The association between out of hours burn centre admission and in-hospital outcomes in patients with severe burns

INTRODUCTION

Patients with severe burns (≥20 % total body surface area [TBSA]) have specific and time sensitive needs on arrival to the burn centre. Burn care systems in Australia and New Zealand are organised differently during weekday business hours compared to overnight and weekends. The aims of this study were to compare the profile of adult patients with severe burns admitted during business hours with patients admitted out of hours and to quantify the association between time of admission and in-hospital outcomes in the Australian and New Zealand context.

METHODS

Data were extracted from the Burns Registry of Australia and New Zealand for adults (≥18 years) with severe burns admitted to Australian or New Zealand burn centres between July 2016 and June 2020. Differences in patient profiles, clinical management, and in-hospital outcomes were investigated. Univariable and multivariable logistic and linear regression models were used to quantify associations between time of admission and in-hospital outcomes of interest.

RESULTS

We found 623 patients eligible for inclusion. Most patients were admitted out of hours (69.2 %), their median age was 42 years, and most were male (78 %). The median size burn was 30 % TBSA and 32 % of patients had an inhalation injury. A greater proportion of patients admitted out of hours had alcohol and/or drugs involved with injury compared to patients admitted during business hours. No other differences between groups were observed. Patients in both groups had similar odds of dying in hospital (Odds Ratio [OR], 95 % Confidence Interval [95 %CI] 1.49 [0.64, 3.48]), developing acute kidney injury within 72 h (OR, 95 %CI 0.58 [0.32, 1.07]), or sepsis (OR, 95 %CI 1.04 [0.46, 2.35]). No association was found between time of admission and hospital (%, 95 %CI 1.00 [0.82, 1.23]) nor intensive care length of stay (%, 95 %CI 0.97 [0.73, 1.27]).

DISCUSSION

In this first Australian and/or New Zealand study to explore the association between time of admission and burn patient in-hospital outcomes, out of hours admission was not associated with patient outcomes of interest.

CONCLUSION

These findings support current models of care in Australian and New Zealand burn centres, however further investigation is required. Nonetheless, given most severe burns patients arrive out of hours to burn the centre, it is plausible that out of hours availability of senior burn clinicians will improve patient care and safety resilience within burn care systems.

Delayed onset sequential bilateral abducens nerve palsies secondary to traumatic CSF leak

Abducens nerve palsy via direct or indirect injury is well described following head trauma likely due to its long anatomical course with several vulnerable segments. However, bilateral abducens palsies due to non-iatrogenic intracranial hypotension is unique. This report describes the case of a male with sequential delayed onset abducens nerve palsies following head and neck trauma due to intracranial hypotension secondary to cerebrospinal fluid (CSF) leak from a dural tear at the C6/7 level. Signs of intracranial hypotension were evident on magnetic resonance imaging (MRI). We hypothesise that the traction effect from ongoing CSF leak resulted in sequential palsies. His clinical course was also complicated by pulmonary embolus and a prolonged period of immobility, the anti-gravity effects of which likely mitigated the CSF leak in the early period. Conservative management was undertaken with bed rest, fluids and caffeine with good response and resolving abducens dysfunction after ten weeks. Further management with epidural blood patch or surgical fixation was not necessary and deemed unlikely to succeed given the location of the dural tear and the need for concurrent anticoagulation. It is important to recognise CSF leak and intracranial hypotension as potential, albeit rare, causes for sequential abducens nerve palsy in patients with head and spinal injuries. Management strategies of this condition range from conservative measures to surgical intervention.

Regional anaesthesia for rib fractures: A pilot study of serratus anterior plane block

OBJECTIVE

Rib fractures are not only painful but are associated with morbidity and mortality, especially in older patients. The serratus anterior plane block (SAPB) is a plane block distant from major neurovascular bundles and may provide anaesthesia to a substantial area of the hemithorax. This pilot study was designed to assess if the SAPB can be safely and efficiently incorporated to the trauma reception workflow of an adult, level 1 trauma centre.

METHODS

A convenience sample of 20 adult patients with at least two or more unilateral rib fractures received a SAPB performed by an emergency physician in addition to their standard analgesic regime. Time to perform the procedure, the number of attempts and complications were recorded as feasibility measures. Secondary outcome was the safety of the block. Numerical pain scores at pre-determined time points over 4 h, the diagnosis of hospital-acquired pneumonia, hospital length of stay and mortality at hospital discharge were collected to provide pilot data on effectiveness.

RESULTS

The median time to perform the procedure was 5.5 (interquartile range 4.6-10) mins with a range of 2-10.5 min. Most (16; 80%) SAPBs were completed in a single attempt. There were no documented complications. Median pain scores reduced from 6.5 (6-8) and were maintained at 3 (2-5) at 4 h after the SAPB.

CONCLUSIONS

The present study demonstrated the feasibility of ultrasound-guided SAPB among patients with multiple rib fractures in the ED. No complications were observed. Further prospective evaluation of analgesic effects in a larger cohort is indicated.

