Abdominal Compartment Syndrome

Question 1

What is Abdominal Compartment Syndrome (ACS)?

Answer 1

Pathological condition caused by sustained elevations in intraabdominal pressure, leading to organ dysfunction and end-organ failure

Question 2

What is the difference between primary and secondary ACS?

Answer 2

-Primary ACS originates from pathologic processes in the abdomen, like peritoneal hemorrhage.
-Secondary ACS arises from systemic processes, such as sepsis or large-volume resuscitation.

Question 3

What conditions are associated with secondary ACS?

Answer 3

Secondary ACS is associated with conditions like sepsis, large-volume resuscitation, massive transfusion, and inflammation, which increase capillary permeability.

Question 4

What are the primary strategies for reducing intraabdominal pressure (IAP) and managing refractory intraabdominal hypertension (IAH)?

Answer 4

The strategies include evacuating space-occupying masses and collections, decompression of intraluminal content, improving abdominal wall and diaphragm compliance, and optimizing fluid management.

Question 5

What simple maneuvers can help reduce intraabdominal pressure?

Answer 5

-Nasogastric and rectal tube decompression help reduce intraabdominal pressure
-Intestinal promotility agents can help evacuate intraluminal content and gas, in cases of gastric or intestinal obstruction, severe dysmotility, or large fecal burden
-percutaneous drainage catheters into space-occupying collections can effectively lower IAP, particularly when a substantial volume (e.g., ~1 L) is drained

Question 6

How does increased intraabdominal pressure (IAP) affect the inferior vena cava?

Answer 6

causes compression of the intraabdominal inferior vena cava, decreasing venous return to the heart, reducing cardiac preload, and leading to systemic hypotension.

Question 7

What is the impact of increased IAP on the thoracic cavity and ventilation?

Answer 7

decreases compliance, and increases peak airway and plateau pressures on the mechanical ventilator, potentially causing barotrauma and compressive atelectasis, leading to poor gas exchange, refractory hypoxia, and hypercarbia.

Question 8

How does intraabdominal hypertension affect renal function?

Answer 8

decreased urine output, declining glomerular filtration rate (GFR), or increased creatinine levels due to poor systemic perfusion and direct compression of the renal system by increased intraabdominal pressure

Question 9

What are the late findings in Abdominal Compartment Syndrome (ACS)?

Answer 9

include intestinal and solid organ ischemia, which can present as metabolic acidosis with increasing lactate levels, renal failure, or abnormal liver function tests (LFTs)

Question 10

How frequently should intraabdominal pressure (IAP) be monitored in patients at risk for ACS?

Answer 10

should be monitored every 4 to 6 hours in patients at risk for ACS.

Question 11

What is the standard modality for measuring intraabdominal pressure?

Answer 11

Trans-bladder pressure monitoring is the standard modality for measuring intraabdominal pressure

Question 12

Describe the standard technique for bladder pressure measurement in IAP monitoring.

Answer 12

instilling 25 mL of normal saline via a Foley catheter, connected to a transducer placed at the midaxillary line at the level of the iliac crest, in a supine and relaxed patient. The pressure is measured at the end of expiration when the abdominal wall is relaxed.

Question 13

What defines Abdominal Compartment Syndrome (ACS)?

Answer 13

sustained intraabdominal hypertension (IAH) > 20 mm Hg combined with new or worsening organ dysfunction

Question 14

Grading of Intraabdominal Hypertension

Answer 14

-Grade I IAP is between 12–15 mm Hg
-Grade II IAP is between 16–20 mm Hg
-Grade III IAP is between 21–25 mm Hg
-Grade IV IAP is greater than 25 mm Hg

Question 15

What is the definitive management for Abdominal Compartment Syndrome (ACS)?

Answer 15

emergent decompressive laparotomy.

Bedside decompressive laparotomy > IF hemodynamic instability, respiratory compromise, severely elevated intracranial pressure, or other barriers to transport.

Question 16

How can bedside surgical decompression confirm the diagnosis of ACS?

Answer 16

diagnosis of ACS is often confirmed if hemodynamics or ventilator mechanics improve following decompression.

Question 17

What is the purpose of a hybrid approach to managing ACS in critical settings?

Answer 17

performing a sharp laparotomy with temporary abdominal dressing at the bedside to rapidly relieve pressure
followed by transporting the patient to the operating room once hemodynamic or pulmonary decompensation has improved for further exploration and management.

