Colistin Therapy, Survival and Renal Replacement Therapy in Burn Patients: A 10-Year Single-Center Cohort Study.

Purpose: Colistin is still a therapeutic cornerstone against multidrug-resistant gram-negative bacteria (MDRGN), mostly when other antibiotics do not gain adequate activity on these strains. In the present study, we evaluated in a cohort of burn patients the relationship between colistin therapy, survival and requirement of renal replacement therapy (CRRT). Patients and Methods: Retrospective study of 133 burn patients treated with iv colistimethate sodium (loading dose 9.0 × 106 IU, maintenance dose 4.5 × 106 IU BID) and 35 treated with other antibiotics for MDRGN infection including Acinetobacter baumannii, Pseudomonas aeruginosa, and Klebsiella pneumoniae between January 2008 and December 2017. Multivariate analysis with logistic regression was used to determine the effect of the predictors such as age, total body surface area (TBSA), third-degree burn areas, Revised Baux score, Charlson comorbidity score, length of stay, colistin dose and duration of treatment, mechanical ventilation, and need of CRRT on in-hospital mortality. To investigate the relationship between colistin and renal function, we focused on survivor patients as the completion of the therapeutic course of colistin represented the basic requirement to analyze its impact on the kidney. Results: Out of 133 colistin- and 35 other antibiotics-treated patients, 83 (62.4%) and 31 (88.6%) survived, and 53 (39.8%) and 3 (9.7%) required CRRT, respectively. The severity of burns, as well as CRRT requirement and mortality, was significantly higher in colistin-treated patients than in other antibiotics-treated patients. Age and TBSA% were the significant predictors of mortality. Out of 83 colistin-treated survivors, 19 (22.9%) required CRRT (9 before and 10 after the start of colistin), and 64 (77.1%) had a normal renal function. No difference about the colistin dose and baseline characteristics, but the revised Baux score was found between the 9 patients requiring CRRT before the colistin course and the 10 patients after. Similarly, among the 64 patients not undergoing CRRT, no difference was found between the patients treated with the cumulative dose of colistin <99.0 × 106 IU (n = 33, median daily dose of 4.0 × 106 IU) and >99.0 × 106 IU (n = 31, median daily dose of 9.0 × 106 IU) about the baseline characteristics and the daily median plasma creatinine over 24 days of therapy. Conclusion: Colistin therapy was associated with more severe burns, mortality, and CRRT requirement. A short course therapy, at appropriate cumulative dosage, can lead to clinical success without a significant association with severe renal impairment.

Coupled-plasma filtration and adsorption for severe burn patients with septic shock and acute kidney injury treated with renal replacement therapy.

BACKGROUND: Coupled-plasma filtration adsorption (CPFA) is a sorbent-based technology aimed at removing soluble mediators of septic shock. We present our experience on the use of CPFA in septic shock severe burn patients with acute kidney injury (AKI) needing renal replacement therapy (RRT) with the main goal to evaluate efficacy and safety of CPFA in this specific subset of septic shock patients. METHODS: In this observational study, we retrospectively reviewed the medical notes of all burn patients admitted to our adult Burn Center who received CPFA, as part of the septic shock treatment requiring RRT, between January 2001 and December 2017 (CPFA group). We compared CPFA group with all the burn patients admitted to our Center in the same period of time, with the same range of relevant clinical characteristics, who developed AKI and were treated with RRT, but not CPFA (control group). We collected demographic characteristics, burn size, Sequential Organ Assessment Failure (SOFA) score, microbiological data, and patient outcome, in terms of in-hospital mortality rate and the probability of survival calculated using the revised Baux score. We also collected data regarding CPFA safety (hemorrhagic episodes, catheter associated-complications, hypersensitivity reactions) and efficiency (number and duration of CPFA sessions, plasma treated amount, plasma processed dose). RESULTS: 39 severe burn patients were treated with CPFA (CPFA group) (mean age 46.0 years, range 40.0-56.0 years; mean burn size 48.0% TBSA, range 35.0-60.0% TBSA), and 87 patients treated with RRT, but not CPFA, who had similar clinical characteristics (control group). Observed mortality rate was 51.3% in the CPFA group and 77.1% in the control group (p 0.004). Regarding factors affecting survival in the CPFA group, SOFA score on the 1st day of CPFA resulted significant (OR 2.016, 95% CI, 1.221-3.326; p < 0.004) in the multivariate analysis logistic model. CONCLUSIONS: CPFA treatment for burn patients with AKI-RRT and septic shock, sustained by bacterial strains non or poorly responsive to therapy, was associated with a lower mortality rate, compared to RRT alone. However, further research, such as large prospective studies, is required to clarify the role of CPFA in the treatment of burns with septic shock and AKI-RRT.

