Resuscitation, anaesthesia and analgesia of the burned patient

A Critical Update of the Assessment and Acute Management of Patients with Severe Burns

Significance: Burns are debilitating, life threatening, and difficult to assess and manage. Recent advances in assessment and management have occurred since a comprehensive review of the care of patients with severe burns was last published, which may influence research and clinical practice. Recent Advances: Recent advances have occurred in the understanding of burn pathophysiology, which has led to the identification of potential biomarkers of burn severity, such as protein C. There is new evidence about the potential superiority of natural colloids over crystalloids during fluid resuscitation, and new evidence about components of initial and perioperative management, including an improved understanding of pain following burns. Critical Issues: The limitations of the clinical examination highlight the need for imaging and biomarkers to assist in estimations of burn severity. Fluid resuscitation reduces mortality, although there is conjecture over the ideal method. The subsequent perioperative period is associated with significant morbidity and the evidence for preventing and treating pain, infection, and fluid overload while maximizing wound healing potential is described. Future Directions: Promising developments are ongoing in imaging technology, histopathology, biomarkers, and wound healing adjuncts such as hyperbaric oxygen therapy, topical negative pressure therapy, stem cell treatments, and skin substitutes. The greatest benefit from further research on management of patients with burns would most likely be derived from the elucidation of optimal fluid resuscitation protocols, pain management protocols, and surgical techniques from randomized controlled trials.

Monitoring End Points of Burn Resuscitation

This article discusses commonly used methods of monitoring and determining the end points of resuscitation. Each end point of resuscitation is examined as it relates to use in critically ill burn patients. Published medical literature, clinical trials, consensus trials, and expert opinion regarding end points of resuscitation were gathered and reviewed. Specific goals were a detailed examination of each method in the critical care population and how this methodology can be used in the burn patient. Although burn resuscitation is monitored and administered using the methodology as seen in medical/surgical intensive care settings, special consideration for excessive edema formation, metabolic derangements, and frequent operative interventions must be considered.

The abdominal compartment syndrome in patients with burn injury

INTRODUCTION

Intra-abdominal hypertension (IAH) and subsequent abdominal compartment syndrome (ACS) in burned patients is common. This sequence of events typically occurs in patients with larger burns receiving high volume fluid resuscitation.

METHODS

A review of the literature was performed. The National Library of Medicine (PUBMED) was queried for "Burn" and "Abdominal Compartment Syndrome". Twenty-nine articles were retained for study.

RESULTS

Abdominal pressure monitoring is appropriate in all patients with burns that require significant volume resuscitation (>30% total burned surface area- TBSA). Prevention of ACS in burns includes limiting fluid resuscitation, burn escharotomy, and percutaneous drainage when abdominal pressures are reaching perilous levels. Treatment includes all of the above and in addition, decompressive laparotomy when needed. However, despite decompressive laparotomy, mortality rates among burn victims with ACS remain unacceptably high.

CONCLUSION

Increasing amounts of volume delivery are associated with an increased risk of IAH. Therefore, intra-abdominal pressure should be monitored in all burn patients requiring massive fluid resuscitation. Escharotomy, paracentesis, and decompressive laparotomy may all be needed to counter the side effects of appropriate fluid resuscitation in the severely burned patient. Nevertheless, the prognosis in burn patients developing ACS is grim.

Comparison of three techniques for calculation of the Parkland formula to aid fluid resuscitation in paediatric burns

CONTEXT

Inadequate fluid resuscitation of acute burns may result in hypovolaemic shock. Excessive fluid resuscitation may result in fluid overload. A nomogram which uses the popular Parkland formula and '4-2-1' regime has been recently described to facilitate the calculation of fluid requirements in children during the first 24 h following burn injury.

OBJECTIVE

To compare the accuracy and speed of calculation of three different methods (pen and paper, electronic calculator and nomogram), which all use the Parkland formula and '4-2-1' regime to calculate maintenance and resuscitation fluid requirements for children in the first 24 h after burn injury.

DESIGN

A randomised volunteer study using computer-generated simulated patient data.

SETTING

Welsh Centre for Burns, ABM University Local Health Board, Swansea, UK. Data were collected between February 2011 and October 2011.

PARTICIPANTS

The group consisted of 36 volunteers including trainee and consultant surgeons and anaesthetists.

INTERVENTION

Thirty-six participants performed 318 calculations, using each of the three methods of calculation up to three times.

MAIN OUTCOME MEASURES

Accuracy, speed and acceptability of the different methods.

RESULTS

For nomogram, calculator and pen and paper: magnitude of error [low (≥25%), medium (≥50%) and high (≥75%)]: [5.7, 4.7 and 3.8%], [12.1, 12.1 and 7.5%], [28.6, 21.9 and 16.2%]; [P <0.001, P = 0.001 and P = 0.006]. Calculation time: [s; mean (SD)]: 121 (48), 109 (52) and 240 (140); P <0.001. The mean (SD) of the difficulty scores were 17.3 (13), 20.6 (13.4) and 62.2 (23.4); P <0.001.

