Biomedical subjects

Manuel Gomez

Publications and source records attributed to Manuel Gomez.

36 records · Page 2Linked to original sources

PubMed2002

Pheromone-based trapping of West Indian sugarcane weevil in a sugarcane plantation.

Attraction of Metamasius hemipterus (Oliver) to gallon and bamboo traps baited with insecticide-treated sugarcane, the male-produced pheromone, 4-methyl-5-nonanol, and 2-methyl-4-heptanol is more efficient if ethyl acetate is added. The optimal traps are ground-level gallon traps baited with insecticide-laced sugarcane, pheromone, and ethyl acetate. Capture rates of ground-level gallon traps are doubled by placing an insecticide-laced pad under the trap, but significantly decreased by placing the trap on a stick above ground. The efficiency of ground-level gallon traps is the same as ground level ramp traps. Mass-trapping M. hemipterus in newly planted sugarcane using ground level bamboo traps baited with insecticide-laced sugarcane and pheromone over six months revealed populations were low for the first two months, became maximum at five months, and declined thereafter. Capture rates of traps bordering newly planted and mature sugarcane were not significantly different from capture rates of traps in the interior of the plots. Capture rates of bamboo traps containing only insecticide-laced sugarcane and deployed at 30 traps/ha averaged 6 weevils/trap/week compared with 66 weevils/trap/week for traps additionally containing pheromone lures and deployed at 5 traps/ha. Capture rates for bamboo traps baited with insecticide-laced sugarcane and pheromone and deployed at 10 and 15 traps/ha were 43 and 38 weevils/trap/week, respectively. Total captures were higher in those plots with a higher density of insecticide-laden sugarcane and pheromone baited traps, and the differences were approximately proportional to trap density in the range of 5-15 traps/ha. Capture rates of traps containing insecticide-laced sugarcane and pheromone were always higher than of traps containing only insecticide-laced sugarcane, but in the first two months after planting the differences were much greater than in months 3-6 after planting.

Animals↗

PubMed2002

Role of the extracytoplasmic-function sigma factor sigma(H) in Mycobacterium tuberculosis global gene expression.

Like other bacterial species, Mycobacterium tuberculosis has multiple sigma (sigma) factors encoded in its genome. In previously published work, we and others have shown that mutations in some of these transcriptional activators render M. tuberculosis sensitive to various environmental stresses and, in some cases, cause attenuated virulence phenotypes. In this paper, we characterize a M. tuberculosis mutant lacking the ECF sigma factor sigma(H). This mutant was more sensitive than the wild type to heat shock and to various oxidative stresses, but did not show decreased ability to grow inside macrophages. Using quantitative reverse transcription-PCR and microarray technology, we have started to define the sigma(H) regulon and its involvement in the global regulation of the response to heat shock and the thiol-specific oxidizing agent diamide. We identified 48 genes whose expression increased after exposure of M. tuberculosis to diamide; out of these, 39 were not induced in the sigH mutant, showing their direct or indirect dependence on sigma(H). Some of these genes encode proteins whose predicted function is related to thiol metabolism, such as thioredoxin, thioredoxin reductase and enzymes involved in cysteine and molybdopterine biosynthesis. Other genes under sigma(H) control encode transcriptional regulators such as sigB, sigE, and sigH itself.

Animals↗

PubMed2002

An outbreak due to multiresistant Acinetobacter baumannii in a burn unit: risk factors for acquisition and management.

