Utility of venous blood gases for the assessment of traumatic shock: a prospective observational study.

BACKGROUND: ABG samples are often obtained in trauma patients to assess shock severity. Venous blood gas (VBG) sampling, which is less invasive, has been widely used to assess other forms of shock. The study aim was to determine the agreement between VBG and ABG measurements in trauma. METHODS: Patients were enrolled at an Australian trauma centre between October 2016 and October 2018. Bland-Altman limits of agreement (LOA) between paired blood gas samples taken <30 min apart were used to quantify the extent of agreement. The impact of using only VBG measurements was considered using an a priori plan. Cases where venous sampling failed to detect 'concerning levels' were flagged using evidence-based cut-offs: pH ≤7.2, base deficit (BD) ≤-6, bicarbonate <21 and lactate ≥4. Case summaries of these patients were assessed by independent trauma clinicians as to whether an ABG would change expected management. RESULTS: During the study period 176 major trauma patients had valid paired blood gas samples available for analysis. The median time difference between paired measurements was 11 min (IQR 6-17). There was a predominance of men (81.8%) and blunt trauma (92.0%). Median Injury Severity Score was 13 (range 1-75) and inpatient mortality was 6.3%. Mean difference (ABG-VBG) and LOA between paired arterial and venous measurements were 0.036 (LOA -0.048 to 0.120) for pH, -1.27 mmol/L (LOA -4.35 to 1.81) for BD, -0.64 mmol/L (LOA -1.86 to 0.57) for lactate and -1.97 mmol/L (LOA -5.49 to 1.55) for bicarbonate. Independent assessment of the VBG 'false negative' cases (n=20) suggested an ABG would change circulatory management in two cases. CONCLUSIONS: In trauma patients VBG and ABG parameters displayed suboptimal agreement. However, in cases flagged as VBG 'false negative' independent review indicated that the availability of an ABG was unlikely to change management.

Randomised controlled trial of simulation-based education for mechanical cardiopulmonary resuscitation training.

INTRODUCTION: Mechanical cardiopulmonary resuscitation (M-CPR) is increasingly used in the management of cardiac arrest. There are no previously reported randomised studies investigating M-CPR training. This study of newly trained M-CPR providers hypothesised that a brief simulation-based intervention after 4 months would improve M-CPR performance at 6 months. METHODS: This study used a simulated 'in situ' cardiac arrest model. The M-CPR device used was a proprietary Lund University Cardiac Assist System 3 machine (Physio Control, Redmond, Washington, USA). Standardised baseline training was provided to all participants. Following training, baseline performance was assessed. The primary outcome measure was the time taken to initiate M-CPR and the secondary outcome was performance against a checklist of errors. Participants were then randomised to intervention group (simulation training) or control group (routine clinical use of M-CPR). After 6 months the outcome measures were reassessed. Comparative statistical tests used an intention-to-treat analysis. RESULTS: 112 participants were enrolled. The intervention group (n=60) and control group (n=52) had similar demographic characteristics. At the 6-month assessment, median time to M-CPR initiation was 27.0 s (IQR 22.0-31.0) in the intervention group and 31.0 s (IQR 25.6-46.0) in the control group (p=0.003). The intervention group demonstrated fewer errors compared with controls at 6 months (p<0.001) CONCLUSION: In this randomised study of approaches to M-CPR training, providers receiving additional simulation-based training had higher retention levels of M-CPR skills. Therefore, when resuscitation skills are newly learnt, provision follow-up training should be an important consideration.

The association between systolic blood pressure and in-hospital mortality in older emergency department patients who are hospitalised with a suspected infection.

