Damage Control Surgery

 

DAMAGE CONTROL SURGERY

Damage control surgery is defined as rapid termination of an operation after control of life-threatening bleeding and contamination followed by correction of physiologic abnormalities and definitive management.

·         This modern strategy involves a staged approach to multiply injured patients designed to avoid or correct the lethal triad of hypothermia, acidosis, and coagulopathy before definitive management of injuries. It is applicable to a wide variety of disciplines.

·         First stage of DCS > hemorrhage is stopped, and contamination is controlled using the simplest and most rapid means available. Temporary wound closure methods are employed.

·         Second stage of DCS > correction of physiologic abnormalities in the ICU. Patients are warmed and resuscitated, and coagulation defects are corrected.

·         Final phase of DCS > definitive operative management is completed in a stable patient.

Indications for damage control surgery

Anatomical

·         Inability to achieve haemostasis

·         Complex abdominal injury, e.g. liver and pancreas

·         Combined vascular, solid and hollow organ injury, e.g. aortic or caval injury

·         Inaccessible major venous injury, e.g. retrohepatic vena cava

·         Demand for non-operative control of other injuries, e.g. fractured pelvis

·         Anticipated need for a time-consuming procedure

Physiological (decline of physiological reserve)

·         Temperature                                        < 34ºC

·         pH                                                       < 7.2

·         Serum lactate                                       > 5 mmol l–1 [N (Normal) < 2.5 mmol l–1]

·         Prothrombin time (PT)                                     > 16 s

·         Partial thromboplastin time (PTT)        > 60 s

·         10 units blood transfused

·         Systolic blood pressure                                    < 90 mmHg for > 60 min

Environmental

·         Operating time                                                 > 60 min

·         Inability to approximate the abdominal incision

·         Desire to reassess the intra-abdominal contents (directed relook)

The lethal triad

·         The philosophy of damage control is to abbreviate surgical interventions before the development of irreversible physiologic endpoints.

·         Uncontrolled hemorrhage and iatrogenic interventions ultimately result in the development of hypothermia, coagulopathy, and acidosis.

·         Each of these life-threatening abnormalities exacerbates the others, contributing to a spiraling cycle that rapidly results in death unless hemorrhage is stopped, and the abnormalities reversed.

 

HYPOTHERMIA

·         The definition of hypothermia in humans is a core temperature < 35C.

·         The greatest potential for heat loss occurs secondary to fluid resuscitation . Heat loss is proportional to the mass of fluid used to resuscitate the patient and the temperature gradient from the patient to the fluid.

·         The equation for heat loss is: Q = mc(T2 – T1), where Q equals heat in kilojoules, m equals mass in kilograms, and c equals the specific heat of water, which is 4.19 kJ/kg/C.

·         The heat lost when a single liter of room temperature fluid is given is to a patient with a temperature of 37C is shown: Q = (1 kg) (4:19 kJ/kg/C) (37C - 25C)

·         Q = 50.3 kJ

Etiology

·         Massive resuscitations > tremendous amount of heat loss.

·         Full Exposure of the patient for ATLS > convection and radiation.

·         Patients with wet clothing – evaporation.

·         Operative therapies require large incisions > peritoneal and pleural heat loss

·         Heat loss in the OR = the size of the incision and the length of the procedure.

·         Blood loss > ↓oxygen consumption> ↓ heat production by the body.

·         Hypothermia in trauma patients has been associated with a poor outcome.

·         Mortality increases significantly in trauma patients with a core temperature less than 34C and approaches 100% in trauma patients with a core temperature less than 32C

Available rewarming methods (yield heat kJ/h)

·         Airway rewarming                                           33.5– 50.3

·         Overhead radiant warmer                                71.2

·         Heating blankets                                              83.8

·         Convective warmers                                        62.8– 108.9

·         Body cavity lavage                                          150.8

·         Continuous arteriovenous rewarming              385.5– 582.4

·         Cardiopulmonary bypass                                 2974.9

Detrimental effects of heat loss

·         decreased HR and CO

·         decrease GFR

·         Increased SVR, arrhythmias,

·         Increased fibrinolytic activity

·         impaired sodium absorption,

·         central nervous system depression

·         Coagulopathy (↑fibrinolytic activity, Coag: cascade)

ACIDOSIS

·         Occurs primarily as a result of lactate production from anaerobic metabolism.

·         Hemorrhage results in decreased oxygen delivery secondary to decreased cardiac output and anemia.

·         Resuscitation with fluids rich in chloride also has been associated with acidosis in trauma patients.

·         This occurs most prominently with normal saline resuscitation but also may occur with lactated Ringer’s resuscitation.

·         The presence of hyperchloremic acidosis does not correlate with mortality in surgical ICU patients

Detrimental effects of acidosis

·         depressed myocardial contractility,

·         diminished inotropic response to catecholamines,

·         ventricular arrhythmias

·         increased ICP (may worsen outcomes in patients with head injuries)

·         Coagulopathy (prolongation of the PTT and decreased factor V activity

·         Disseminated intravascular coagulation and a consumptive coagulopathy.

