and is less likely to respond to conservative management. The diagnosis may be confirmed via ultrasound or CT demonstrating pericholecystic fluid, intramural gas, and/or gallbladder wall thickening. Critically ill patients, who are often too unstable to undergo surgery, may undergo percutaneous cholecystostomy tube placement for decompression.