OBJECTIVE: In existing risk stratification and resuscitation guidelines for sepsis, a hypotension threshold of systolic blood pressure (SBP) below 90-100 mmHg is typically used. However, for older patients, the clinical relevance of a SBP in a seemingly 'normal' range (>100 mmHg) is still poorly understood, as they may need higher SBP for adequate tissue perfusion due to arterial stiffening. We therefore investigated the association between SBP and mortality in older emergency department (ED) patients hospitalised with a suspected infection. METHODS: In this observational multicentre study in the Netherlands, we interrogated an existing prospective database of consecutive ED patients hospitalised with a suspected infection between 2011 and 2016. We investigated the association between SBP categories (≤100, 101-120, 121-139, ≥140 mmHg) and in-hospital mortality in patients of 70 years and older. We adjusted for demographics, comorbidity, disease severity and admission to ward/intensive care using multivariable logistic regression. RESULTS: In the 833 included older patients, unadjusted in-hospital mortality increased from 4.7% (n=359) in SBP ≥140 mmHg to 20.8% (n=96) in SBP ≤100 mmHg. SBP categories were linearly associated with case-mix-adjusted in-hospital mortality. The adjusted ORs (95% CI) for ≤100, 101-120 and 121-139 mmHgcompared with the reference of ≥140 mmHg were 3.8 (1.8 to 7.8), 2.8 (1.4 to 5.5) and 1.9 (0.9 to 3.7), respectively. CONCLUSION: In older ED patients hospitalised with a suspected infection, we found an inverse linear association between SBP and case-mix-adjusted in-hospital mortality. Our data suggest that the commonly used threshold for hypotension is not clinically meaningful for risk stratification of older ED patients with a suspected infection.

ABG needle study: a randomised control study comparing 23G versus 25G needle success and pain scores.

OBJECTIVE: To determine whether a narrower gauge needle used in ABG sampling is associated with lower pain scores and complication rates without increasing the level of difficulty of the procedure. METHODS: We performed a prospective single-blinded randomised control study of patients from a tertiary-level emergency department in Sydney who required an ABG analysis over the period of June 2010-July 2012. Patients were randomised to either a 23G or 25G needle and the primary outcome that included pain experienced by these patient were recorded as pain scores on a 10 cm hatched visual analogue scale. The difficulty scores and complications were also noted from the operator. RESULTS: Data for 119 consenting eligible patients were included in the analysis. 63 patients were allocated to the 23G needle group and 56 to the 25G needle group. The mean pain score was 3.5 (SD=2.7) for the 23G group and 3.4 (SD=2.7) for the 25G group with a mean difference between the pain scores of 0.1 (95% CI -0.9 to 1.1, p=0.83). The 23G and 25G mean difficulty score was 3.4 (SD=2.6) and 4.3 (SD=2.4), respectively, with a mean difference of 0.9 (95% CI -0.03 to 1.7, p=0.06). 21.6% of patient in the 23G needle group experienced some complication with regard to the sampling in the form of haematoma, tenderness or paraesthesia in comparison to 5.4% of patients in the 25G needle group (p=0.03). CONCLUSIONS: There was no significant difference in pain scores experienced by patients undertaking ABG sampling with either a 23G or 25G needle. TRIAL REGISTRATION NUMBER: ACTRN12609000957291.

Serum lactate cut-offs as a risk stratification tool for in-hospital adverse outcomes in emergency department patients screened for suspected sepsis.

OBJECTIVES: We investigated specific lactate thresholds for adverse outcomes in patients presenting to emergency departments (EDs) with suspected sepsis identified based on the performance of a sepsis screening algorithm. DESIGN AND SETTING: A standardised sepsis bundle was implemented across public hospitals in New South Wales, Australia, as a quality improvement initiative. A register of all adult ED presentations (≥18 years) meeting predefined criteria for sepsis was created, using a combination of data linkage and direct reporting from 97 participating sites. PARTICIPANTS: A total of 12 349 adult ED presentations with 8310 (67.3%) having serum lactate analysis on arrival. Analysis of outcomes was based on dataset for 12 349 subjects obtained through multiple imputation for missing data. INTERVENTIONS: A sepsis management bundle including early antibiotic prescribing, fluid therapy and referral to intensive care unit (ICU) services was implemented. OUTCOME MEASURES: A primary composite adverse event (AE) outcome of inhospital mortality (IHM) and/or prolonged ICU stay ≥72 hours (ICU 72 hours) was used for this study. RESULTS: There was statistically significant increase both in the ORs of AE and IHM with each integer increase in serum lactate values. After adjusting for the presence of hypotension, the estimated ORs for the combined AE outcome were 2.71 (95% CI 2.05 to 3.57), 2.65 (95% CI 2.29 to 3.08), 3.10 (95% CI 2.71 to 3.53) and 3.89 (95% CI 3.36 to 4.50) for serum lactate levels at or above 1, 2, 3 and 4 mmol/L, respectively. The corresponding ORs for IHM were 2.93 (95% CI 2.08 to 4.13), 2.77 (95% CI 2.34 to 3.29), 3.26 (95% CI 2.80 to 3.80) and 4.01 (95% CI 3.40 to 4.73), respectively (all P<0.0001). More than 10% of patients with suspected sepsis and with serum lactate ≥2 mmol/L experienced a prolonged ICU stay or died in hospital. CONCLUSIONS: ED sepsis screening algorithms intended to identify patient adverse outcomes should incorporate a serum lactate cut-off of ≥2 mmol/L as a threshold for the initiation of specific interventions and increased monitoring.