OBJECTIVES: To describe the investigation and management of an outbreak due to multiresistant Acinetobacter baumannii and to determine risk factors for acquisition of the organism. SETTING: A 14-bed regional burn unit in a Canadian tertiary-care teaching hospital. DESIGN: Case-control study with multivariate analysis of potential risk factors using logistic regression analysis. Surveillance cultures were obtained from the hospital environment, from noninfected patients, and from healthcare providers. RESULTS: A total of 31 (13%) of 247 patients with acute burn injuries acquired multiresistant A. baumannii between December 1998 and March 2000; 18 (58%) of the patients were infected. The organism was recovered from the hospital environment and the hands of healthcare providers. Significant risk factors for acquisition of multiresistant A. baumannii were receipt of blood products (odds ratio [OR], 10.8; 95% confidence interval [CI95], 3.4 to 34.4; P < .001); procedures performed in the hydrotherapy room (OR, 4.1; CI95, 1.3 to 13.1; P = .02); and increased duration of mechanical ventilation (OR, 1.1 per day; CI95, 1.0 to 1.1; P= .02). INTERVENTIONS: Improved compliance with hand hygiene, strict patient isolation, meticulous environmental cleaning, and temporary closure of the unit to new admissions. CONCLUSIONS: Acquisition of multiresistant A. baumannii was likely multifactorial, related to environmental contamination and contact with transiently colonized healthcare providers. Control measures addressing these potential sources of multiresistant A. baumannii were successful in terminating the outbreak. Ongoing surveillance and continued attention to hand hygiene and adequate environmental cleaning are essential to prevent recurrent outbreaks due to antibiotic-resistant bacteria in burn units.

Acinetobacter Infections↗

PubMed1997

BofC encodes a putative forespore regulator of the Bacillus subtilis sigma K checkpoint.

A mutation, bofC1, that restores sigma K activation in Bacillus subtilis strains unable to produce active sigma G has been identified. This mutation defines a new sporulation gene, bofC, that has been cloned and sequenced and encodes a 19 kDa protein. bofC is transcribed in the forespore by RNA polymerase associated with the transcription factors sigma F (E sigma F) and sigma G (E sigma G). BofC acts negatively on SpoIVB and the results described suggest that BofC regulates SpoIVB activity and its intercompartmental signalling role in the sigma K checkpoint.

Amino Acid Sequence↗

PubMedDate not supplied

Hypercapnic respiratory failure and partial upper airway obstruction during high frequency oscillatory ventilation in an adult burn patient.

PURPOSE: To present a case of severe hypercapnic respiratory failure in an adult burn patient and to describe our clinical problem solving approach during support with an unconventional mode of mechanical ventilation. CLINICAL FEATURES: A 19-yr-old male with smoke inhalation and flame burns to 50% total body surface area was admitted to the Ross Tilley Burn Centre. High frequency oscillatory ventilation (HFOV) was initiated on day three for treatment of severe hypoxemia. By day four, the patient met consensus criteria for acute respiratory distress syndrome. On day nine, alveolar ventilation was severely compromised and was characterized by hypercapnea (PaCO(2) 136 mmHg) and acidosis (pH 7.10). Attempts to improve CO(2) elimination by a decrease in the HFOV oscillatory frequency and an increase in the amplitude pressure failed. An intentional orotracheal tube cuff leak was also ineffective. A 6.0-mm nasotracheal tube was inserted into the supraglottic hypopharynx to palliate presumed expiratory upper airway obstruction. After nasotracheal tube placement, an intentional cuff leak of the orotracheal tube improved ventilation (PaCO(2) 81 mmHg) and relieved the acidosis (pH 7.30). The improvement in ventilation (with normal oxygen saturation) was sustained until the patient's death from multiple organ dysfunction four days later. CONCLUSION: During HFOV in burn patients, postresuscitation edema of the supraglottic upper airway may cause expiratory upper airway obstruction. The insertion of a nasotracheal tube, combined with an intentional orotracheal cuff leak may improve alveolar ventilation during HFOV in such patients.

Accidents, Traffic↗

PubMedDate not supplied

The effect of silicone gel sheets on perfusion of hypertrophic burn scars.

