Risks associated with obese patient handling in emergency prehospital care.

The number of ambulance crewmembers may affect the quality of cardiopulmonary resuscitation in particular situations. However, few studies have investigated how the number of emergency care providers affects the quality of CPR. Nonetheless, problems in the initial handling of patients due to small ambulance crew sizes may have significant consequences. These difficulties may be more frequent in an obese population than in a non-obese population. Hence such problems may be frequently encountered because obesity is epidemic in developed countries. In this report, we illustrate the fatal consequences of initial problems in patient handling due to a small ambulance crew size in an obese patient who suffered an out-of-hospital cardiac arrest. Following successful resuscitation, this patient presented humeral fractures that may have promoted a disorder of hemostasis. The patient eventually died. This case highlights the requirement for specific instructions for paramedics to manage obese patients in these emergency conditions. This case also highlights the need to take into account body mass index when deciding on appropriate pre-hospital care, especially regarding the number of ambulance crewmembers.

Are central venous lactate and arterial lactate interchangeable? A human retrospective study.

BACKGROUND: In critically ill patients, arterial blood lactate concentration (Lact(a)) and Lact(a) clearance are used for the diagnosis of shock, for prognosis assessment, and to guide therapy. In recent years, central venous oxygen saturation (ScvO(2)), a surrogate for mixed venous blood saturation, either measured by fiberoptic catheters or from central venous blood samples, was used in shock to estimate the global balance between oxygen delivery and consumption. When central venous blood is drawn for ScvO(2) measurement, it also could be used to measure central venous lactate concentration (Lact(cv)). In this study, we evaluated the utility of Lact(cv) and Lact(cv) clearance as predictors of Lact(a) and Lact(a) clearance, respectively, in critically ill patients. METHODS: This retrospective study was performed in an intensive care unit of a regional and teaching hospital. Using the electronic registry of our blood gas analyzer from March 2007 to December 2009, we identified patients with circulatory or respiratory failure who had pairs of Lact(cv) and Lact(a) obtained within a 30-minute interval. To assess the utility of Lact(cv) as a predictor of Lact(a) above 2 and 4 mmol/L, we calculated the area under receiver operating characteristic curves (AUCs) for these thresholds. We also calculated AUC of Lact(cv) clearance to detect a Lact(a) clearance <10% or >10%. RESULTS: Six hundred seventy-three Lact(cv)/Lact(a) pairs in 188 patients were analyzed. AUC of Lact(cv) to predict a Lact(a) above 2 and 4 mmol/L was 0.98 (95% confidence interval: 0.97-0.99) and 0.98 (95% confidence interval: 0.96-0.99), respectively. Lact(cv) with the cutoff value of 2 mmol/L can predict a Lact(a) above 2 mmol/L with sensitivity >92% and specificity >90%. AUC for Lact(cv) clearance to detect a Lact(a) clearance <10% or >10% was 0.93 or 0.94, respectively. CONCLUSION: Lact(cv) and Lact(a) collected within a 30-minute range are interchangeable for clinical practice.

Pressurized Metered Dose Inhaler Aerosol Delivery Within Nasal High-Flow Circuits: A Bench Study.

