Integument: Burns

Accidental burn injury during surgery may occur as a result of electrical current, thermal injury, chemical irritation, or mechanical stress during surgery resulting in temporary or permanent injury to the skin, muscle and nerves.Reference Russell and Gaetz^2, Reference Lee, Chen and Cheng³ The ROOT definition for the term “Burn” is presented below:

Modifiers are listed to further define the depth and aetiology of the burn.

Though the incidence of burn injuries is low, these rare injuries can be catastrophic and traumatic for the patient and the surgical team and can cause a significant prolongation of the hospital course.Reference Nahlieli, Baruchin, Levi, Shapira and Yoffe⁴ Demir and colleagues reported a series of 19 patients who suffered intraoperative burn injuries,Reference Demir, O’Dey and Pallua⁵ 15 of whom had undergone cardiac surgery. The average affected body surface area was 2.1% with 79% suffering superficial burns and the remaining 21% suffering deep dermal or full-thickness injuries. Forty-two percent of the patients required surgical intervention to treat the burn, whereas the remaining patients were treated with conservative measures. Sixty-eight percent of the patients had electrical injuries related to electrocautery devices. Twenty-six percent of the patients suffered chemical burns related to Betadine and in one patient, or 5 percent of the series, the cause of the burn was unclear. The authors conclude that attention to detail regarding the proper maintenance of intraoperative equipment, knowledge of the proper set-up and use of electrocautery devices, and knowledge of the chemical properties of and the proper application of sterilizing agents will avoid most intraoperative thermal injuries.

Integument: Pressure Sores or Pressure Ulcers

Pressure sores or pressure ulcers are localized areas of tissue destruction that develop when soft tissue is compressed between a bony prominence and an external surface for a prolonged period of time.⁶ The ROOT definition for the term “Pressure sore(s)” is presented below:

Pressure ulcers can be stratified according to the revised staging guidelines of the National Pressure Ulcer Advisory Panel⁶ adopted by the Agency for Healthcare Research and Quality as follows:

• • Stage 1 – Observable pressure related alteration of intact skin whose indicators, as compared with the adjacent or opposite area on the body, may include changes in one or more of the following: skin temperature (warmth or coolness), tissue consistency (firm or boggy feel), and/or sensation (pain, itching). The ulcer appears as a defined area of persistent redness in lightly pigmented skin, whereas in darker skin tones, the ulcer may appear with persistent red, blue or purple hues.

• • Stage II – This involves partial thickness loss of skin layers involving the epidermis and possibly penetrating into, but not through, the dermis. It may present as blistering with erythema and/or induration and with a moist and pink wound base that is painful and free of necrotic tissue.

• • Stage III – This involves full-thickness tissue loss extending through the dermis to involve the subcutaneous tissue. It presents as a shallow crater unless covered by eschar. This may include necrotic tissue, undermining, sinus tracts formation, exudate, and/or infection. The wound base is usually not painful.

• • Stage IV – This involves deep tissue destruction extending through the subcutaneous tissue to the fascia and may involve muscle layers, joint and/or bone. It may present as a deep crater and include necrotic tissue, undermining, sinus tracts formation, exudate, and/or infection. The wound base is usually not painful.

