Renal clearance of heparin-binding protein and elimination during renal replacement therapy: Studies in ICU patients and healthy volunteers

Background

Heparin-binding protein (HBP) is released by neutrophils upon activation, and elevated plasma levels are seen in inflammatory states like sepsis, shock, cardiac arrest, and burns. However, little is known about the elimination of HBP. We wanted to study renal clearance of HBP in healthy individuals and in burn patients in intensive care units (ICUs). We also wished to examine the levels of HBP in the effluent of renal replacement circuits in ICU patients undergoing continuous renal replacement therapy (CRRT).

Methods

We measured plasma and urine levels of HBP and urine flow rate in 8 healthy individuals and 20 patients in a burn ICU. In 32 patients on CRRT, we measured levels of HBP in plasma and in the effluent of the CRRT circuit.

Results

Renal clearance of HBP (median (IQR) ml/min) was 0.19 (0.08–0.33) in healthy individuals and 0.30 (0.01–1.04) in burn ICU patients. In ICU patients with cystatin C levels exceeding 1.44 mg/l, clearance was 0.45 (0.15–2.81), and in patients with cystatin C below 1.44 mg/l clearance was lower 0.28 (0.14–0.55) (p = 0.04). Starting CRRT did not significantly alter plasma levels of HBP (p = 0.14), and the median HBP level in the effluent on CRRT was 9.1 ng/ml (IQR 7.8–14.4 ng/ml).

Conclusion

In healthy individuals and critically ill burn patients, renal clearance of HBP is low. It is increased when renal function is impaired. Starting CRRT in critically ill patients does not alter plasma levels of HBP significantly, but HBP can be found in the effluent.

It seems unlikely that impaired kidney function needs to be considered when interpreting concentrations of HBP in previous studies. Starting CRRT does not appear to be an effective way of reducing HBP concentrations.

Children aged 0-16 admitted to Swedish intensive care units and paediatric intensive care units showed low mortality rates

AIM

This study described the basic characteristics of children aged 0-16 years who were treated in intensive care units (ICUs) and paediatric ICUs (PICUs), compared their outcomes and examined any causes of death.

METHODS

This was a retrospective cohort study of admissions to 74 ICUs and three PICUs in Sweden that were recorded in the Swedish Intensive Care Registry from January 1, 2008 to December 31, 2012.

RESULTS

We retrieved data on 12 756 children who were admitted 17 003 times. The case mix differed between the ICUs, which were mainly admissions for injuries, accidents and observation, and PICUs, which were mainly admissions for malformations, genetic abnormalities and respiratory problems (p < 0.001). The median stays in the ICUs and PICUs were 1.4 and 3.5 days (p < 0.001), respectively. The respective crude mortality rates were 1.1% and 2.0, and the Paediatric Index of Mortality version 2 standardised mortality ratios were 0.43 and 0.50. None of these differences were significant. Most deaths were within 24 hours: About 57% in the ICUs, mainly from brain anomalies, and 13% in the PICUs, mainly from circulatory problems.

CONCLUSION

Sweden had a low mortality rate in both ICUs and PICUs and the children admitted to these two types of unit differed.

The Effect of Enzymatic Digestion on Cultured Epithelial Autografts

Severe burns are often treated by means of autologous skin grafts, preferably following early excision of the burnt tissue. In the case of, for example, a large surface trauma, autologous skin cells can be expanded in vitro prior to transplantation to facilitate the treatment when insufficient uninjured skin is a limitation. In this study we have analyzed the impact of the enzyme (trypsin or accutase) used for cell dissociation and the incubation time on cell viability and expansion potential, as well as expression of cell surface markers indicative of stemness. Skin was collected from five individuals undergoing abdominal reduction surgery and the epidermal compartment was digested in either trypsin or accutase. Trypsin generally generated more cells than accutase and with higher viability; however, after 7 days of subsequent culture, accutase-digested samples tended to have a higher cell count than trypsin, although the differences were not significant. No significant difference was found between the enzymes in median fluorescence intensity of the analyzed stem cell markers; however, accutase digestion generated significantly higher levels of CD117- and CD49f-positive cells, but only in the 5 h digestion group. In conclusion, digestion time appeared to affect the isolated cells more than the choice of enzyme.

