Performance of pre-hospital evaluations in ruling out invasive chest stab wounds

BACKGROUND

Some guidelines advocate for managing patients with penetrating thoracic wounds in trauma centres with cardiothoracic surgery. This systematic approach is questionable. Only 15% of these patients require surgery. It is known that clinical examination fails to detect hemopneumothorax in penetrating trauma. However, no studies have evaluated the combined diagnostic performance of vital signs and the clinical evaluation of wounds. The clinical characteristics of wounds have not been investigated. We aimed to evaluate the ability of combinations of pre-hospital signs to rule out invasive chest stab trauma.

METHODS

This was a prospective observational study. All consecutive adult patients hospitalized in the perioperative acute care unit of a tertiary university hospital were included. Injury diagnoses were provided by exploratory surgery and imaging tests. Patients with a final diagnosis of invasive wounds (IWs) and patients with only superficial wounds were compared. Data regarding management and outcome were analysed.

RESULTS

A total of 153 patients were included. After imaging or surgery, 58 (38%) patients were diagnosed with only superficial wounds, and 95 (62%) were diagnosed with thoracic or abdominal IWs. The false-negative rate of pre-hospital evaluations in the diagnosis of IWs was 42% [31-51]IQR25-75. In stable patients, pre-hospital data could not rule out IWs, with a negative predictive value of 58% and a positive predictive value of 70%. Twenty-nine (19%) patients required early emergent cardiothoracic surgery. Among these patients, 8 (28%) had no evidence of IWs in the pre-hospital period. Among the 59 patients without pre-hospital signs of IWs, 19 (33%) underwent at least one emergent procedure.

CONCLUSIONS

The combination of pre-hospital vital signs, visual evaluation of wounds, and physical examination failed to rule out IWs in patients with chest stab wounds. This implies that caution is needed in triage decision-making.

Pulmonary Effects of Adjusting Tidal Volume to Actual or Ideal Body Weight in Ventilated Obese Mice

Obese patients could be more susceptible to mechanical ventilation (MV)-induced lung injury than non-obese patients due to weight-dependent changes in lung properties. The aim of this study was therefore to evaluate the pulmonary effects of 2 hours low V_T MV in a diet-induced obese mice model, with V_T calculated on either the actual body weight (V_Taw) or the ideal body weight (V_Tiw) . First, we hypothesized that a MV with V_Taw would be associated with altered lung mechanics and an increased lung inflammation. Second, we hypothesised that a MV with a V_Tiw would preserve lung mechanics and limit lung inflammation. We analyzed lung mechanics and inflammation using bronchoalveolar lavage (BAL) cell counts, flow cytometry tissue analysis and histology. Lung mechanics and inflammation were comparable in control and obese mice receiving V_Tiw. By contrast, obese mice receiving V_Taw had significantly more alterations in lung mechanics, BAL cellularity and lung influx of monocytes as compared to control mice. Their monocyte expression of Gr1 and CD62L was also increased. Alveolar neutrophil infiltration was significantly increased in all obese mice as compared to controls. In conclusion, our findings suggest that protective MV with a V_Taw is deleterious, with a marked alteration in lung mechanics and associated lung inflammation as compared to lean mice. With V_Tiw, lung mechanics and inflammation were close to that of control mice, except for an increased alveolar infiltrate of polymorphonuclear neutrophils. This inflammation might be attenuated by a blunted recruitment of inflammatory cells associated with obesity.

Esmolol Corrects Severe Hypoxemia in Patients with Femoro-Femoral Venoarterial Extracorporeal Life Support for Lung Transplantation

Competitive flows syndrome result in severe regional hypoxemia when the deoxygenated flow from the native left ventricle (LV) competes with oxygenated flow from extracorporeal life support (ECLS) pump with potentially severe consequences for the cerebral and coronary circulations. Fast correction of hypoxemia could be obtained by decreasing native LV flow by infusion of a short-acting beta-blocker (esmolol). Our purpose was to retrospectively review the efficacy of esmolol in this situation and hypothesize on the potential mechanisms of action and the associated risks. This is a retrospective analysis of five clinical cases, who underwent lung transplantation and a femoro-femoral venoarterial (VA) ECLS. The patients presented severe hypoxemia (SpO₂ < 85%) measured through photoplethysmography on a right hand finger. From the patients' medical records and anesthesia flowcharts, hemodynamic, right heart catheterization, echocardiography variables, and arterial blood gas results were noted before and after injection of esmolol. Mechanical ventilation and VA ECLS function variables were optimized and unchanged before and after esmolol injection. All patients had terminal respiratory failure with pulmonary hypertension and conserved LV systolic function. Immediately following esmolol injection (1.3 ± .7 mg/kg; mean ± 1 SD), SpO₂ increased from 73% ± 12 to 95% ± 6; blood to arterial partial pressure in CO₂ (PaCO₂) decreased from 52 ± 18 to 35 ± 7 mmHg systolic pulmonary artery pressure decreased from 61 ± 8 to 50 ± 12 mmHg; the pulmonary artery oxygen saturation (SvO₂); increased from 51% ± 24 to 77% ± 12; systemic arterial pressure or catecholamine requirements were unchanged. In conclusion, these results suggest that injection of esmolol allowed rapid correction of regional hypoxemia occurring during lung transplantation despite femoro-femoral VA ECLS. The mechanism is probably a decreased cardiac output of the native LV due to esmolol-induced negative inotropic and chronotropic effects without significant adverse effects on systemic tissue perfusion.

Markers of intestinal injury are associated with endotoxemia in successfully resuscitated patients

AIMS

Gut dysfunction is suspected to play a major role in the pathophysiology of post-resuscitation disease through an increase in intestinal permeability and endotoxin release. However this dysfunction often remains occult and is poorly investigated. The aim of this pilot study was to explore intestinal failure biomarkers in post-cardiac arrest patients and to correlate them with endotoxemia.

METHODS

Following resuscitation after cardiac arrest, 21 patients were prospectively studied. Urinary intestinal fatty acid-binding protein (IFABP), which marks intestinal permeability, plasma citrulline, which reflects the functional enterocyte mass, and whole blood endotoxin were measured at admission, days 1-3 and 6. We explored the kinetics of release and the relationship between IFABP, citrulline and endotoxin values.

RESULTS

IFABP was extremely high at admission and normalized at D3 (6668 pg/mL vs 39 pg/mL, p=0.01). Lowest median of citrulline (N=20-40 μmol/L) was attained at D2 (11 μmol/L at D2 vs 24 μmol/L at admission, p=0.01) and tended to normalize at D6 (21 μmol/L). During ICU stay, 86% of patients presented a detectable endotoxemia. Highest endotoxin level was positively correlated with highest IFABP level (R(2)=0.31, p=0.01) and was inversely correlated with lowest plasma citrulline levels (R(2)=0.55, p<0.001). Endotoxin levels increased between admission and D2 in patients with post-resuscitation shock, whereas it decreases in patients with no shock (median +0.33 EU vs -0.19 EU, p=0.03). Highest endotoxin level was positively correlated with D3 SOFA score (R(2)=0.45, p=0.004).

CONCLUSION

Biomarkers of intestinal injury are altered after cardiac arrest and are associated with endotoxemia. This could worsen post-resuscitation shock and organ failure.