Therapeutic outcome of CT-guided radiofrequency ablation in patients with osteoid osteoma.

OBJECTIVE: To assess the long-term outcome of computed tomography-guided radiofrequency ablation (CT-guided RFA) in patients with suspected osteoid osteoma (OO). MATERIALS AND METHODS: Single-center retrospective study. Patients with clinical suspicion and imaging diagnosis of osteoid osteoma were treated by CT-guided RFA using the same device with either a 7- or 10-mm active tip electrode. Specific precautions were applied in case of articular or spinal OO. Patients were contacted by phone to evaluate the long-term outcome in terms of pain, ability to perform daily activities (including sports), and long-term complications. Success was defined as the absence of residual pain and ability to perform daily activities normally. RESULTS: From 2008 to 2015, 126 patients were treated by CT-guided RFA for OO in our institution. Mean patient age was 26.1 years (SD = 11, range 1-53); mean delay to diagnosis was 16.9 months (SD = 15.2, range 1-120). Among patients who answered the follow-up call (n = 88), the overall success rate was 94.3%: 79/88 (89.8%) had primary success of the procedure, and 4/88 (4.5%) had a secondary success (repeat-RFA after pain recurrence). Mean follow-up time was 34.6 months (SD = 24.7, range 3-90). Few complications occurred: two mild reversible peripheral nerve injuries, one brachial plexus neuropathy, one broken electrode tip fragment, and one muscular hematoma. CONCLUSION: Osteoid osteoma can be effectively and safely treated by CT-guided RFA using the presented ablation protocol. Beneficial effects of the treatment persist at long-term follow-up.

[Pharmacokinetic evaluation of linezolid in patients with major thermal injuries]. / Pharmacocinétique du linézolide chez des patients souffrant de brûlures sévères.

The aims of this multicentre open-label study was to evaluate the pharmacokinetics of linezolid in patients with burn injury above 20 % BSA and to compare them with healthy volunteers, matched in age, sex and weight. After a single 600 mg IV dose of linezolid, multiple blood and urine samples were taken from subjects, in order to determine linezolid concentrations, using a HPLC assay. C(max) and volume of distribution at steady state were not different between the two groups. Values describing clearance were altered in burns, leading to a reduction by half in AUC in these patients (42.5 versus 98.1 mghL(-1)). The enhancement of clearance was due to which of non renal clearance (323+/-191 versus 80.4+/-27.5 mLmin(-1)). We conclude that pharmacokinetics of linezolid are altered in burn patients, in a magnitude sufficient that linezolid concentration may be subtherapeutic in some patients and we suggest that the dosage interval may need to be decreased in this patient population.

Human skin allografts as a useful adjunct in the treatment of purpura fulminans.

OBJECTIVE: The aim of this report is to discuss the role of human skin allografts in surgical coverage procedures for patients with purpura fulminans. METHOD: We describe cases of purpura fulminans in three adults and one infant treated at our burns unit between October 2006 and January 2008. RESULTS: The application of cryopreserved human skin allografts allowed us to obtain immediate wound closure after necrosis excision and enabled our team to subsequently perform autografts on favourable graft recipient sites. CONCLUSION: Recourse to human skin allografts must be considered a pertinent therapeutic option in patients with purpura fulminans.

Pharmacokinetic evaluation of linezolid in patients with major thermal injuries.

AIMS: To evaluate the pharmacokinetics of linezolid following its administration in patients with major thermal injuries and in a group of healthy volunteers. METHODS: In an open-label, multicentre design with two parallel groups, a group of patients with major thermal injuries (>20% body area) and a group of age-, sex- and weight-matched healthy volunteers, subjects received a single 600 mg intravenous dose of linezolid. Serial blood and urine collections were made and the concentrations of linezolid in these samples were determined by HPLC. Non-compartmental analyses were used to describe the pharmacokinetic disposition of linezolid. RESULTS: C(max) concentrations and the volume of distribution at steady state (V(ss)) were not statistically different (P > 0.05) between the two groups of subjects. In contrast, values describing clearance [elimination rate constant (k(el)), t(1/2) and mean residence time (MRT)] were significantly different (P < 0.05) in patients with thermal injuries compared with volunteers, which lead to an approximate reduction by half in AUC(0-infinity) from 98.1 mg.h/L (volunteers) to 42.5 mg.h/L (patients). Although renal clearance was similar in the two groups (24.7 +/- 23 versus 30.6 +/- 14.3 mL/min; P = 0.156), non-renal clearance was substantially increased (323 +/- 191 versus 80.4 +/- 27.5 mL/min) in the patients with thermal injuries, though this difference did not achieve statistical significance (P = 0.063). CONCLUSIONS: The pharmacokinetics of linezolid are altered in patients with major thermal injuries, mainly as a result of increased non-renal clearance. These changes are of sufficient magnitude that linezolid concentrations may be sub-therapeutic in some patients and we suggest that the dosage interval may need to be decreased in this patient population.

