Intraabdominal Hypertension and the Abdominal Compartment Syndrome in Burn Patients

The Complexity of the Post-Burn Immune Response: An Overview of the Associated Local and Systemic Complications

Burn injury induces a complex inflammatory response, both locally and systemically, and is not yet completely unravelled and understood. In order to enable the development of accurate treatment options, it is of paramount importance to fully understand post-burn immunology. Research in the last decades describes insights into the prolonged and excessive inflammatory response that could exist after both severe and milder burn trauma and that this response differs from that of none-burn acute trauma. Persistent activity of complement, acute phase proteins and pro- and anti-inflammatory mediators, changes in lymphocyte activity, activation of the stress response and infiltration of immune cells have all been related to post-burn local and systemic pathology. This "narrative" review explores the current state of knowledge, focusing on both the local and systemic immunology post-burn, and further questions how it is linked to the clinical outcome. Moreover, it illustrates the complexity of post-burn immunology and the existing gaps in knowledge on underlying mechanisms of burn pathology.

Risk factors for abdominal compartment syndrome in trauma – A review

" Background and Aim: Abdominal compartment syndrome is a life-threatening complication that can occur in trauma patients and greatly increase their mortality. Although there is a better scientific understanding of the general phenomena involved in the pathogenesis of this complication, the particular risk factors and their implications in the trauma patient population are yet to be deciphered. Methods: The authors conducted research through 3 electronic databases (PubMed, Scopus, and ScienceDirect) using the following search formula: “(ACS OR abdominal compartment syndrome) AND (*trauma*) AND (risk factor)”. Subsequently, additional search formulas were used, including the risk factors taken into consideration (i.e. “shock”, “hypotension”, “acidosis”, “base deficit”, ”coagulopathy”, “retroperitoneal hematoma”, “HOB elevation”, “fluid resuscitation”, “damage control laparotomy”). Results: Throughout the 41 articles analyzed in this paper, 7 risk factors transcended and were further discussed: head of bed elevation/patient positioning, fluid resuscitation, the “lethal triad” of acidosis hypothermia and coagulopathy, Damage Control Laparotomy, shock/hypotension, retroperitoneal hematoma and demographics (age, gender, and race). Conclusions: To summarize, many potential risk factors were evaluated for the envisagement of the present paper, but the ones that prevailed the most were excessive fluid resuscitation, shock/hypotension, retroperitoneal hematomas, and the lethal triad. Consistent with other studies, no connection was found between age, gender, or race and the development of ACS. Further studies should focus more on the likely involvement of damage control laparotomy and patient positioning, as well as hypocalcemia, in the unfolding of ACS in trauma patients"

Preliminary study of reliability of transcutaneous sensors in measuring intraabdominal pressure

Early recognition of elevated intraabdominal pressure (IAP) in critically ill patients is essential, since it can result in abdominal compartment syndrome, which is a life-threatening condition. The measurement of intravesical pressure is currently considered the gold standard for IAP assessment. Alternative methods have been proposed, where IAP assessment is based on measuring abdominal wall tension, which reflects the pressure in the abdominal cavity. The aim of this study was to evaluate the feasibility of using patch-like transcutaneous sensors to estimate changes in IAP, which could facilitate the monitoring of IAP in clinical practice. This study was performed with 30 patients during early postoperative care. All patients still had an indwelling urinary catheter postoperatively. Four wearable sensors were attached to the outer surface of the abdominal region to detect the changes in abdominal wall tension. Additionally, surface EMG was used to monitor the activity of the abdominal muscles. The thickness of the subcutaneous tissue was measured with ultrasound. Patients performed 4 cycles of the Valsalva manoeuvre, with a resting period in between (the minimal resting period was 30 s, with a prolongation as necessary to ensure that the fluid level in the measuring system had equilibrated). The IAP was estimated with intravesical pressure measurements during all resting periods and all Valsalva manoeuvres, while the sensors continuously measured changes in abdominal wall tension. The association between the subcutaneous thickness and tension changes on the surface and the intraabdominal pressure was statistically significant, but a large part of the variability was explained by individual patient factors. As a consequence, the predictions of IAP using transcutaneous sensors were not biased, but they were quite variable. The specificity of detecting intraabdominal pressure of 20 mmHg and above is 88%, with an NPV of 96%, while its sensitivity and PPV are currently far lower. There are inherent limitations of the chosen preliminary study design that directly caused the low sensitivity of our method as well as the poor agreement with the gold standard method; in spite of that, we have shown that these sensors have the potential to be used to monitor intraabdominal pressure. We are planning a study that would more closely resemble the intended clinical use and expect it to show more consistent results with a far smaller error.