Question 18

Why is a limited laparotomy inadequate in ACS management?

Answer 18

limited laparotomy may be insufficient for complete release of pressure, leading to a risk of therapy failure and recurrent ACS, similar to extremity compartment syndrome.

Question 19

How can improvements in the patient’s condition confirm the diagnosis of ACS?

Answer 19

through improvements in hemodynamics, intracranial pressure (ICP), peak airway pressures, cardiac output, or oxygenation, often observed after decompressive laparotomy

Question 20

What should be done if minimal improvement is observed after initial decompression?

Answer 20

the midline incision should be extended through both the skin and fascia to ensure adequate decompression.

Question 21

What is the role of intraoperative exploration during ACS surgery?

Answer 21

to evaluate any associated intraabdominal pathology, such as bowel ischemia or infection, which may require further surgical intervention

Question 22

What is the purpose of Temporary Abdominal Closure (TAC)?

Answer 22

allows the surgical procedure to be paused with the abdominal fascia open, preventing reexacerbation of intraabdominal hypertension (IAH) and allowing for safe transition to other urgent patient needs or “second-look” explorations

Question 23

How has the use of Temporary Abdominal Closure evolved?

Answer 23

with vacuum-assisted negative pressure wound therapy now commonly used across multiple specialties

Question 24

What should a Temporary Abdominal Closure technique provide?

Answer 24

adequate visceral protection
allow drainage of intraabdominal fluid
mitigate fascia edge retraction
prevent the redevelopment of IAH and compartment syndrome.

Question 25

What was one of the earlier techniques used for rapid abdominal closure in surgery?

Answer 25

skin-only closure, achieved either by placing penetrating towel clips 2 cm apart or using a continuous running monofilament suture to approximate the skin edges.

Question 26

What were the limitations of skin-only closure techniques

Answer 26

Did not allow sufficient expansion of abdominal contents, retained significant risk for recurrent ACS, did not allow fluid egress, and caused damage to skin edges, leading to retraction of the abdominal wall musculature and fascia.

Question 27

Why do skin-only closure techniques increase the difficulty of subsequent closure attempts?

Answer 27

do not prevent abdominal wall retraction or adhesions to the lateral abdominal wall, making future closure attempts more difficult and worsening the loss of abdominal domain

Question 28

What materials are used as a protective cover over the viscera in a resource-limited setting for preventing intraabdominal hypertension (IAH)?

Answer 28

A sterile x-ray cassette cover or a 3-L sterile irrigation bag cut to size is used as a nonadherent, easily distensible protective cover over the viscera

Question 29

How is the protective cover secured to the skin or fascial edges in this technique?

Answer 29

-circumferentially approximated to the skin or fascial edges using running small bites of heavy monofilament sutures. -placing closed-suction drains

Question 30

What are the disadvantages of this technique?

Answer 30

inability to prevent fascial retraction and loss of domain, increased difficulty of future fascial closure due to adhesion formation, risk of bowel injury during suturing, and being more labor-intensive compared to newer techniques.

Question 31

What is the Barker vacuum pack, and how does it differ from the Bogota bag?

Answer 31

The Barker vacuum pack is a development from the Bogota bag. It uses a sterile polyethylene sheet with small fenestrations placed between the viscera and the anterolateral abdominal wall to prevent adhesion formation, with saline-soaked towels and closed drains layered over the sheet to allow effective fluid drainage.

Question 32

What is the AbThera vac, and how does it improve on the Barker vacuum pack technique?

Answer 32

The AbThera vac is a prepackaged, vacuum-assisted dressing system that includes polyurethane foam, a fenestrated non-adherent polyethylene sheet, and a negative pressure pump.

Question 33

When is the abdomen typically closed after the acute resuscitative phase in surgical management?

Answer 33

-once hemorrhage and contamination sources are controlled -surgical reconstruction is complete -patient shows physiological normalization, such as weaning off vasopressors, reduced fluid requirements, improved tissue perfusion, and resolved coagulopathy.

Question 34

Why might primary closure of the abdomen be delayed after large-volume resuscitation?

Answer 34

Large-volume resuscitation can cause visceral congestion, making the abdominal contents too large for the abdominal wall to close properly

Question 35

What risks increase with prolonged open abdomen?

Answer 35

increases the risk of visceral adhesions injury during manipulation enteroatmospheric fistula lateral abdominal wall retraction leading to a loss of domain and a larger fascial gap, making primary closure more difficult.