Effects of low flow on pulmonary vascular flow-pressure curves and pulmonary vascular impedance.

OBJECTIVE: Flow-pressure curves and vascular impedance are commonly used to investigate pulmonary circulation, but they may be affected at low flow by reflex neurohumoral activation. We therefore investigated the mechanical effects and the reflex effects of decreased flow on pulmonary vascular resistance and impedance. METHODS: In ten anaesthetized dogs, we compared flow-pressure curves generated in less than 10 s to prevent sympathetic activation (fast curves), or generated over 20-30 min to allow neurohumoral equilibration (slow curves), in hyperoxia (inspired oxygen, 40%) and in hypoxia (inspired oxygen, 10%), before and after adrenergic blockade by phentolamine and propranolol. Resistance was assessed from the flow-pressure relationship. Impedance was computed from instantaneous flow and pressure obtained with an ultrasonic flowmeter and a micromanometer-tipped catheter. RESULTS: At baseline, fast flow-pressure curves were steeper and had a lower pressure intercept. Transient low flow did not affect heart rate or pulmonary arterial elastance. Sustained low flow increased heart rate, resistance and elastance, suggesting baroreceptor-induced sympathetic stimulation. After adrenergic blockade, no difference persisted between effects of transient and sustained low flow. In hypoxia, slow and fast flow-pressure curves were similar. Hypoxia increased heart rate and resistance but did not decrease elastance, suggesting chemoreceptor-induced sympathetic stimulation. In hypoxia, differences between transient and sustained low flow were no longer significant, and were completely suppressed by adrenergic blockade. In two additional dogs, epinephrine infusion increased pulmonary vascular resistance and elastance. CONCLUSIONS: We conclude that (1) compared to transient low flow, sustained low flow is associated with increases in distal resistance and proximal elastance due to sympathetic stimulation and (2) these differences between the effects of transient and sustained low flow do not persist in hypoxia, because of an already present chemoreceptor-induced sympathetic stimulation.

PCC-FISH in skin fibroblasts for local dose assessment: biodosimetric analysis of a victim of the Georgian radiological accident.

We propose a new method of biodosimetry that could be applied in cases of localized irradiation. The approach is based on excess chromosome segments determination by the PCC-FISH technique in fibroblasts isolated from skin biopsy. Typically, 0 to 10 Gy ex vivo gamma-irradiated human skin biopsies were dissociated and fibroblasts were isolated and grown for several days. Cells next underwent PCC-FISH painting of whole chromosome 4, and the number of excess chromosome segments per metaphase was determined. An ex vivo reference curve correlating the number of excess chromosome segments per metaphase to the radiation dose was established and used to assess the dose delivered to the skin of one of the victims of the radiological accident that occurred at Lia in Georgia in December 2001. Specifically, the victim suffering from moist desquamation underwent skin excision in Hospital Percy (France). Measurement of excess chromosome segments per metaphase was done in fibroblasts isolated and grown from removed wounded skin and subsequent conversion to radiation doses was performed. The radiation dose map obtained was shown to be in accordance with clinical data and physical dosimetry as well as with conventional biodosimetry. These results demonstrated that PCC-FISH painting applied to skin fibroblasts may be a suitable technique for dose estimation. To assess its worth, this approach needs to be extended to future accidents involving localized radiation exposure.

Cultured epithelial autografts in extensive burn coverage of severely traumatized patients: a five year single-center experience with 30 patients.

OBJECTIVE: We report recent five-year experience in a large, single center series of severely burned and otherwise traumatized patients given cultured epithelial autografts (CEA) from a single commercial laboratory. SUMMARY BACKGROUND DATA: Initial optimism over CEA application has been tempered by subsequent reports asserting that this modality is unreliable and expensive. Discussion continues over its clinical role. METHODS: From 1991 to 1996, CEA were applied to a mean 37+/-17% of total body surface area (TBSA) of 30 patients. These patients had 78+/-10% average burn size, 65+/-16% average third-degree burn size, 90% prevalence of endoscopically confirmed inhalation injury and 37% prevalence of other serious conditions. RESULTS: CEA achieved permanent coverage of a mean 26+/-15% of TBSA, an area greater than that covered by conventional autografts (a mean 25+/-10% of TBSA). Survival was 90% in these severely burned and otherwise traumatized patients. Final CEA take was a mean 69+/-23%. In subset analyses, only younger age was significantly associated with better CEA take (p = 0.0001 in univariate analysis, p<0.04 in multivariate analysis, Student's t-test). CONCLUSIONS: Epicel CEA successfully provided extensive, permanent burn coverage in severely traumatized patients, proving an important adjunct to achievement of a high survival rate in a patient population whose prognosis previously had been poor. In our experience CEA appear to have a very high beneficial value in the management of bur ns >60% TBSA. In some cases studied it is very likely that CEA was a life-saving treatment.