COAGULOPATHY

·         In addition to hypothermia and acidosis, dilution contributes to coagulopathy.

·         Primary trauma resuscitation fluids (crystalloids, colloids, and packed red blood cells) are devoid of coagulation factors.

·         Tissue factor exposure secondary to trauma results in activation of the coagulation cascade and consumption of coagulation factors.

·         Fluid resuscitation before hemorrhage control also raises intravascular hydrostatic

·         pressure, potentially causing displacement of established clots and increased bleeding.

·         Immediate resuscitation of trauma victims with penetrating torso injuries has been shown to result in a higher mortality than delaying resuscitation until operative therapy is initiated

Factors contributing to coagulopathy

·         Hypothermia

·         Dilution of coagulation factors

·         Continued loss of coagulation factors from bleeding

·         Thrombocytopaenia

·         Non-functional platelets

·         Acidosis

·         Hypocalcaemia

·         Reduced synthesis of coagulation factors due to liver dysfunction secondary to hypoxic/ischaemic insult

·         Fibrinolysis

·         Disseminated intravascular coagulation (DIC)

Surgical techniques

            Before proceeding with a particular incision and surgical approach, it is important that steps are taken to anticipate and avoid pitfalls, when possible. This should include:

1.      Warming of operating theatre to 27.8C.

1.      Advising nursing staff of anticipated major blood loss.

2.      Organisation of sponge packs before incision is made.

3.      Avoid use of suction in the early stages of laparotomy.

4.      Avoid over-resuscitation before surgical haemorrhage control.

Stage 1—the damage control operation

ABDOMEN

·         Most damage control procedures are performed in the abdomen

·         Most common abdominal injuries that induce a DC approach are liver injuries and abdominal vascular injuries

·         Primary method of hemorrhage control for complex liver injuries is packing - to tamponade bleeding while maintaining organ perfusion.

·         Plastic drapes may be placed between the hepatic parenchyma and the packs to avoid displacement of clots when the packs are removed.

Abdominal vascular injuries

·         Tx - Several options exist.

·         Many abdominal vascular injuries can be treated safely by simple ligation (not tolerated in patients with aortic or proximal superior mesenteric artery injuries)

·         Temporary intraluminal shunts (easy to place, and they maintain end organ perfusion, allowing early termination of laparotomy)

·         Inflatable balloon catheters - persistent hemorrhage from inaccessible locations or difficulty in controlling the injured vessel.

Hollow viscus injuries

·         Resection of affected areas using stapling devices.

·         Reanastomosis is postponed until the patient is stabilized and returned to the operating room for definitive operation.

·         The majority of biliopancreatic injuries can be temporized with closed suction drainage

Kidney injuries

·         Patients with extensive kidney injuries that are reaching their physiologic limits frequently are best treated with rapid nephrectomy (if they do not respond to packing)

Ureteral injuries

·         Options for the management of patients with ureteral injuries - ligation and exteriorization.

·         Ligation of a transected ureter will result in obstruction of the nephric unit, which may be treated by temporary nephrostomy if definitive laparotomy is delayed for a prolonged period.

·         Another option for ureteral injuries is placement of a percutaneous ureterostomy > avoids ureteral obstruction and the need for a nephrostomy.

Bladder injuries

·         Most can be rapidly sewn closed with a single layer running suture or temporized using closed suction drainage.

Temporary management of the abdominal wound.

·         After controlling hemorrhage and contamination, a decision must be made concerning the temporary management of the abdominal wound.

·         The goals of temporary closure include containment of the abdominal viscera, control of abdominal secretions, maintenance of pressure on tamponaded areas, and optimizing the likelihood of ultimate abdominal closure.

·         Formal closure of the abdominal fascia - increased risk of abdominal compartment syndrome (ACS), adult respiratory distress syndrome (ARDS), and multiple organ failure (MOF)

Options for the temporary closure of the abdomen

·         Simple options include closure of the skin alone using towel clips or a running suture (does not expand the abdominal volume significantly and still may result in the ACS)

·         The Bogota bag is a sterilized 3 L urologic bag that is sewn to the skin .>  inexpensive method of containing the viscera and abdominal secretions, but it allows the abdominal fascia to retract, potentially lessening the likelihood of successful closure later.

·         Vacuum-assisted techniques - nonadherent plastic drape with small perforations is placed over the bowel. A towel is placed over the drape, followed by two closed suction drains. An adherent drape then is placed over the skin surrounding the wound, creating an airtight seal. A vacuum is achieved by placing the drains on suction. In addition to containment of the viscera, this technique maintains some tension on the abdominal fascia and allows accurate quantification of abdominal fluid output and maintenance of a relatively sterile environment.

·         Sewing a prosthesis to the abdominal fascia ( absorbable mesh, non-absorbable mesh, or Silastic The theoretical advantage of these techniques is that they maintain constant tension on the fascia, increasing the likelihood of definitive closure. A relatively new technique involves the use of synthetic Velcro - is sewn to either side of the abdomen and closed - allows the surgeon to adjust abdominal tension frequently and at the bedside.