The mechanism of action of topical silicone gel sheets on hypertrophic scars is not well understood and their effect on the blood flow within hypertrophic scars has not been investigated. The purpose of this study was to examine whether application of silicone gel sheets produced any acute effects on blood flow in hypertrophic burn scars. Perfusion of hypertrophic scars and adjacent normal skin was measured using a laser Doppler with and without application of silicone gel sheets. Continuous measurements were made for 5 minutes before gel application, for 30 minutes during gel application and for 5 minutes following gel removal. Surface temperature of the scar was continuously monitored. An occupational therapist, blinded to the perfusion level, rated each scar using the Vancouver Scar Scale. Eighteen scars and adjacent control sites in sixteen adult burn patients (11 male, 5 female; mean age: 42 +/- 14 years) were evaluated. The mean scar age was 5.4 +/- 3.7 months. The mean Vancouver Scar Scale was 5.5 +/- 2.4. Hypertrophic scars demonstrated higher perfusion measurements at baseline compared to control areas (58.5 +/- 19.3 flux units vs 25.0 +/- 8.4 flux units; P < 0.001). Application of silicone sheeting gel did not significantly alter perfusion in either the hypertrophic scar or normal tissue from the baseline measurements. However, application of silicone gel sheeting did significantly increase the mean baseline surface temperature of the hypertrophic scar from 29 +/- 0.8 degrees C to 30.7 +/- 0.6 degrees C (P < 0.001). The mechanism of action of silicone gel sheeting probably does not involve an acute alteration in blood flow within the scar. However, surface temperature of the scar increased significantly following gel application, raising the possibility that temperature alteration is involved in the mechanism of action.

Adult↗

PubMedDate not supplied

How well does the Parkland formula estimate actual fluid resuscitation volumes?

We had anecdotally observed that fluid resuscitation volumes often exceed those estimated by the Parkland Formula in adults with isolated cutaneous burns. The purpose of this study was to compare estimated and actual fluid resuscitation volumes using the Parkland Formula. We performed a retrospective study of fluid resuscitation in patients with burns > or = 15% TBSA. Patients with inhalation injury, high voltage electrical injury, delayed resuscitation, or associated trauma were excluded. We studied 31 patients (mean age 51 +/- 20 years, mean TBSA burn 27 +/- 10%). The 24 hour resuscitation volume of 13 354 +/- 7386 ml (6.7 +/- 2.8 ml/kg/%TBSA) was significantly greater than predicted (P = 0.001) and exceeded estimated volume in 84% of the patients. The mean urine output in the first 24 hrs was 1.2 +/- 0.6 ml/kg/hr. After the first 8 hours of resuscitation, the infusion rate decreased by 34% in 16 patients (DCR group), while in 15 patients the rate increased by 47% (INCR group). Both the DCR and INCR groups received significantly more fluid than predicted, (5.6 +/- 2.1 ml/kg/%TBSA and 7.7 +/- 3.1 ml/kg/%TBSA respectively). The INCR patients had significantly larger full thickness burns (14 +/- 11% vs 3 +/- 6%, P < 0.001). Our findings reveal that despite its effectiveness, the Parkland Formula underestimated the volume requirements in most adults with isolated cutaneous burns, and especially in those with large full thickness burns.

Adult↗

PubMedDate not supplied

A prospective study on the implications of a base deficit during fluid resuscitation.

An excessive base deficit (BD) and elevated serum lactate are increasingly recognized as important markers of a malperfusion state during the resuscitation of thermally injured patients. In a previous retrospective study, we found that patients with a BD less than -6 mmol/l during fluid resuscitation developed more severe systemic inflammatory response syndrome (SIRS), more frequent acute respiratory distress syndrome (ARDS), and more severe multiple organ dysfunction syndrome (MODS). The object of this study was to reexamine prospectively the relationship between the BD during fluid resuscitation and the subsequent development of SIRS, ARDS, and MODS by undertaking a prospective observational study of a cohort of consecutive burn patients. Analysis was completed on 38 patients with a mean age of 39 +/- 17 years and a mean %TBSA burn of 36 +/- 15%. The mean BD in the first 24 hours was less than -6 mmol/l in five patients (BD24 < -6 group), and was greater than -6 mmol/L in 33 patients (BD24 > -6 group). Patients in both groups were resuscitated to nearly identical endpoints of urinary output (1.2 ml/kg/hr in the BD24 < -6 group vs 1.3 ml/kg/hr in the BD24 > -6 group). Patients in the BD24 < -6 group had a trend toward a greater number of SIRS signs on the first postburn day, had a significantly higher incidence of ARDS (P =.02), and had significantly more severe MODS (P <.001) than patients in the BD24 > -6 group. The results concur with those of our previous retrospective study. Despite resuscitation to an acceptable urinary output, some burn patients develop a more extreme BD and go on to experience more severe organ dysfunction than do patients who do not generate a BD. The effect of specific correction of the BD during fluid resuscitation is not known at this time.

