Effect of subcutaneous epinephrine/saline/local anesthetic versus saline-only injection on split-thickness skin graft donor site perfusion, healing, and pain

Interventions for postburn pruritus

BACKGROUND

Postburn pruritus (itch) is a common and distressing symptom experienced on healing or healed burn or donor site wounds. Topical, systemic, and physical treatments are available to control postburn pruritus; however, it remains unclear how effective these are.

OBJECTIVES

To assess the effects of interventions for treating postburn pruritus in any care setting.

SEARCH METHODS

In September 2022, we searched the Cochrane Wounds Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), Ovid MEDLINE (including In-Process & Other Non-Indexed Citations), Ovid Embase, and EBSCO CINAHL Plus. We also searched clinical trials registries and scanned references of relevant publications to identify eligible trials. There were no restrictions with respect to language, publication date, or study setting.

SELECTION CRITERIA

Randomised controlled trials (RCTs) that enrolled people with postburn pruritus to compare an intervention for postburn pruritus with any other intervention, placebo or sham intervention, or no intervention.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures expected by Cochrane. We used GRADE to assess the certainty of the evidence.

MAIN RESULTS

We included 25 RCTs assessing 21 interventions with 1166 randomised participants. These 21 interventions can be grouped into six categories: neuromodulatory agents (such as doxepin, gabapentin, pregabalin, ondansetron), topical therapies (such as CQ-01 hydrogel, silicone gel, enalapril ointment, Provase moisturiser, beeswax and herbal oil cream), physical modalities (such as massage therapy, therapeutic touch, extracorporeal shock wave therapy, enhanced education about silicone gel sheeting), laser scar revision (pulsed dye laser, pulsed high-intensity laser, fractional CO2 laser), electrical stimulation (transcutaneous electrical nerve stimulation, transcranial direct current stimulation), and other therapies (cetirizine/cimetidine combination, lemon balm tea). Most RCTs were conducted at academic hospitals and were at a high risk of performance, attrition, and detection bias. While 24 out of 25 included studies reported change in burn-related pruritus, secondary outcomes such as cost-effectiveness, pain, patient perception, wound healing, and participant health-related quality of life were not reported or were reported incompletely. Neuromodulatory agents versus antihistamines or placebo There is low-certainty evidence that doxepin cream may reduce burn-related pruritus compared with oral antihistamine (mean difference (MD) -2.60 on a 0 to 10 visual analogue scale (VAS), 95% confidence interval (CI) -3.79 to -1.42; 2 studies, 49 participants). A change of 2 points represents a minimal clinically important difference (MCID). Due to very low-certainty evidence, it is uncertain whether doxepin cream impacts the incidence of somnolence as an adverse event compared to oral antihistamine (risk ratio (RR) 0.64, 95% CI 0.32 to 1.25; 1 study, 24 participants). No data were reported on pain in the included study. There is low-certainty evidence that gabapentin may reduce burn-related pruritus compared with cetirizine (MD -2.40 VAS, 95% CI -4.14 to -0.66; 1 study, 40 participants). A change of 2 points represents a MCID. There is low-certainty evidence that gabapentin reduces the incidence of somnolence compared to cetirizine (RR 0.02, 95% CI 0.00 to 0.38; 1 study, 40 participants). No data were reported on pain in the included study. There is low-certainty evidence that pregabalin may result in a reduction in burn-related pruritus intensity compared with cetirizine with pheniramine maleate (MD -0.80 VAS, 95% CI -1.24 to -0.36; 1 study, 40 participants). A change of 2 points represents a MCID. There is low-certainty evidence that pregabalin reduces the incidence of somnolence compared to cetirizine (RR 0.04, 95% CI 0.00 to 0.69; 1 study, 40 participants). No data were reported on pain in the included study. There is moderate-certainty evidence that ondansetron probably results in a reduction in burn-related pruritus intensity compared with diphenhydramine (MD -0.76 on a 0 to 10 numeric analogue scale (NAS), 95% CI -1.50 to -0.02; 1 study, 38 participants). A change of 2 points represents a MCID. No data were reported on pain and adverse events in the included study. Topical therapies versus relevant comparators There is moderate-certainty evidence that enalapril ointment probably decreases mean burn-related pruritus compared with placebo control (MD -0.70 on a 0 to 4 scoring table for itching, 95% CI -1.04 to -0.36; 1 study, 60 participants). No data were reported on pain and adverse events in the included study. Physical modalities versus relevant comparators Compared with standard care, there is low-certainty evidence that massage may reduce burn-related pruritus (standardised mean difference (SMD) -0.86, 95% CI -1.45 to -0.27; 2 studies, 166 participants) and pain (SMD -1.32, 95% CI -1.66 to -0.98). These SMDs equate to a 4.60-point reduction in pruritus and a 3.74-point reduction in pain on a 10-point VAS. A change of 2 VAS points in itch represents a MCID. No data were reported on adverse events in the included studies. There is low-certainty evidence that extracorporeal shock wave therapy (ESWT) may reduce burn-related pruritus compared with sham stimulation (SMD -1.20, 95% CI -1.65 to -0.75; 2 studies, 91 participants). This equates to a 5.93-point reduction in pruritus on a 22-point 12-item Pruritus Severity Scale. There is low-certainty evidence that ESWT may reduce pain compared with sham stimulation (MD 2.96 on a 0 to 25 pressure pain threshold (PPT), 95% CI 1.76 to 4.16; 1 study, 45 participants). No data were reported on adverse events in the included studies. Laser scar revision versus untreated or placebo controls There is moderate-certainty evidence that pulsed high-intensity laser probably results in a reduction in burn-related pruritus intensity compared with placebo laser (MD -0.51 on a 0 to 1 Itch Severity Scale (ISS), 95% CI -0.64 to -0.38; 1 study, 49 participants). There is moderate-certainty evidence that pulsed high-intensity laser probably reduces pain compared with placebo laser (MD -3.23 VAS, 95% CI -5.41 to -1.05; 1 study, 49 participants). No data were reported on adverse events in the included studies.