Low-Flow Acute Kidney Injury: The Pathophysiology of Prerenal Azotemia, Abdominal Compartment Syndrome, and Obstructive Uropathy

AKI is a syndrome, not a disease. It results from many different primary and/or secondary etiologies and is often multifactorial, especially in the hospitalized patient. This review discusses the pathophysiology of three etiologies that cause AKI, those being kidney hypoperfusion, abdominal compartment syndrome, and urinary tract obstruction. The pathophysiology of these three causes of AKI differs but is overlapping. They all lead to a low urine flow rate and low urine sodium initially. In all three cases, with early recognition and correction of the underlying process, the resulting functional AKI can be rapidly reversed. However, with continued duration and/or increased severity, cell injury occurs within the kidney, resulting in structural AKI and a longer and more severe disease state with increased morbidity and mortality. This is why early recognition and reversal are critical.

Direct Peritoneal Resuscitation Improves Survival in a Murine Model of Combined Hemorrhage and Burn Injury

INTRODUCTION

Combined burn injury and hemorrhagic shock are a common cause of injury in wounded warfighters. Current protocols for resuscitation for isolated burn injury and isolated hemorrhagic shock are well defined, but the optimal strategy for combined injury is not fully established. Direct peritoneal resuscitation (DPR) has been shown to improve survival in rats after hemorrhagic shock, but its role in a combined burn/hemorrhage injury is unknown. We hypothesized that DPR would improve survival in mice subjected to combined burn injury and hemorrhage.

MATERIALS AND METHODS

Male C57/BL6J mice aged 8 weeks were subjected to a 7-second 30% total body surface area scald in a 90°C water bath. Following the scald, mice received DPR with 1.5 mL normal saline or 1.5 mL peritoneal dialysis solution (Delflex). Control mice received no peritoneal solution. Mice underwent a controlled hemorrhage shock via femoral artery cannulation to a systolic blood pressure of 25 mm Hg for 30 minutes. Mice were then resuscitated to a target blood pressure with either lactated Ringer's (LR) or a 1:1 ratio of packed red blood cells (pRBCs) and fresh frozen plasma (FFP). Mice were observed for 24 hours following injury.

RESULTS

Median survival time for mice with no DPR was 1.47 hours in combination with intravascular LR resuscitation and 2.08 hours with 1:1 pRBC:FFP. Median survival time significantly improved with the addition of intraperitoneal normal saline or Delflex. Mice that received DPR followed by 1:1 pRBC:FFP required less intravascular volume than mice that received DPR with LR, pRBC:FFP alone, and LR alone. Intraperitoneal Delflex was associated with higher levels of tumor necrosis factor alpha and macrophage inflammatory protein 1 alpha and lower levels of interleukin 10 and intestinal fatty acid binding protein. Intraperitoneal normal saline resulted in less lung injury 1 hour postresuscitation, but increased to similar severity of Delflex at 4 hours.

CONCLUSIONS

After a combined burn injury and hemorrhage, DPR leads to increased survival in mice. Survival was similar with the use of normal saline or Delflex. DPR with normal saline reduced the inflammatory response seen with Delflex and delayed the progression of acute lung injury. DPR may be a valuable strategy in the treatment of patients with combined burn injury and hemorrhage.

A History of Fluid Management-From "One Size Fits All" to an Individualized Fluid Therapy in Burn Resuscitation

Fluid management is a cornerstone in the treatment of burns and, thus, many different formulas were tested for their ability to match the fluid requirements for an adequate resuscitation. Thereof, the Parkland-Baxter formula, first introduced in 1968, is still widely used since then. Though using nearly the same formula to start off, the definition of normovolemia and how to determine the volume status of burn patients has changed dramatically over years. In first instance, the invention of the transpulmonary thermodilution (TTD) enabled an early goal directed fluid therapy with acceptable invasiveness. Furthermore, the introduction of point of care ultrasound (POCUS) has triggered more individualized schemes of fluid therapy. This article explores the historical developments in the field of burn resuscitation, presenting different options to determine the fluid requirements without missing the red flags for hyper- or hypovolemia. Furthermore, the increasing rate of co-morbidities in burn patients calls for a more sophisticated fluid management adjusting the fluid therapy to the actual necessities very closely. Therefore, formulas might be used as a starting point, but further fluid therapy should be adjusted to the actual need of every single patient. Taking the developments in the field of individualized therapies in intensive care in general into account, fluid management in burn resuscitation will also be individualized in the near future.

