Figure 5.3

A Chinese finger trap is used to secure the drain to the skin. The drain and the reservoir have to be well protected to prevent accidental removal of the drain by the patient. A suction device with a reservoir is connected to the drain (Figure 5.3). The device generates a negative pressure close to 10 mmHg. Usually the reservoir can be 100–400 ml, depending on the size of the animal and the amount of effusion that is expected to be produced. The reservoir has to be emptied as needed to maintain constant negative pressure in the abdominal cavity.

      The drain needs to be inspected daily to reduce the risk of contamination and ascending infection.

      5.2.3 Open Abdomen

      An open abdomen allows passive drainage of the abdominal effusion in a sterile bandage applied over the midline incision of the laparotomy (Staatz et al. 2002; D'Hondt et al. 2007; Madback and Dangleben 2015). This technique allows daily lavage of the peritoneal space while the bandage is changed (Staatz et al. 2002; D'Hondt et al. 2007). It can also be associated to a vacuum‐assisted bandage to actively drain the peritoneal space (Buote and Havig 2012; Madback and Dangleben 2015).

At the end of a laparotomy a 2‐0 monofilament nonabsorbable suture is placed loosely across the linea alba (Figure 5.4a). The linea alba should be maintained open on the entire length of the incision. Several loops of sutures are placed 3–5 cm from the edges of the skin incision and 3–4 cm from each other. Loop areas are placed at the cranial and caudal ends of the incision (Figure 5.4a see arrow).

      The laparotomy incision is then covered with two to three layers of sterile laparotomy sponges. Umbilical tape is then laced through the loop of suture over the laparotomy sponges. A sterile sticky plastic drape is then placed over the bandage and the skin to isolate the bandage from the environment (Figure 5.4b and c). If the patient is a male dog, a urinary catheter should be placed to prevent contamination of the bandage with urine.

      Bandage is changed on a daily basis in the operating room. At each bandage change the abdominal cavity is flushed with sterile saline. A cytology is performed daily, and when cytology is improved, with a reduction of the number of bacteria and degenerative neutrophils, the abdominal cavity is closed over a closed suction drain.

      5.2.4 Vacuum‐Assisted Drainage of the Abdominal Cavity

      Vacuum‐assisted bandage has been used instead of an open abdomen drainage technique to actively drain the peritoneal space (Hondt et al. 2011; Buote and Havig 2012; Cioffi et al. 2012; Spillebeen et al. 2017).

      The linea alba is partially closed. Foam used for vacuum‐assisted wound therapy is then applied on the part of the incision left open. A drain and sticky bandage are applied over the foam to establish a water and airtight seal. The drain is connected to the vacuum generator. A negative pressure of 75–125 mmHg is generated through the catheter in the foam in a continuous fashion. Fluids drained out of the peritoneal cavity is collected in a reservoir and the bandage does not need to be changed daily.

5.3 Tips

      It is paramount to keep any of those drains well protected from the environment to prevent ascending infection. Sticky drapes can be used to cover the exit site of the closed suction drain. It should also be well covered to prevent any accidental removal by the patient. An E collar should be placed on the patient.

Cytology of the abdominal fluid should be performed daily basis to follow the progression of the disease process in the abdominal cavity. Fluid can be collected from the reservoir if a closed suction drain has been used, or at each bandage change if the abdomen has been left open. Measurement of lactate and glucose from the abdominal fluid can help determine if septic peritonitis is still present. If septic peritonitis is present, the difference between the concentration of glucose in the fluid and blood is more than 20 units or the difference between the concentration of lactate in the fluid and blood is more than 2 units. Those results are 100% sensitive and specific in dogs and 86 and 100% respectively in cats (Bonczynski et al. 2003). However, if the fluid is collected from the closed suction drain and the reservoir and not the abdomen, those differences are not accurate (Szabo et al. 2011).