Adult↗

PubMedDate not supplied

Changes in subjective vs objective burn scar assessment over time: does the patient agree with what we think?

It is not known whether objective measurements of burn scar quality reflect, or even bear any relationship to, the patient's opinion of their scar. The purpose of this study was to determine whether any correlation exists between the rehabilitation therapist's rating of the scar using the Vancouver Scar Scale (VSS) and the patient's subjective opinion of their scar. A total of 37 scars in 20 adult patients (mean age, 34 +/- 13 years; 30% female; mean %TBSA burn, 16 +/- 11%) were evaluated at 3.1 +/- 1.9 months after injury (early assessment). Patients were asked to rate their own scar (question 1) and to rate how they perceive other people view the scar (question 2). A visual analog scale (VAS) was used to score the answers to both questions. A burn occupational therapist who was blinded to the VAS scores performed a VSS rating of the scar. These evaluations were repeated 1.5 years after injury (late assessment). At the early assessment, there was no correlation between the VSS score and VAS scores for question 1 (r =.291) or question 2 (r =.371). At the late assessment, there was significant improvement in the VSS score and the VAS score for question 2. Also, a significant correlation developed between the VSS score and the VAS score for question 1 (r =.646, P =.003) but not between the VSS score and VAS score for question 2 (r =.099). The VSS measurement of the scar bears no relationship to the patient's opinion of their scar early after a burn injury. As the scar improves over time, the patient's opinion of their scar appears to improve and shows better correlation with the VSS rating. Conversely, the patient's impression of what others think of the scar continues to bear no relationship to the VSS rating, suggesting that scar acceptance by the patient is incomplete despite objective improvement in the quality of the scar. Although the VSS was never intended to measure a patient's opinion of their scar, these preliminary findings emphasize the necessity of including a patient-centered subjective component to routine scar monitoring and assessment.

Adult↗

PubMedDate not supplied

What are the acute cardiovascular effects of subcutaneous and topical epinephrine for hemostasis during burn surgery?

Although subcutaneous and topical epinephrine are widely used for hemostasis during burn surgery, the acute systemic cardiovascular effects of the epinephrine are neither well documented nor completely understood. The purpose of this work was to prospectively study the acute cardiovascular responses to epinephrine (epi) administered subcutaneously and topically during burn surgery. Consecutive patients who received subcutaneous and topical epi during burn surgery were monitored prior to the administration of epi, at 2-minute intervals during subcutaneous epi infiltration, and then after epi infiltration (during which time, topical epi was applied). This period of monitoring lasted up to 20 minutes and was referred to as an epinephrine event (EE). A total of 100 EEs from 38 operations in 24 patients (mean +/- SD: age 43 +/- 16 years, mean % TBSA burn 23 +/- 17%) were studied. The mean dose of subcutaneous epi was 30 +/- 30 microg/kg. Although all patients received topical epi, it was impossible to document the topical dose. There was no significant increase in heart rate from baseline, and no arrhythmias occurred. Mean arterial pressure (MAP) did acutely increase significantly by 17.0 +/- 14.1% from baseline (P =.009) and increased more than 10% from baseline in 64/100 EEs. However, the increase in MAP was independent of the dose of epi (r =.053). The increase in MAP was not clinically significant, did not require intervention, and did not appear to be related to the type of wound that received epi (donor site vs burn wound), or the depth of anesthesia, analgesia, or sedation. On the basis of these findings, the use of subcutaneous and topical epi appears to be safe and produces minimal acute cardiovascular effects.

Acute Disease↗

PubMedDate not supplied

Effective hand function assessment after burn injuries.