Trend Analysis of Current Modalities for Monitoring Fluid Therapy in Patients With Large Burns: Echoing the Call for Better Resuscitation Indices

The aim of this study was to investigate whether current standards at our institution have effectively monitored resuscitations of severely burned patients during the first 48 hours postburn. Demographics, injuries assessed by TBSA and full thickness (FT), and resuscitation volumes (lactated Ringer's [LR]) were compared for all patients and those who died or survived. Means and standard deviations of hourly indices (urinary output [UOP], lactate [LAC], base excess [BE]) vs LR were analyzed. Waveforms, four-quadrant concordance, and correlation were also employed to compare the trending abilities (hourly changes [∆]) of aforementioned variables vs LR. A total of 203 patients were included in the analysis. Of these patients, 71 (35%) died, and 50 (25%) had inhalation injuries. Mean age and weight were 47 ± 19 years and 87 ± 18 kg, respectively. Mean TBSA burned was 41 ± 20%, with a mean FT of 18 ± 24%. Importantly, normalized waveform plots demonstrated the inability of UO, LAC, and BE to follow hourly changes in LR. Correlation of these variables was weak (r>>-1). This was confirmed by concordance plots. Slopes in all groups demonstrated that UOP was a better resuscitative monitor than LAC or BE. ∆UOP responded to ∆LR better in patients who survived than died. Reliance on hourly UOP as the sole index of optimal resuscitation is not supported. This study echoed the call for better resuscitation indices.

Burns: Pathophysiology of Systemic Complications and Current Management

As a result of many years of research, the intricate cellular mechanisms of burn injury are slowly becoming clear. Yet, knowledge of these cellular mechanisms and a multitude of resulting studies have often failed to translate into improved clinical treatment for burn injuries. Perhaps the most valuable information to date is the years of clinical experience and observations in the management and treatment of patients, which has contributed to a gradual improvement in reported outcomes of mortality. This review provides a discussion of the cellular mechanisms and pathways involved in burn injury, resultant systemic effects on organ systems, current management and treatment, and potential therapies that we may see implemented in the future.

A comparison of two different fluid resuscitation management protocols for pediatric burn patients: A retrospective study

OBJECTIVE

Pediatric burn patients are more susceptible to burn shock than adults, and an effective fluid management protocol is critical to successful resuscitation. Our research aim was to investigate the safety and efficacy of two protocols for pediatric burn patients for use within the first 24h.

METHODS

A total of 113 pediatric burn patients were enrolled from January 2007 to October 2012. Of those patients, 57 received fluid titration regimens of alternating crystalloids and colloids once within 2h in the first 24h after burn (Group A), whereas the remaining patients received regimens of alternating crystalloids and colloids once within 1h in the first 24h after burn (Group B). The safety, fluid volume infused and urine output were recorded and compared.

RESULTS

All the patients survived in the first 24h after burn. There were no significant differences between Group A and Group B in lactic acid (LA) level and base excess (BE). The water infused in Group A were greater than that of Group B in the first 24h (P=0.024). No significant differences were found in total volume intake and hourly urine output between the 2 groups in the first 24h.

CONCLUSION

The implementation of fluid resuscitation using either protocol A or protocol B is safe and effective for pediatric burn patients in the first 24h. The total fluid infused were similar between two protocols. But using protocol A may be more convenient and labor-saving for nurses.

The impact of patient weight on burn resuscitation

BACKGROUND

Optimal fluid resuscitation of burn patients with burns greater than 20% total body surface area is critical to prevent burn shock during the initial 24 hours to 48 hours postburn. Currently, most resuscitation formulas incorporate the patient's weight when estimating 24-hour fluid requirements. The objective of this study was to determine the impact of weight on fluid resuscitation requirements and outcomes during the initial 24 hours after admission.