Background: Obstructive patients may benefit from nasal high-flow (NHF) therapy, but the use of pressurized metered-dose inhalers (pMDIs) has not been evaluated in this situation. Methods: Using an adult circuit and medium-sized cannula, we have tested different NHF rates, pMDI positions, breathing patterns, spacers, and spacer orientation. First, we evaluated albuterol delivery at the nasal cannula outlet. The second set of experiments made use of a nasopharyngeal cast to estimate the mass of albuterol potentially reaching the lungs. Albuterol was caught on filters placed at the cannula outlet and downstream of the nasal cast, and albuterol was quantified by spectrophotometry. Results: The highest amounts of albuterol delivered at the cannula outlet were observed with a 30 L/min flow rate (vs. 45 and 60 L/min) and placing the device close to the nasal cannula (in comparison with a position on the dry side of the humidification chamber). The use of a spacer was associated with higher delivery. The highest albuterol delivery was observed placing the spacer close to the nasal cannula, oriented for aerosol delivery following the gas flow and a 30 L/min NHF rate. Using this optimal setting, activating the pMDI at the beginning of inspiration (compared to expiration) increased albuterol delivery downstream of the nasopharyngeal cast. Whether in a quiet- or distress-breathing pattern, our measurements showed an amount of albuterol potentially delivered to the lungs exceeding 10% of the actuated dose in optimal conditions. Conclusions: Albuterol delivery with pMDIs is feasible within NHF circuits. Drug delivery sufficient to induce bronchodilation can be achieved using a spacer placed just upstream of the nasal cannula, a low NHF rate, and activation of the pMDI at the beginning of inspiration. Further testing in a clinical setting is required, however.

Nasal high-flow bronchodilator nebulization: a randomized cross-over study.

BACKGROUND: There is an absence of controlled clinical data showing bronchodilation effectiveness after nebulization via nasal high-flow therapy circuits. RESULTS: Twenty-five patients with reversible airflow obstruction received, in a randomized order: (1) 2.5 mg albuterol delivered via a jet nebulizer with a facial mask; (2) 2.5 mg albuterol delivered via a vibrating mesh nebulizer placed downstream of a nasal high-flow humidification chamber (30 L/min and 37 °C); and (3) nasal high-flow therapy without nebulization. All three conditions induced significant individual increases in forced expiratory volume in one second (FEV1) compared to baseline. The median change was similar after facial mask nebulization [+ 350 mL (+ 180; + 550); + 18% (+ 8; + 30)] and nasal high flow with nebulization [+ 330 mL (+ 140; + 390); + 16% (+ 5; + 24)], p = 0.11. However, it was significantly lower after nasal high-flow therapy without nebulization [+ 50 mL (- 10; + 220); + 3% (- 1; + 8)], p = 0.0009. FEV1 increases after facial mask and nasal high-flow nebulization as well as residual volume decreases were well correlated (p < 0.0001 and p = 0.01). Both techniques showed good agreement in terms of airflow obstruction reversibility (kappa 0.60). CONCLUSION: Albuterol vibrating mesh nebulization within a nasal high-flow circuit induces similar bronchodilation to standard facial mask jet nebulization. Beyond pharmacological bronchodilation, nasal high flow by itself may induce small but significant bronchodilation.

Nasal high flow nebulization in infants and toddlers: An in vitro and in vivo scintigraphic study.

Aerosol therapy in infants and toddlers is challenging. Nebulization within a nasal high flow (NHF) circuit is attractive. The aim of this study was to quantify aerosol lung deposition when combined with NHF as compared with standard practice. Lung doses were measured scintigraphically after nebulization with jet and mesh nebulizer placed within a NHF circuit in a spontaneously breathing non-human primate model (macaque) and in the anatomical bench SAINT model, respectively representing a full-term newborn and a 9-month-old toddler. In the SAINT model, lung depositions observed with the mesh nebulizer placed in the NHF circuit set at 2 and 4 L/min were 3.3% and 4.2% of the nebulizer charge, respectively, and similar to the 1.70% observed with the control standard facemask jet nebulization (6 L/min flow). In the macaque model, the depositions observed with the mesh nebulizer in the NHF circuit set at 2 and 4 L/min were 0.49% and 0.85%, respectively, also similar to the control measurement (0.71%). Mesh nebulization within a NHF circuit set at 8 L/min and jet nebulization either within a NHF circuit or placed on top of the cannula (NHF set at 2 L/min; total flow of 8 L/min), resulted in a significantly lower lung depositions. Mesh nebulization within a NHF circuit delivering up to 4 L/min gas is likely to be at least as effective than jet nebulization with a facemask in infants and toddlers. Aerosol facemask placement on top of cannulas or jet nebulization within the NHF circuit may be less effective. Pediatr Pulmonol. 2017;52:337-344. © 2016 Wiley Periodicals, Inc.