Question 36

How does prolonged open abdomen affect the lateral abdominal wall musculature?

Answer 36

The longer the abdomen remains open, the more the lateral abdominal wall musculature retracts, leading to a loss of domain and an enlargement of the fascial gap

Question 37

What factors can affect the timing of adhesion formation in an open abdomen?

Answer 37

depends on the patient’s underlying comorbidities, physiological state, degree of malnutrition, and immunosuppression

Question 38

What is the ideal timeframe for attempting abdominal closure after resuscitative surgery?

Answer 38

The ideal timeframe for attempting abdominal closure is within 7 days, provided the patient can be anatomically and physiologically optimized

Question 39

What is the preferred method of abdominal closure for patients who clear the resuscitative fluid burden and maintain abdominal muscular domain?

Answer 39

Primary approximation of the fascia is optimal for these patients.

Question 40

What suture materials are recommended for primary fascial closure?

Answer 40

Interrupted closure with #0 or #1 polydioxanone (PDS) or polyglycolide-trimethylene carbonate (Maxon) sutures is recommended.

Question 41

What are the benefits of using polydioxanone (PDS) or Maxon sutures for fascial closure?

Answer 41

retain tensile strength for 40–90 days, which allows for extended time for fascial healing, and decrease the risks of infection or suture granuloma associated with permanent suture materials.

Question 42

What are retention sutures, and when are they used?

Answer 42

-risk-reduction strategy used for patients at increased risk of poor fascial healing. -useful when the fascia can be closed primarily, but the patient has substantial risk factors for fascial dehiscence and would poorly tolerate evisceration or may lack access to rapid surgical care.

Question 43

What type of suture material is commonly used for retention sutures?

Answer 43

-Heavy #2 nylon sutures are commonly used for retention sutures. -placed either in an interrupted or mattress fashion through the skin and fascia, lateral to and across the midline wound.

Question 44

What is sequential fascia closure, and how is it performed?

Answer 44

involves interrupted closure of the most superior and inferior portions of the wound until the tension becomes too high to approximate. The remainder of the defect is then temporarily closed with a closure apparatus, and the process is repeated in subsequent surgeries

Question 45

What is the goal of sequential fascia closure in abdominal surgery?

Answer 45

progressively close the fascia while limiting fascial retraction eventually achieving full closure or reducing the size of the defect to use a smaller bridging mesh.

Question 46

What happens if the fascia cannot be fully closed using sequential closure

Answer 46

a smaller bridging mesh can be used to close the remaining defect

Question 47

What technique for sequential fascia closure is described by the Denver group?

Answer 47

placing a protective layer of white wound vac sponge over the bowel followed by interrupted full-thickness fascia bites using heavy monofilament sutures placed 5 cm apart, starting from the inferior and superior parts of the incision and meeting in the center.

Question 48

How often does the patient return to the operating room if fascia closure is not achieved during the initial attempt?

Answer 48

returns to the operating room every 48 hours until primary fascia closure is achieved

Question 49

What is the “piano wire” effect, and why is it a disadvantage of this technique?

Answer 49

The “piano wire” effect refers to the risk of firm, tense monofilament sutures causing deep pressure necrosis of the fascia, potentially injuring the underlying bowel.

Question 50

What are the risks associated with repeated fascia injury in sequential closure?

Answer 50

Repeated fascia injury can increase the risk of fascia dehiscence, evisceration, and hernia defect formation due to the repetitive placement of sutures

Question 51

What factors should be considered when deciding between progressive closure and abdominal wall reconstruction techniques?

Answer 51

The decision should balance the degree of visceral edema and the potential for further diuresis as the patient’s inflammatory state improves, against the extent of fascial retraction and loss of domain

Question 52

When should abdominal wall reconstruction techniques be considered?

Answer 52

These techniques should be considered when fascial retraction and loss of domain have progressed beyond what can be improved with further fluid optimization.

Question 53

What is the role of fascio-cutaneous flap elevation in managing the open abdomen?

Answer 53

allows a few centimeters of fascial advancement, which can help reduce tension and achieve a safe primary closure when the residual defect is less than 5 to 8 cm

Question 54

What are the risks associated with fascio-cutaneous flap elevation?

Answer 54

flap/skin ischemia, necrosis, and infection under the flap, especially in patients with small-vessel vascular disease, diabetes, significant smoking history, thin subcutaneous tissue, or larger flaps

Question 55

What are the risks of more complex tissue rearrangements like component separation in emergency surgery patients?