This study compared two methods of hand function assessment, the Michigan Hand Outcomes Questionnaire (MHQ) and the Test d'Evaluation des Membres Supérieurs des Personnes Agées (TEMPA) in 20 patients discharged from a regional adult burn center (1995-1999). Spearman's rank correlation coefficient analysis was used to compare the MHQ and TEMPA scores, with P <.05 considered significant. The MHQ revealed that 68% of patients reported hand function deterioration, mainly with the nondominant hand (65%). Activities of daily living (76%) and work (59%) were the most affected. According to the MHQ, patient satisfaction correlated with work performance (r =.66, P =.002), aesthetics (r =.64, P =.003), pain (r =.59, P =.008), and activities of daily living (r =.54, P =.017). The MHQ indicated more hand function deterioration than the TEMPA. There was a significant correlation between the MHQ and TEMPA total scores (r =.68, P =.001). This study supports using the MHQ to determine which patients would benefit from the more resource-consuming TEMPA.

Activities of Daily Living↗

PubMedDate not supplied

Intravenous immunoglobulin does not improve outcome in toxic epidermal necrolysis.

Intravenous Immunoglobulin (IVIG) has been proposed as a beneficial therapy for toxic epidermal necrolysis (TEN). However, this has been based on a limited amount of Class 5 evidence. To compare outcomes in TEN patients treated in our burn unit since 1999, when we began to use IVIG (IG group), with TEN patients treated between 1995 and 1999 who did not receive IVIG (control group). Retrospective cohort review of the records of all TEN patients admitted between April 5, 1995 and December 4, 2002. There were 16 patients in the IG group (age 53 +/- 21 years, with initial rash involving 65 +/- 29% TBSA) and 16 patients in the control group (age 52 +/- 20 years, with initial rash involving 65 +/- 27% TBSA). The IG group received 0.7 +/- 0.2 g/kg/day of IVIG for 4 +/- 1 days. There were no significant differences between the groups with respect to the length of stay, duration of mechanical ventilation, severity of systemic inflammatory response syndrome and multiple organ dysfunction syndrome, or the incidence of sepsis. Significant progression of the wound occurred in 13% of the IG patients and in 27% of control patients, whereas no wound progression was observed in 47% of the IG patients and in 18% of the control patients (P =.299). The time to healing did not differ between IG and control groups (11.2 +/- 3.6 vs 11.4 +/- 2.6 days, respectively). There was no significant difference in the mortality rate between the IG group (25%) and the control group (38%). There were no complications from IVIG aside from one case of hyponatremia from the hypotonic IVIG solution. Although there may have been a trend towards less severe wound progression in patients who received IVIG, this was not associated with any substantial improvement in outcome in our TEN patients. A prospective randomized study with a larger sample size is needed to confirm our findings.

Burn Units↗

PubMedDate not supplied

Effectiveness of a burn prevention campaign for older adults.

Older adults are involved in one fifth of burn injury admissions in the Province of Ontario Canada. Most burn injuries in this population occur at home while cooking, bathing, or smoking. The purpose of this study was to evaluate the effectiveness of an educational campaign to improve burn prevention knowledge in older adults of a major metropolitan city. Changes in participants' burn prevention knowledge were determined using standardized precampaign and postcampaign (4-6 weeks) surveys. Of 209 older adult participants, 126 (60.3%) completed the precampaign and postcampaign surveys. There was a significant increase (P <.05) in burn prevention knowledge postintervention. Age, education level, and living conditions did not influence the change in burn prevention knowledge. This burn prevention campaign for older adults was effective in improving burn prevention knowledge, but it remains unclear as to whether this will ultimately result in a change in burn prevention behavior.

Age Distribution↗

PubMedDate not supplied

Late outcomes in adult survivors of toxic epidermal necrolysis after treatment in a burn center.

