The totality of burn care

The overall improvement in mortality following severe burns has dramatically increased in the last half century with enhanced methods of resuscitation, treatment of inhalation injury, control of infection, early wound excision and novel methods of skin resurfacing. Although burn care begins at the onset of injury, reconstruction and rehabilitation feature highly throughout the various stages of treatment. Ultimately, we will have achieved little if the patient cannot be integrated back into society. For descriptive purposes burn care has been considered chronologically under the following headings: (1) First Two Minutes (Prehospital Care/First Aid), (2) First Two Hours (Emergency Room care), (3) First two days (resuscitation), (4) First Two Weeks (surgical excision and grafting), (5) First Two Months (rehabilitation and psychology), (6) First Two Years (reconstruction).

Noise levels in a burn intensive care unit

INTRODUCTION

Increased noise levels in hospitals, critical care units, and peri-operative areas have been associated with higher levels of sleep deprivation and patient stress. The World Health Organization (WHO) guidelines stipulate a limit of 35 decibels (dB(A)) equivalent continuous sound level (LEq) during the day and 30 dB(A) LEq at night in patients' rooms. To date, no quantitative studies of noise levels have been performed in burn units. The objective of this study was to quantify noise levels in a burn critical care unit to ascertain compliance with guidelines in order to minimize this potential insult.

METHODS

An A-weighted sound pressure level meter was used to measure the ambient noise levels in a burn intensive care unit. Maximum and minimum sound pressure levels were measured at 30-min intervals on 10 days over a 1 month period. Measurements were obtained during shift changes and random times during the day and night-time. Descriptive statistical analyses were performed, to calculate means and standard deviations. Noise measurements at specified times were compared using analysis of variance (ANOVA).

RESULTS

Mean dB(A) LEq values for shift changes, day, and night-time were 65.9 ± 2.8, 65.7 ± 2.6, and 60.9 ± 5.2 dB(A), respectively. There was no significant difference in dB(A)(max) or dB(A)(min) between shift changes, day or night-time (p>0.05). However, night-time minimum values were consistently lower. There was no significant difference between sound pressure level (SPL) inside and outside patients' rooms (p>0.05) at any time.

CONCLUSIONS

Irrespective of time or location, the mean dB(A) LEq in the burn unit was significantly greater than World Health Organization (WHO), National Institute for Occupational Safety and Health (NIOSH), and the Environmental Protection Agency (EPA) recommendations. Guidelines for decreasing noise exposure are necessary to reduce potential negative effects on patients, visitors, and staff.

From cholera to burns: a role for oral rehydration therapy

According to the practice guidelines of the American Bum Association on burn shock resuscitation, intravenous (i.v.) fluid therapy is the standard of care for the replacement of fluid and electrolyte losses in burn injury of > or = 20% of the total body surface area. However, in mass burn casualties, i.v. fluid resuscitation may be delayed or unavailable. Oral rehydration therapy (ORT), which has been shown to be highly effective in the treatment of dehydration in epidemics of cholera, could be an alternate way to replace fluid losses in burns. A prospective case series of three patients was carried out as an initial step to establish whether oral Ceralyte 90 could replace fluid losses requiring i.v. fluid therapy in thermal injury. The requirement of the continuing i.v. fluid therapy was reduced by an average of 58% in the first 24 hours after the injury (range 37-78%). ORT may be a feasible alternative to i.v. fluid therapy in the resuscitation of burns. It could also potentially save many lives in mass casualty situations or in resource-poor settings where i.v. fluid therapy is not immediately available. Further studies are needed to assess the efficacy of this treatment and to determine whether the present formulations of ORT for cholera need modification.

