Plus-Hex CLINICAL
Skin
Subcutaneous tissue
Deep soft tissue ( fascia and muscle )
Superficial incisional SSI Deep incisional SSI
Organ / space
Organ / space SSI
Figure 1 . SSI classification tiers and the tissues affected . Adapted from He et al . [ 8 ]
Deep incisional SSI
This tier of SSI can occur 30 days postoperatively , but this can be up to a year if an implant is involved [ 2 ] . Signs include a purulent discharge from deeper tissue layers , possible SWD , pyrexia , localised pain or tenderness , and possible abscessation of the site [ 2 ] .
Organ / space SSI
This tier of SSI can occur 30 – 90 days postoperatively and can involve any part of the body that has been opened or manipulated during the surgical procedure , excluding the skin incision , fascia or muscle layers . Signs include a purulent discharge from a body cavity drain or organ drain ( separate from the incision site ), body space abscessation , pyrexia , positive blood cultures or the presence of micro-organisms on a diagnostic swab [ 2 ] . SSIs in this category are associated with the highest mortality rates and require significant intervention .
The identification of an SSI should be confirmed by the clinical judgement of a veterinary surgeon ( VS ) based on the reported signs , and often supported by a positive wound culture assessment from a pathologist [ 2 ] .
Care should be taken not to mistake signs of inflammation for signs of infection . It is also important to bear in mind that inflammation is a normal response within the first few days after surgery .
Other factors to consider include : that patient interference can lead to mechanical dehiscence ; seromas with serosanguineous fluid are not indicators of an SSI ; and systemic antibiosis may have no effect , other than contributing to antimicrobial resistance [ 2 ] .
With any postoperative SSI , early identification is vital , particularly in patients and wounds at higher risk of infection . A full list of factors known to increase the risk of SSIs is given in Table 1 .
Table 1 . Factors associated with increased risk of SSIs .
Patient-related factors Surgery-related factors Physiological conditions Independent factors Pre-existing infection
Inadequate aseptic surgical site preparation
Multi-trauma Abdominal / colorectal / obstetric-related surgeries
Malnutrition Emergency surgeries Shock Contaminated procedures Low serum albumin
Geriatric
Immunosuppression
Physiological / psychological stress
Prolonged procedures > 90 min
Substandard sterilisation procedures
Inadequate handling of tissue and instruments
Poor postoperative monitoring
Perioperative hypothermia
Hypoxia / ischaemia
Hyperglycaemia
Wounds closed under tension or left partially open
Dirty procedures
Poor client compliance
Home environment and third-hand smoke
Ongoing mechanical trauma or pressure
Volume 39 ( 4 ) • August 2024
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