Abdominal Compartment Syndrome Flashcards
What is Abdominal Compartment Syndrome (ACS)?
Pathological condition caused by sustained elevations in intraabdominal pressure, leading to organ dysfunction and end-organ failure
What is the difference between primary and secondary ACS?
-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.
What conditions are associated with secondary ACS?
Secondary ACS is associated with conditions like sepsis, large-volume resuscitation, massive transfusion, and inflammation, which increase capillary permeability.
What are the primary strategies for reducing intraabdominal pressure (IAP) and managing refractory intraabdominal hypertension (IAH)?
The strategies include evacuating space-occupying masses and collections, decompression of intraluminal content, improving abdominal wall and diaphragm compliance, and optimizing fluid management.
What simple maneuvers can help reduce intraabdominal pressure?
-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
How does increased intraabdominal pressure (IAP) affect the inferior vena cava?
causes compression of the intraabdominal inferior vena cava, decreasing venous return to the heart, reducing cardiac preload, and leading to systemic hypotension.
What is the impact of increased IAP on the thoracic cavity and ventilation?
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.
How does intraabdominal hypertension affect renal function?
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
What are the late findings in Abdominal Compartment Syndrome (ACS)?
include intestinal and solid organ ischemia, which can present as metabolic acidosis with increasing lactate levels, renal failure, or abnormal liver function tests (LFTs)
How frequently should intraabdominal pressure (IAP) be monitored in patients at risk for ACS?
should be monitored every 4 to 6 hours in patients at risk for ACS.
What is the standard modality for measuring intraabdominal pressure?
Trans-bladder pressure monitoring is the standard modality for measuring intraabdominal pressure
Describe the standard technique for bladder pressure measurement in IAP monitoring.
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.
What defines Abdominal Compartment Syndrome (ACS)?
sustained intraabdominal hypertension (IAH) > 20 mm Hg combined with new or worsening organ dysfunction
Grading of Intraabdominal Hypertension
-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
What is the definitive management for Abdominal Compartment Syndrome (ACS)?
emergent decompressive laparotomy.
Bedside decompressive laparotomy > IF hemodynamic instability, respiratory compromise, severely elevated intracranial pressure, or other barriers to transport.
How can bedside surgical decompression confirm the diagnosis of ACS?
diagnosis of ACS is often confirmed if hemodynamics or ventilator mechanics improve following decompression.
What is the purpose of a hybrid approach to managing ACS in critical settings?
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.
Why is a limited laparotomy inadequate in ACS management?
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.
How can improvements in the patient’s condition confirm the diagnosis of ACS?
through improvements in hemodynamics, intracranial pressure (ICP), peak airway pressures, cardiac output, or oxygenation, often observed after decompressive laparotomy
What should be done if minimal improvement is observed after initial decompression?
the midline incision should be extended through both the skin and fascia to ensure adequate decompression.
What is the role of intraoperative exploration during ACS surgery?
to evaluate any associated intraabdominal pathology, such as bowel ischemia or infection, which may require further surgical intervention
What is the purpose of Temporary Abdominal Closure (TAC)?
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
How has the use of Temporary Abdominal Closure evolved?
with vacuum-assisted negative pressure wound therapy now commonly used across multiple specialties
What should a Temporary Abdominal Closure technique provide?
adequate visceral protection
allow drainage of intraabdominal fluid
mitigate fascia edge retraction
prevent the redevelopment of IAH and compartment syndrome.
What was one of the earlier techniques used for rapid abdominal closure in surgery?
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.
What were the limitations of skin-only closure techniques
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.
Why do skin-only closure techniques increase the difficulty of subsequent closure attempts?
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
What materials are used as a protective cover over the viscera in a resource-limited setting for preventing intraabdominal hypertension (IAH)?
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
How is the protective cover secured to the skin or fascial edges in this technique?
-circumferentially approximated to the skin or fascial edges using running small bites of heavy monofilament sutures.
-placing closed-suction drains
What are the disadvantages of this technique?
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.
What is the Barker vacuum pack, and how does it differ from the Bogota bag?
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.
What is the AbThera vac, and how does it improve on the Barker vacuum pack technique?
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.
When is the abdomen typically closed after the acute resuscitative phase in surgical management?
-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.
Why might primary closure of the abdomen be delayed after large-volume resuscitation?
Large-volume resuscitation can cause visceral congestion, making the abdominal contents too large for the abdominal wall to close properly
What risks increase with prolonged open abdomen?
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.
How does prolonged open abdomen affect the lateral abdominal wall musculature?
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