METHODS

We performed a retrospective review of patients admitted to our burn intensive care unit from December 2007 to April 2013, resuscitated with a computerized decision support system. We classified patients into body mass index (BMI) categories of underweight (BMI: <18.5), normal (BMI: 18.5-24.9), overweight (BMI: 25.0-29.9), or obese (BMI: >30.0). We also calculated the percent difference from ideal body weight (IBW) and compared 24-hour fluid volumes received.

RESULTS

Patients with missing weight and/or height values were excluded from the study, resulting in a final cohort of 161 patients for analysis. Mean total body surface area was 42 ± 20% with a full thickness burn of 18 ± 23%. Mean age, weight, and height were 47 ± 19 years, 83 ± 19 kg, and 68 ± 4 inches, respectively. IBW for this cohort was 68 ± 11 kg with a BMI of 28 ± 6. Univariate analysis showed significant differences in 24-hour resuscitation volumes (mL/kg) between normal and obese patients (p < 0.05). Further analysis revealed that increasing percent difference from IBW was associated with lower fluid volumes. Although obesity was not associated with inhalation injury or renal replacement therapy, it was correlated to an increased risk for mortality (p < 0.05).

CONCLUSION

This analysis showed that increasing weight was associated with lower fluid resuscitation volume requirements and a higher mortality rate, despite the low incidence of inhalation injury and renal replacement therapy in our obese patients. The use of actual body weight to drive resuscitation volumes may result in overresuscitation of obese patients, depending on the resuscitation formula. Further studies are needed to better explain the relationship between mortality and obesity in burn patients.

LEVEL OF EVIDENCE

Therapeutic/care management, level IV.

Predicting the proportion of full-thickness involvement for any given burn size based on burn resuscitation volumes

INTRODUCTION

The depth of burn has been an important factor often overlooked when estimating the total resuscitation fluid needed for early burn care. The goal of this study was to determine the degree to which full-thickness (FT) involvement affected overall 24-hour burn resuscitation volumes.

METHODS

We performed a retrospective review of patients admitted to our burn intensive care unit from December 2007 to April 2013, with significant burns that required resuscitation using our computerized decision support system for burn fluid resuscitation. We defined the degree of FT involvement as FT Index (FTI; percentage of FT injury/percentage of total body surface area (TBSA) burned [%FT / %TBSA]) and compared variables on actual 24-hour fluid resuscitation volumes overall as well as for any given burn size.

RESULTS

A total of 203 patients admitted to our burn center during the study period were included in the analysis. Mean age and weight were 47 ± 19 years and 87 ± 18 kg, respectively. Mean %TBSA was 41 ± 20 with a mean %FT of 18 ± 24. As %TBSA, %FT, and FTI increased, so did actual 24-hour fluid resuscitation volumes (mL/kg). However, increase in FTI did not result in increased volume indexed to burn size (mL/kg per %TBSA). This was true even when patients with inhalation injury were excluded. Further investigation revealed that as %TBSA increased, %FT increased nonlinearly (quadratic polynomial) (R = 0.994).

CONCLUSION

Total burn size and FT burn size were both highly correlated with increased 24-hour fluid resuscitation volumes. However, FTI did not correlate with a corresponding increase in resuscitation volumes for any given burn size, even when patients with inhalation injury were excluded. Thus, there are insufficient data to presume that those who receive more volume at any given burn size are likely to be mostly full thickness or vice versa. This was influenced by a relatively low sample size at each 10%TBSA increment and larger burn sizes disproportionately having more FT burns. A more robust sample size may elucidate this relationship better.

LEVEL OF EVIDENCE

Therapeutic/care management study, level IV.

Vitamin C in Burn Resuscitation

The inflammatory state after burn injury is characterized by an increase in capillary permeability that results in protein and fluid leakage into the interstitial space, increasing resuscitative requirements. Although the mechanisms underlying increased capillary permeability are complex, damage from reactive oxygen species plays a major role and has been successfully attenuated with antioxidant therapy in several disease processes. However, the utility of antioxidants in burn treatment remains unclear. Vitamin C is a promising antioxidant candidate that has been examined in burn resuscitation studies and shows efficacy in reducing the fluid requirements in the acute phase after burn injury.

A novel mathematical model to predict prognosis of burnt patients based on logistic regression and support vector machine

OBJECTIVE

To develop a mathematical model of predicting mortality based on the admission characteristics of 6220 burn cases.