Female risk-adjusted survival advantage after injuries caused by falls, traffic or assault: a nationwide 11-year study

BACKGROUND

A female survival advantage after injury has been observed, and animal models of trauma have suggested either hormonal or genetic mechanisms as component causes. Our aim was to compare age and risk-adjusted sex-related mortality in hospital for the three most common mechanisms of injury in relation to hormonal effects as seen by age.

METHODS

All hospital admissions for injury in Sweden during the period 2001-2011 were retrieved from the National Patient Registry and linked to the Cause of Death Registry. The International Classification of Diseases Injury Severity Score (ICISS) was used to adjust for injury severity, and the Charlson Comorbidity Index to adjust for comorbidity. Age categories (0-14, 15-50, and ≥ 51 years) were used to represent pre-menarche, reproductive and post- menopausal women.

RESULTS

Women had overall a survival benefit (OR 0.51; 95% CI 0.50 to 0.53) after adjustment for injury severity and comorbidity. A similar pattern was seen across the age categories (0-14 years OR 0.56 (95% CI 0.25 to 1.25), 15-50 years OR 0.70 (95% CI 0.57 to 0.87), and ≥ 51 years OR 0.49 (95% CI 0.48 to 0.51)).

CONCLUSION

In this 11-year population-based study we found no support for an oestrogen-related mechanism to explain the survival advantage for females compared to males following hospitalisation for injury.

Three Years' Experience of a Novel Biosynthetic Cellulose Dressing in Burns

Objective: The use of porcine xenograft (PX) is widely spread in burn care. However, it may cause immunologic responses and other ethical and cultural considerations in different cultures. Therefore, there is a need for alternatives. The aim of this work is to test a novel biosynthetic cellulose dressing (Epiprotect^®) on burn patients.

Approach: Charts from 38 patients with superficial burns (SBs) (n = 18) or excised burns (n = 20) that got biosynthetic cellulose dressing instead of PX at a national burn center during 3 years were reviewed. Time to healing, length of stay, and wound infection were extracted from the medical records.

Results: SBs hospitalization time was 11 days comparable to PXs reported by others. In the excised group, median duration of hospital stay was 35 days. Time to healing was 28 days. Seven wound infections were confirmed in the superficial group (39%) and 11 infections in the excised group (61%). Patients with superficial wounds reported pain relief on application.

Innovation: A dressing (17 × 21 cm) consisting of biosynthetic cellulose replacing PX.

Conclusion: Outcome of treatment of SBs or temporary coverage of excised deep burns with biosynthetic cellulose is comparable to treatment with PX. However, biosynthetic cellulose has benefits such as providing pain relief on application and ethical or cultural issues with the material is nonexistent.

Use of the burn intervention score to calculate the charges of the care of burns

BACKGROUND

To our knowledge this is the first published estimate of the charges of the care of burns in Sweden. The Linköping Burn Interventional Score has been used to calculate the charges for each burned patient since 1993. The treatment of burns is versatile, and depends on the depth and extension of the burn. This requires a flexible system to detect the actual differences in the care provided. We aimed to describe the model of burn care that we used to calculate the charges incurred during the acute phase until discharge, so it could be reproduced and applied in other burn centres, which would facilitate a future objective comparison of the expenses in burn care.

METHODS

All patients admitted with burns during the period 2010-15 were included. We analysed clinical and economic data from the daily burn scores during the acute phase of the burn until discharge from the burn centre.

RESULTS

Total median charge/patient was US$ 28 199 (10th-90th centiles 4668-197 781) for 696 patients admitted. Burns caused by hot objects and electricity resulted in the highest charges/TBSA%, while charges/day were similar for the different causes of injury. Flame burns resulted in the highest mean charges/admission, probably because they had the longest duration of stay. Mean charges/patient increased in a linear fashion among the different age groups.