Current Insights into the role of HIF-1 in cutaneous wound healing

Hypoxia Inducible Factor-1 (HIF-1) is considered the major coordinator of the cellular adaptive response to hypoxia. Over recent years, its activity in the context of wound healing has been the object of increasing investigation. On the molecular level, HIF-1 transcriptional target products have been shown to regulate the process of endothelial cell survival, migration and proliferation (VEGF, ANGPT-1, ANGPT-2, ANGPT-4, FGF-2, PlGF, PDGF-B, RGC-32), vascular smooth muscle cell migration and proliferation (FGF-2, EGF, PDGF, thrombospondin) and mobilization of Circulating Angiogenic Cells to the periphery (SFD-1/CXCR4). Studies on the effect of HIF-1 on the expression and activity of extracellular cell matrix modifying enzymes, such as MMPs and prolidase, have been conducted in the context of tumor angiogenesis and metastasis, and have resulted in controversial findings. A growing body of evidence suggests that HIF-1 also affects reepithelialization of the wound bed, through increasing keratinocyte migration, but decreasing their proliferation. Diminished HIF-1 levels and activity have been documented in conditions of impaired wound healing, such as wound healing in aged and in diabetic mice. The increasing number of studies on the role of HIF-1 in wound healing, apart from answering certain questions, has also raised an equal number, if not more. Clarifying the topics that still remain unclear could introduce a new era of HIF-1 targeted management of a wide range of problematic wounds.

Hypoxia and hypoxia-inducible factor in the burn wound

The importance of hypoxia-inducible factor (HIF) in promoting angiogenesis and vasculogenesis during wound healing has been demonstrated. It is widely accepted that HIF activity can be promoted by many factors, including hypoxia in the wound or cytokines from inflammatory cells infiltrating the wound. However, there has not been a systematic exploration of the relationship between HIF activity and hypoxia in the burn wound. The location of the hypoxic tissue has not been clearly delineated. The time course of the appearance of hypoxia and the increased activity of HIF and appearance of HIF's downstream transcription products has not been described. The aim of this study was to utilize pimonidazole, a specific tissue hypoxia marker, to characterize the spatial and temporal course of hypoxia in a murine burn model and correlate this with the appearance of HIF-1α and its important angiogenic and vasculogenic transcription products vascular endothelial growth factor and SDF-1. Hypoxia was found in the healing margin of burn wounds beginning at 48 hours after burn and peaking at day 3 after burn. On sequential sections of the same tissue block, positive staining of HIF-1α, SDF-1, and vascular endothelial growth factor all occurred at the leading margin of the healing area and peaked at day 3, as did hypoxia. Immunohistochemical analysis was used to explore the characteristics of the hypoxic region of the wound. The localization of hypoxia was found to be related to cell growth and migration, but not to proliferation or inflammatory infiltration.

Alterations in content and localization of defensins in rat ileum and jejunum following ischemia-reperfusion. Specific peptides, in specific places, for specific jobs?

OBJECTIVE

To determine alterations in quantities and distributions of natural antimicrobials following ischemia-reperfusion injury. We hypothesized that these compounds would be upregulated in areas of small intestine where changes in permeability and cellular disruption were likely and where protective mechanisms would be initiated.

METHODS

Rats with ischemia-reperfusion underwent superior mesenteric artery clamping and reperfusion. Shams were subjected to laparotomy but no clamping. Ileum and jejunum were harvested and sectioned, and subjected to fluorescence deconvolution microscopy for determinations of content and localization of rat beta defensins, 1, 2, 3; rat neutrophil protein-1; and cathelicidin LL-37. Modeling was performed to determine cellular location of antimicrobials.

RESULTS

Ischemia-reperfusion increased neutrophil defensin alpha (RNP-1) in jejunum; rat beta defensin 1 was increased 2-fold in ileal mucosa and slightly reduced in jejunal mucosa; rat beta defensin 2 was reduced by ischemia-reperfusion in ileum, but slightly increased in jejunum; rat beta defensin 3 was concentrated in the muscularis externa and myenteric plexus of the jejunum; ischemia-reperfusion did not alter cathelicidin LL-37 content in the small intestine, although a greater concentration was seen in jejunum compared with ileum.

CONCLUSION

Ischemia-reperfusion injury caused changes in antimicrobial content in defined areas, and these different regulations might reflect the specific roles of jejunum versus ileum.