METHODS

Data on all the burn patients presenting to Institute of Burn Research, Southwest Hospital, Third Military Medical University from January of 1999 to December of 2008 were extracted from the departmental registry. The distributions of burn cases were scattered by principal component analysis. Univariate associations with mortality were identified and independent associations were derived from multivariate logistic regression analysis. Using variables independently and significantly associated with mortality, a mathematical model to predict mortality was developed using the support vector machine (SVM) model. The predicting ability of this model was evaluated and verified.

RESULTS

The overall mortality in this study was 1.8%. Univariate associations with mortality were identified and independent associations were derived from multivariate logistic regression analysis. Variables at admission independently associated with mortality were gender, age, total burn area, full thickness burn area, inhalation injury, shock, period before admission and others. The sensitivity and specificity of logistic model were 99.75% and 85.84% respectively, with an area under the receiver operating curve of 0.989 (95% CI: 0.979-1.000; p<0.01). The model correctly classified 99.50% of cases. The subsequently developed support vector machine (SVM) model correctly classified nearly 100% of test cases, which could not only predict adult group but also pediatric group, with pretty high robustness (92%-100%).

CONCLUSION

A mathematical model based on logistic regression and SVM could be used to predict the survival prognosis according to the admission characteristics.

Melanocortin-4 receptor agonists alleviate intestinal dysfunction in secondary intra-abdominal hypertension rat model

BACKGROUND

Intra-abdominal hypertension (IAH) is a potentially life-threatening disease. Melanocortin-4 (MC4) receptor activation exhibits life-saving properties. The aim of the present study was to examine whether treatment with the MC4 receptor agonist RO27-3225 ameliorates intestinal injury in IAH rats.

METHODS

A total of 72 male Sprague-Dawley rats were randomized into six groups. Group 1 was the sham group. Group 2, the sham + RO group, received RO27-3225 (180 μg/kg, intraperitoneally). IAH was induced in group 3, the IAH group, by blood draw (mean arterial pressure = 30 mm Hg for 90 min) followed by shed blood and/or Ringer solution reinfusion. Intra-abdominal pressure was increased to 20 mm Hg by injecting air into the peritoneal cavity. Group 4, the RO group, was administered RO27-3225 at 5 min after blood draw. Groups 5 and 6 were the chlorisondamine (Chl) and HS024 groups, in which the rats were pretreated with the nicotinic acetylcholine receptor antagonist Chl or selective MC4 receptor antagonist (HS024), respectively, at 2 min before RO27-3225 was administered.

RESULTS

RO27-3225 restored mean arterial pressure, reduced tumor necrosis factor-α, and interleukin-1β messenger RNA expression increased by IAH, alleviated histologic damage, and improved superoxide dismutase activity in the intestine. Compared with the IAH group, the levels of intestinal fatty acid-binding protein, intestinal edema and intestinal permeability were lower in the RO group. Furthermore, the RO27-3225 treatment increased the expression of Rho-associated coiled-coil-containing protein kinase 1 and phosphorylated myosin light chain. Chl and HS024 abrogated the protective effects of RO27-3225.

CONCLUSIONS

These data indicate that the MC4 receptor agonist counteracts the intestinal inflammatory response, ameliorating intestinal injury in experimental secondary IAH by MC4 receptor-triggered activation of the cholinergic anti-inflammatory pathway. It may represent a promising strategy for the treatment of IAH in the future.

Five-year cohort study of open pancreatic necrosectomy for necotizing pancreatitis suggests it is a safe and effective operation

INTRODUCTION

Despite advances in the management of necrotizing pancreatitis, open necrosectomy remains an important management option for necrotizing pancreatitis, and patients undergoing necrosectomy suffer significant morbidity and mortality. The aim of this study was to report the outcomes of open necrosectomy from a recent large cohort of patients with necrotizing pancreatitis.

METHODS

Data are reported from a cohort of 276 consecutive patients with necrotizing pancreatitis who underwent open surgical debridement. Nutritional status, nutritional methods, bleeding, infection, demarcation of necrotic tissues, and time from onset of disease were scored. Scores ≥ 10 were considered as an indication for debridement.

RESULTS

One hundred sixty-two (58.7%) and 52 (18.8%) patients underwent minimally invasive peritoneal and retroperitoneal drainage, respectively, before necrosectomy. Median delay from disease onset to debridement was 48 days. Fifty-five patients (19.9%) underwent more than one operation; 352 operations were performed in total. There were 17 deaths (6.2%) postoperatively.

