The records of 7 patients (5 women, 2 men; age range 57– 93 years) on whom a direct antimicrobial stewardship benefit was noted are herein described.
Case 1. Mr. K, an 83-year-old with ependymoma (central nervous system tissue cancer) and diminishing mobility and minimal at-home care, presented with a septic sacral ulcer. Mr. K had a past history of hypothyroidism, hypertension, mild cognitive impairment, neurogenic bladder, and seizure disorder. At the time of hospital admittance, Mr. K’s diagnosis included a large sacral pressure injury measuring 12 cm x 10 cm x 2.5 cm, osteomyelitis of the sacrum, seizure disorder, deconditioning, and aspiration pneumonia. Mr. K was taking levetiracetam, levothyroxine, perindopril, phenytoin, amlodipine, atenolol, tamsulosin, and systemic antibiotics at the time of his admission. A wound care specialist was consulted to determine whether the wound simply required cleaning and debridement or if a further course of antibiotics was warranted. Assessment findings indicated considerable size and depth of wound, drainage, and odor. Measures employed to ensure suitable offloading also were assessed. Fluorescence images acquired of his wound revealed an extensive area of bioburden (see Figure 1; bacteria appear red on fluorescence images) that remained after conservative surgical wound debridement of necrotic tissue. Based on these fluorescence images, the antibiotic course was continued. In addition to guiding this treatment decision, fluorescence images demonstrating the presence and location of bioburden were used to guide swab location as well as additional surgical debridement, conservatively targeted solely to the regions of red fluorescence. Mr. K’s blood cultures confirmed the presence of bacteria (Bacteroides spp), and fluorescence-guided swabs confirmed heavy growth of Morganella morganii, E coli, and Enterococcus faecalis. Due to the fragile nature of the wound tissue post debridement, the wound received packing dampened with povidine iodine for 24 hours, at which point negative pressure wound therapy (NPWT) with instillation of saline was begun. Fluorescence images acquired on day 5 of NPWT and instillation treatment showed persistent bioburden (see Figure 1) and guided additional targeted debridement of slough and necrotic tissue (sparing noncontaminated regions). Images acquired at each subsequent dressing change showed decreases in red fluorescence, demonstrating the effectiveness of the treatment. Because the low intensity violet light illumination of the device is entirely safe for clinical use per Rennie et al,15 repeat imaging sessions and high frequency of use have no known adverse effects. Six (6) weeks after hospital admittance the wound was managed with NPWT along with offloading, nutrition changes, and other modifiable patient lifestyle factors.16 At this time, the wound bed was 100% granulated with no signs of infection.
Case 2. During her hospital stay, Ms. Z, a 93-year-old inpatient originally admitted for pneumonia, developed a pressure injury on her coccyx measuring 5 cm x 4 cm x 2.7 cm with 4 cm of undermining at 12 o’clock. Comorbidities included chronic heart failure, chronic renal failure, chronic obstructive pulmonary disease (COPD), atrial fibrillation, hypertension, and hypothyroidism. Ms. Z was taking bisoprolol, diltiazem, furosemide, levothyroxine, and warfarin at the time of admission. The pressure injury was being treated with an absorbent foam dressing and packing ribbon that was impregnated with sodium chloride. Ms. Z’s respiratory status improved and her hospitalist requested a consult with a wound care specialist to inquire about discharge/transfer from the acute ward. Bacterial fluorescence images were taken as part of wound assessment; they revealed and documented a widespread area of bioburden in and around her wound (see Figure 2A,B). Clinical assessment included periwound area of erythema of approximately 2 cm to 3 cm and minimal progress with granulation tissue. Ms. Z still required twice-daily dressing changes because considerable exudate was noted. This resulted in a consult with an infectious disease specialist, who prescribed systemic antibiotics and suspended all plans for immediate discharge. Swabs analyzed for typical culture and sensitivity later confirmed heavy growth of mixed anaerobes. In addition to antibiotic management, the wound was treated twice daily with 1-inch packing dampened with povidone iodine; 7 days later, NPWT was initiated for 2.5 weeks. Bacterial fluorescence images acquired 6 days after antibiotic initiation demonstrated antibiotic effectiveness, as noted by an absence of red fluorescence (see Figure 2C). Based on these images, no additional antibiotics were prescribed. Bioburden in the wound then was controlled with an absorbent dressing containing methylene blue and gentian violet. The wound was deemed healable provided all established, modifiable risk factors were addressed (eg, offloading, mobility, nutrition, recovery from pneumonia). At Ms. Z’s 6-month follow up, the wound was almost healed (0.5 cm x 0.5 cm x 0.5 cm).
Case 3. Ms. U, a 63-year-old patient with lymphoma, presented to the outpatient chemotherapy unit where she was being treated with combination chemotherapy (R-CHOP) for follow-up. Known patient comorbidities included type 2 diabetes, diabetic retinopathy, dyslipidemia, hypothyroidism, and hypertension for which she was taking metformin, glibenclamide, empagliflozin, levothyroxine, and bisoprolol perindopril atorvastatin. On this visit, a sacral injury (6 cm x 6 cm, 100% slough) also was noted for which Ms. U had not been receiving treatment. A wound care specialist was consulted; standard wound assessment and bacterial fluorescence images of the wound were performed. Standard assessment did not suggest infection; however, bacterial fluorescence images verified the presence of a large region of bioburden (see Figure 3A,B) and Ms. U was admitted for treatment of her sacral injury. Swabs taken from regions of red fluorescence on images later confirmed heavy growth of S aureus and E coli. Upon Ms. U’s admission, systemic antibiotics were started immediately and she received additional measures such as fluorescence-guided surgical debridement targeting areas of red fluorescence and offloading to manage her unstageable (obscured by necrotic tissue), complex pressure injury. After 7 days of antibiotic treatment and NPWT, visualized bacterial fluorescence in the wound bed was notably decreased (see Figure 3C). Wound size increased over the following weeks due to debridement and cleaning of the necrotic region (7 cm x 6 cm x 3.5 cm), revealing the patient’s coccyx bone and prompting further antibiotic treatment for osteomyelitis. After 2 months of inpatient wound care treatment, Ms. U was transferred to a residential care setting where bioburden was controlled using a tunnelling absorbent dressing containing methylene blue and gentian violet. At the time of transfer, Ms. U’s wound was deemed healable, recognizing that healing the wound would take a minimum of 6 to 8 months. At 6 months after originally discovering the wound, it measured 2 cm x 1.3 cm x 1.5 cm with 100% granulation tissue.