CHEST

·         Trauma patients with possible thoracic injuries who are in extremis should undergo emergency department thoracotomy (EDT)

·         EDT permits rapid access to the thoracic cavity. If present, cardiac tamponade is treated by opening the pericardium.

·         Cardiac injuries may be temporized by digital pressure or the careful use of a Foley catheter to tamponade bleeding.

·         Clamping the pulmonary hilum or twisting the lung along its hilar axis to stop exsanguinating bleeding from the pulmonary parenchyma.

·         Cannulation of RA with a Foley catheter for massive resuscitation.

·         Cross-clamped to descending aorta > reduce blood flow to distal injuries and to increase brain perfusion

·         Deep through-and-through lung injuries that do not involve hilar vessels or the main airways traditionally have been treated with formal lung resections to include lobectomy or pneumonectomy.

Stage 2—resuscitation

Hypothermia

·         Following the DCP, patients are returned to the ICU for correction of their physiologic abnormalities.

·         Evidence of the lethal triad is frequently most apparent immediately following the operation, and aggressive measures are indicated.

·         Initial operating room conditions should be recreated in the ICU. The room and airway circuit should be warmed, and a Bair Hugger should be applied to the patient.

·         All fluids and blood products should be warmed

·         Continuous arteriovenous rewarming is a relatively new technology that permits rapid rewarming of hypothermic patients without requiring cardiopulmonary bypass or heparinization.

·         This technique originally was described by Gentilello, and it involves the placement of 8.5 F femoral arterial and venous catheters to create an arteriovenous fistula that diverts part of the cardiac output through a heat exchanger

·         Blood flows out of the femoral arterial catheter into tubing attached to the level I rewarmer. The blood is warmed and flows back into the body through the femoral venous catheter (Fig. 6).

·         The effectiveness of this technique is dependent on the patient’s cardiac output.

·         Continuous arteriovenous rewarming has been shown to significantly reduce time to normothermia, resuscitation requirements, and early mortality in hypothermic trauma patients who are critically injured .

Acidosis

·         Optimization of O2 delivery (cardiac output, hemoglobin, and the O2 saturation)

·         Hemorrhage - blood is an ideal resuscitation fluid.

·         Central venous monitoring - for young healthy patients

·         Elderly patients, who may suffer from comorbidities, and patients with cardiopulmonary injuries are more likely to benefit from pulmonary artery monitoring.

·         Inotropic support - patients with underlying cardiac disease that contributes to inadequate oxygen delivery.

·         Persistent acidosis - almost always secondary to hyperchloremic acidosis

·         The direct use of IV sodium bicarbonate to raise the pH > 7:2 remains an option but may be better avoided (particularly for patient who appear to be stable) because of well recognised adverse effects of bicarbonate administration.

·         Hyperchloremic acidosis and lactic acidosis usually can be discriminated by determination of the anion gap.

·         Hyperchloremic acidosis - a narrowed anion gap.

·         Lactic acidosis - a widened anion gap.

·         Borderline cases can be differentiated by lactate measurement.

·         Hyperchloremic acidosis rapidly resolves when resuscitation fluids are changed to sodium acetate, which contains no chloride.

Coagulopathy

Strategies to correct coagulopathy

·         Reverse hypothermia and maintain an effective circulating blood volume and oxygenation

·         Preferably use whole blood and/or the freshest available

·         Give FFP to replace coagulation factors (10—15 ml/kg approx. 2 units will achieve 30% factor activity in adults)

·         Give platelets

·         Give cryoprecipitate if fibrinogen level is <1 g

·         Give calcium (10 mmol) to reverse hypocalacaemia

·         Consider the use of adjuncts to promote coagulation/reduce fibrinolysis (e.g. aprotinin)

·         Consider the use of rVIIa

·         Give Vitamin K

·         Repeat coagulation tests and blood count and modify treatment accordingly

 Stage 3—definitive operation

·         Following reversal of the lethal triad, the patient is returned to the operating room for definitive treatment.

·         The exact timing of reoperation has not been standardized.

·         Premature return to the operating room may result in rebleeding and the need for additional operations.

·         A complete exploration is performed.

·         Packs are removed.

·         Bleeding sites are identified and treated when possible.

·         Small bowel continuity is restored.

·         large bowel injuries are treated with exteriorization or repair.

·         Closing the abdominal fascia may not be possible because of diffuse edema secondary to injury and resuscitation.

·         Additional operations were required in patients who had an unplanned second operation for bleeding or unexpected complications and in patients who could not be closed successfully.

Predictable complications seen in DCS patients

1.      ACS

2.      Peptic ulceration

3.      Venous thromboembolism

4.      ARDS

5.      Nosocomial infection

6.      Intra-abdominal infection, fistula, dehiscence

7.      Nutritional failure

8.      Critical illness myoneuropathy

Strategies to reduce complications

1.      Measurement of IAP

2.      Peptic ulceration prophylaxis

3.      Thromboprophylaxis

4.      Protective lung ventilation

5.      Infection control and appropriate antimicrobial therapy

6.      Early nutritional support (preferably enteral)