The same risk factors that predispose adults to the development of pressure ulcers,Reference Jiricka, Ryan, Carvalho and Buckvich⁷ namely immobility and physiological instability, are active in the pediatric population,Reference Quigley and Curley^8, Reference Zollo, Gotisha, Berens, Schmidt and Weigle⁹ producing a similar increase in hospital morbidity and expense.Reference Allman, Goode, Burst, Bartolucci and Thomas¹⁰ Because relatively little specific research on the aetiology, prevention and management of pediatric pressure ulcers exists, extrapolations are frequently derived from the literature related to adults. However, the limited existing pediatric research has shown that the distribution of pediatric pressure ulcers is different from the adult population. Upper body lesions, specifically the head (occiput and ears) are more common in children because the head is proportionally the largest and heaviest bony structure in infants.Reference Zollo, Gotisha, Berens, Schmidt and Weigle^9, Reference EscherNeidig, Kleiber and Oppliger¹¹ Curley and colleagues performed a multi-institutional, prospective, cohort study of the incidence, location and factors associated with the development of pressure ulcers in a critically ill pediatric intensive care unit population.Reference Curley, Quigley and Lin¹² Along with other clinical variables, these authors studied the Braden Q Scale for Predicting Pediatric Pressure Ulcer Risk (Braden Q Scale)Reference Curley, Razmus, Roberts and Wypij¹³ and found that mechanical ventilation, hypotension and a lower Braden Q Scale score were independent predictors for the development of pressure related ulcers. They also reported a 27% overall incidence of pressure ulcers which is similar to three other studies that reported a 17%,Reference EscherNeidig, Kleiber and Oppliger¹¹ 19%Reference Huffines and Logsdon¹⁴ and 26%Reference Zollo, Gotisha, Berens, Schmidt and Weigle⁹ incidence of tissue breakdown in the pediatric intensive care unit setting. These authorsReference Curley, Quigley and Lin¹² found that a significant percentage of the pediatric pressure-related skin injury was created by medical devices such as pulse oximetry probes and artificial airways, including nasotracheal and orotracheal tubes, and BiPAP masks. Most of these studies document that pressure ulcers develop within the first two days stay in the pediatric intensive care unit, underscoring the importance of instituting early preventive measures at the time of admission to the pediatric intensive care unit. Evidence-based practices known to prevent pressure-related skin injury have been published by the Agency for Health Care Policy and Research,Reference Allman, Goode, Burst, Bartolucci and Thomas^10, Reference Bergstrom, Allman and Alvarez¹⁵ and include the following:

• • the use of pressure reducing devices that redistribute weight over a larger surface area

• • head-of-bed elevation consistent with the medical condition of the patient

• • elevation of the heels off the bed, and

• • implementation and documentation of an effective turning schedule.

Acute Limb Ischemia

The ROOT definition for the term “Acute limb ischemia” is presented below:

Several modifiers are listed for acute limb ischemia to specify the aetiology of the ischemia and whether surgical intervention was required for its treatment. Limb ischemia caused by arterial and venous line complications are captured both in this section titled “Acute limb ischemia” and within the section titled “Vascular-Line(s)”. Given the frequency with which arterial monitoring catheters are used in the surgical treatment of congenital heart disease it is interesting to note that permanent ischemic complications are relatively rare (0.09%) compared to temporary occlusion of the cannulated vessel (20%).Reference Scheer, Perel and Pfeiffer¹⁶ One study documents that ulnar arterial catheterization for hemodynamic monitoring in pediatric patients is relatively safe in terms of ischemic and infectious complications even when more traditional arterial cannulation sites have been previously exhausted.Reference Kahler and Mirza¹⁷

Aortic Dissection

An aortic dissection can occur anywhere in the thoracic or abdominal aorta and is rare in the pediatric population.Reference Fikar and Koch¹⁸ The ROOT definition for the term “Dissection-Aortic dissection” is presented below:

The Stanford classificationReference Daily, Trueblood, Stinson, Wuerflein and Shumway¹⁹ divides aortic dissections into two types:

• • A Stanford type A dissection is a proximal dissection that involves the ascending aorta

• • A Stanford type B dissection is a distal dissection that involves aorta distal to left subclavian artery and does not involve the ascending aorta.

The DeBakey classificationReference DeBakey, Henly, Cooley, Morris, Crawford and Beall²⁰ divides aortic dissections into three types:

• • A DeBakey type 1 dissection starts in the ascending aorta and involves the entire length of the aorta

• • A DeBakey type 2 dissection is limited to the ascending aorta

• • A DeBakey type 3 dissection is a distal dissection that involves aorta distal to left subclavian artery and spares the ascending aorta and the aortic arch.

In the database, aortic dissections are subdivided according to location and according to whether they are acute or chronic.

• • Dissections that are acute are of sudden onset. Clinically, dissections seen within the first 2 weeks following onset of symptoms are considered acute.

• • Dissections that are chronic are long standing conditions. Clinically, dissections beyond the first 2 weeks following onset of symptoms are considered chronic.

Modifiers further define the dissection by the systems of classification of Stanford and DeBakey, the extension of the dissection, the diameter of the aorta at the site of the dissection, and whether the dissection is calcific, ruptured or thrombosed. It is recommended that if a dissection of the aorta, iliac or femoral vessels produces acute lower extremity ischemia, one should also consider using any of the appropriate complications listed in the section titled “Acute limb ischemia”.

Arterial Thromboembolism

The ROOT definition for the term “Thromboembolism-Arterial thromboembolism” is presented below:

Arterial thromboemboli are subdivided according to the body location or internal organ in which their ischemic effects are clinically manifested.