CONCLUSION

Our intervention-based estimate of charges has proved to be a valid tool that is sensitive to the procedures that drive the costs of the care of burns such as large TBSA%, intensive care, and operations. The burn score system could be reproduced easily in other burn centres worldwide and facilitate the comparison regardless of the differences in the currency and the economic circumstances.

Are there any differences in the provided burn care between men and women? A retrospective study

Background

Disparity between medical treatment for men and women has been recorded worldwide. However, it is difficult to find out if the disparities in both the use of resources and outcome depend entirely on sex-related discrimination. Our aim was to investigate if there are differences in burn treatments between the sexes.

Methods

All patients admitted with burns to Linköping University Hospital during the 16-year period 2000–2015 were included. Interventions were prospectively recorded using the validated Burn SCoring system (BSC). Data were analysed using a multivariable panel regression model adjusted for age, percentage total body surface area (%TBSA), and in-hospital mortality.

Results

A total of 1363 patients were included, who generated a total of 22,301 daily recordings while they were inpatients. Males were 70% (930/1363). Sex was not an independent factor for daily scores after adjustment for age, %TBSA, and mortality in hospital (model R²=0.60, p < 0.001).

Conclusion

We found no evidence of inequity between the sexes in treatments given in our burn centre when we had adjusted for size of burn, age, and mortality. BSC seems to be an appropriate model in which to evaluate sex-related differences in the delivery of treatments.

Microbial cellulose dressing compared with silver sulphadiazine for the treatment of partial thickness burns: A prospective, randomised, clinical trial

BACKGROUND

The current treatment for partial thickness burns at the trial site is silver sulphadiazine, as it minimises bacterial colonisation of wounds. Its deleterious effect on wound healing, together with the need for repeated, often painful, procedures, has brought about the search for a better treatment. Microbial cellulose has shown promising results that avoid these disadvantages. The aim of this study was therefore to compare microbial cellulose with silver sulphadiazine as a dressing for partial thickness burns.

METHOD

All patients who presented with partial thickness (superficial and deep dermal) burns from October 2014 to October 2016 were screened for this randomised clinical trial. Twenty patients were included in each group: the cellulose group was treated with microbial cellulose sheets and the control group with silver sulphadiazine cream 10mg/g. The wound was evaluated every third day. Pain was assessed using the Face, Legs, Activity, Cry, Consolability (FLACC) scale during and after each procedure. Other variables recorded were age, sex, percentage total body surface area burned (TBSA%), clinical signs of infection, time for epithelialisation and hospital stay. Linear multivariable regression was used to analyse the significance of differences between the treatment groups by adjusting for the size and depth of the burn, and the patient's age.

RESULTS

Median TBSA% was 9% (IQR 5.5-12.5). The median number of dressing changes was 1 (IQR 1-2) in the cellulose group, which was lower than that in the control group (median 9.5, IQR 6-16) (p<0.001). Multivariable regression analysis showed that the group treated with microbial cellulose spent 6.3 (95% CI 0.2-12.5) fewer days in hospital (p=0.04), had a mean score that was 3.4 (95% CI 2.5-4.3) points lower during wound care (p<0.001), and 2.2 (95% CI 1.6-2.7) afterwards (p<0.001). Epithelialisation was quicker, but not significantly so.

CONCLUSION

These results suggest that the microbial cellulose dressing is a better first choice for treatment of partial thickness burns than silver sulphadiazine cream. Fewer dressings of the wound were done and, combined with the low pain scores, this is good for both the patients and the health care system. The differences in randomisation of the area of burns is, however, a concern that needs to be included in the interpretation of the results.