Epigenetically induced changes in nuclear textural patterns and gelatinase expression in human fibrosarcoma cells

OBJECTIVE

Chromatin texture patterns of tumour cell nuclei can serve as cancer biomarkers, either to define diagnostic classifications or to obtain relevant prognostic information, in a large number of human tumours. Epigenetic mechanisms, mainly DNA methylation and histone post-translational modification, have been shown to influence chromatin packing states, and therefore nuclear texture. The aim of this study was to analyse effects of these two mechanisms on chromatin texture, and also on correlation with gelatinase expression, in human fibrosarcoma tumour cells.

MATERIALS AND METHODS

We investigated effects of DNA hypomethylating agent 5-aza-2'-deoxycytidine (5-azadC) and histone deacetylase inhibitor trichostatin A (TSA) on nuclear textural characteristics of human HT1080 fibrosarcoma cells, evaluated by image cytometry, and expression of gelatinases MMP-2 and MMP-9, two metalloproteinases implicated in cancer progression and metastasis.

RESULTS

5-azadC induced significant variation in chromatin higher order organization, particularly chromatin decondensation, associated with reduction in global DNA methylation, concomitantly with increase in MMP-9, and to a lesser extent, MMP-2 expression. TSA alone did not have any effect on HT1080 cells, but exhibited differential activity when added to cells treated with 5-azadC. When treated with both drugs, nuclei had higher texture abnormalities. In this setting, reduction in MMP-9 expression was observed, whereas MMP-2 expression remained unaffected.

CONCLUSIONS

These data show that hypomethylating drug 5-azadC and histone deacetylase inhibitor TSA were able to induce modulation of higher order chromatin organization and gelatinase expression in human HT1080 fibrosarcoma cells.

Endotracheal tube cuff pressure before, during, and after fixed-wing air medical retrieval

Abstract Background. Increased endotracheal tube (ETT) cuff pressure is associated with compromised tracheal mucosal perfusion and injuries. No published data are available for Australia on pressures in the fixed-wing air medical retrieval setting. Objective. After introduction of a cuff pressure manometer (Mallinckrodt, Hennef, Germany) at the Royal Flying Doctor Service (RFDS) Base in Dubbo, New South Wales (NSW), Australia, we assessed the prevalence of increased cuff pressures before, during, and after air medical retrieval. Methods. This was a retrospective audit in 35 ventilated patients during fixed-wing retrievals by the RFDS in NSW, Australia. Explicit chart review of ventilated patients was performed for cuff pressures and changes during medical retrievals with pressurized aircrafts. Pearson correlation was calculated to determine the relation of ascent and ETT cuff pressure change from ground to flight level. Results. The mean (± standard deviation) of the first ETT cuff pressure measurement on the ground was 44 ± 20 cmH2O. Prior to retrieval in 11 patients, the ETT cuff pressure was >30 cmH2O and in 11 patients >50 cmH2O. After ascent to cruising altitude, the cuff pressure was >30 cmH2O in 22 patients and >50 cmH2O in eight patients. The cuff pressure was reduced 1) in 72% of cases prior to take off and 2) in 85% of cases during flight, and 3) after landing, the cuff pressure increased in 85% of cases. The correlation between ascent in cabin altitude and ETT cuff pressure was r = 0.3901, p = 0.0205. Conclusions. The high prevalence of excessive cuff pressures during air medical retrieval can be avoided by the use of cuff pressure manometers. Key words: cuff pressure; air medical retrieval; prehospital.

Natural chalcones as dual inhibitors of HDACs and NF-κB

Histone deacetylase enzymes (HDACs) are emerging as a promising biological target for cancer and inflammation. Using a fluorescence assay, we tested the in vitro HDAC inhibitory activity of twenty-one natural chalcones, a widespread group of natural products with well-known anti-inflammatory and antitumor effects. Since HDACs regulate the expression of the transcription factor NF-κB, we also evaluated the inhibitory potential of the compounds on NF-κB activation. Only four chalcones, isoliquiritigenin (no. 10), butein (no. 12), homobutein (no. 15) and the glycoside marein (no. 21) showed HDAC inhibitory activity with IC₅₀ values of 60–190 μM, whereas a number of compounds inhibited TNFα-induced NF-κB activation with IC₅₀ values in the range of 8–41 μM. Interestingly, three chalcones (nos. 10, 12 and 15) inhibited both TNFα-induced NF-κB activity and total HDAC activity of classes I, II and IV. Molecular modeling and docking studies were performed to shed light into dual activity and to draw structure-activity relationships among chalcones (nos. 1–21). To the best of our knowledge this is the first study that provides evidence for HDACs as potential drug targets for natural chalcones. The dual inhibitory potential of the selected chalcones on NF-κB and HDACs was investigated for the first time. This study demonstrates that chalcones can serve as lead compounds in the development of dual inhibitors against both targets in the treatment of inflammation and cancer.

Curcumin-Induced Cell Death in Two Leukemia Cell Lines: K562 and Jurkat

Curcumin presents strong antioxidant and anticancer properties. However, molecular mechanisms leading to curcumin-induced cell death are poorly understood. The effect of curcumin was compared in two different leukemia cell lines: K562 and Jurkat. Cell death was induced in both cell lines, and apoptosis pathways were investigated by Western blot analysis. Decreases in pro-caspase 8 and 9 levels were observed. BH(3) interacting domain death agonist (Bid) was also cleaved. Jurkat cells appeared to be more sensitive to curcumin, and apoptosis takes place earlier.