Long-term follow-up of negative pressure wound therapy with instillation: a limb salvage procedure?

Negative pressure wound therapy (NPWT) is a treatment to reduce oedema, stimulate granulation tissue formation, remove wound exudate and diminish wound area, thus preparing it for secondary healing, skin grafting or coverage with flaps. The association of instillation to NPWT (NPWTi) is a new method for treating severe wounds, in particular, limb lesions at high risk for amputation. This therapy helps to deliver instillation fluid automatically into the contaminated wound, before application of negative pressure. These steps, repeated cyclically, help to remove infectious material, leading to a better moist environment, a necessary condition for wound healing. We report our experience of treating three patients with complex wounds and associated noble structure exposition conservatively with NPWTi and flap coverage. In a long-term follow-up (5 years), we were able to achieve a stable surgery reconstruction on preserved limbs, without evidence of chronic infection and other sequelae or complications. Despite the fact that our experience is limited , as it is based on only a few cases, it suggests how NPWTi could be considered useful in a conservative approach to the treatment of acute complex wounds of the lower extremities. In these patients with high risk of amputation, a long-term follow-up becomes fundamental in order to evaluate wound bed status after NPTWi.

Negative pressure surgical management after pathological scar surgical excision: a first report.

Wound dehiscence is a surgical complication caused by the application of opposing and distracting forces tending to pull apart the suture line. In recent years, a novel negative pressure surgical management system has been developed to prevent surgical wound complications. This system creates a closed environment that removes exudates and other potentially infectious material, protects the surgical site from external contamination, provides support in holding the edges of the incision together and promotes wound healing. In this study, we describe our first experience with Prevena™, a closed incision negative pressure management system used on suture line following wide pathological scars excision for the prevention of postoperative wound dehiscence. Eight patients with wide and mature pathological skin scars were treated with Prevena™. The device was positioned directly after surgical correction for 8 days with a continuous application of -125 mmHg negative pressure. All treated patients had no postoperative surgical wound dehiscence. In one case, a limit of the device was represented by its poor adherence on hairy surface, hampering the maintenance of an appropriate local negative pressure. In another case, suture line was longer than Prevena™ foam and it was covered partially. Prevena™ system appears to be safe, easy to use and may represent a support technique to wide pathological skin scars surgical correction.

Effects of sodium hydroxide exposure on esophageal epithelial cells in an in vitro ovine model: implications for esophagus tissue engineering.

BACKGROUND: Esophagus tissue engineering holds promises for esophageal replacement after severe caustic injuries. The aim of this study was to determine whether viable esophageal epithelial cells could be isolated from an esophagus exposed to varying concentrations of alkali with regard to number, viability, and morphology during in vitro culture. METHODS: Ovine esophagi were exposed to phosphate-buffered saline 2.5%, 15%, or 25% sodium hydroxide (NaOH). The effect of NaOH concentrations on epithelial damage was assessed histologically. Esophageal epithelial cells were then isolated, and cell count and viability were investigated. Finally, cell number, viability, and morphology of esophageal epithelial cells were determined for 24 days of in vitro culture. RESULTS: Histologic analysis showed a progressive destruction of the epithelium proportional to increasing NaOH concentrations. Esophagi treated with phosphate-buffered saline and 2.5% NaOH showed significantly higher viable cell counts after isolation and culture in comparison with those treated with 15% to 5% NaOH. CONCLUSION: The evidence presented in this study indicates that epithelial biopsies from an esophagus exposed to low concentrations (2.5%) of NaOH will still yield large numbers of viable cells suitable for tissue engineering applications. In cases of exposure to higher concentrations (15%-25%), alternative cell sources for epithelial regeneration, such as stem cells, will be necessary for tissue engineering applications.

In vitro effect of bethanechol and suberyldicholine on regions of guinea pig esophagus.