Better Protection of Glass-Fronted Stoves Is Needed in Sweden Because of the Increase in the Number of Contact Burns Among Small Children

The impression among the attending physicians at their Burn Centre is that the number of contact burns caused by glass-fronted stoves is increasing, particularly in the youngest group of patients. It is an interesting subgroup, as these injuries are preventable. The authors' aim of this study was to find out whether the incidence of burns after contact with glass-fronted stoves has increased.The authors included all patients aged between 0 and 3.9 years who presented to the National Burn Centre during the period 2008-2015 with contact burn injuries caused by glass-fronted stoves. The change in incidence over time was calculated from national records and analyzed with simple linear regression.Fifty-six patients were included, of whom 20 were treated during the past 2 years of the study. Thirty-seven of the 56 were boys (66%), median (10-90 percentiles) age was 1.1 (0.7-2.5) years, percentage total body surface area burned was 0.6% (0.1-2.0), 12 were admitted for overnight stay in hospital, and seven needed operations. The incidence was 0.34/100 000 children-years during the first 2 years, and it was three times as high during the past 2 years. The increase in incidence was 0.24/100 000 children-years by each 2-year period (P = .02).The authors' results indicate that contact burns among children caused by glass-fronted stoves are increasing in Sweden. The authors propose that there should be a plan for their prevention put in place.

Decreased risk adjusted 30-day mortality for hospital admitted injuries: a multi-centre longitudinal study

Background

The interpretation of changes in injury-related mortality over time requires an understanding of changes in the incidence of the various types of injury, and adjustment for their severity. Our aim was to investigate changes over time in incidence of hospital admission for injuries caused by falls, traffic incidents, or assaults, and to assess the risk-adjusted short-term mortality for these patients.

Methods

All patients admitted to hospital with injuries caused by falls, traffic incidents, or assaults during the years 2001–11 in Sweden were identified from the nationwide population-based Patient Registry. The trend in mortality over time for each cause of injury was adjusted for age, sex, comorbidity and severity of injury as classified from the International Classification of diseases, version 10 Injury Severity Score (ICISS).

Results

Both the incidence of fall (689 to 636/100000 inhabitants: p = 0.047, coefficient − 4.71) and traffic related injuries (169 to 123/100000 inhabitants: p < 0.0001, coefficient − 5.37) decreased over time while incidence of assault related injuries remained essentially unchanged during the study period. There was an overall decrease in risk-adjusted 30-day mortality in all three groups (OR 1.00; CI95% 0.99–1.00). Decreases in traffic (OR 0.95; 95% CI 0.93 to 0.97) and assault (OR 0.93; 95% CI 0.87 to 0.99) related injuries was significant whereas falls were not during this 11-year period.

Discussion

Risk-adjustment is a good way to use big materials to find epidemiological changes. However after adjusting for age, year, sex and risk we find that a possible factor is left in the pre- and/or in-hospital care.

Conclusions

The decrease in risk-adjusted mortality may suggest changes over time in pre- and/or in-hospital care. A non-significantdecrease in risk-adjusted mortality was registered for falls, which may indicate that low-energy trauma has not benefited for the increased survivability as much as high-energy trauma, ie traffic- and assault related injuries.

Deaths caused by injury among people of working age (18-64) are decreasing, while those among older people (64+) are increasing

Background

Injury is an important cause of death in all age groups worldwide, and contributes to many losses of human and economic resources. Currently, we know a few data about mortality from injury, particularly among the working population. The aim of the present study was to examine death from injury over a period of 14 years (1999–2012) using the Swedish Cause of Death Registry (CDR) and the National Patient Registry, which have complete national coverage.

Method

CDR was used to identify injury-related deaths among adults (18 years or over) during the years 1999–2012. ICD-10 diagnoses from V01 to X39 were included. The significance of changes over time was analyzed by linear regression.

