VE/VCO2 slope threshold optimization for preoperative evaluation in lung cancer surgery: identifying true high- and low-risk groups.

Background: Cardiopulmonary exercise testing (CPET) enables measurement of the slope of the increase in minute ventilation in relation to carbon dioxide elimination during exercise (the VE/VCO2 slope). Several studies have shown that the VE/VCO2 slope is a strong marker for postoperative complications and mortality. However, current thresholds for adverse outcomes are generated from historical data in heart failure patients. Methods: This was a retrospective analysis of 158 patients with lung cancer who underwent lobectomy or pneumonectomy during 2008-2020. The main outcome was major pulmonary complications (MPC) or death ≤30 days of cancer surgery. Patients were first categorized using two different single threshold approaches; the traditional threshold of 35 and the highest Youden value from the receiver operating curve (ROC) analysis. Secondly, patients were categorized into three risk groups using two thresholds. These two thresholds were determined in an ROC analysis, where the VE/VCO2 slope values generating either a 90% sensitivity (lower threshold) or a 90% specificity (upper threshold) for the main outcome were chosen. The frequency of complications was compared using Chi2. The overall model quality was evaluated by an area under the curve (AUC) analysis. Positive predictive values (PPVs) and negative predictive values (NPVs) are presented. Results: The two thresholds, <30 (90% sensitivity) and >41 (90% specificity), created three risk groups: low risk (VE/VCO2 slope <30, n=44, 28%); intermediate risk (VE/VCO2 slope 30-41, n=95, 60%) and high risk (VE/VCO2 slope >41, n=19, 12%). The frequency of complications differed between groups: 5%, 16% and 47% (P<0.001). Using two thresholds compared to one threshold increased the overall model quality (reaching AUC 0.70, 95% confidence interval: 0.59-0.81), and identified a high sensitivity threshold (VE/VCO2 slope <30) which generated a NPV of 95% but importantly, also a high specificity threshold (VE/VCO2 slope >41) with a PPV of 47%. Conclusions: Risk stratification based on three risk groups from the preoperative VE/VCO2 slope increased the model quality, was more discriminative and generated better PPV and NPV compared to traditional risk stratification into two risk groups.

Tactical leaders' and collaborative organizations' non-technical skills during major road tunnel incidents - An iterative focus group study.

INTRODUCTION: Leadership during major incidents has been described as challenging and dependent on the non-technical skills of leaders. The complex tunnel environment contributes to an even more challenging incident response. Hence, this study aims to identify elements of non-technical skills when leading collaborative road-tunnel incident responses. METHODS: The study was conducted using four focus group discussions with tactical leaders from the rescue services, emergency medical services, police, and collaborative organizations from the emergency dispatch center and road-traffic control center. The data was analyzed using a non-technical skills taxonomy. RESULTS: Twelve non-technical skill elements emerged. Abilities to gather, sort, and proactively share relevant information and dispatch the correct resources were described. Additionally, abilities to prioritize actions and cooperate to establish a shared operational picture were found. Abilities to adjust leadership to the tunnel environment and conditions and assess the severity of the incident to make decisions were also described. CONCLUSION: When managing a road-tunnel incident response, tactical leaders utilizes a range of non-technical skills. The elements of these skills were found to be specific both to the tunnel environment and the collaborative nature of the response. Further studies into and development of these skills are needed to facilitate a timely response and minimize potential risks to personnel or evacuees in future tunnel incident responses.

Ventilatory efficiency in combination with peak oxygen uptake improves risk stratification in patients undergoing lobectomy.

Objective: We aimed to evaluate whether or not using the slope of the increase in minute ventilation in relation to carbon dioxide (VE/VCo2-slope), with a cutoff value of 35, could improve risk stratification for major pulmonary complications or death following lobectomy in lung cancer patients at moderate risk (Vo2peak = 10-20 mL/kg/min). Methods: Single center, retrospective analysis of 146 patients with lung cancer who underwent lobectomy and preoperative cardiopulmonary exercise testing in 2008-2020. The main outcome was any major pulmonary complication or death within 30 days of surgery. Patients were categorized based on their preoperative cardiopulmonary exercise testing as: low-risk group, peak oxygen uptake >20 mL/kg/min; low-moderate risk, peak oxygen uptake 10 to 20 mL/kg/min and VE/VCo2-slope <35; and moderate-high risk, peak oxygen uptake 10 to 20 mL/kg/min and VE/VCo2-slope ≥35. The frequency of complications between groups was compared using χ2 test. Logistic regression was used to calculate the odds ratio with 95% CI for the main outcome based on the cardiopulmonary exercise testing group. Results: Overall, 25 patients (17%) experienced a major pulmonary complication or died (2 deaths). The frequency of complications differed between the cardiopulmonary exercise testing groups: 29%, 13%, and 8% in the moderate-high, low-moderate, and low-risk group, respectively (P = .023). Using the low-risk group as reference, the adjusted odds ratio for the low-moderate risk group was 3.44 (95% CI, 0.66-17.90), whereas the odds ratio for the moderate-high risk group was 8.87 (95% CI, 1.86-42.39). Conclusions: Using the VE/VCo2-slope with a cutoff value of 35 improved risk stratification for major pulmonary complications following lobectomy in lung cancer patients with moderate risk based on a peak oxygen uptake of 10 to 20 mL/kg/min. This suggests that the VE/VCo2-slope can be used for preoperative risk evaluation in lung cancer lobectomy.