Answer 55

More complex tissue rearrangements, such as retrorectus dissection with transversus abdominis release, should be used sparingly due to their potential to limit future surgical repair options if abdominal closure fails during the index admission.

Question 56

What is the goal of using a bridging mesh in abdominal wall management?

Answer 56

preserve fascial integrity limit retraction of abdominal musculature prevent abdominal fluid and protein losses protect the viscera facilitate epithelial closure (with flaps or skin grafting), and avoid compromising future abdominal wall reconstruction attempts.

Question 57

What types of mesh are preferred for abdominal closure in patients with open abdomens, and why?

Answer 57

Biologic or absorbable biosynthetic mesh is preferred because it degrades slowly, is replaced by native tissue, and minimizes the risks of infection, fistula, and intestinal erosion seen with permanent synthetic mesh.

Question 58

How does biologic mesh benefit patients with contaminated or high-bioburden wounds?

Answer 58

Biologic mesh incorporates into the body as it degrades, allowing tissue ingrowth and minimizing infection-related complications

Question 59

What role does biologic or absorbable synthetic mesh play in cases where the overlying tissue cannot cover the wound?

Answer 59

In such cases, the mesh can serve as a substrate for tissue ingrowth and facilitate epithelial closure, potentially with the addition of a skin graft.

Question 60

How does having an open abdomen contribute to a hypercatabolic state?

Answer 60

open abdomen leads to high energy expenditure, severe protein loss, and significant lean body mass turnover, resulting in worsened malnutrition, immunocompromise, elevated infection risk, poor wound healing, longer ICU stays, and increased mortality.

Question 61

Why is optimizing the nutritional status important in patients with an open abdomen?

Answer 61

it helps prevent malnutrition, supports immune function, improves wound healing, and reduces the risk of complications and mortality in critically ill patients

Question 62

What is the NUTRIC score, and how is it used?

Answer 62

The NUTRIC score is a validated nutritional risk assessment tool for critically ill patients. It helps calculate the risk of adverse events that can be mitigated with nutritional support. A score greater than 5 identifies patients at high nutritional risk

Question 63

When should early enteral nutrition be initiated in patients with an open abdomen?

Answer 63

Early enteral nutrition should be initiated within 24 to 48 hours in all patients with an open abdomen unless contraindicated by conditions like massive fluid resuscitation, high-dose vasopressor use, or intestinal discontinuity

Question 64

What are the benefits of early enteral nutrition in patients with an open abdomen?

Answer 64

earlier fascial closure, lower rates of fistula formation, reduced infectious complications, and decreased mortality

Question 65

When is total parenteral nutrition (TPN) considered for patients with an open abdomen?

Answer 65

TPN is considered for patients with contraindications to enteral nutrition or those unable to meet at least 60% of their daily nutritional intake.

Question 66

When should supplemental total parenteral nutrition be initiated in patients at low nutritional risk?

Answer 66

-In patients at low nutritional risk who cannot meet caloric goals, supplemental TPN should ideally be started by day 7 to avoid overfeeding complications -In high-risk patients unable to receive enteral nutrition, TPN should be started earlier, around days 3 to 4, as studies show superior outcomes with this timing

Question 67

Why is fluid management critical in patients with an open abdomen?

Answer 67

Patients with an open abdomen often require large volumes of fluid resuscitation to support gastrointestinal, peritoneal, and insensible losses. Mismanagement of fluid can lead to setbacks and complications such as visceral congestion, bowel edema, and recurrent Abdominal Compartment Syndrome (ACS).

Question 68

What factors should be considered in fluid calculations for open abdomen patients?

Answer 68

Insensible fluid losses from the open peritoneum and direct losses from large-volume abdominal drainage should be considered in fluid calculations to avoid underestimation.

Question 69

Why is urine output not always a reliable indicator of fluid status in critically ill patients?

Answer 69

because it can be influenced by various factors unrelated to actual fluid status.

Question 70

What additional tools can be used to assess fluid status and management in complex cases?

Answer 70

bedside echocardiography arterial waveform analysis or direct measurement of hemodynamics with a pulmonary artery catheter can improve precision in fluid and vasoactive medication management.

Question 71

What is the risk of excessive fluid administration in patients with an open abdomen?

Answer 71

lead to visceral congestion, bowel edema, and make attempts at primary fascial closure challenging, as well as increase the risk of recurrent ACS.