AUTHORS' CONCLUSIONS

There is moderate to low-certainty evidence on the effects of 21 interventions. Most studies were small and at a high risk of bias related to blinding and incomplete outcome data. Where there is moderate-certainty evidence, practitioners should consider the applicability of the evidence for their patients.

Tumescent technique for split-thickness skin graft donor sites: A systematic review of randomized controlled trials

BACKGROUND

Split-thickness skin grafting (STSG) is widely used for reconstructive wound management. This review aimed to use level I evidence to determine if tumescent techniques were safe and effective compared to other interventions for STSG donor sites. It was hypothesized that tumescent techniques were safe and effective for STSG donor sites.

METHODS

Five databases (MEDLINE via PubMed, Embase, Cochrane Library, Web of Science, and Scopus) were searched to identify studies concerning the use of tumescent solutions for STSG. Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) and Cochrane's guidelines were strictly followed.

RESULTS

Nine randomized controlled trials met the criteria. Included studies were published from 2001 to 2021, with results from 40 of 121 possible queried outcomes and complications. Outcomes included patient demographics, formulations of tumescent solutions, tumescent technique, hemodynamics, pain, perfusion, graft take, healing time, and postoperative complications. The tumescent technique reduced estimated blood loss (standard mean differences [SMD]: -2.68, 95%CI: -3.41 to -1.94; participants = 72; studies = 2; I2 = 96%; p < 0.001), and postoperative analgesic use within 24 hours (SMD: -1.75, 95%CI: -2.09 to -1.41; participants = 202; studies = 2; I2 = 96%; p < 0.001), without increasing graft loss/take (SMD: 0.29, 95%CI: -0.02 to 0.61; participants = 158; studies = 3; I2 = 41%; p = 0.07) and infection (risk ratios [RR]: 0.52, 95%CI: 0.08 to 3.54; participants = 87; studies = 3; I2 = 0%; p = 0.58) complications compared to other interventions.

CONCLUSIONS

Level I evidence demonstrated tumescent techniques were safe and effective for STSG donor sites. Tumescent techniques reduced blood loss and postoperative analgesic use within 24 hours without increasing graft loss/take and infection complications compared to other interventions. Inconsistencies between studies limit conclusions and emphasize the need for standardized protocols regarding tumescent solution formulations, techniques, and reported outcomes.