Despite improved survival after burn center treatment for patients with toxic epidermal necrolysis (TEN), little is known about the overall long-term outcomes in these patients. In this work we sought to analyze late outcomes in survivors of TEN who were treated in our burn center. Subjects completed a questionnaire that included the RAND 36-Item Health Survey (SF-36) and the Dermatology Life Quality Index. Subjects were examined, when possible, and completed the Functional Independence Measure. Scores on the SF-36 were compared with age- and sex-matched National normative data. All results are presented as the mean +/- SD. Of 35 adults admitted with TEN between January 1, 1995, and January 6, 2003, 10 have died in hospital, 4 have died since discharge, and 8 have been lost to follow-up, leaving a study population of 13 subjects (age 45 +/- 18 years with initial %TBSA involvement 65 +/- 29). Follow-up occurred at 38 +/- 27 months after discharge. The most common ophthalmic problems were chronic photosensitivity (54%) and dry eyes (31%). The Dermatology Life Quality Index (maximum-worst score = 30) was 9 +/- 10. SF-36 scores were significantly lower than in the age- and sex-matched normal population across all domains except mental health. The Functional Independence Measure score (maximum-best score = 126) was 123 +/- 4. Survivors of TEN demonstrate a high level of independent function in activities of daily living, but numerous complications of TEN significantly impair their overall quality of life, emphasizing the need for long-term follow-up.

Activities of Daily Living↗

PubMedDate not supplied

Emotional implications of working in a burn unit.

Burnout is a syndrome that has been characterized by emotional exhaustion, depersonalization, and reduced personal accomplishment associated with chronic occupational stressors. The purpose of this study was to determine the prevalence of burnout in healthcare professionals involved in primary burn care and to gain an understanding of the stressors and pleasures they experience. A cross-sectional survey was administered between February and March 2004 to healthcare professionals working in the burn unit (BU, study group) and critical care unit (CrCU, control group) of a teaching hospital. Three questionnaires were administered: a demographic data sheet, the Maslach Burnout Inventory (MBI), and a questionnaire evaluating sources of stress, pleasures of work, and coping mechanisms used by staff. All 75 surveys distributed were completed (BU=36, CrCU=39). Respondents from the BU were nurses (66.7%), occupational or physical therapists (11.1%), physicians (8.3%), respiratory therapists (5.6%), social workers (2.8%), and others (5.6%). There were no significant differences between BU and CrCU professionals in years of experience on the unit (6.7 vs 8.0 years), years in the field (16.5 vs 14.7 years), weekly hours of patient care (35.1 vs 39.6 hours), and number of ventilated patients cared for per month (8.4 vs 19.3 patients). On the MBI, there were no significant differences between units with respect to the emotional exhaustion and personal accomplishment subscales. However, staff in the BU reported lower rates of depersonalization (P=.049) compared with the CrCU counterparts. There was no significant difference in the perceived sources of workplaces stressors, but differences existed in the coping mechanisms. BU professionals exercised less (P=.007), talked less with their families (P=.006), ate less (P=.002), and watched less television (P=.002) compared with CrCU professionals as a means of coping with their workplace stress. In conclusion, although BU and CrCU have similar work environments, BU staff was significantly less depersonalized compared with CrCU staff. However, the two units had comparable rates of emotional exhaustion and depersonalization. The mechanisms for coping with workplace stress differed significantly between the two units.

Adaptation, Psychological↗

PubMedDate not supplied

National Burn Repository 2005: a ten-year review.

In the early 1990s, the American Burn Association (ABA) started its first burn registry development initiatives. The impetus for the registry development software originated from several directions, including the following: (1) the recognition that national registries were widespread and of proven benefit; (2) growing demands from accrediting institutions, payers, and patient advocacy groups for objective and verifiable data regarding patient costs, treatments, and outcomes; and (3) the shift toward "evidence-based" medicine and the ongoing analysis of treatment effectiveness. The ABA has issued three calls for burn registry data for its National Burn Repository (NBR): 1994, 2002, and 2005. In 1994, 28 burn centers contributed data for more than 6,400 patients treated from 1991 to 1993. The ABA announced its second call for data in 2001 and distributed the published results of more than 54,000 acute burn admissions treated from 1974 to 2002 at the Association's 2002 Annual Meeting. The third ABA call for data was issued in the Fall of 2005. The results are detailed in this report, which provides a summary of more than a quarter million acute burn admissions from 1995 to 2005, representing 70 hospitals from 30 states plus the District of Columbia. Statistics are presented in chart and table format to illustrate such key factors as patient age, burn size group, types of injuries, mortality rates, and average hospital charges by etiology and length of hospital stay. The data presented herein should help stimulate quality improvement programs in burn care, as burn centers compare their performance with the national data and as research is expanded using the NBR. The NBR will be published annually and, with continued refinements to the registry software, should become of increasing importance to clinicians, payers, researchers, and the public.