Mobilisation of emergency services for chemical incidents in Sweden - a multi-agency focus group study.

BACKGROUND: In chemical incidents, infrequent but potentially disastrous, the World Health Organization calls for inter-organizational coordination of actors involved. Multi-organizational studies of chemical response capacities are scarce. We aimed to describe chemical incident experiences and perceptions of Swedish fire and rescue services, emergency medical services, police services, and emergency dispatch services personnel. METHODS: Eight emergency service organizations in two distinct and dissimilar regions in Sweden participated in one organization-specific focus group interview each. The total number of respondents was 25 (7 females and 18 males). A qualitative inductive content analysis was performed. RESULTS: Three types of information processing were derived as emerging during acute-phase chemical incident mobilization: Unspecified (a caller communicating with an emergency medical dispatcher), specified (each emergency service obtaining organization-specific expert information), and aligned (continually updated information from the scene condensed and disseminated back to all parties at the scene). Improvable shortcomings were identified, e.g. randomness (unspecified information processing), inter-organizational reticence (specified information processing), and downprioritizing central information transmission while saving lives (aligned information processing). CONCLUSIONS: The flow of information may be improved by automation, public education, revised dispatcher education, and use of technical resources in the field. Future studies should independently assess these mechanism's degree of impact on mobilisation of emergency services in chemical incidents.

Senior ambulance officers in Swedish emergency medical services: a qualitative study of perceptions and experiences of a new management role in challenging incidents.

OBJECTIVES: Increased demands are placed on emergency services and their role and ability to act in incidents in challenging environments, for example, road tunnels. Collaboration between officers from emergency services (fire brigade, police and ambulance services) is important for an effective rescue effort. In Gothenburg, Sweden, a position as a senior ambulance officer (SAO) within the emergency medical services (EMS) has been introduced to support the regular force during major incidents. The aim of this paper was to explore the perceptions and experiences of the SAO's new management role in challenging incidents, such as those occurring in road tunnels. DESIGN: A qualitative interview study. SETTING: The study was carried out from February to June 2019 in Gothenburg, Sweden, which is a municipality with several road tunnels and a population of approximately 580 000 people. SAOs collaborate with the corresponding function within the police and fire brigade, both having senior officers at major incident sites. PARTICIPANTS: Twelve SAOs. METHODS: The study used semistructured interviews. The collected data were analysed using qualitative content analysis. RESULTS: According to SAOs' experience, prehospital medical management included not only leadership, but also planning, training and indepth knowledge of, for example, tunnel environments. Furthermore, SAOs adopted an encouraging and teaching role for their colleagues. SAOs' responsibilities also included proactive planning together with the fire brigade and police, which was regarded as enhancing interorganisational collaboration. An overall theme emerged which the SAOs described as 'A new holistic approach to EMS leadership and management'. CONCLUSIONS: The participants considered that the new SAO role not only seems to improve the prehospital medical management, but also makes the EMS command structure during challenging incidents symmetrical with the fire brigade and police command structure. The implementation of national guidelines is desirable and is requested by the SAOs.

Prehospital management provided by medical on-scene commanders in tunnel incidents in Oslo, Norway - an interview study.

BACKGROUND: High demands are placed on the emergency medical services to handle rescue operations in challenging environments such as tunnels. In Oslo, Norway a specialised management function within the emergency medical services, the medical on-scene commander, in line with the command structure within the police and fire brigade, might support or take over command and control from the ambulance incident officer arriving as the first ambulance personnel on scene. The aim was to shed light on the emergency medical service experiences from real tunnel incidents described by the Oslo medical on-scene commanders. METHODS: Interviews were conducted with six of the seven medical on-scene commander in Oslo, Norway. Data were analysed using a qualitative content analysis. RESULTS: The overall theme was "A need for mutual understanding of a tunnel incident". The medical on-scene commander provided tactical support, using their special knowledge of risk objects and resources in the local area. They established operation plans with other emergency services (the police and fire brigade) in a structured and trustful way, thus creating a fluent and coordinated mission. Also, less time was spent arguing at the incident site. By socialising also outside ordinary working hours, a strong foundation of reliance was built between the different parties. A challenge in recent years has been the increasing ordinary workload, giving less opportunity for training and exchange of experiences between the three emergency services. CONCLUSIONS: The enthusiastic pioneers within the three emergency services have created a sense of familiarity and trust. A specially trained medical on-scene commander at a tunnel incident is regarded to improve the medical management. To improve efficiency, this might be worth studying for other emergency medical services with similar conditions, i.e. tunnels in densely populated areas.