Reducing Blood Loss in a Burn Care Unit: A Review of Its Key Determinants

Patients with a major burn injury differ considerably from the typical critical ill and trauma population. Very often, burn patients suffer from anemia throughout their hospital stay. This is caused both by combination of persistent blood loss with decreased erythropoiesis. Therefore, burn patients do have major transfusion requirements. However, transfusion is not devoid of risks or costs. We hereby review the best surgical techniques and medical approaches, aiming to reduce blood loss in a burn patient and optimize red cell production, so that we can reduce the need of RBC transfusion. The implementation of a combination of surgical techniques aiming to reduce blood loss and medical care approaches to prevent anemia, rather than single attitudes, should be adopted in burn care. There is an urgent need for clear guidelines that can easily be accepted, applied, and spread across different burn units to methodically implement measures to reduce blood loss and transfusion needs, and ultimately improve burn patients' outcome and the health care financial status.

Topical Hemostatic Agents in Burn Surgery: A Systematic Review

Acute burn surgery has long been associated with significant intra-operative bleeding. Several techniques were introduced to limit hemorrhage, including tourniquets, tumescent infiltration, and topical agents. To date, no study has comprehensively investigated the available data regarding topical hemostatic agents in burn surgery. A systematic review was performed by two independent reviewers using electronic databases (PubMed, Scopus, Web of Science) from first available to September 10, 2021. Articles were included if they were published in English and described or evaluated topical hemostatic agents used in burn excision and/or grafting. Data were extracted on the agent(s) used, their dosage, mode of delivery, hemostasis outcomes, and complications. The search identified 1982 nonduplicate citations, of which 134 underwent full-text review, and 49 met inclusion criteria. In total, 32 studies incorporated a vasoconstrictor agent, and 28 studies incorporated a procoagulant agent. Four studies incorporated other agents (hydrogen peroxide, tranexamic acid, collagen sheets, and TT-173). The most common vasoconstrictor used was epinephrine, with doses ranging from 1:1000 to 1:1,000,000. The most common procoagulant used was thrombin, with doses ranging from 10 to 1000 IU/ml. Among the comparative studies, outcomes of blood loss were not reported in a consistent manner, therefore meta-analysis could not be performed. The majority of studies (94%) were level of evidence III-V. Determining the optimal topical hemostatic agent is limited by low-quality data and challenges with consistent reporting of intra-operative blood loss. Given the routine use of topical hemostatic agents in burn surgery, high-quality research is essential to determine the optimal agent, dosage, and mode of delivery.

Comparing the Efficiency of Tumescent Infiltration Techniques in Burn Surgery

Tangential excision and grafting of burn wounds result in significant intraoperative blood loss, and infiltration of a dilute epinephrine solution (tumescence) is routinely performed to reduce such bleeding. Tumescent infiltration has been described using both a manual technique (syringe) and a pump device. The purpose of this study is to compare the efficiency of these two methods in terms of time and economy of motion. Consecutive adult burn patients at a single center requiring excision and grafting were enrolled in the study and randomized into either the manual or pump technique. Excisions involving less than 2% TBSA were excluded, along with specific anatomic regions (eg, head and neck). Infiltration with epinephrine solution (1:500,000) was performed to the endpoint of tumescence by a single surgeon and filmed/coded for duration, number of maneuvers, and volume of tumescence injected. Fourteen patients were enrolled, and 16 cases were randomized to either manual (N = 8) or pump infiltration (N = 8). The pump method required less time (2.0 vs 1.1 cm2/s, P < .001) and fewer maneuvers (37.8 vs 1.1 cm2/move, P < .001) to reach the desired endpoint of tumescence. Use of the infiltration pump also resulted in a reduced volume of tumescent fluid required to reach this point of tumescence (1.7 vs 2.4 mL/cm2, P = .01). Compared to the manual technique, an infiltration pump was significantly more efficient in terms of both time and economy of motion. These reductions are potentially useful for improving operating room efficiency as well as minimizing operator fatigue.