BACKGROUND: Tissue engineering and regenerative medicine is envisaged as the future option for esophageal replacement; however, engineering of a functional esophagus is impeded by the limited understanding of the anatomical complexity of this dynamic muscular organ. The aim of this study was to characterize the function of native esophageal tissue and determine differences in functional response to stimulation between anatomical sites. MATERIALS AND METHODS: The in-vitro response of guinea pig esophageal preparations, from various anatomical sites, to muscle agonists was investigated. Esophageal strips were exposed to bethanechol, an agonist of muscarinic receptors located on smooth muscle, and suberyldicholine, an agonist of nicotinic receptors located on striated muscle, within a Schuler organ bath, to determine the contractile response on the various segments of the esophagus. RESULTS: The esophagus responded in a reliable and consistent manner to agonist stimulation. Bethanechol dose response curves were constructed with doses of 10 to 300 µM. The average maximal contractions to bethanechol exposure were 4.51, 4.80, 5.55, and 9.15 mN for upper, upper middle, lower middle, and lower esophageal segments, respectively. Responses to singular stimulation with 30 µM suberyldicholine in the presence of tetrodotoxin (100 µM) gave average contractions of 1.07, 0.84, 2.60, and 3.02 mN for upper, upper middle, lower middle, and lower esophageal segments, respectively. Bethanechol and suberyldicholine-induced responses were greater in the lower esophagus in comparison to the upper esophageal segments. CONCLUSION: These findings pave the way for the use of an in-vitro bethanechol and suberyldicholine-induced contraction model for future assessment of engineered esophageal tissue.

Effectiveness of primary endoscopic incision in treatment of ectopic ureterocele associated with duplex system.

OBJECTIVES: To report our experience with the endoscopic treatment of ectopic ureterocele to demonstrate its long-term effectiveness. Endoscopic treatment is often recommended as the initial and definitive treatment in patients with ureterocele. METHODS: A total of 46 children with ectopic ureterocele in a duplex system underwent primary endoscopic incision from January 1998 to January 2006. The mean follow-up was 3.8 years. Of the 46 children, 35 had been diagnosed prenatally and 11 had been diagnosed after birth because of a urinary tract infection. Low-dose antibiotic prophylaxis was administered to all children and was maintained until voiding cystourethrography showed no reflux. The pre- and postoperative evaluation included clinical assessment, ultrasound evaluation, diethylenetriaminepentacetic acid renography, and cyclic voiding cystourethrography. RESULTS: Ureterocele decompression was achieved in 43 patients (93%). Three patients required additional surgery for persistent ureterocele (1 underwent ureteroureterostomy and 2 ureteropyelostomy). None of our patients showed deterioration of renal function after the procedures. Vesicoureteral reflux was seen in the lower moiety of the ipsilateral kidney in 14 patients (30%). Of the 14 patients with vesicoureteral reflux, 10 had spontaneous resolution. The remaining 4 underwent endoscopic correction. Five patients (10%) developed de novo vesicoureteral reflux in the ipsilateral ureterocele moiety. Of these 5 patients, 3 were treated with endoscopic injection and 2 had spontaneous resolution after 6 months of follow-up. CONCLUSIONS: Our data have shown that primary endoscopic puncture of a ureterocele is a simple, long-term, effective, and safe procedure, avoiding complete reconstruction in most patients.

The importance of patient selection in the treatment of distal hypospadias using modified Koff procedure.

OBJECTIVE: We present our experience in the treatment of distal hypospadias using a modified Koff procedure, emphasizing the importance of patient selection for a good outcome. MATERIALS AND METHODS: In 2003-2008, 90 patients, mean age 52.1 months, underwent surgical repair of distal hypospadias using urethral advancement according to Koff, modified with a Ψ incision on the tip of the glans. Meatal defect was glanular in six (8%), subglanular in 24 (26%) and coronal in 60 (66%) cases. Mild chordee was present in 19 patients (21%). Follow-up was 8-66 months. All patients were evaluated in terms of cosmetic results, and early and late postoperative complications. RESULTS: All patients showed excellent cosmetic results with urethral meatus on the tip. There was only one postoperative fistula due to extensive use of electrocautery during urethral mobilization that was surgically corrected 8 months after appearance. One patient had a postoperative meatal stenosis treated conservatively. No cases of residual chordee were detected. CONCLUSIONS: Successful use of the modified Koff procedure depends on careful selection of patients. Good candidates are those with distal or mid-shaft hypospadias, presenting with: (1) absence or low degree of ventral chordee; (2) distal plate of urethra well developed; (3) distance between meatus and tip of glans at most 10-12 mm; and (4) glanular morphology preserved.