Question 72

What is the role of direct peritoneal resuscitation (DPR) in managing patients with an open abdomen

Answer 72

used during damage control surgery, can reduce the need for crystalloid administration, decrease the inflammatory response, reduce bowel edema, and help achieve early primary fascial closure.

Question 73

What is an enteroatmospheric fistula?

Answer 73

abnormal communication between the intestinal lumen and the external environment, characterized by a large-diameter defect and a lack of a tract through other tissues.

Question 74

How does an enteroatmospheric fistula differ from an enterocutaneous fistula?

Answer 74

enteroatmospheric fistula lacks a tract through other tissues, which increases the risk of undrained intraabdominal collections and makes spontaneous closure highly unlikely.

Question 75

What complications are associated with enteroatmospheric fistulae?

Answer 75

uncontrolled spillage of intestinal content into the wound, failure of fascial or mesh closure, skin breakdown, and complex wound care needs, often preventing progress out of critical care.

Question 76

What are the risks of uncontrolled spillage from an enteroatmospheric fistula?

Answer 76

Uncontrolled spillage can lead to sepsis, wound contamination, failure of fascial closure or mesh, and ongoing skin breakdown.

Question 77

What are the risk factors for developing an enteroatmospheric fistula?

Answer 77

large-volume crystalloid administration multiple abdominal reexplorations, intestinal anastomosis, and large bowel resection.

Question 78

What are the key focus areas in the management of enteroatmospheric fistulae?

Answer 78

controlling and directing drainage anatomic characterization wound care fluid/electrolyte/nutritional planning and long-term operative strategy

Question 79

How is sepsis controlled in patients with enteroatmospheric fistulae?

Answer 79

diverting enteric contents to prevent their accumulation, transforming an uncontrolled fistula into a controlled (ostomy-like) fistula

Question 80

What is the goal of acute surgical intervention for an enteroatmospheric fistula?

Answer 80

The goal is not to repair the fistula but to control it, often by transforming it into a controlled fistula, rather than focusing on closure or take-down during the acute phase

Question 81

What techniques are commonly used to control an enteroatmospheric fistula?

Answer 81

Techniques include tube diversion (e.g., insertion of a large Malecot tube) sump drain placement wound vac therapy wet-to-dry dressings, and maturing the fistula to the skin.

Question 82

Why is excision and direct repair of an enteroatmospheric fistula rarely successful?

Answer 82

Most patients have severe visceral adhesions that make excision and repair challenging, so resection and reanastomosis are often required, but these may not be feasible during the initial admission

Question 83

Why is controlling fistula output critical in the management of enteroatmospheric and enterocutaneous fistulae?

Answer 83

Uncontrolled output is highly caustic causing recurrent wound infections, skin breakdown, and significant pain making effective management essential to prevent these complications

Question 84

What are “chimney” appliances, and how are they used in fistula management?

Answer 84

Chimney appliances are purposely manufactured or improvised devices used to isolate fistula drainage into an ostomy appliance, allowing for granulation and skin grafting of the surrounding wound.

Question 85

What technique can be used for challenging cases of fistula management?

Answer 85

A pediatric silo conduit can be sutured to the ostomy opening for enteral diversion, combined with circumferential excision of surrounding tissue, placement of a wound vac sponge, and the application of negative-pressure wound therapy

Question 86

What is the role of a split-thickness skin graft in fistula management?

Answer 86

A split-thickness skin graft is applied 7 to 10 days after wound vac therapy to provide a stable, epithelialized surface for long-term placement of an ostomy appliance

Question 87

What imaging techniques can be used to anatomically map a fistula?

Answer 87

CT with enteral contrast or fluoroscopic sinography

Question 88

How does the location of a fistula along the gastrointestinal tract affect management?

Answer 88

Distally located fistulae are more likely to have modest output and allow enteral nutrition without severe fluid and electrolyte loss while more proximally located fistulae tend to have higher output and greater risk of dehydration and electrolyte imbalance.

Question 89

How can the response of a fistula to enteral nutrition be assessed?

Answer 89

A trial of enteral feeding can help determine how the fistula responds, especially if its behavior is unclear.

Question 90

What nutritional support is typically required for patients with high-output enteroatmospheric fistulae?

Answer 90

require a prolonged course of total parenteral nutrition (TPN) for 6 to 12 months before they are safe for operative fistula takedown

Question 91

What surgical procedure is commonly performed alongside fistula takedown?

Answer 91

Fistula takedown is typically performed in conjunction with complex hernia repair