Management of skin graft donor site in pediatric patients with tumescent technique and AQUACEL® Ag foam dressing

Split thickness skin graft donor sites are challenging to manage in children because of patient fear and anxiety. Therefore, strategies that minimize the frequency of dressing change are beneficial. This paper describes a technique to simplify wound care for split thickness skin graft donor sites. A tumescent solution of saline containing 0.25% bupivacaine with epinephrine is infiltrated into the graft donor site. Skin grafts are harvested with an electric dermatome. The donor sites are dressed with AQUACEL^® Ag Foam, which is a sodium carboxymethylcellulose hydrofiber dressing that contains silver ions. A total of 17 split thickness skin grafts were performed with this technique. Patient age ranged from 2.4 year to 16.9 years (average 12 years). The AQUACEL^® Ag Foam dressings were removed at an average of 23 days (range 11 to 31 days) at which time complete donor site epithelialization was seen in 13/17 (76.5%) patients. The remaining 4 patients had < 5% of the donor site that had not epithelialized; these went on to heal uneventfully with a brief period of petrolatum gauze dressing changes. Two patients had foul smelling discharge under the dressing that resolved promptly with dressing removal. The above technique allows the primary dressing to stay in place long enough for epithelialization to take place. The obviation of dressing changes in the early post-operative period results in patient comfort and care giver convenience.

Effect of Subcutaneous Adrenaline/Saline/Lidocaine Injection on Split-Thickness Skin Graft Donor Site Wound Healing

Background

Subcutaneous injection of tumescent solution, which contains local anesthetic, adrenaline, and saline, before split-thickness skin graft harvesting, shows a significant hemostatic effect. This method can reduce the initial bleeding from the donor site. The aim of this study is to assess the benefits of controlling the bleeding from donor sites by tumescent injection. A randomized, controlled trial was performed to compare the wound healing of split-thickness skin graft donor sites treated with or without tumescent injection.

Methods

This randomized, controlled trial examined donor site healing days as the main measure of outcome. postoperative pain, donor site ulceration, and scar quality were evaluated as secondary outcome measures. Patients planned for split-thickness skin graft harvest were randomly assigned to receive either pre-harvest subcutaneous injection of local anesthetic, adrenaline, and saline solution (tumescent solution) (Group 1) or post-harvest application of adrenaline solution-soaked gauze to the skin graft donor sites (Group 2). Donor sites were treated with calcium alginate dressings after graft harvesting. On the 10th postoperative day, the dressings were removed and donor site healing were measured. Follow-up evaluation of scar quality was performed 6 months after surgery. Postoperative pain was evaluated on the 1st day after operating.

Results

Forty-five patients (26 males; average age 61.8 years) completed the late follow-up evaluation (6 months postoperatively), with 26 patients in group 1 and 19 in group 2. There were no significant differences between the two groups in any of the outcome measures.

Conclusion

Tumescent technique provides sufficient hemostasis in split skin graft donor sites, especially the initial bleeding just after graft harvesting, without any negative effects. Larger series should be studied to evaluate the effect in donor site wound healing.

Regional Anesthetic Blocks for Donor Site Pain in Burn Patients: A Meta-Analysis on Efficacy, Outcomes, and Cost

Background

Skin graft donor site pain significantly affects pain management, narcotic use, and hospital length of stay. This study is intended to evaluate the efficacy of regional anesthesia in the burn population to decrease narcotic consumption and to assess the impact on hospitalization costs.

Methods

PubMed/MEDLINE, Embase, and ScienceDirect were searched with the following inclusion criteria: comparative studies, adult populations, burn patients, autologous skin grafting, regional nerve blocks, and traditional narcotic regimens. Outcomes assessed included narcotic consumption, pain scores, and opioid side effects. Meta-analysis obtained pooled values for morphine consumption and side effects. Cost analysis was performed using published data in the literature.

Results

Final analysis included 101 patients. Cumulative morphine consumption at 72 hours was lower for patients treated with regional anesthesia versus patient-controlled analgesia (PCA; single shot 25 ± 12 mg, continuous regional 23 ± 16 mg, control 91.5 ± 24.5 mg; P < .05). Regional anesthesia decreased nausea/vomiting (P < .05) and lowered subjective pain scores. Regional anesthesia interventions cost less than PCA, single shot less than continuous (P < .05).

Conclusion

Regional anesthesia at skin graft donor sites significantly decreases narcotic consumption in burn patients. Regional anesthesia is cost-effective, decreases side effects, and may result in shorter hospital stays due to improved pain management.