Initial general management and surgery of six extensively burned children treated with cultured epidermal autografts.

PURPOSE: The aim of this study was to document the surgical and intensive care methods used in six extensively burned children (EBC), ie, total body surface area (TBSA) burned over 70% or TBSA with deep burns over 60%, treated with cultured epidermal autografts (CEA). METHODS: Six EBC, with a mean age of 7.5 years (range, 2.5 to 12) received CEA. Their mean TBSA burned was 82% (range, 70-94) with 74% (range, 60-90) of TBSA with deep burns. All sustained flame burns and inhalation injuries. RESULTS: The survival rate was six of six. The average initial and final engraftment rates of CEA were, respectively, 79% (range, 70 to 95) and 84% (range, 72 to 100). CEA definitively covered 45% (range, 18 to 57) of TBSA for a mean cost per child of $80,000 (range, 55,000 to 110,000). CONCLUSION: Even if CEA are expensive, such engraftment rates and survival ratio results make them an excellent alternative wound covering method for EBC when donor sites for widely meshed autografts are exhausted.

[Ambulatory treatment of burns in children]. / Traitement ambulatoire des brûlures de l'enfant.

A majority of burns in children may have an ambulatory management for which the paediatrician has an important role. He must assess the severity of the burn by quoting extent, depth and localization of the burn injuries and then send the most severe to a specialized burn centre. The circumstances and the social situation are important in the decision of either hospitalization or ambulatory care, remembering that the burn may correspond to child abuse. The treatment consists of initially refreshing the burn to limit the extension, then washing the lesions using topical antiseptic soap, finally applying standard silver sulfadiazine cream. Local care is accomplished daily the first few days, then every three days to follow the healing and to keep a watch on possible complications such as infections or failure to heal, which must be treated in burn units. Pain relief treatment is an important part of the management.

[Right ventricular function: physiological and physiopathological features]. / Fonction ventriculaire droite: bases physiologiques et physiopathologiques.

Sinus and conus constitute the two cavities of the right ventricle. They are anatomically and functionally different. The sinus is a flow-generator and the conus a pressure-regulator. The coronary circulation of the right ventricle is provided by the right coronary artery and the left anterior descending artery. The right ventricle is perfused during systole and diastole. When oxygen demand increases, coronary arteries dilate and oxygen extraction rises. As for the left ventricle, right ventricular performance depends upon heart rate, rhythm, contractility and loading conditions. Ventricular interactions are very important for right ventricular function. Loading conditions and contractility of the left ventricle are of major significance for right ventricular performance. For the right ventricle, the end of the ejection is different from the end of the active contraction. The time between them allows to achieve ventricular emptying. This duration is linked to afterload. Presently, it is impossible to accurately and simply assess these conditions. Pressure and volume overloadings result in right ventricular failure. They are responsible for ventricular dilation and ischaemia with a decrease in cardiac output, generating a vicious circle. Treatment includes the removal of the cause, and the maintenance of systemic arterial pressure and biventricular contractility. It is difficult to assess the effects of intravenous vasodilators on right ventricular afterload.

[Objectives, results and future prospects of burn treatment in 1997]. / Objectifs, résultats et perspectives du traitement des brûlés en 1997.

When burn injuries to the skin are extensive, delays in wound closure contribute to multiple organ failure because the availability of donor sites does not allow early and permanent coverage of excised wounds. From 1991 to 1996, 30 patients with a mean burn size of 78% total body surface area (65% full-thickness) underwent skin grafting with autologous cultured epidermis (AEC) performed in the labs of Genzyme Tissue Repair Company. Twenty three were adults and seven children under 15 (mean age 29, range 2.5 to 70); 27 suffered inhalation injury; 3 presented with multiple trauma and 2 with blast injury. As soon as possible wound beds were excised and temporarily covered with allografts or with sandwich or meshed autografts; the mean surface covered with autografts was 28 +/- 12%. Keratinocytes grafts were applied to a mean of 37 +/- 16.5%, an average of 210 grafts of 25 to 30 cm2. Three patients died respectively at day 67, 81 and 90. At time of gaze backing removal, the mean percentage of culture engraftment was 69% (range 25 to 95); this engraftment was higher for children (74%) and very bad above 60 (25%). The mean length of hospitalisation was 114 +/- 30 days. The definitive coverage by AEC was evaluated through the percentage of secondary autografted area: 10 +/- 9.5% (range 0 to 46). The average cost by patient was 98,500$ or 16$ by cm2 of culture. The weakness of epithelialisation makes essential a dermal support to the keratinocytes cultures, allodermis is now currently used, perhaps the new skin substitutes will give the ideal missing piece.