Adolescent↗

PubMedDate not supplied

Safe and successful restriction of transfusion in burn patients.

An acceptable strategy for transfusion of burn patients has not been specifically identified. In 1999, we empirically adopted a hemoglobin (Hb) transfusion trigger of 7.0 g/dl or greater in our burn center. The purpose of this study was to evaluate the effects of this restrictive transfusion strategy. Retrospective comparison of adults with 20% or greater TBSA treated from 1999 to 2004 (restrictive group; REST) with patients treated before our adoption of the restrictive transfusion strategy (1997-1998: liberal group; LIB). The REST group (n = 135, age 42 +/- 17 years, %TBSA burn 37 +/- 14, and 26% incidence of inhalation injury) did not differ significantly from the LIB group (n = 37, age 42 +/- 16 years, %TBSA burn 38 +/- 17, and 35% inhalation injury). The Hb triggering a transfusion was 7.1 +/- 1.2 g/dl in the REST group, compared with 9.2 +/- 2.1 g/dl in the LIB group (P < .001). The REST group received significantly fewer units of blood per day than the LIB Group. Patients in the REST group appeared to have significantly better organ function, and there were no differences between the groups in the incidence of acute myocardial infarction. Mortality at 30 days was significantly lower in the REST group (19% vs 38%; P = .03), as was overall in-hospital mortality (22% vs 46%; P = .003). Transfusion restriction appears to be safe and resulted in fewer transfusions among this group of burn patients. Prospective studies are needed before broadly recommending a transfusion trigger of 7.0 g/dl.

Adult↗

PubMedDate not supplied

Classification of burn injuries using near-infrared spectroscopy.

Early surgical management of those burn injuries that will not heal spontaneously is critical. The decision to excise and graft is based on a visual assessment that is often inaccurate but yet continues to be the primary means of grading the injury. Superficial and intermediate partial-thickness injuries generally heal with appropriate wound care while deep partial- and full-thickness injuries generally require surgery. This study explores the possibility of using near-infrared spectroscopy to provide an objective and accurate means of distinguishing shallow injuries from deeper burns that require surgery. Twenty burn injuries are studied in five animals, with burns covering <1% of the total body surface area. Carefully controlled superficial, intermediate, and deep partial-thickness injuries as well as full-thickness injuries could be studied with this model. Near-infrared reflectance spectroscopy was used to evaluate these injuries 1 to 3 hours after the insult. A probabilistic model employing partial least-squares logistic regression was used to determine the degree of injury, shallow (superficial or intermediate partial) from deep (deep partial and full thickness), based on the reflectance spectrum of the wound. A leave-animal-out cross-validation strategy was used to test the predictive ability of a 2-latent variable, partial least-squares logistic regression model to distinguish deep burn injuries from shallow injuries. The model displayed reasonable ranking quality as summarized by the area under the receiver operator characteristics curve, AUC = 0.879. Fixing the threshold for the class boundaries at 0.5 probability, the model sensitivity (true positive fraction) to separate deep from shallow burns was 0.90, while model specificity (true negative fraction) was 0.83. Using an acute porcine model of thermal burn injuries, the potential of near-infrared spectroscopy to distinguish between shallow healing burns and deeper burn injuries was demonstrated. While these results should be considered as preliminary and require clinical validation, a probabilistic model capable of differentiating these classes of burns would be a significant aid to the burn specialist.

Algorithms↗