Systematic review of clinical outcome reporting in randomised controlled trials of burn care

INTRODUCTION

Systematic reviews collate trial data to provide evidence to support clinical decision-making. For effective synthesis, there must be consistency in outcome reporting. There is no agreed set of outcomes for reporting the effect of burn care interventions. Issues with outcome reporting have been identified, although not systematically investigated. This study gathers empirical evidence on any variation in outcome reporting and assesses the need for a core outcome set for burn care research.

METHODS

Electronic searches of four search engines were undertaken from January 2012 to December 2016 for randomised controlled trials (RCTs), using medical subject headings and free text terms including 'burn', 'scald' 'thermal injury' and 'RCT'. Two authors independently screened papers, extracted outcomes verbatim and recorded the timing of outcome measurement. Duplicate outcomes (exact wording ± different spelling), similar outcomes (albumin in blood, serum albumin) and identical outcomes measured at different times were removed. Variation in outcome reporting was determined by assessing the number of unique outcomes reported across all included trials. Outcomes were classified into domains. Bias was reduced using five researchers and a patient working independently and together.

RESULTS

147 trials were included, of which 127 (86.4%) were RCTs, 13 (8.8%) pilot studies and 7 (4.8%) RCT protocols. 1494 verbatim clinical outcomes were reported; 955 were unique. 76.8% of outcomes were measured within 6 months of injury. Commonly reported outcomes were defined differently. Numbers of unique outcomes per trial varied from one to 37 (median 9; IQR 5,13). No single outcome was reported across all studies demonstrating inconsistency of reporting. Outcomes were classified into 54 domains. Numbers of outcomes per domain ranged from 1 to 166 (median 11; IQR 3,24).

CONCLUSIONS

This review has demonstrated heterogeneity in outcome reporting in burn care research which will hinder amalgamation of study data. We recommend the development of a Core Outcome Set.

PROSPERO REGISTRATION NUMBER

CRD42017060908.

Longitudinal progress of transepidermal water loss, color, and sensory elements in split-thickness skin graft donor sites in East Asians

BACKGROUND

There is little research available that describes the natural progression of split-thickness skin graft (STSG) donor site wounds after re-epithelialization. The purpose of this study was to evaluate the longitudinal clinical progress of transepidermal water loss (TEWL), color, and sensory elements in STSG donor sites in East Asians.

METHODS

Eighteen patients participated in this study. The TEWL, color, pressure threshold, and static two-point discrimination were evaluated from the center and upper lateral corner of the wounds and adjacent normal skin preoperatively and at 1, 2, 7, and 12 months postoperatively.

RESULTS

The age was negatively correlated with preoperative values of TEWL (r = -0.49, P = 0.039). The elevated TEWL level from the STSG donor sites did not return to normal until 12 months after surgery. In the measurement of skin color, the elevated L* value normalized after 12 months following surgery, while the elevated a* and b* values persisted. In the sensory testing, there were no significant changes during the observation period except at 2 months postoperatively, representing a significant increase of pressure threshold in the periphery.

CONCLUSIONS

In East Asians, elevated skin lightness level in STSG donor sites returned to normal at 12 months postoperatively, while the elevated TEWL and skin redness levels were improved but were not normalized at 12 months after surgery.

Ultrasound-Guided Regional Anesthesia for Pediatric Burn Reconstructive Surgery: A Prospective Study

