Intradermal methylene blue administration on the progression of burn injuries

OBJECTIVE

A burn injury has two defined areas: central necrosis and an adjacent area of ischaemia, which may or may not progress to necrosis. The concentration of nitric oxide (NO) increases after burn injury and may originate from potent oxidising agents. Methylene blue (MB) may act as an antioxidant and is supposed to reduce burn progression. This investigation was carried out to evaluate the effects of intradermal MB on necrosis progression in burns.

METHODS

Full-thickness burn injuries were performed by applying a heated metal comb on the shaved back of male Wistar rats. The animals were divided into three groups: Control (C, n=7); MB (2mg/kg) one hour after burn injury (MB1h, n=11); and MB (2mg/kg) six hours after burn injury (MB6h, n=8). After seven days the lesions were photographed for visual assessment of burn necrosis; full-thickness cuts of lesions were dyed with Masson and Giemsa for microscopic histopathology; and tissue fragments of unburned interspaces were processed for chemiluminescence with nitrite/nitrate (NOX) and malondialdehyde (MDA) as oxidative stress markers.

RESULTS

No statistically significant differences between groups were observed during visual analysis and NOX dosage. However, in microscopic analysis, the MB1h and MB6h groups showed smaller areas of necrosis, less inflammatory infiltration, and a more significant extension of interspaces. Furthermore, the dosage of MDA revealed that the MB1h group showed lower values when compared with the control group (p=0.001).

CONCLUSIONS

The study provided good evidence that MB intradermal injection can reduce necrosis progression in ischaemic perilesional areas and suggests an alternative to treating burns.

Curbing inflammation in burn patients

Patients who suffer from severe burns develop metabolic imbalances and systemic inflammatory response syndrome (SIRS) which can result in multiple organ failure and death. Research aimed at reducing the inflammatory process has yielded new insight into burn injury therapies. In this review, we discuss strategies used to curb inflammation in burn injuries and note that further studies with high quality evidence are necessary.

Reliability and validity of the Impact of Event Scale (IES): version for Brazilian burn victims

AIMS

The aims of this study were to assess the internal reliability (internal consistency), construct validity, sensitivity and ceiling and floor effects of the Brazilian-Portuguese version of the Impact of Event Scale (IES).

DESIGN

Methodological research design.

METHOD

The Brazilian-Portuguese version of the IES was applied to a group of 91 burned patients at three times: the first week after the burn injury (time one), between the fourth and the sixth months (time two) and between the ninth and the 12th months (time three). The internal consistency, construct validity (convergent and dimensionality), sensitivity and ceiling and floor effects were tested.

RESULTS

Cronbach's alpha coefficients showed high internal consistency for the total scale (0·87) and for the domains intrusive thoughts (0·87) and avoidance responses (0·76). During the hospitalisation (time one), the scale showed low and positive correlations with pain measures immediately before (r=0·22; p<0·05) and immediately after baths and dressings (r=0·21; p<0·05). After the discharge, we found strong and negative correlations with self-esteem (r=-0·52; p<0·01), strong and positive with depression (r=0·63; p<0·01) and low and negative with the Bodily pain (r=-0·24; p<0·05), Social functioning (r=-0·34; p<0·01) and Mental health (r=-0·27; p<0·05) domains of the SF-36 at time two. Regarding the sensitivity, no statistically significant differences were observed between mean scale scores according to burned body surface (p=0·21). The floor effect was observed in most of the IES items.

CONCLUSION

The adapted version of the scale showed to be reliable and valid to assess postburn reactions on the impact of the event in the group of patients under analysis.

RELEVANCE TO CLINICAL PRACTICE

The Impact of Event Scale can be used in research and clinical practice to assess nursing interventions aimed at decreasing stress during rehabilitation.

High-voltage electrical burn injuries: functional upper extremity assessment

High-voltage electric injuries have many manifestations, and an important complication is the damage of the central/peripheral nervous system. The purpose of this work was to assess the upper limb dysfunction in patients injured by high-voltage current. The evaluation consisted of analysis of patients' records, cutaneous-sensibility threshold, handgrip and pinch strength and a specific questionnaire about upper limb dysfunctions (DASH) in 18 subjects. All subjects were men; the average age at the time of the injury was 38 years. Of these, 72% changed job/retired after the injury. The current entrance was the hand in 94% and grounding in the lower limb in 78%. The average burned surface area (BSA) was 8.6%. The handgrip strength of the injured limb was reduced (p<0.05) and so also that of the three pinch types. The relationship between the handgrip strength and the DASH was statistically significant (p<0.001) as well as the relationship between the three pinch types (p<or=0.02) to the injured limb. The ability to perceive cutaneous touch/pressure was decreased in the burnt hand, principally in the median nerve area. These data indicate a reduction of the hand muscular strength and sensibility, reducing the function of the upper limb in patients who received high-voltage electrical shock.