CONCLUSION

This study demonstrated the results for open debridement in a recent large cohort of patients. Although minimally invasive necrosectomy has been developed in recent years, open necrosectomy remains an important approach for the debridement of necrotizing pancreatitis effectively and safely.

Respiratory functions of burn patients undergoing decompressive laparotomy due to secondary abdominal compartment syndrome

INTRODUCTION

The development of secondary abdominal compartment syndrome (ACS) is associated with multiple organ dysfunction. There is little information about the effects of decompressive laparotomy (DL) on respiratory function (RF) in burn patients developing ACS.

PATIENTS AND METHODS

We retrospectively obtained data characterising RF from the database of an adult burn intensive care unit (BICU). Peak inspiratory pressure (Pip), PaO2/FiO2-ratio (P/F), static compliance (Cstat) and airway resistance (Raw) were analysed over the course of 60 h at 8 time points relative to DL.

RESULTS

Thirty-five patients with ACS underwent DL with a mean percentage of total burned body surface area (TBSA) 39 ± 23% and mean intra-abdominal pressure 33 ± 7 mmHg. All patients presented with significantly deteriorating RF within 12h of DL (Pip 33 ± 4 to 39 ± 7 cm/H2O, p=0.003; P/F 232 ± 59 to 160 ± 55 mmHg, p<0.001, Cstat 34 ± 5 to 26 ± 6 mL/cmH2O, p<0.001; Raw 18 ± 3 to 24 ± 9 cm H2O/L/s, p=0.02). All these parameters improved significantly (p<0.001) after DL, regardless of the presence of inhalation injury or torso burns. Mortality was 71.4%.

CONCLUSIONS

Variables characterising RF demonstrated a rapid deterioration before and a significant and sustained improvement after DL in burn patients developing ACS. Despite these respiratory improvements, DL was associated with low survival rates. Secondary ACS remains a challenge in burn patients and thus warrants particular attention during intensive care treatment.

New management strategy for fluid resuscitation: quantifying volume in the first 48 hours after burn injury

This study evaluated a 24-hour resuscitation protocol, established a formula to quantify resuscitation volume for the second 24 hours, described the relationship between the first and second 24 hours, and identified which patients required high volumes. A protocol for patients with burn >15% TBSA was implemented in 2009. Initial fluid was based on the Parkland calculation and adjusted to meet a goal urine output. Protocol compliance was defined as appropriate fluid titration to maintain urine output. Resuscitation ratio in the second 24 hours was tabulated as total fluid /(evaporative loss + maintenance fluid + estimated colloid). Data were collected prospectively from 2009 to 2011. A Wilcoxon rank test compared differences between groups. Regression analyses analyzed volume administered. P < .05 was statistically significant. Forty patients with burn >15% TBSA met criteria for inclusion. Mean age, burn size, and resuscitation volumes in the first and second 24 hours (mean + SD) were 47+ 20.7 years, 29.9 + 14.6% TBSA, 7.4 + 3.7 ml/kg/% TBSA, and a ratio of 1.9 times expected volume (SD, 1.3), respectively. Protocol compliance was 34%. Intubation, older age, and increased narcotic administration correlated with higher resuscitation volumes. A higher resuscitation volume in the first 24 hours significantly correlated with a higher resuscitation volume in the second 24 hours (P < .001). In conclusion, there is a significant relationship between fluid administration in the first and second 24 hours of resuscitation; intubation, older age, and narcotics correlate with higher volumes. A formula for observed/expected volumes in the second 24 hours is total fluid/(evaporative loss + maintenance fluid +estimated colloid).

The use of negative-pressure wound therapy to manage enteroatmospheric fistulae in two patients with large abdominal wounds

Enteric fistulae are a relatively common complication of bowel surgery or in surgery where the bowel has been exposed. Fistulae can present a significant threat to patients' well-being. Changes in surgical techniques and in particular the rise in damage control surgery for emergency patients have led to an increase in open abdominal wounds. The presence of an enteroatmospheric fistula on the surface of a wound can cause a number of distressing symptoms/issues for the patient whilst providing a significant challenge for the clinician. The loss of fluid, proteins and electrolytes will place the patient in danger of becoming hypokalaemic and malnourished. A variety of techniques are available, most refer to a method of isolating the fistula using stoma rings or washers and ostomy paste. The role of negative pressure in the management of wounds with fistula is in its infancy; however, there is evidence to suggest that isolation techniques can be advantageous in managing wounds with fistulae.