Pediatric patients face multiple reconstructive surgeries to reestablish function and aesthetics postburn injury. Often, the site of the harvested graft for these reconstructions is reported to be the most painful part of the procedure and a common reason for deferring these reconstructive procedures. This study in pediatric burn patients undergoing reconstructive procedures examined the analgesia response to local anesthetic infiltration versus either a single ultrasound-guided regional nerve block of the lateral femoral cutaneous nerve (LFCN) or a fascia iliaca compartment block with catheter placement and continuous infusion. Nineteen patients were randomized to one of three groups (infiltration, single-shot nerve block, or compartment block with catheter) and received intraoperative analgesia intervention. Postoperatively, visual analog scale pain scores were recorded-for pain at the donor site-every 4 hours while awake-for 48 hours. This nonparametric data was analyzed using a two-way ANOVA, Friedman's test, and Kruskal-Wallis test, with significance determined at P < 0.05. The analysis demonstrated that the patients in the regional anesthesia groups were significantly more comfortable over the 48 hour hospital course than the patients in the control group. The patients receiving a single-shot block of the LFCN were more comfortable on postoperative day (POD) 0 while the catheter patients were more comfortable on POD 1 and POD 2. There was not a statistically significant difference in opioid requirements in any group. Regional anesthetic block of the LFCN, with or without catheter placement, provides an improved postoperative experience for the pediatric patient undergoing reconstructive surgery with lateral/anterolateral skin graft versus local anesthesia infiltration of donor site. For optimal comfort throughout the postoperative period, an ultrasound-guided block with continuous catheter may be beneficial.

Effectiveness of collagen/oxidised regenerated cellulose/silver-containing composite wound dressing for the treatment of medium-depth split-thickness skin graft donor site wounds in multi-morbid patients: a prospective, non-comparative, single-centre study

Split-thickness skin grafting (STSG) is a widely used method in reconstructive surgery, but donor site wounds (DSWs) are often slow healing and painful. This prospective study evaluated the performance of a composite wound dressing containing collagen/oxidised regenerated cellulose in the treatment of medium-depth (0·4 mm) DSWs in 25 multi-morbid patients with chronic leg ulcers requiring STSG. The range of patients' ages was 44-84 years (mean 71·6 years) with DSW sizes ranging between 12 and 162 cm2 (mean 78 cm2 ). Comorbidities included anticoagulation therapy (15 patients), anaemia (11 patients), diabetes (6 patients) and methicillin-resistant Staphylococcus aureus (MRSA) ulcer colonisation (6 patients). The first dressing change was performed after 10 days. Complete reepithelialisation was observed between the 10th and 34th day (mean 17·2, median 14 days). Postoperative medium to strong bleeding occurred in only five patients (four with anticoagulation). Wound pain levels one day after harvesting were only moderate (range 0-1·5, mean 0·5, median 0·5 on a six-item scale). No wound infection was observed during the first dressing. The composite dressing used allowed for the fast healing of medium-depth DSWs with minimal or no postoperative pain and bleeding in older multi-morbid patients under anticoagulation treatment.

Prevention of Surgical Site Infections and Biofilms: Pharmacokinetics of Subcutaneous Cefazolin and Metronidazole in a Tumescent Lidocaine Solution

BACKGROUND

Tumescent anesthesia antibiotic delivery (TAAD) consists of subcutaneous infiltration of antibiotic(s) dissolved tumescent lidocaine anesthesia. Tumescent lidocaine anesthesia contains lidocaine (≤ 1 g/L), epinephrine (≤ 1 mg/L), sodium bicarbonate (10 mEq/L) in 0.9% saline. Our aim was to measure cefazolin and metronidazole concentrations over time in subcutaneous tumescent interstitial fluid (TISF) after TAAD, in serum after TAAD and after intravenous antibiotic delivery (IVAD). We hypothesize that the pharmacokinetic/pharmacodynamic profiles of TAAD + IVAD are superior to IVAD alone for the prevention of surgical site infections and biofilms.

METHODS

Concentrations of cefazolin and metronidazole in TISF and serum following TAAD and in serum following IVAD were compared in 5 female volunteers. Subjects received cefazolin or cefazolin plus metronidazole by IVAD alone and by TAAD alone. One subject also received concomitant IVAD and TAAD of these 2 antibiotics. Sequential samples of serum or subcutaneous TISF were assayed for antibiotic concentration.

RESULTS

Cefazolin (1 g) by TAAD resulted in an area under the curve of the concentration-time profile and a maximum concentration (Cmax) in subcutaneous tissue that were 16.5 and 5.6 times greater than in serum following 1 g by IVAD. Metronidazole (500 mg) by TAAD resulted in an area under the curve and Cmax that were 8.1 and 24.7 times greater in TISF, than in serum after 500 mg by intravenous delivery. IVAD + TAAD resulted in superior antibiotic concentrations to IVAD alone.