Comparative study of isovolemic hemodilution with 3% albumin, dextran-40, and prophylactic enoxaparin (LMWH) on thrombus formation at venous microanastomosis in rats

The objective of the present investigation was to compare the effect of isovolemic hemodilution with 3% albumin, dextran-40, and enoxaparin on the prevention of thrombosis in femoral vein microanastomosis using an experimental model in rats. Forty male Wistar rats were allocated into four groups: group 1, control, thrombogenic model without previous treatment; group 2, hemodiluted, thrombogenic model with previous hemodilution; group 3, dextran-40, thrombogenic model with dextran infusion (10 ml/kg), and group 4, enoxaparin, thrombogenic model with administration of enoxaparin (0.5 mg/kg/day). Hemostatic parameters, hematologic examinations, patency of anastomosis, and histopathological examination were evaluated. The hemostatic parameters were similar in the four groups studied. Group hemodiluted, dextran-40, and enoxaparin showed significantly reduced number of red blood cells and platelets as compared with the control group. The hemodilution significantly increased the patency rates of the vein at 20 min and 48 h. Dextran-40 and enoxaparin improved the patency of the vein only at 20 min, but failed to show a significant increase in the final patency at 48 h. After 48 h, the rate of venous thrombosis, as evaluated microscopically, was significantly decreased in hemodiluted animals (1/8) as compared with controls (10/10); in rats treated with dextran-40 (7/10) and enoxaparin (5/10) the rate of venous thrombosis was significantly higher as compared with rats of the group hemodiluted. Based on these observations, it can be concluded that hemodilution with albumin 3% was a safe and more adequate procedure than the use of the schemes of administration of dextran-40 and enoxaparin used in this study to prevent thrombus formation at femoral vein microanastomosis in rats. Since hemodilution promotes reduction in blood viscosity and in erythrocyte and platelet aggregation as well as dilution of the coagulation factors themselves, its use could provide better microcirculatory blood perfusion, decreasing the risk of thrombosis, and making possible safer microsurgical procedures.

Effect of isovolemic hemodilution with 3% albumin on thrombus formation at venous microanastomosis in rats

The present investigation was undertaken to evaluate the effect of isovolemic hemodilution with 3% albumin per se on the prevention of microvascular venous thrombosis, using an experimental model in rats mimicking the thrombotic mechanisms similar to those in clinical situations. Male Wistar rats were allocated into two groups of 15 rats each: group 1, the nonhemodiluted group, consisted of animals submitted to microsurgical procedure to induce thrombosis without previous hemodilution; group 2, the hemodiluted group, consisted of animals submitted to microsurgical procedure to induce thrombosis with previous hemodilution. The histopathological examination clearly showed that the nonhemodiluted group presented well-defined venous thrombosis in the anastomoses in 9 animals, totally occlusive in 8, and mural in 1. In contrast, in the hemodiluted group none of the anastomoses presented venous thrombosis, except for the presence of nonadherent blood clots. The clinical analysis of the anastomoses' patency, as evaluated by the empty-full test, showed a significant reduction in rate of venous occlusion in the previously hemodiluted animals as compared with the nonhemodiluted animals 20 min after microsurgical anastomosis. Forty-eight hours after anastomosis, the rate of venous occlusion was 66.7% in the nonhemodiluted group and 33.3% in the hemodiluted group; even though no significant difference could be detected during this time, the patency of anastomoses tended to be greater in the hemodiluted group than that of controls. The rate of spontaneous recanalization after 48 h was identical in both groups (16.6%) in comparison with the rates observed 20 min after the surgical procedure. In summary, moderate isovolemic hemodilution with 3% albumin was effective in reducing the rate of venous microanastomosis occlusion in rats 20 min after the surgical procedure, tending to maintain the anastomoses' patency after 48 h. In addition, 48 h after the microsurgical procedure, the rate of venous thrombosis as evaluated microscopically was significantly lower in the hemodiluted animals as compared with nonhemodiluted control animals. This points out that hemodilution with albumin could be a safe and adequate procedure to prevent thrombus formation at venous microanastomosis.

Autogenous transplantation of impacted maxillary canines

The authors report on three patients who received four autogenous transplantations of impacted maxillary canines, relate the technique used, and discuss the advantages and disadvantages of this surgical procedure.