Thrombosis (Arterial/Venous)

The ROOT definition for the term “Thrombosis-Arterial thrombosis” is presented below:

The ROOT definition for the term “Thrombosis-Venous thrombosis” is presented below:

Intraluminal catheters are one of the most common aetiologies for the development of arterial and venous thromboses. In the intensive care setting, symptomatic thrombotic complications of central venous catheters can present within four days of catheter insertion, with neonates having the highest rate of symptomatic venous thromboses.Reference Beck, Dubois, Grignon, Lacroix and David²³ Children with acute life-threatening illnesses are likely at greatest risk for acute catheter-related thrombosis. Furthermore, the excessive thrombin production associated with patients in intensive care unit settings, who may have disseminated intravascular coagulation, hastens the development of thrombosis around intravascular catheters.²³ Whether catheter-related or not, not all venous thrombosis is symptomatic. Nevertheless, the potential complications associated with venous thrombosis include recurrent thrombosis, loss of subsequent intravenous access, pulmonary embolism, post-thrombotic syndrome and death.Reference Journeycake and Buchanan²⁴ One pediatric study documented that the prognosis after thrombosis of the inferior caval vein depends upon its extent, with persisting venous occlusion being absent after limited thrombosis and being frequent (80%) after extensive thrombosis. Persisting venous occlusion is frequently symptomatic with leg and abdominal pain as well as the development of varicose veins and post-thrombotic syndrome.Reference Hausler, Hubner, Delhaas and Muhler²⁵ Since most inferior caval vein thrombosis occurs after the indwelling line has been in place for over six days, some authors recommend routine replacement at six-day intervals or twice-weekly caval ultrasounds with prompt catheter removal if any evidence of thrombosis is discovered.Reference Shefler, Gillis, Lam, O’Connell and Lammi²⁶ Routine catheter replacement frequently may not be performed in children due to the difficulty in obtaining venous access and the lack of appropriate sites.

Renal vein thrombosis is a somewhat distinctive subset of venous thrombosis. The ROOT definition for the term “Thrombosis-Venous thrombosis, Renal vein” is presented below:

Controversies surrounding Vascular Catheter Infections

The Centers for Disease Control and Prevention of the United States of America sponsors the National Healthcare Safety Network. The National Healthcare Safety Network utilizes the terms “Catheter Related Bloodstream Infection” and “Catheter Associated Bloodstream Infection” to define health care acquired central vascular infections. In this manuscript, the Multi-Societal Database Committee for Pediatric and Congenital Heart Disease uses the term “Documented line infection”, which closely parallels the term “Catheter Related Bloodstream Infection” and is a rigorous clinical definition that attempts to exclude other sources of bacteremia and/or fungemia. In this manuscript, the Multi-Societal Database Committee for Pediatric and Congenital Heart Disease uses the term “Clinically suspected line infection”, which closely parallels the term “Catheter Associated Bloodstream Infection” and is a surveillance definition that overestimates the actually incidence of infections attributable to vascular catheters.Reference O’Grady, Alexander and Dellinger²⁸

Healthcare organizations report vascular catheter infections to the National Healthcare Safety Network as the rate of infections per 1000 catheter days utilizing the “clinically suspected line infection” definition. While the definition is clearly defined by the National Healthcare Safety Network, there continues to be wide variation in interpretation by infection control practitioners. In addition, as the terms “Clinically suspected line infection” and “Catheter Associated Bloodstream Infection” are surveillance definitions, their use will accordingly overestimate the “true” rate of infections that were a result of a vascular catheter. This overestimation can result in differing opinions regarding the veracity of a reported line infection, between the clinical team and the “infection control team”. This controversy has the capability to undermine the reporting process, causing clinicians to lose faith in the reported infection rate. Paradoxically, while some clinicians have lost faith in this rate, state and national oversight agencies are increasingly requiring public reporting of rates of healthcare acquired infection. It is and continues to be incumbent on clinicians to understand the limitations of these surveillance definitions and work to refine the national consensus definition, as required, to reflect clinical reality.

Sterile Sternal Instability (non-union)

The ROOT definition for the term “Sternal instability (sterile)” is presented below:

While most cases of sternal instability after median sternotomy are caused by infection, non-union of the sternal edges can also be caused by other factors not related to infection such as ischemia, nutritional deficiencies, use of corticosteroids, vitamin C deficiency, trauma and others. This complication is reserved to describe isolated sterile sternal non-union. If sterile separation of the superficial or deep layers of the incision coexists with the sternal non-union, then the term, “Wound dehiscence (sterile)” should be used to describe the complication.