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).

Should we measure intra-abdominal pressures in every intensive care patient?

Intra-abdominal pressure (IAP) is seldom measured by default in intensive care patients. This review summarises the current evidence on the prevalence and risk factors of intra-abdominal hypertension (IAH) to assist the decision-making for IAP monitoring.IAH occurs in 20% to 40% of intensive care patients. High body mass index (BMI), abdominal surgery, liver dysfunction/ascites, hypotension/vasoactive therapy, respiratory failure and excessive fluid balance are risk factors of IAH in the general ICU population. IAP monitoring is strongly supported in mechanically ventilated patients with severe burns, severe trauma, severe acute pancreatitis, liver failure or ruptured aortic aneurysms. The risk of developing IAH is minimal in mechanically ventilated patients with positive end-expiratory pressure < 10 cmH2O, PaO2/FiO2 > 300, and BMI < 30 and without pancreatitis, hepatic failure/cirrhosis with ascites, gastrointestinal bleeding or laparotomy and the use of vasopressors/inotropes on admission. In these patients, omitting IAP measurements might be considered.In conclusions, clear guidelines to select the patients in whom IAP measurements should be performed cannot be given at present. In addition to IAP measurements in at-risk patients, a clinical assessment of the signs of IAH should be a part of every ICU patient's bedside evaluation, leading to prompt IAP monitoring in case of the slightest suspicion of IAH development.

Abdominal compartment syndrome: risk factors, diagnosis, and current therapy

Abdominal compartment syndrome's manifestations are difficult to definitively detect on physical examination alone. Therefore, objective criteria have been articulated that aid the bedside clinician in detecting intra-abdominal hypertension as well as the abdominal compartment syndrome to initiate prompt and potentially life-saving intervention. At-risk patient populations should be routinely monitored and tiered interventions should be undertaken as a team approach to management.

Damage control resuscitation is associated with a reduction in resuscitation volumes and improvement in survival in 390 damage control laparotomy patients

OBJECTIVE

To determine whether implementation of damage control resuscitation (DCR) in patients undergoing damage control laparotomy (DCL) translates into improved survival.

BACKGROUND

DCR aims at preventing coagulopathy through permissive hypotension, limiting crystalloids and delivering higher ratios of plasma and platelets. Previous work has focused only on the impact of delivering higher ratios (1:1:1).

METHODS

A retrospective cohort study was performed on all DCL patients admitted between January 2004 and August 2010. Patients were divided into pre-DCR implementation and DCR groups and were excluded if they died before completion of the initial laparotomy. The lethal triad was defined as immediate postoperative temperature less than 95°F, international normalized ratio more than 1.5, or a pH less than 7.30.

RESULTS

A total of 390 patients underwent DCL. Of these, 282 were pre-DCR and 108 were DCR. Groups were similar in demographics, injury severity, admission vitals, and laboratory values. DCR patients received less crystalloids (median: 14 L vs 5 L), red blood cells (13 U vs 7 U), plasma (11 U vs 8 U), and platelets (6 U vs 0 U) in 24 hours, all P < 0.05. DCR patients had less evidence of the lethal triad upon intensive care unit arrival (80% vs 46%, P < 0.001). 24-hour and 30-day survival was higher with DCR (88% vs 97%, P = 0.006 and 76% vs 86%, P = 0.03). Multivariate analysis controlling for age, injury severity, and emergency department variables, demonstrated DCR was associated with a significant increase in 30-day survival (OR: 2.5, 95% CI: 1.10-5.58, P = 0.028).

CONCLUSION

In patients undergoing DCL, implementation of DCR reduces crystalloid and blood product administration. More importantly, DCR is associated with an improvement in 30-day survival.

Computerized decision support system improves fluid resuscitation following severe burns: an original study

OBJECTIVE

Several formulas have been developed to guide resuscitation in severely burned patients during the initial 48 hrs after injury. These approaches require manual titration of fluid that may result in human error during this process and lead to suboptimal outcomes. The goal of this study was to analyze the efficacy of a computerized open-loop decision support system for burn resuscitation compared to historical controls.