Aerosol Therapy in Adults Receiving High Flow Nasal Cannula Oxygen Therapy.

BACKGROUND: High flow nasal cannula oxygen therapy (HFT) is increasingly used in intensive and emergency care departments. Patients suffering from respiratory failure, who are likely to benefit from HFT, may require aerosolized bronchodilators; therefore, combining nebulization with HFT may be relevant. This study aimed to identify the optimal settings for the implementation of nebulization within an adult HFT circuit. METHODS: We assessed the mass and the particle size distribution of the aerosol emitted from the nasal cannula (inhalable mass) using mesh- and jet-nebulizers placed at various positions in the HFT circuit. Thereafter, the most relevant combination was used to evaluate the mass of salbutamol delivered downstream of an anatomical model reproducing aerosol deposition and leakage at the nasal and pharyngeal levels (respirable mass). The influence of HFT flow rate (30, 45, and 60 L/min), of breathing pattern (quiet and respiratory distress pattern) as well as of opened and closed mouth breathing was assessed. RESULTS: The most efficient position was that of a nebulizer placed upstream from the humidification chamber (inhalable mass ranging from 26% to 32% of the nebulizer charge). Using a mesh nebulizer, we observed a respirable mass ranging from 2% to 10% of the nebulizer charge. Higher HFT flow rates and open mouth breathing were associated with a lower efficiency. Simulating respiratory distress (i.e., increasing the simulated patient inspiratory flow) did not hamper drug delivery as compared to a quiet breathing pattern. CONCLUSIONS: Placing nebulizers within a HFT circuit upstream from the humidification chamber may enable to deliver clinically relevant masses of aerosol at the cannula outlet, but more importantly downstream of the nose and pharynx, even in case of high patients' inspiratory flow. This method of aerosol therapy is expected to produce a bronchodilatatory effect to be evaluated in the clinical settings.

Volume expansion in the first 4 days of shock: a prospective multicentre study in 19 French intensive care units.

PURPOSE: To describe the current practices of volume expansion in French intensive care units (ICU). METHODS: In 19 ICUs, we prospectively observed the prescription and monitoring practices of volume expansion in consecutive adult patients with shock [sustained hypotension and/or need of vasopressor therapy, associated with at least tachycardia and/or sign (s) of hypoperfusion]. Patients were included at the time of prescription of the first fluid bolus (FB). Thereafter, all the FBs administered during the 96 h following shock onset were surveyed. An FB was defined as an intravenous bolus of at least 100 ml of a blood volume expander intended to rapidly improve the patient's circulatory condition. RESULTS: We included 777 patients [age: 63 ± 15 years; female gender: 274 (35 %); simplified acute physiology score II: 55.9 ± 20.6; ICU length of stay: 6 days (interquartile range (IQR) 3-13); ICU mortality: 32.8 %] and surveyed 2,694 FBs. At enrolment mean arterial pressure was 63 mmHg (IQR 55-71). The most frequent triggers of FB were hypotension, low urine output, tachycardia, skin mottling and hyperlactataemia. Amount of fluid given at each FB was highly variable between centres. Crystalloids were used in 91 % (2,394/2,635) and synthetic colloids in 3.3 % (87/2,635) of FBs. Overall, clinicians used any kind of haemodynamic assessment (central venous pressure measurement, predictive indices of fluid responsiveness, echocardiography, cardiac output monitoring or a combination of these) in 23.6 % (635/2,694) of all FBs surveyed, with an important between-centre heterogeneity. CONCLUSIONS: High between-centre variability characterised all the aspects of FB prescription and monitoring, but overall haemodynamic exploration to help guide and monitor FB was infrequent.