Little is written about sterile sternal non-union in both the pediatric and adult cardiac surgical literature.Reference Olbrecht, Barreiro and Bonde^29, Reference Robicsek, Fokin, Cook and Bhatia³⁰ Multivariate analysis in an series of adult patients, in which this specific clinical condition was analyzed, determined that new York Heart Association class IV, obesity, and chronic obstructive pulmonary disease were preoperative risk factors with an incidence of 0.39% and a mean interval between index operation and diagnosis of/reoperation for sterile sternal non-union of 5.4 months.²⁹ These risk factors have limited applicability to the pediatric population. Some partial cases of sterile sternal non-union are relatively minor and do not require operative intervention, whereas most, because of pain, instability, or aesthetic concerns, require reconstruction.³⁰ Both of these possibilities are listed in the Long List of complications.

Omental Herniation

This relatively uncommon wound complication is defined as herniation of the omentum through a surgical incision or through a tube or catheter tract.

Sterile Wound Dehiscence

The ROOT definition for the term “Wound dehiscence (sterile)” is presented below:

Separation of the superficial or deep layers of a surgical incision can rarely occur in the absence of an infection. Wound dehiscence due to wound infection should be recorded as a wound infection (see below). In the case of a median sternotomy incision, when the sterile separation includes the skin and sternum, use this code (“Wound dehiscence (sterile)”). As described above, the code “Sternal instability (sterile)” should be used to record the complication when the superficial and deep layers of the incision remain intact but non-union of the sternal edges is present.

Wound Foreign Body

The ROOT definition for the term “Wound foreign body” is presented below:

Wound Hematoma

The ROOT definition for the term “Wound hematoma” is presented below:

Wound Infection (Deep/Superficial)

Wound infections (otherwise known as surgical site infections) can be superficial or deep. The ROOT definition for the term “Wound infection-Superficial wound infection” is presented below:

1. 1) The infection involves only the skin and the subcutaneous tissue of the incision and

2. 2) The patient has at least ONE of the following lettered features:

   1. A) purulent drainage from the superficial portion of the incision

   2. B) organisms isolated from an aseptically obtained culture of fluid or tissue from the superficial portion of the incision

   3. C) at least ONE of the following numbered signs or symptoms:

      1. [1] pain or tenderness

      2. [2] localized swelling, redness, or heat, and

      3. [3] the superficial portion of the incision is deliberately opened by a surgeon, unless the incision is culture negative, or

   4. D) a diagnosis of superficial wound infection by the surgeon or by the attending physician.”

The ROOT definition for the term “Wound infection-Deep wound infection” is presented below:

1. 1) Purulent drainage from the deep portion of the incision (but not from the organ/space component of the surgical site and no evidence of sternal osteomyelitis)

2. 2) The deep incision spontaneously dehisces or is deliberately opened by a surgeon when the patient has ONE of the following lettered signs or symptoms (unless the incision is culture negative):

   1. A) fever

   2. B) localized pain, or

   3. C) tenderness

3. 3) An abscess or other evidence of infection involving the deep incision is found on direct examination, during reoperation, or by histopathologic or radiologic examination, or

4. 4) A diagnosis of a deep wound infection by a surgeon or by an attending physician.”

These definitions are adapted from those established by the Hospital Infection Control Practices Advisory Committee of The Centers for Disease Control and Prevention of the United States of America, in order to maintain uniformity with the definitions currently used by hospitals to track and report infections of surgical sites of all kinds.Reference Mangram, Horan, Pearson, Silver and Jarvis³¹ For a superficial wound infection, the definition of the Centers for Disease Control requires that the infection occurs within 30 days after the index operation. For a deep wound infection, the definition of the Centers for Disease Control definition requires that the infection occurs within 30 days after the index operation if no implant is left in place. These timing requirements of the Centers for Disease Control are rejected in favour of the timing standard that is uniformly applied in this database of complications, as described below in the definition of the term “complication”

If an implant is in place and a deep surgical site infection appears to be related to the index operation, the Centers for Disease Control definition arbitrarily extends the time interval from thirty days to one year. While this time interval extension is logical and reasonable, it is rejected in this database of complications for the sake of internal consistency. Many types of postoperative complications that are clearly related to the index operation can occur at varying time intervals postoperatively, some perhaps being diagnosed months after discharge from the hospital. This complications database adheres consistently to the time interval outlined above for both intraoperative and postoperative complications to promote consistency in the reporting of complications and to ensure the validity of comparisons of complication rates between institutions.