CONCLUSION

The nomogram was the most accurate method of calculating fluid requirements using the Parkland formula, was only slightly slower than the electronic calculator and was deemed the easiest to use. The nomogram is also low cost, robust, and provides a rapid means of detecting and preventing the large errors that we have shown can occur when an electronic device is used as the primary method of resuscitation fluid calculation. We, therefore, suggest that the nomogram is a suitable method for the calculation of the Parkland formula to guide resuscitation and maintenance fluid requirements in the first 24 h of paediatric burns or for cross-checking the results obtained by other means of calculation.

Comparison of three techniques using the Parkland Formula to aid fluid resuscitation in adult burns

We performed a randomised study to compare the accuracy and speed of three different techniques (pen and paper, electronic calculator and a novel graphic device: 'nomogram') for calculation of resuscitation fluid requirements for adults in the first 24 h of burn injury, based on the Parkland Formula. We also assessed acceptability of each technique using visual analogue scores and qualitative analysis of free text responses. 28 participants performed 252 calculations using a series of computer generated simulated patient data. For nomogram, electronic calculator, pen and paper: Magnitude of error [low (≥25%), medium (≥50%), high (≥75%)]: [6.0%, 1.2%, 0%], [17.9%, 14.3%, 8.3%], [25%, 16.7%, 9.5%]; p<0.002. Calculation time: [sec: mean (SD)]: 94(34), 73(31), 214(103); p<0.001. The mean (SD) of the difficulty scores for each method were 23(17), 17(14) and 70(21) out of 100. Of the 28 participants 15 preferred the calculator, 12 preferred the nomogram and 1 scored the calculator and nomogram equally (table 3). The nomogram was significantly more accurate at all levels, almost as fast as an electronic calculator, and deemed easy to use. It is low cost and robust, and provides a rapid means of detecting and preventing the large errors that we have shown can occur when an electronic device is used as the only method of calculation. We therefore suggest that the Parkland Formula nomogram is a suitable method for calculation of resuscitation fluid requirements in adult burns. Fluid requirement should, however, be reviewed frequently, and adjusted to ensure adequate organ perfusion.

Health-related quality of life of hospitalized patients with burns-comparison with general population and a 2-year follow-up

OBJECTIVE

Health-related quality of life (HRQoL) has gained increasing interest as an important indicator of adaptation after a burn injury. Our objective was to compare HRQoL of medium severity hospitalized burn victims with no need for intensive care treatment with that of the general population.

METHODS

The 15D HRQoL questionnaire at discharge, and 6, 12 and 24 months thereafter.

RESULTS

44 patients filled in the baseline questionnaire between June 2007 and December 2009. At discharge the mean (SD) HRQoL score (on a scale of 0-1) of the patients was worse in comparison with that of the general population (0.839 (0.125) vs. 0.936 (0.071)), p<0.001. The most striking differences (p<0.001) were seen on the dimensions of sleeping, usual activities, discomfort and symptoms, and sexual activity. At the 2-year follow-up the mean HRQoL score had increased from 0.835 (0.121) to 0.856 (0.149), but the difference was not statistically significant. Of the dimensions, moving and usual activities improved statistically significantly.

CONCLUSIONS

HRQoL of patients hospitalized for treatment of burns is, at discharge, compromised compared with that of the general population. During follow-up HRQoL showed slight improvement but remained at a clearly lower level.

[Estimation of substitution volume after burn trauma. Systematic review of published formulae]

BACKGROUND

Fluid resuscitation after severe burns remains a challenging task particularly in the preclinical and early clinical phases. To facilitate volume substitution after burn trauma several formulae have been published and evaluated, nevertheless, the optimal formula has not yet been identified.

METHODS

A systematic PubMed search was performed to identify published formulae for fluid resuscitation after severe burns. The search terms "burn", "thermal", "treatment", "therapy" or "resuscitation", "fluid", "formula" and "adult", "pediatric" or "paediatric" were used in various combinations. Analysis was limited to the period from 01.01.1950 to 30.06.2010 and database entries in PubMed (http://www.pubmed.com). Additionally, references cited in the papers were analyzed and relevant publications were also included. Publications and formulae were assessed and classified by two independent investigators.

RESULTS

Within the specified time frame eight publications (five original contributions and three book chapters) were identified of which three formulae recommended colloid solutions, four recommended electrolyte solutions and one suggested hypertonic solutions within the first 24 h for fluid resuscitation. Only one formula specifically dealt with fluid resuscitation in infants.

CONCLUSION

The identified formulae led to sometimes strikingly diverse calculations of resuscitation fluid volumes. Therefore their use should be monitored closely and clinical values included. Urine output is a well established individual parameter. Use of colloid and hypertonic solutions leads to a reduced total fluid volume but is still controversially discussed.