Results

The incidence of prehospital death decreased significantly (coefficient −0.22, r² = 0.30; p = 0.041) during the study period, while that of deaths in hospital increased significantly (coefficient 0.20, r² = 0.75; p < 0.001). Mortality/100,000 person-years in the working age group (18–64 years) decreased significantly (coefficient −0.40, r² = 0.37; p = 0.020), mainly as a result of decrease in traffic-related deaths (coefficient −0.34, r² = 0.85; p < 0.001). The incidence of deaths from injury among elderly (65 years and older) patients increased because of the increase in falls (coefficient 1.71, r² = 0.84; p < 0.001) and poisoning (coefficient 0.13, r² = 0.69; p < 0.001).

Conclusion

The epidemiology of injury in Sweden has changed during recent years in that mortality from injury has declined in the working age group and increased among those people 64 years old and over.

Improvement in mortality at a National Burn Centre since 2000: Was it the result of increased resources?

The aim of this study was to find out whether the charging costs (calculated using interventional burn score) increased as mortality decreased.During the last 2 decades, mortality has declined significantly in the Linköping Burn Centre. The burn score that we use has been validated as a measure of workload and is used to calculate the charging costs of each burned patient.We compared the charging costs and mortality in 2 time periods (2000-2007 and 2008-2015). A total of 1363 admissions were included. We investigated the change in the burn score, as a surrogate for total costs per patient. Multivariable regression was used to analyze risk-adjusted mortality and burn score.The median total body surface area % (TBSA%) was 6.5% (10-90 centile 1.0-31.0), age 33 years (1.3-72.2), duration of stay/ TBSA% was 1.4 days (0.3-5.3), and 960 (70%) were males. Crude mortality declined from 7.5% in 2000-2007 to 3.4% in 2008-2015, whereas the cumulative burn score was not increased (P  =  .08). Regression analysis showed that risk-adjusted mortality decreased (odds ratio 0.42, P  =  .02), whereas the adjusted burn score did not change (P  =  .14, model R 0.86).Mortality decreased but there was no increase in the daily use of resources as measured by the interventional burn score. The data suggest that the improvements in quality obtained have been achieved within present routines for care of patients (multidisciplinary/orientated to patients' safety).

Division of overall duration of stay into operative stay and postoperative stay improves the overall estimate as a measure of quality of outcome in burn care

Total duration of stay adjusted for percentage of the total body surface area burned (TBSA%) is a commonly used outcome measure in burn care. However, it has been criticised as it is affected by many factors, some of which are not strictly part of burn care. A division into operative stay and postoperative stay may improve this measure. The aim was to evaluate if operative stay can serve as a more standardised measure by: comparing the variation in operative stay/TBSA% with the variation in total stay/TBSA%, and to study different factors associated with operative stay and postoperative stay.

Staged excisions of moderate-sized burns compared with total excision with immediate autograft: an evaluation of two strategies

BACKGROUND

Different surgical techniques have evolved since excision and autografting became the treatment of choice for deep burns in the 1970s. The treatment plan at the Burn Center, Linköping University Hospital, Sweden, has shifted from single-stage excision and immediate autografting to staged excisions and temporary cover with xenografts before autografting. The aim of this study was to find out if the change in policy resulted in extended duration of hospital stay/total body surface area burned (LOS/TBSA%).

METHODS

Retrospective clinical cohort including surgically-managed patients with burns of 15%-60% TBSA% within each treatment group. The first had early full excisions of deep dermal and full thickness burns and immediate autografts (1997-98), excision and immediate autograft group) and the second had staged excisions before final autografts using xenografts for temporary cover (2010-11, staged excision group).

RESULTS

The study included 57 patients with deep dermal and full-thickness burns, 28 of whom had excision and immediate autografting, and 29 of whom had staged excisions with xenografting before final autografting. Adjusted (LOS/TBSA%) was close to 1, and did not differ between groups. Mean operating time for the staged excision group was shorter and the excised area/operation was smaller. The total operating time/TBSA% did not differ between groups.

CONCLUSION

Staged excisions with temporary cover did not affect adjusted LOS/TBSA% or total operating time. Staged excisions may be thought to be more expensive because of the cost of covering the wound between stages, but this needs to be further investigated as do the factors that predict long term outcome.