DESIGN

Fluid infusion rates and urinary output from 39 severely burned patients with >20% total body surface area burns were recorded upon admission (Model group). A fluid-response model based on these data was developed and incorporated into a computerized open-loop algorithm and computer decision support system. The computer decision support system was used to resuscitate 32 subsequent patients with severe burns (computer decision support system group) and compared with the Model group.

SETTING

Burn intensive care unit of a metropolitan Level 1 Trauma center.

PATIENTS

Acute burn patients with >20% total body surface area requiring active fluid resuscitation during the initial 24 to 48 hours after burn.

MEASUREMENTS AND MAIN RESULTS

We found no significant difference between the Model and computer decision support system groups in age, total body surface area, or injury mechanism. Total crystalloid volume during the first 48 hrs post burn, total crystalloid intensive care unit volume, and initial 24-hr crystalloid intensive care unit volume were all lower in the computer decision support system group. Infused volume per kilogram body weight (mL/kg) and per percentage burn (mL/kg/total body surface area) were also lower for the computer decision support system group. The number of patients who met hourly urinary output goals was higher in the computer decision support system group.

CONCLUSIONS

Implementation of a computer decision support system for burn resuscitation in the intensive care unit resulted in improved fluid management of severely burned patients. All measures of crystalloid fluid volume were reduced while patients were maintained within urinary output targets a higher percentage of the time. The addition of computer decision support system technology improved patient care.

Percutaneous catheter decompression in the treatment of elevated intraabdominal pressure

BACKGROUND

Intraabdominal hypertension (IAH) and abdominal compartment syndrome (ACS) traditionally have been treated surgically through emergent laparotomy. Intensivist-performed bedside drainage of free intraperitoneal fluid or blood (percutaneous catheter decompression [PCD]) has been advocated as a less-invasive alternative to open abdominal decompression (OAD).

METHODS

A single-center disease and severity of illness-matched case-control comparison of 62 patients with IAH/ACS treated with PCD vs traditional OAD was performed. The relative efficacy of each treatment in reducing elevated intraabdominal pressure (IAP) and improving organ dysfunction was assessed. Physiologic and demographic predictors of successful PCD therapy were determined.

RESULTS

PCD and OAD both were effective in significantly decreasing IAP and peak inspiratory pressure as well as in increasing abdominal perfusion pressure. PCD potentially avoided the need for subsequent OAD in 25 of 31 patients (81%) treated. Successful PCD therapy was associated with fluid drainage of > 1,000 mL or a decrease in IAP of > 9 mm Hg in the first 4 h postdecompression.

CONCLUSIONS

Intensivist-performed PCD is an effective and less-invasive technique for treating patients with IAH/ACS where free intraperitoneal fluid or blood is present as determined by bedside ultrasonography. Failure to drain at least 1,000 mL of fluid and decrease IAP by at least 9 mm Hg in the first 4 h postdecompression is associated with PCD failure and should prompt urgent OAD.

Abdominal compartment syndrome in trauma resuscitation

PURPOSE OF REVIEW

Swelling is inexorably linked to shock and resuscitation in trauma. In many forms, swelling complicates and interacts with traumatic injury to raise pressures in the abdomen, resulting in intraabdominal hypertension, which may overtly manifest as abdominal compartment syndrome (ACS) driving multiple organ failure. Despite renewed clinical interest in posttraumatic intraabdominal pressure, there remains a chiasm between knowledge of the risks and clinical interventions to mitigate them. This review provides a concise overview of definitions, risk factors, diagnosis and management using an illustrative trauma case.

RECENT FINDINGS

Intraabdominal pressure commonly increases following trauma, wherein ACS may manifest earlier than generally appreciated and complicate other insults such as shock and hemorrhage. Contemporary resuscitation strategies may exacerbate intraabdominal hypertension, particularly massive crystalloid resuscitation. Although unproven, the recent transition to crystalloid restriction and high plasma resuscitation strategies may influence the prevalence of ACS. Nonetheless, aggressive intraabdominal pressure monitoring should be mandatory in the critically ill. Despite potential nonoperative options, decompressive laparotomy remains the only definitive but often morbid treatment.

SUMMARY

ACS results from many dysfunctions acting in concert with each other in self-propagating vicious cycles. Starting with greater awareness, it is imperative that the growing knowledge should be translated into clinical practice.