Impact of emergency department discharge stream short stay unit performance and hospital bed occupancy rates on access and patient flowmeasures: A single site study.

OBJECTIVE: The ED discharge stream short stay units (EDSSUs) aim to facilitate patient flows through EDs. We investigate the relationship between EDSSU census and hospital bed occupancy rates (BORs) on National Emergency Access Target (NEAT) performance and did-not-wait (DNW) rates at a tertiary metropolitan adult ED in Sydney, Australia. METHODS: We collated data for all ED presentations between 1 January 2012 and 31 December 2014. Daily ED, EDSSU census and ED-accessible hospital BORs were tabulated with daily ED NEAT performance and DNW rates. Non-parametric regression analyses was conducted on cohorts of appropriate, inappropriate, successful and failed EDSSU admissions based on local admission policies and BOR for NEAT and DNW outcomes. RESULTS: Among all presentations (n = 192 506) during the study period, 43.8% of patients were admitted in hospital including 10.4% for EDSSU (n = 20 081). Analyses reveal modest positive correlation of EDSSU admissions with NEAT performance (τ = 0.35, P < 0.001) and weak negative correlation with DNW rates (τ = -0.29, P < 0.001). These associations were more pronounced on days when BOR >100% (τ = 0.39 and τ = -0.36, P < 0.001). BOR of >100% were associated with reduced EDSSU admits, NEAT performance and increased DNW rates (P < 0.001). Appropriate EDSSU admissions had shorter EDSSU length of stay than inappropriate EDSSU admissions (350 vs 557 min, median difference -158 min, P < 0.001). CONCLUSION: Appropriate use of EDSSU provides effective conduit for ongoing patients' management beyond mandated timelines. Health systems should focus on reducing hospital BORs to mitigate exclusive ED pressure to deliver NEAT performance targets.

Perceived incivility during emergency department phone consultations.

OBJECTIVE: Perceived incivility during ED medical phone consultations is poorly researched. We aimed to determine frequency and factors influencing perceived incivility during ED phone consultations. METHODS: We conducted a prospective self-reported survey of 40 consecutive phone consultations for 21 ED volunteer doctors. Consultations were classified based on the aim of consultation and deemed as 'positive', 'neutral' or 'negative' based on the perceptions of the consulting doctor. Training levels, time bands and specialty data were collected for both consulting and consulted parties. RESULTS: Fifty-seven of 714 included consultations (7.98%, 95% CI 6.2-10.2%) were reported as negative by ED medical staff. Factors associated with significant incidence of negative grading of consultation involved requests for investigations (19.3% vs 5.3%, P < 0.01), consultations with specialist trainees postgraduate year > 4 (9.1% vs 3.8%, P < 0.01) and those involving radiology specialty (18% vs 5.32%, P < 0.01). The risk was lower when the consulted professional was a specialist medical practitioner as compared to specialist trainee (4.1% vs 9.4%, P = 0.02). Multiple logistical modelling suggests that female (adjusted OR 2.4, 95% CI 1.1-5.2) medical staff are more likely to report perceived incivility during ED phone consultations. CONCLUSIONS: Perceived incivility occurs infrequently during ED phone consultations. ED female medical staff are at an increased risk of perceived incivility during phone consultations with non-ED medical professionals. Health organisations should actively pursue programmes to investigate the occurrence of incivility during healthcare consultations and implement programmes to mitigate the risk of developing a negative workplace culture.

Systemic inflammatory response syndrome-based severe sepsis screening algorithms in emergency department patients with suspected sepsis.