Temporary coverage of burns with a xenograft and sequential excision, compared with total early excision and autograft

During the 80s and 90s, early and total excision of full thickness burns followed by immediate autograft was the most common treatment, with repeated excision and grafting, mostly for failed grafts. It was hypothesized, therefore, that delayed coverage with an autograft preceded by a temporary xenograft after early and sequential smaller excisions would lead to a better wound bed with fewer failed grafts, a smaller donor site, and possibly also a shorter duration of stay in hospital. We carried out a case control study with retrospective analysis from our National Burn Centre registry for the period 1997-2011. Patients who had been managed with early total excision and autograft were compared with those who had had sequential smaller excisions covered with temporary xenografts until the burn was ready for the final autograft. The sequential excision and xenograft group (n=42) required one-third fewer autografts than patients in the total excision and autograft group (n=45), who needed more than one operation (p<0.001). We could not detect any differences in duration of stay in hospital / total body surface area burned% (duration of stay/TBSA%) (2.0 and 1.8) (p=0.83). The two groups showed no major differences in terms of adjusted duration of stay, but our findings suggest that doing early, smaller, sequential excisions using a xenograft for temporary cover can result in shorter operating times, saving us the trouble of making big excisions. However, costs tended to be higher when the burns were > 25% TBSA.

Scald management protocols - outcome differences in two different time periods using different treatment strategies

Over the years the treatment of scalds in our centre has changed, moving more towards the use of biological dressings (xenografts). Management of scalds with mid dermal or deep dermal injuries differs among centers using different types of dressings, and recently biological membrane dressings were recommended for this type of injury. Here we describe differences in treatment outcome in different periods of time. All patients with scalds who presented to the Linkoping Burn Centre during two periods, early (1997-98) and later (2010-12) were included. Data were collected in the unit database and analyzed retrospectively. A lower proportion of autograft operations was found in the later period, falling from 32% to 19%. Hospital stay was shorter in the later period (3.5 days shorter, p=0.01) and adjusted duration of hospital stay/TBSA% was shorter (1.2 to 0.7, p=0.07). The two study groups were similar in most of the studied variables: we could not report any significant differences regarding outcome except for unadjusted duration of hospital stay. Further studies are required to investigate functional and aesthetic outcome differences between the treatment modalities.

A prospective randomized cost billing comparison of local fasciocutaneous perforator versus free Gracilis flap reconstruction for lower limb in a developing economy

Distal half leg complex wounds are usually a formidable problem that necessitates either local or free flap coverage. The aim of this study was to compare cost billing charges in free Gracilis flap (fGF) and local fasciocutaneous perforator flap (lFPF) in reconstructing complex soft tissue leg and foot defects.

PATIENTS AND METHODS

Thirty consecutive adult (>15-year-old) patients with soft tissue defects in the leg and/or foot requiring tissue coverage with a flap in the period between 2012 and 2015 were randomly assigned (block randomization) to either an fGF or lFPF procedure. The outcome measures addressed were total billed charges costs, perioperative billed charges cost, partial or complete flap loss, length of hospital stay, inpatient postsurgical care duration, complications, operating time and number of operative scrub staff.

RESULTS

One patient suffered from complete flap loss in each group. Reconstruction with lFPF showed total lower billed charges costs by 62% (2509 USD) (p < 0.001) and perioperative billed charges cost by 54% (779 USD) (p < 0.001), and shorter total hospital stay (36.5 days; p < 0.001), inpatient postsurgical care duration (6.4 days; p < 0.001), operating time (4.3 h; p < 0.001) and fewer scrub staff (2.2 persons; p < 0.001).

CONCLUSION

These results suggest that neither flap is totally superior to the other; the choice should instead be based on the outcome sought and logistics. lFPF requires lower billed charges cost and resource use and saves operative time and personnel and reduces length of hospital stay. Our approach changed towards using perforator flaps in medium-sized defects, keeping the free flap option for larger defects.