[Subxiphoid pericardiostomy and pericardioscopy. Value and indications apropos of a series of 25 cases]. / Péricardotomie et péricardoscopie sous-xiphoïdiennes. Intérêt et indications à propos d'une série de 25 cas.

An experience of 25 subxiphoid pericardial windows with pericardioscopy in eleven cases is reviewed and presented. The operative indications in pericardial effusions result from hemodynamic compromise or from the need for etiologic criteria. Validated in its technical simplicity, its safety, its etiologic findings, its efficacy on immediate and delayed no recurrence of pericardial effusion, the low rate of late constrictive changes, this operative procedure is worth listing in the therapeutic know-how of a general surgeon. Indications in patients with suspected traumatic pericardial tamponade by chest wound are related.

Effects of candidaemia on outcome of burns.

AIM: To evaluate the diversity and antifungal susceptibilities of Candida isolates from wounds and blood of burn victims, and the associated mortality rates compared with those of controls without candidaemia. METHODS: We performed a nested case-control study within a database of clinical data for all patients admitted to our burn unit from January 2001 to December 2005. Each candidaemic patient was compared with two matched controls. Bloodstream cultures were performed if the core temperature was >39 degrees C, and three sites were cultured weekly for fungal identification (burn wound, pharynx, urinary tract). RESULTS: At least one episode of candidaemia was diagnosed among 20 of 851 persons admitted during the study period. Isolates in bloodstream infection were Candida albicans (65%), C. parapsilosis (25%) and C. tropicalis (10%). The median time between admission and onset of candidaemia was greater with C. albicans infection (42.6+/-31 days) than with infection by other yeasts (18+/-12 days). Candidaemia was associated with more extensive burn and longer duration of hospital stay but with similar mortality, compared with controls. CONCLUSION: Candidaemia in burn cases is mostly due to fluconazole-susceptible C. albicans and is not associated with increased mortality.

[Inflammatory reaction and infection in severe burns]. / Réaction inflammatoire et infection chez le brûlé grave.

Major burn injury is a lesion where the inflammatory reaction is exported to the whole body. After a short time of hemodynamic changes, this inflammation is kept by necrotic tissues, persistence of an opened wound, and by the pulmonary and gut reactions. When infection starts, it becomes difficult to distinguish its symptoms among the inflammatory signals. The main point of the care of burn patient consists in trying to control this reaction and the immuno-depression it leads to: early excision and grafts, early enteral nutrition, perfect nursing care. There is no specific medical treatment of this state. The antibiotic use must be well weighed up. Infection is often the trigger of the multiple organ dysfunction which is the way the burn patient dies but is not mandatory.

Sub-MAC concentrations of desflurane do not inhibit hypoxic pulmonary vasoconstriction in anesthetized piglets.

PURPOSE: In vitro, halogenated agents reduce the pulmonary vasoconstrictor response to alveolar hypoxia in isolated perfused lungs. However, studies in intact animals have been less convincing. The aim of the present study was to assess the effect of sub-MAC concentrations of desflurane on hypoxic pulmonary vasoconstriction (HPV) in anesthetized piglets using the pressure/cardiac output relationship (P/Q). METHODS: Eleven large white piglets were anesthetized and ventilated mechanically, alternatively in hyperoxia (FIO2=0.4) and in hypoxia (FIO2=0.12). Multipoint plots of pulmonary arterial pressure (PAP), or differences between PAP and left atrial pressure (LAP) against Q were generated by gradual inflation of a balloon advanced into the inferior vena cava. P/Q relationships were established in hyperoxia and in hypoxia at baseline, and then with gradual concentrations of desflurane. RESULTS: In hypoxia, pressure gradients (PAP-LAP) increased significantly at every level of Q, demonstrating active pulmonary vasoconstriction. Desflurane did not affect these P/Q relationships either in hyperoxia, or in hypoxia, when compared with baseline. CONCLUSION: Desflurane at a clinically relevant dose has no significant effect on HPV in anesthetized piglets.