CONCLUSIONS

TAAD + IVAD produced superior antibiotic bioavailability in both subcutaneous interstitial fluid and serum compared with IVAD alone. There was no evidence that TAAD of cefazolin and metronidazole poses a significant risk of harm to patients.

Estimated Maximal Safe Dosages of Tumescent Lidocaine

Supplemental Digital Content is available in the text.

Published ahead of print February 18, 2016

BACKGROUND:

Tumescent lidocaine anesthesia consists of subcutaneous injection of relatively large volumes (up to 4 L or more) of dilute lidocaine (≤1 g/L) and epinephrine (≤1 mg/L). Although tumescent lidocaine anesthesia is used for an increasing variety of surgical procedures, the maximum safe dosage is unknown. Our primary aim in this study was to measure serum lidocaine concentrations after subcutaneous administration of tumescent lidocaine with and without liposuction. Our hypotheses were that even with large doses (i.e., >30 mg/kg), serum lidocaine concentrations would be below levels associated with mild toxicity and that the concentration-time profile would be lower after liposuction than without liposuction.

METHODS:

Volunteers participated in 1 to 2 infiltration studies without liposuction and then one study with tumescent liposuction totally by local anesthesia. Serum lidocaine concentrations were measured at 0, 2, 4, 6, 8, 10, 12, 14, 16, 18, and 24 hours after each tumescent lidocaine infiltration. Area under the curve (AUC∞) of the serum lidocaine concentration-time profiles and peak serum lidocaine concentrations (Cmax) were determined with and without liposuction. For any given milligram per kilogram dosage, the probability that Cmax >6 μg/mL, the threshold for mild lidocaine toxicity was estimated using tolerance interval analysis.

RESULTS:

In 41 tumescent infiltration procedures among 14 volunteer subjects, tumescent lidocaine dosages ranged from 19.2 to 52 mg/kg. Measured serum lidocaine concentrations were all <6 μg/mL over the 24-hour study period. AUC∞s with liposuction were significantly less than those without liposuction (P = 0.001). The estimated risk of lidocaine toxicity without liposuction at a dose of 28 mg/kg and with liposuction at a dose of 45 mg/kg was ≤1 per 2000.

CONCLUSIONS:

Preliminary estimates for maximum safe dosages of tumescent lidocaine are 28 mg/kg without liposuction and 45 mg/kg with liposuction. As a result of delayed systemic absorption, these dosages yield serum lidocaine concentrations below levels associated with mild toxicity and are a nonsignificant risk of harm to patients.

Reduction of pain via platelet-rich plasma in split-thickness skin graft donor sites: a series of matched pairs

In the past decade, autologous platelet-rich plasma (PRP) therapy has seen increasingly widespread integration into medical specialties. PRP application is known to accelerate wound epithelialization rates, and may also reduce postoperative wound site pain. Recently, we observed an increase in patient satisfaction following PRP gel (Angel, Cytomedix, Rockville, MD) application to split-thickness skin graft (STSG) donor sites. We assessed all patients known to our university-based hospital service who underwent multiple STSGs up to the year 2014, with at least one treated with topical PRP. Based on these criteria, five patients aged 48.4±17.6 (80% male) were identified who could serve as their own control, with mean time of 4.4±5.1 years between operations. In both therapies, initial dressing changes occurred on postoperative day (POD) 7, with donor site pain measured by Likert visual pain scale. Paired t-tests compared the size and thickness of harvested skin graft and patient pain level, and STSG thickness and surface area were comparable between control and PRP interventions (p>0.05 for all). Donor site pain was reduced from an average of 7.2 (±2.6) to 3 (±3.7), an average reduction in pain of 4.2 (standard error 1.1, p=0.0098) following PRP use. Based on these results, the authors suggest PRP as a beneficial adjunct for reducing donor site pain following STSG harvest.

Local anesthetics for skin grafting and local flaps

In plastic surgery, there are many procedures that can be performed using local instead of general anesthesia. Not only can this help mitigate health care costs, but precious operating-room resources can also be directed to areas of greater need. Common procedures that can be performed under local anesthetics include skin grafts and local flaps. However, as not all patients are suitable for local anesthesia, careful patient selection is necessary to maintain the standard of care. This article describes the detailed surgical approach to using local anesthetics for skin grafts and local flaps.