OBJECTIVE: Systemic inflammatory response syndrome (SIRS)-based severe sepsis screening algorithms have been utilised in stratification and initiation of early broad spectrum antibiotics for patients presenting to EDs with suspected sepsis. We aimed to investigate the performance of some of these algorithms on a cohort of suspected sepsis patients. METHODS: We conducted a retrospective analysis on an ED-based prospective sepsis registry at a tertiary Sydney hospital, Australia. Definitions for sepsis were based on the 2012 Surviving Sepsis Campaign guidelines. Numerical values for SIRS criteria and ED investigation results were recorded at the trigger of sepsis pathway on the registry. Performance of specific SIRS-based screening algorithms at sites from USA, Canada, UK, Australia and Ireland health institutions were investigated. RESULTS: Severe sepsis screening algorithms' performance was measured on 747 patients presenting with suspected sepsis (401 with severe sepsis, prevalence 53.7%). Sensitivity and specificity of algorithms to flag severe sepsis ranged from 20.2% (95% CI 16.4-24.5%) to 82.3% (95% CI 78.2-85.9%) and 57.8% (95% CI 52.4-63.1%) to 94.8% (95% CI 91.9-96.9%), respectively. Variations in SIRS values between uncomplicated and severe sepsis cohorts were only minor, except a higher mean lactate (>1.6 mmol/L, P < 0.01). CONCLUSIONS: We found the Ireland and JFK Medical Center sepsis algorithms performed modestly in stratifying suspected sepsis patients into high-risk groups. Algorithms with lactate levels thresholds of >2 mmol/L rather than >4 mmol/L performed better. ED sepsis registry-based characterisation of patients may help further refine sepsis definitions of the future.

Age and admission times as predictive factors for failure of admissions to discharge-stream short-stay units.

OBJECTIVE: Discharge-stream emergency short-stay units (ESSU) improve ED and hospital efficiency. Age of patients and time of hospital presentations have been shown to correlate with increasing complexity of care. We aim to determine whether an age and time cut-off could be derived to subsequently improve short-stay unit success rates. METHODS: We conducted a retrospective audit on 6703 (5522 inclusions) patients admitted to our discharge-stream short-stay unit. Patients were classified as appropriate or inappropriate admissions, and deemed successful if discharged out of the unit within 24 h; and failures if they needed inpatient admission into the hospital. We calculated short-stay unit length of stay for patients in each of these groups. A 15% failure rate was deemed as acceptable key performance indicator (KPI) for our unit. RESULTS: There were 197 out of 4621 (4.3%, 95% CI 3.7-4.9%) patients up to the age of 70 who failed admission to ESSU compared with 67 out of 901 (7.4%, 95% CI 5.9-9.3%, P < 0.01) of patients over the age of 70, reflecting an increased failure rate in geriatric population. When grouped according to times of admission to the ESSU (in-office 06.00-22.00 hours vs out-of-office 22.00-06.00 hours) no significant difference rates in discharge failure (4.7% vs 5.2%, P = 0.46) were noted. CONCLUSION: Patients >70 years of age have higher rates of failure after admission to discharge-stream ESSU. Although in appropriately selected discharge-stream patients, no age group or time-band of presentation was associated with increased failure rate beyond the stipulated KPI.

The CO2 GAP Project--CO2 GAP as a prognostic tool in emergency departments.

OBJECTIVE: To determine whether CO2 GAP [(a-ET) PCO2] value differs consistently in patients presenting with shortness of breath to the ED requiring ventilatory support. To determine a cut-off value of CO2 GAP, which is consistently associated with measured outcome and to compare its performance against other derived variables. METHODS: This prospective observational study was conducted in ED on a convenience sample of 412 from 759 patients who underwent concurrent arterial blood gas and ETCO2 (end-tidal CO2) measurement. They were randomized to test sample of 312 patients and validation set of 100 patients. The primary outcome of interest was the need for ventilatory support and secondary outcomes were admission to high dependency unit or death during stay in ED. The randomly selected training set was used to select cut-points for the possible predictors; that is, CO2 GAP, CO2 gradient, physiologic dead space and A-a gradient. The sensitivity, specificity and predictive values of these predictors were validated in the test set of 100 patients. RESULTS: Analysis of the receiver operating characteristic curves revealed the CO2 GAP performed significantly better than the arterial-alveolar gradient in patients requiring ventilator support (area under the curve 0.950 vs 0.726). A CO2 GAP ≥10 was associated with assisted ventilation outcomes when applied to the validation test set (100% sensitivity 70% specificity). CONCLUSIONS: The CO2 GAP [(a-ET) PCO2] differs significantly in patients requiring assisted ventilation when presenting with shortness of breath to EDs and further research addressing the prognostic value of CO2 GAP in this specific aspect is required.