It should also be noted that, according to the definition of the Centers for Disease Control, the sternal wires within the base of a typical median sternotomy incision constitute a “foreign body” and would, therefore, theoretically extend the time interval during which a diagnosis of deep wound infection and/or mediastinitis could be made to one year after the index operation. Certainly, mediastinitis and deep wound infections can occur after the time interval of operative complications has expired; however, these late cases of mediastinitis and wound infections are classified as mediastinitis and/or wound infections, but they are not counted amongst the “operative complications”.

With the exception of these timing issues, the definitions of superficial and deep wound infection adopted by The Multi-Societal Database Committee for Pediatric and Congenital Heart Disease are identical in substance to those promoted by the Centers for Disease Control.

It should be noted that younger age and longer duration of surgery, as well as the surrogate variable of cardiopulmonary bypass time, have been suggested as independent predictors of surgical site infections after pediatric cardiovascular surgery.Reference Allpress, Rosenthal, Goodrich, Lupinetti and Zerr³²

Mediastinitis

The incidence of mediastinitis after pediatric open-heart surgery varies widely but is usually reported in the range of 0.2%Reference Tortoriello, Friedman and Mckenzie³³ to 1.4%.Reference Long, Shah and Lautenbach³⁴ The median time from operation to diagnosis is usually 11Reference Long, Shah and Lautenbach³⁴ to 14Reference Tortoriello, Friedman and Mckenzie³³ days. Two-thirds of patients will be infected with gram-positive organisms, whereas the remaining one-third will grow gram-negative organisms. The most commonly cultured organisms are Staphylococcus aureus (46%), coagulase-negative staphylococci (17%) and Pseudomonas aeruginosa (17%).³⁴ One study documented concurrent bacteremia in 35%³³ and another study in 53%.³⁴

The definition for Deep Sternal Infection used by the Society of Thoracic Surgeons Adult Cardiac Database Version 2.61 is presented below:

1. 1. Wound opened with excision of tissue (incision and drainage) or re-exploration of mediastinum

2. 2. Positive culture

3. 3. Treatment with antibiotics.”

The Centers for Disease Control states that the diagnosis of mediastinitis must meet one of the following criteria:

• Criterion 1: Patient has organisms cultured from mediastinal tissue or fluid that is obtained during a surgical operation or by needle aspiration.

• Criterion 2: Patient has evidence of mediastinitis by histopathologic examination or visual evidence of mediastinitis seen during a surgical operation.

• Criterion 3: Patient has at least ONE of the following numbered signs or symptoms with no other recognized cause:

  1. 1) fever

  2. 2) chest pain

  3. 3) sternal instability

AND at least one of the following numbered features:

1. 1) purulent mediastinal drainage

2. 2) organisms cultured from mediastinal blood, drainage or tissue

3. 3) widening of the cardio-mediastinal silhouette.

   Criterion 4: Patient ⩽ 1 year of age has at least one of the following numbered signs or symptoms with no other recognized cause:

4. 1) fever

5. 2) hypothermia

6. 3) apnea

7. 4) bradycardia

8. 5) sternal instability

   AND at least one of the following numbered features:

9. 1) purulent mediastinal discharge

10. 2) organisms cultured from mediastinal blood, drainage or tissue

11. 3) widening of the cardio-mediastinal silhouette.Reference Horan, Gaynes and Mayhall³⁵

This latter definition is more detailed than the Society of Thoracic Surgeons definition and also has the advantage of including more specific criteria for defining mediastinitis in infants. Since this definition of the Centers for Disease Control, though more complex, is essentially the same in core substance to that of the Society of Thoracic Surgeons, it is used by The Multi-Societal Database Committee for Pediatric and Congenital Heart Disease, with the presupposition that the maintenance of close conformity with established national standards, when they are scientifically accurate, is the best policy. Infections of the sternum (sternal osteomyelitis) should be classified as mediastinitis. Sternal instability that is not associated with a wound infection or mediastinitis is documented as “Sternal instability”.

Wound Seroma

The ROOT definition for the term “Wound seroma” is presented below: