Prognostic significance of early cardiac index measurements in severely burned patients

Effect of comorbidities on clinical outcome of patients with burn injury - An analysis of the German Burn Registry

BACKGROUND

Severe burn injuries are associated with high morbidity and mortality. Well-implemented scoring systems for patients with major burns exist in the literature. A major disadvantage of these scores is the partial non-consideration of patient-related comorbidities. Published data on this matter is limited to small study cohorts and/or single center studies. Further, the effect of comorbidities on clinical outcome of patients with severe burn injuries has not yet been examined nationwide in a large cohort in Germany. Hence, the aim of this study was to examine the influence of comorbidities on clinical outcome of these patients based on data from the national registry.

METHODS

Anonymized data from a total of 3455 patients with documented burns of 1% or more Total Burn Surface Area (TBSA) and over 16 years of age included in the German Burn Registry between 2017 and 2018 were analyzed retrospectively. Data included burn extent, body weight, age, burn depth, inhalation injury, comorbidities, mortality, number of operations and length of hospital stay (LOS).

RESULTS

In the logistic regression analysis age (OR 1.07 [1.06-1.09], p < 0.001), TBSA (OR 1.09 [1.08-1.11], p < 0.001), IHT (OR 2.15 [1.44-3.20], p < 0001), third degree burn (OR 2.08 [1.39-3.11], p < 0.001), Chronic Obstructive Pulmonary Disease (COPD) (OR 2.45 [1.38-4.35], p = 0.002) and renal insufficiency (OR 2.02 [1.13-3.59], p = 0.017) influenced mortality significantly. If a patient had more than one comorbidity, mortality was higher and in-hospital length of stay (LOS) longer. Renal insufficiency was significantly (p < 0.001) associated with the most prolonged LOS by 11.44 days. TBSA (p < 0.001), Abbreviated Burn Severity Index (ABSI) > 3 (p < 0.001) and IHT (p = 0.001) correlated with the amount of required surgeries and significantly predicted the need for intubation. Patients with arrhythmia significantly required more surgeries (p = 0.041), whereas patients with COPD required significantly less surgical interventions (p = 0.013).

CONCLUSION

Preexisting comorbidities have a significant impact on the clinical outcome of patients with severe burn injuries. Further investigation is warranted in order to supplement existing prognostic scores with new mortality-associated parameters.

Pediatric burn resuscitation: past, present, and future

Burn injury is a leading cause of unintentional death and injury in children, with the majority being minor (less than 10%). However, a significant number of children sustain burns greater than 15% total body surface area (TBSA), leading to the initiation of the systemic inflammatory response syndrome. These patients require IV fluid resuscitation to prevent burn shock and death. Prompt resuscitation is critical in pediatric patients due to their small circulating blood volumes. Delays in resuscitation can result in increased complications and increased mortality. The basic principles of resuscitation are the same in adults and children, with several key differences. The unique physiologic needs of children must be adequately addressed during resuscitation to optimize outcomes. In this review, we will discuss the history of fluid resuscitation, current resuscitation practices, and future directions of resuscitation for the pediatric burn population.

Low cardiac index and stroke volume on admission are associated with poor outcome in critically ill burn patients: a retrospective cohort study

Background

Impact of early systemic hemodynamic alterations and fluid resuscitation on outcome in the modern burn care remains controversial. We investigate the association between acute-phase systemic hemodynamics, timing of fluid resuscitation and outcome in critically ill burn patients.

Methods

Retrospective, single-center cohort study was conducted in a university hospital. Forty critically ill burn patients with total body surface area (TBSA) burn-injured >20 % with invasive blood pressure and cardiac output monitoring (transpulmonary thermodilution technique) within 8 h from trauma were included. We retrospectively examined hemodynamic variables during the first 24 h following admission, and their association with 90-day mortality.

Results

The median (interquartile range 25th–75th percentile) TBSA, Simplified Acute Physiology Score II (SAPS II) and Abbreviated Burn Severity Index of the study population were 41 (29–56), 31 (23–50) and 9 (7–11) %, respectively. 90-Day mortality was 42 %. There was no statistical difference between the median pre-hospital and 24-h administered fluid volume in survivors and non-survivors. On admission, stroke volume (SV), cardiac index (CI), oxygen delivery index and mean arterial pressure (MAP) were significantly lower in patients who died despite similar fluid resuscitation volume. ROC curves comparing the ability of initial SV, CI, MAP and lactate to discriminate 90-day mortality gave areas under curves of, respectively, 0.89 (CI 0.77–1), 0.77 (CI 0.58–0.95), 0.73 (CI 0.53–0.93) and 0.78 (CI 0.63–0.92); (p value <0.05 for all). In multivariate analysis, SAPS II and initial SV were independently associated with 90-day mortality (best cutoff value for SV was 27 mL, sensitivity 92 %, specificity 69 %). During 24 h, no interaction was found between time and outcome regarding macrocirculatory parameters changes. Hemodynamic parameters improved during the first 24-h resuscitation in all patients but patients who died had lower SV and CI on admission, which remained through the first 24 h.

Conclusion

Low initial SV and CI were associated with poor outcome in critically ill burn patients. Very early hemodynamic monitoring may in help detecting under-resuscitated patients. Future prospective interventional studies should explore the impact of early goal-directed therapy in these specific patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s13613-016-0192-y) contains supplementary material, which is available to authorized users.

Burn resuscitation--hourly urine output versus alternative endpoints: a systematic review

Controversy remains over appropriate endpoints of resuscitation during fluid resuscitation in early burns management. We reviewed the evidence as to whether utilizing alternative endpoints to hourly urine output produces improved outcomes. MEDLINE, CINAHL, EMBASE, Cochrane Library, Web of Science, and full-text clinicians' health journals at OVID, from 1990 to January 2014, were searched with no language restrictions. The keywords burns AND fluid resuscitation AND monitoring and related synonyms were used. Outcomes of interest included all-cause mortality, organ dysfunction, length of stay (hospital, intensive care), time on mechanical ventilation, and complications such as incidence of pulmonary edema, compartment syndromes, and infection. From 482 screened, eight empirical articles, 11 descriptive studies, and one systematic review met the criteria. Utilization of hemodynamic monitoring compared with hourly urine output as an endpoint to guide resuscitation found an increased survival (risk ratio [RR], 0.58; 95% confidence interval, 0.42-0.85; P < 0.004), with no effect on renal failure (RR, 0.77; 95% confidence interval, 0.39-1.43; P = 0.38). However, inclusion of the randomized controlled trials only found no survival advantage of hemodynamic monitoring over hourly urine output (RR, 0.72; 95% confidence interval, 0.43-1.19; P = 0.19) for mortality. There were conflicting findings between studies for the volume of resuscitation fluid, incidence of sepsis, and length of stay. There is limited evidence of increased benefit with utilization of hemodynamic monitoring, however, all studies lacked assessor blinding. A large multicenter study with a priori-determined subgroup analysis investigating alternative endpoints of resuscitation is warranted.

Volume overload of fluid resuscitation in acutely burned patients using transpulmonary thermodilution technique

In recent years, transpulmonary thermodilution techniques (PICCO) offer an attractive and more ideal end point for fluid resuscitation. The study included 30 adult burned patients between 25 and 60% TBSA. The study group received fluid resuscitation guided by the PICCO. The control group resuscitated using Parkland formula, guided by traditional monitoring parameters. Fluid administration in the initial 72 hours after burn injury was significantly higher in the study group. Furthermore, it was difficult, perhaps even impossible, to achieve the goals of normovolemia and cardiac output normalization during the early postburn period. Nevertheless, the attempt to achieve them was associated with a significant tissue edema. Although PICCO is a very beneficial tool in the estimation of amounts of fluid resuscitation, the values of ideal end points need to be adjusted in burn patients. The traditional values of intrathoracic blood volume, extravascular lung water, and cardiac index are associated with significant tissue edema that can easily complicate sepsis in these immunocompromised patients.

The association between fluid administration and outcome following major burn: a multicenter study

OBJECTIVE

To determine patient and injury variables that influence fluid requirements following burn injury and examine the association between fluid volume received and outcome.

BACKGROUND

Fluid resuscitation remains the cornerstone of acute burn management. Recent studies suggest that patients today are receiving more fluid per percent total body surface area (TBSA) than in the past. Therefore, there is a need to better define the factors that impact fluid requirements and to determine the effects of fluid volumes on outcome.

METHODS

This study was part of a federally funded multicenter study. Multilinear regression analyses were performed to determine the patient and injury characteristics that most influenced fluid resuscitation volumes received. To assess the association of fluid volumes on outcome, propensity scores were developed to provide a predicted volume of fluid for each patient. Logistic models were then used to assess the impact of excess fluid beyond predicted volumes on outcome.

RESULTS

Seventy-two patients were included in this analysis. Average patient age was 40.6 years and average TBSA was 44.5%. Average fluid volume received during the first 24 hours after injury was 5.2/mL/kg/TBSA. Significant predictors of fluid received included % TBSA, age, intubation status, and weight. Increased fluid volume received increased risk of development of pneumonia (odds ratio [OR] = 1.92), bloodstream infections (OR =2.33), adult respiratory distress syndrome (OR = 1.55), multiorgan failure (OR= 1.49), and death (OR = 1.74).

CONCLUSION

TBSA, age, weight, and intubation status on admission were significant predictors of fluid received. Patients who received larger volumes of resuscitation fluid were at higher risk for injury complications and death.

[Epidemiology, initial management and analysis of morbidity-mortality of severe burn patient]

OBJECTIVE

Describe the epidemiological characteristics of severe burn patients and analyze the factors related with morbidity-mortality.

DESIGN AND SCOPE

Observational, retrospective study of patients admitted to an intensive care unit of a level III hospital due to severe burns from January 1998 to December 2004.

PATIENTS

59 patients with criteria of "severe burn" and expected stay in ICU greater than three days. MAIN ENDPOINTS OF INTEREST: We studied epidemiological endpoints of this type of patients, diagnosis and initial treatment, early complications and morbidity-mortality.

RESULTS

The burned body surface was 41% +/- 25% and age 49 +/- 21 years. Patients remained hospitalized in ICU for a median of 4 days (interquartile range: 2-19). A total of 78% of the patients needed mechanical ventilation, 47% had some infection during admission and 28% developed acute kidney failure during the first week. Mortality in the ICU was 42%. Endpoints associated independently with a significant increase of mortality were burned body surface greater than 35% (OR 1.08; 95% CI: 1.03-1.12) and development of kidney failure (OR 5.47; 95% CI: 2.02 -8.93).

CONCLUSIONS

Mortality of these patients is very high and is conditioned largely by initial care. Percentage of burned body surface (BBS) and kidney failure entails greater mortality in our series.

A clinical randomized study on the effects of invasive monitoring on burn shock resuscitation

BACKGROUND

Ever since Charles Baxter's recommendations the standard regime for burn shock resuscitation remains crystalloid infusion at a rate of 4 ml/kg/% burn in the first 24h following the thermal injury. A growing number of studies on invasive monitoring in burn shock, however, have raised a debate regarding the adequacy of this regime. The purpose of this prospective, randomised study was to compare goal-directed therapy guided by invasive monitoring with standard care (Baxter formula) in patients with burn shock.

PATIENTS AND METHODS

Fifty consecutive patients with burns involving more than 20% body surface area were randomly assigned to one of two treatment groups. The control group was resuscitated according to the Baxter formula (4 ml/kg BW/% BSA burn), the thermodilution (TDD) group was treated according to a volumetric preload endpoint (intrathoracic blood volume) obtained by invasive haemodynamic monitoring.

RESULTS

The baseline characteristics of the two treatment groups were similar. Fluid administration in the initial 24h after burn was significantly higher in the TDD treatment group than in the control group (P = 0.0001). The results of haemodynamic monitoring showed no significant difference in preload or cardiac output parameters. Signs of significant intravasal hypovolemia as indicated by subnormal values of intrathoracic and total blood volumes were present in both treatment groups. Mortality and morbidity were independent on randomisation.

CONCLUSION

Burn shock resuscitation due to the Baxter formula leads to significant hypovolemia during the first 48 h following burn. Haemodynamic monitoring results in more aggressive therapeutic strategies and is associated with a significant increase in fluid administration. Increased crystalloid infusion does not improve preload or cardiac output parameters. This may be due to the fact that a pure crystalloid resuscitation is incapable of restoring cardiac preload during the period of burn shock.

Trends in burn resuscitation: shifting the focus from fluids to adequate endpoint monitoring, edema control, and adjuvant therapies

Bum shock is a complex process involving a series of intertwined physiologic responses to injury that require more rigorous intervention than simply a change in fluid tonicity, fluid composition, or fluid resuscitation volume. Controversy ensues over monitoring techniques and resuscitation goals, in part because the identification of true markers of perfusion is clouded by intradependence of endpoints on other metabolic processes. The persistence of cellular hypoperfusion in patients who have been deemed adequately resuscitated by global indices supports the growing realization that failure of conventional endpoint-monitoring strategies to detect compensated bum shock can lead to significant organ injury from SIRS or MODS. Current endpoints should be interpreted in the aggregate, because none have yet been demonstrated to reflect tissue perfusion status independently and accurately. Numerous technologically advanced endpoints to predict patient outcome, which may be useful in determining futility of treatment or end-of-life decisions, are now available. Still lack-ing, however, is a reliable tool proven to improve outcome that can guide bum shock resuscitation therapies successfully. Exciting new research in tissue oxygenation and perfusion has revealed that damaging mediator cascades and irreversible microvascular changes may preclude complete resolution of bum shock solely through restoration of oxygen delivery. Because bum patients now frequently survive the early resuscitation phase. the focus should be on controlling derangements in oxygen use and correcting occult hypoperfusion to reduce later adverse patient outcomes from SIRS, sepsis, and MODS. Bum-specific research on resuscitation endpoints and monitoring strategies lags behind research in other patient populations. Present standards and monitoring guidelines for bum shock resuscitation should be critically evaluated and based on true, scientifically validated data rather than on observational studies or personal beliefs. Thus the continuing challenge for clinicians and researchers:burn centers must collaborate to perform large, multi-center studies to evaluate critically and to prove resuscitation endpoints and therapies. Future technologies targeted at microcirculatory perfusion and cellular oxygenation offer an exciting promise for less invasive, easily accessible, more accurate endpoints and treatments for bum shock resuscitation.

Systemic hemodynamics, gastric intramucosal PCO2 changes, and outcome in critically ill burn patients

OBJECTIVES

To define the hemodynamic and gastric intramucosal PCO2 (PiCO2) changes during the first 48 hrs after burn trauma and to analyze their relationship with outcome.

DESIGN

Prospective, observational study in a cohort of consecutively admitted critically ill burn patients.

SETTING

Intensive care burn unit in a university hospital.

PATIENTS

Forty-two patients with burns covering >20% of body surface area or inhalation injury.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Patients were monitored with an oximetric pulmonary arterial catheter and a gastric tonometer to measure PiCO2. The difference between arterial and gastric mucosal PCO2 (P[i-a]CO2) was considered indicative of gastric mucosal hypoxia. Hemodynamic and PiCO2 measurements were performed during the first 48 hrs after admission. Patients suffered burns covering 36.1% +/- 14.3% (mean +/- SD) and 45.3% +/- 21.9% of body surface area (survivors and nonsurvivors, respectively). All patients were successfully resuscitated by conventional standards. Nonsurvivors (n = 16) died a median of 17 days after admission. In univariate analysis, the presence of shock during the resuscitation phase, age, mixed venous pH, P[i-a]CO2, right atrial pressure, pulmonary arterial pressure, pulmonary arterial occlusion pressure, cardiac index, systemic and pulmonary vascular resistance, left ventricular stroke work index, mixed venous oxygen saturation, and systemic oxygen delivery, consumption, and extraction ratio, measured over the first 12 hrs after admission, were significantly (p < .05) different between survivors and nonsurvivors. These differences disappeared after 12 hrs after admission. Multivariate analysis identified age, percentage body surface area burned, and oxygen delivery index (6 hrs after admission) as factors independently associated with a poor outcome. P[i-a]CO2 (12 hrs after admission) was significantly greater in patients with than in those without inhalation injury (17 +/- 13 torr [2.26 +/- 1.73 kPa] vs. 6 +/- 10 torr [0.79 +/- 1.33 kPa]; p = .005). Patients with a P[i-a]CO2 difference (6 hrs after admission) > or =10 torr (1.33 kPa) had a mortality rate of 56% vs. 25% of those patients with <10 torr (p = .044).

CONCLUSIONS

Our data indicate that there are hemodynamic and biochemical changes that occur early after burn trauma that are associated with prognosis after an apparently successful resuscitation. Particularly, a hemodynamic profile characterized by systemic acidosis, low systemic blood flow, and systemic and pulmonary vasoconstriction early after trauma is associated with a poor outcome. Additionally, intestinal mucosal acidosis occurs after burn trauma, is influenced by inhalation injury, and is a variable related to outcome.

Cardiac compromise in a patient with Down's Syndrome: a lesson learnt

A 49 year old burn victim with Down's Syndrome (Trisomy 21) was admitted with 15% body surface area (BSA) superficial burns. This was complicated by a large atrioseptal defect. Her course was stormy with difficulties encountered in managing her fluid status. Adequate fluid resuscitation was difficult to maintain with a fragile compromise between pulmonary insufficiency and renal impairment. She expired 12 days post-injury. Cardiac anomalies are not uncommon in the subgroup of patients with major burns who respond poorly to fluid resuscitation.

Resuscitation in shock associated with burns. Tradition or evidence-based medicine?

OBJECTIVE

To summarize the present standards and guidelines for fluid treatment of shock associated with burns, and to evaluate their scientific support in the literature.

DESIGN

Nonsystematic, critical review of the literature regarding the indications for crystalloid and colloid fluid treatment, invasive monitoring and the use of resuscitation end points in shock associated with burns.

SUMMARY POINTS

Crystalloid fluid resuscitation of patients with burns is traditionally managed using empirical resuscitation formulae, with the efficacy monitored by vital signs and urinary output The value of these end points has been questioned by recent studies, which have suggested that such noninvasive parameters may be inadequate for detecting malperfusion. No consensus exists regarding appropriate assessment of adequate resuscitation, and the impact on survival of invasive measures has still to be proven in controlled randomized trials. Generally, a significantly higher fluid requirement has been demonstrated when resuscitation is based on invasive cardiorespiratory monitoring. Colloid resuscitation in burns patients is controversial. Published reports suggest that colloid infusion should be started between 6 and 36 h following thermal injury. A recent meta-analysis highlighted the shortcomings of albumin in patients with burns, and this, together with restrictions for the use of plasma products, has obscured the choice of colloid solution. The effect of colloid resuscitation on survival remains to be proven in burned patients.

CONCLUSION

The current standards for monitoring fluid therapy in patients with large burns are not supported by scientific data. Further randomized, controlled trials are indicated, and should help establish general guidelines regarding monitoring and treatment end points in these patients.

Haemodynamic and oxygen transport responses in survivors and non-survivors following thermal injury

Resuscitation from shock based on invasive hemodynamic monitoring has been widely used in trauma and surgical patients, but has been only sparsely evaluated in thermally injured patients, probably due to fear of invasive monitoring in this group of patients. However, end-point resuscitation to fixed circulatory and oxygen transport values has been proposed to be associated with an improved survival rate following trauma and high-risk surgery. Furthermore, the early circulatory response to resuscitation has been shown to be predictive of survival in these patients. In this study the early hemodynamic and oxygen transport profile following thermal injury was analysed with the aim to detect possible differences in the response of survivors and non-survivors. The transpulmonary thermodilution technique was used for hemodynamic monitoring of 21 patients, who were admitted to our burn unit with severe burns. Six patients died and 15 patients survived to leave the intensive care unit. Survivors were found to have a significantly higher cardiac index and oxygen delivery rate during the early postburn period than non-survivors. Furthermore, initial serum lactate levels as well as the ability to clear elevated lactate were found to be significantly associated with survival. Blood pressure and heart rate were not significantly different between the two groups of patients. All patients received significantly higher volumes of crystalloids during the first 24 h than predicted from the Baxter formula, independent of outcome. We concluded that standard vital signs such as blood pressure and heart rate may be invalid as outcome related resuscitation goals, and too insensitive to ensure appropriate fluid replacement. The response to fluid therapy may be significantly associated with outcome; survivors responding with an augmentation of cardiac output and oxygen delivery not seen in non-survivors. Lactate levels seem to correlate with organ failure and death and appear a suitable end-point for resuscitation of severely burned patients.

[Management of severe burns during the 1st 72 hours]

Early and efficient management of severely burned patients facilitates outcome improvement. Pre-hospital care includes fluid loading with 2 mL.kg-1/% burn over the first six hours, sedation and analgesia, prevention of hypothermia and ventilatory support for either critically burned patients or facial, cervical or pulmonary burn injury. The transient stay in a general hospital before transfer to a burn centre allows extension of initial care, the critical investigation for associated injuries (intoxication, multiple trauma) and to perform initial local treatment with sterile coverage or vaseline gauze after a revised assessment of the burned skin area, and possibly escharotomies. The main aim of care in the burn centre is to control hypovolaemia and to obtain maximal tissue perfusion and oxygen delivery to burned tissues, as well as to healthy organs. To manage the burn shock (initially hypovolemic and later on hyperdynamic) catecholamines are often indicated when appropriate fluid loading remains insufficient. Mechanical ventilation is indicated in case of either a deep extensive burn over 60% of total body surface area, or facial and cervical burns or severe pulmonary burn injury from smoke inhalation, carbon monoxide intoxication, tracheobronchial thermal injury and blast injury. Because of the severity of burn-related pain, and the stimulus linked to intensive care, continuous sedation is usually required. Early surgical treatment such as escharotomies, excision and grafting, which cause significant pain as well as blood loss, and hydrotherapy, often require general anaesthesia. Burn injury can modify the volume of distribution and the pharmacokinetics of anaesthetic agents. Finally, chemical or electrical burn, radiation, associated CO intoxication or multiple trauma, as well as burn injury in infants, raise specific problems. With improvement in early intensive care, the survival rate of the most severely burned patients is obviously improving. New techniques in skin substitution will probably further improve the final outcome.

In the early stage of major burns, is there a correlation between survival, interleukin-6 levels and oxygen delivery and consumption?

The correlation between haemodynamic and oxymetric parameters, and circulating cytokines has been little studied for the early phase of extensive burns. The aim of this prospective study was to evaluate survival, looking at variations in cardiac index (CI), oxygen delivery (DO2I) and consumption (VO2I) indexed to the body surface area (BSA), and circulating interleukin-6 (IL6) levels in the acute stage of major burns. Over a 12-month period, all patients admitted within 6 h of extensive thermal injury with total burn surface area (TBSA) of over 60 per cent, necessitating standardized resuscitation and mechanical ventilation, were included. Routine intensive care monitoring, including pulmonary and femoral artery catheters, was set up. During the first 3 days post-injury haemodynamic and oxymetric profiles were recorded every 6 h. Circulating IL6 samples were taken within 6 h of admission, then daily (at 24, 48 and 72 h). A comparison of the results in survivors (S) and non-survivors (NS) at those previously determined times was made. Ten consecutive patients were studied. Six patients survived (Age = 33 +/- 10 years; TBSA = 76 +/- 11 per cent) and four died (Age = 40 +/- 14 years; TBSA = 77 +/- 13 per cent). Similar initial hypovolemic profiles were found in both groups. From 24 h, a hyperdynamic status was observed which increased until 72 h. This hyperkinetic evolution was more marked in the survivors (CI: 4.6 +/- 2.0 for NS and 6.9 +/- 1.51 min-1 m-2 for S; SVRI: 2125 +/- 1288 for NS and 918 +/- 232 dyne s cm-5 m2 for S at 72 h). DO2I and VO2I were always higher in the survivors. DO2I and VO2I increased from admission to 72 h in the survivors whereas a significant drop in DO2I and VO2I occurred in the non-survivors at 48 h (DO2I:536 +/- 222 for NS and 1228 +/- 268 ml min-1 m-2 for S; VO2I:120 +/- 50 for NS and 251 +/- 56 ml min-1 m-2 for S (P < 0.01)). Plasma IL6 revealed abnormal values with consistent peaks at 24-48 h in the survivors (respectively 17,411 +/- 24,542 and 10,746 +/- 11,802 pg ml-1) and only moderate peaks in the non-survivors (865 +/- 652 and 912 +/- 485 pg ml-1). Finally, CI, DO2I, VO2I and circulating IL6 were always higher, and SVRI lower, in the survivors than in the non-survivors. The ability to increase DO2 and to optimize VO2 during the 'turning point' of 48 h seems to improve the prognosis of critically burned patients: the role of IL6 in this systemic inflammatory response is discussed.

The impact of risk factors and pre-existing conditions on the mortality of burn patients and the precision of predictive admission-scoring systems

Clinical experience has shown that concomitant diseases and risk factors have a significant influence on the patient's outcome. Since none of the currently available score systems consider the impact of concomitant diseases or risk factors on burn trauma mortality, the present study was planned to further evaluate the role of these factors. Four hundred and ninety-eight patients could be included in this retrospective analysis of prospectively collected data. Parameters documented were: sex, age, weight, height, laboratory data, TBSA, inhalation trauma (IHT), full thickness (3 degrees) burn and pre-existing conditions. Single-variable analysis (SVA), logistic regression and CART analysis were performed. The data confirm the role of age and TBSA as the strongest prognostic variables. Chronic alcohol abuse and smoking, IHT and pre-existing cardiac and neurologic conditions were also found to be significant. Borderline groups could be identified in the ABSI score (7-10), where the risk factors cause 'mortality-shifting'. It can be concluded that risk factors and pre-existing conditions have a significant impact on the prognosis of burn mortality and should be incorporated into further refinements of burn admission scores.

Temperature profiles during resuscitation predict survival following burns complicated by smoke inhalation injury

Temperature and resuscitation profiles of 15 non-survivors were compared with matched survivors of major burns. All patients were intubated and ventilated for smoke inhalation injury, survived more than 3 days postburn and had a cutaneous burn greater than 15 per cent of the body surface area (mean 32.3 +/- 11.0 per cent SD). Cases were matched for similar ages (within 10 years) and total body surface area burn (within 10 per cent). The rate of core temperature rise following admission to the burn unit was significantly greater in survivors (mean 0.46 +/0 0.18 degree C/h) compared with matched non-survivors (mean 0.30 +/- 0.15 degrees C/h; p < 0.01). Core temperature increased at a rate of 0.27 degrees C/h or greater in all survivors, whereas 7 non-survivors raised their core temperature at a rate less than this. The rate of skin temperature rise was also significantly greater in the survivors (mean 1.35 +/- 0.91 degrees C/h) compared with matched non-survivors (mean 0.63 +/- 0.43 degrees C/h, p < 0.01). In 13/15 survivors, the skin temperature increased at a rate of 0.6 degree C/h or greater, whereas in 8/15 non-survivors skin temperature increased at a rate less than this. There was a negative relationship between initial core temperature and delay from time of burn to admission to the burns unit in non-survivors (correlation coefficient = -0.92; p < 0.01), whereas there was no effect of delay in the survivors. These findings suggest that patients with a high mortality probability can be detected early in their clinical course by means of temperature profiles.

Use of invasive cardiovascular monitoring in patients with burns greater than 30 per cent body surface area: a survey of 251 centres

A survey of the use of invasive cardiovascular monitoring in patients with burns greater than 30 per cent body surface area was performed. Questionnaires were sent to a total of 251 burns units in the UK, USA, Canada, Australia and New Zealand. The overall response rate was 68 per cent. Most centres reported that they managed less than 20 of these patients each year. Fifty-five per cent of centres used central venous pressure monitoring in more than half of their patients. In contrast, only 8 per cent of burn units used pulmonary artery catheters in over half of their patients. Few centres described the use of predetermined goals to direct therapy associated with PA catheter insertion.

[Severe burnt patients: hemodynamic state, oxygen transport and consumption, plasma cytokines]

OBJECTIVE

To assess the haemodynamic and oxymetric variations measured by a pulmonary artery catheter and to correlate them with the variations of the circulating cytokines during the initial intensive care phase of severely burned patients.

STUDY DESIGN

Prospective study covering an 18-month period.

PATIENTS

Thirteen successive patients, aged over 12 years, without significant medical history, with a thermal burn affecting more than 50 percent of their total body surface area and admitted to our centre during the first six postburn hours.

METHODS

The haemodynamic and oxymetric profile was investigated by inserting a blood flow-directed balloon-tipped pulmonary artery fiberoptical catheter. All patients were treated according to the protocol previously used in our centre. Blood samples were drawn on admission, every 12 hours post-injury until the 2nd day, then on the 3rd and 5th days. Cytokines were analyzed by Elisa method. Haemodynamic and oxymetric measurements were achieved simultaneously with the biological samples during the first 5 postburn days. The analysis of variance (ANOVA) with the Duncan test was utilized for multiple comparisons between continuous variables.

RESULTS

(mean +/- SEM): The patients were 32 +/- 3 years-old and had a burn surface of 72 +/- 4%. After a short hypovolemic shock period lasting a 12 hours, a hyperdynamic shock occured which increased until the 5th day, with an increased cardiac index (6.9 +/- 0.4 at h120 vs 2.9 +/- 0.3 L.min-1.m-2 at h6, P < 0.05), increased oxygen transport and consumption (respectively 880 +/- 77 at h72 vs 543 +/- 58 mL.min-1 at h12, P < 0.05 and, 203 +/- 15 at h72 vs 129 +/- 25 mL.min-1 at h6, P < 0.05) and markedly decreased systemic vascular resistances (1,002 +/- 118 at h36 vs 2,330 +/- 328 dyn.s.cm-5.m2 at h6, P < 0.05). Circulating cytokines were not clearly modified except for interleukine-6 which reached early striking peaks (16,858 +/- 10,330 at h24 and 15,406 +/- 6,509 pg.mL-1 at h36) simultaneously with the decrease in systemic vascular resistances.

CONCLUSIONS

During the first post-injury week, critically burned patients develop a specific hyperdynamic circulatory status during which interleukine-6 could be a mainfactor decreasing systemic arterial resistances.