Case 4. Eighty-two (82)-year-old Ms. T was admitted to the hospital for a painful venous leg ulcer with nondemarcated edges. Her comorbidities included noninsulin-dependent diabetes, hypertension, chronic heart failure, gout, and hypothyroidism. At the time of admission, Ms. T was taking gabapentin, pantoprazole, hydromorphone, levothyroxine, hydrochlorothiazide, ferrous gluconate, amlodipine, glycopyrronium bromide (for sweating), and metformin. Her wound was treated with absorptive silicone foam and light compression. A wound care protocol for discharge and community follow-up was requested from the wound care team. Upon evaluation by the wound care specialist, traditional signs and symptoms of extensive erythema (ie, >2 cm from the wound edge) were not present, although pain was still a factor. Additionally, bacterial fluorescence images revealed an extensive area (ie, >2 cm from the wound edge) of bacterial burden (see Figure 4A,B), leading to a suspension of patient discharge, prescription of a systemic antibiotic, and a modified wound care protocol to include an antimicrobial dressing (sustained-release povidine iodine). Swabs of the region that fluoresced red/blush on bacterial fluorescence images later confirmed heavy growth of Acinetobacter baumannii. The wound was deemed healable (taking 2 to 3 months to heal), provided compression and antimicrobial dressing therapy were maintained; the wound closed within 6 weeks.
Case 5. Ms. R was an 88-year-old with right lower leg cellulitis who presented at a wound outpatient clinic. Comorbidities included hemorrhagic stroke with no deficits, atypical seizures, hypothryodism, dyslipidemia, hypertension, and COPD. At the time of admission, Ms. R was taking pantoprazole, hydrochlorothiazide, atenolol, phenytoin, atorvastatin, levothyroxine, losartan, fluticasone (puff), citalopram, and conjugated estrogen. She had received a skin graft (11 cm x 10 cm x 0.5 cm) on the same ankle 1 year prior for squamous cell carcinoma; that wound had closed. The skin encompassing approximately 6 cm x 6 cm within the previously closed graft area was tender and had erythema and superficial splits/tears in the skin with clear exudate. At the time of presentation, Ms. R had just returned from a long overseas flight during which the previously grafted leg had become swollen and red. Standard wound assessment did not reveal any overt signs of infection; however, bacterial fluorescence images revealed blush red (subsurface) bacteria (see Figure 5A,B). These images, together with the patient’s wound history, led to a prescribed course of oral antibiotics and selection of silver-based antimicrobial dressings. Swabs later confirmed heavy growth of S aureus. Ms. R’s wound was deemed healable and closed within 3 to 4 weeks.
Case 6. Ms. P was 64 years old with no notable past medical history. She sustained a type 3 skin tear injury of the lower leg.25 Ms. P presented in the emergency room (ER) 3 weeks later when the wound had not healed; she had been treating the tear herself with over-the-counter antibiotic ointment and was only taking trazadone for sleep. She noted increasing redness and pain, but the ER physician found no other clinical signs or symptoms of infection. Ms. P was concerned about possible infection because in 3 weeks she would be travelling, prompting the physician to prescribe oral antibiotics and a consultation with a wound care specialist. Fluorescence images were acquired and demonstrated no bacterial burden in or around the wound (see Figure 6A,B). The real-time images were negative for bacterial fluorescence, so antibiotic treatment was eliminated. Loose tissue around the wound was debrided, and a silicone foam dressing was applied. Traditional wound care without any antibiotics or antimicrobial treatments lead to wound closure within 2 weeks, prior to Ms. P’s travel (see Figure 6C).
Case 7. Mr. N was a 57-year-old with gastric cancer, hypertension, anemia, and peripheral arterial disease who was prescribed systemic antibiotics after a partial gastrectomy (wound size: 2.9 cm x 1.3 cm x 0.8 cm). Mr. N also was taking pantoprazole, almotriptan, sildenafil, and escitalopram. Several days before his hospital discharge, abdominal midline dehiscence was noted; the general surgeon initiated oral antibiotics and the wound was treated with 0.25-inch antimicrobial packing and an absorptive foam cover dressing. Mr. N returned to the ER 7 days later when he was due to conclude oral antibiotic treatment because he was concerned with increased wound drainage and the midline opening. The wound appeared to be clean and granulating with no evident odor. Fluorescence images showed no evidence of bacterial contamination (see Figure 7A,B). This information was relayed by the wound care specialist to the surgeon, and the decision was made to prescribe no further antibiotics; traditional postsurgical wound care with antimicrobial packing ribbon was continued. No microbiological cultures were obtained at this time point. At Mr. N’s 2-week follow-up with the general surgeon, the wound was virtually closed and by week 3 had closed completely.