Critical care of the burn patient: the first 48 hours

OBJECTIVE

The goal of this concise review is to provide an overview of some of the most important resuscitation and monitoring issues and approaches that are unique to burn patients compared with the general intensive care unit population.

STUDY SELECTION

Consensus conference findings, clinical trials, and expert medical opinion regarding care of the critically burned patient were gathered and reviewed. Studies focusing on burn shock, resuscitation goals, monitoring tools, and current recommendations for initial burn care were examined.

CONCLUSIONS

The critically burned patient differs from other critically ill patients in many ways, the most important being the necessity of a team approach to patient care. The burn patient is best cared for in a dedicated burn center where resuscitation and monitoring concentrate on the pathophysiology of burns, inhalation injury, and edema formation. Early operative intervention and wound closure, metabolic interventions, early enteral nutrition, and intensive glucose control have led to continued improvements in outcome. Prevention of complications such as hypothermia and compartment syndromes is part of burn critical care. The myriad areas where standards and guidelines are currently determined only by expert opinion will become driven by level 1 data only by continued research into the critical care of the burn patient.

Analgo-sedation of patients with burns outside the operating room

Following the initial resuscitation of burn patients, the pain experienced may be divided into a 'background' pain and a 'breakthrough' pain associated with painful procedures. While background pain may be treated with intravenous opioids via continuous infusion or patient-controlled analgesia (PCA) and/or less potent oral opioids, breakthrough pain may be treated with a variety of interventions. The aim is to reduce patient anxiety, improve analgesia and ensure immobilization when required. Untreated pain and improper sedation may result in psychological distress such as post-traumatic stress disorder, major depression or delirium. This review summarizes recent developments and current techniques in sedation and analgesia in non-intubated adult burn patients during painful procedures performed outside the operating room (e.g. staple removal, wound-dressing, bathing). Current techniques of sedation and analgesia include different approaches, from a slight increase in background pain therapy (e.g. morphine PCA) to PCA with rapid-onset opioids, to multimodal drug combinations, nitrous oxide, regional blocks, or non-pharmacological approaches such as hypnosis and virtual reality. The most reliable way to administer drugs is intravenously. Fast-acting opioids can be combined with ketamine, propofol or benzodiazepines. Adjuvant drugs such as clonidine or NSAIDs and paracetamol (acetaminophen) have also been used. Patients receiving ketamine will usually maintain spontaneous breathing. This is an important feature in patients who are continuously turned during wound dressing procedures and where analgo-sedation is often performed by practitioners who are not specialists in anaesthesiology. Drugs are given in small boluses or by patient-controlled sedation, which is titrated to effect, according to sedation and pain scales. Patient-controlled infusion with propofol has also been used. However, we must bear in mind that burn patients often show an altered pharmacokinetic and pharmacodynamic response to drugs as a result of altered haemodynamics, protein binding and/or increased extracellular fluid volume, and possible changes in glomerular filtration. Because sedation and analgesia can range from minimal sedation (anxiolysis) to general anaesthesia, sedative and analgesic agents should always be administered by designated trained practitioners and not by the person performing the procedure. At least one individual who is capable of establishing a patent airway and positive pressure ventilation, as well as someone who can call for additional assistance, should always be present whenever analgo-sedation is administered. Oxygen should be routinely delivered during sedation. Blood pressure and continuous ECG monitoring should be carried out whenever possible, even if a patient is undergoing bathing or other procedures that may limit monitoring of vital pulse-oximetry parameters.

FLUID RESUSCITATION IN MAJOR BURNS

BACKGROUND

The Parkland formula is established as the "gold standard" for initial fluid resuscitation for major burns. The purpose of this study was to review our fluid resuscitation practice for major burns to determine whether anecdotal observations of significant variations from the Parkland formula were wide spread and whether any difference could be used as a basis for a revision of fluid resuscitation in major burns.

METHODS

A retrospective review of 127 presentations to The Alfred Burns Unit with total body surface area (TBSA) affected > or =15% was conducted. A retrospective review of the resuscitation data from these patients was compared with the Parkland formula as well as other studies.

RESULTS

A total of 49 patients with complete data on fluid administration and uncomplicated burns were included in the analysis. Significantly larger volumes of fluid (5.58 mL/kg per %TBSA) were given to these patients in the first 24 h than predicted by the Parkland formula. Mean arterial pressure, pulse rate and urine output were at satisfactory levels. Clinically evident complications from fluid administration were minimal. Mortality was similar to that in other centres.

CONCLUSION

Fluid resuscitation volumes significantly higher than those predicted by the Parkland formula were given, without adverse consequences. This retrospective review supports a prospective, multicentre, randomized, controlled study comparing this study with the Parkland formula, resulting in a better guide to initial fluid resuscitation in major burns.