Relationship between end-tidal carbon dioxide and arterial carbon dioxide in critically ill patients on mechanical ventilation: A cross-sectional study.

ABSTRACT: So far, only a few studies have examined and confirmed the correlation between end-expiratory carbon dioxide partial pressure (PETCO2) and arterial carbon dioxide tension (PaCO2) during invasive mechanical ventilation in critically ill patients. This study aimed to observe the correlation between PaCO2 and PETCO2 in patients on invasive mechanical ventilation.This was a cross-sectional study of adult patients on invasive mechanical ventilation enrolled between June 2018 and March 2019. Patients requiring invasive mechanical ventilation underwent one of the following mechanical ventilation modes: assisted/controlled ventilation, synchronized intermittent mandatory ventilation, and spontaneous breathing. Subsequently, the difference and correlation between PETCO2 and PaCO2 were analyzed.A total of 184 patients with 298 pairs of PETCO2-PaCO2 data were included in the analysis. Without distinguishing the ventilator mode, there was significant positive correlation between PETCO2 and PaCO2. In different ventilator modes, the correlation coefficient was 0.81 for synchronized intermittent mandatory ventilation, 0.47 for assisted/controlled ventilation, and 0.55 for spontaneous breathing, respectively. In patients with chronic obstructive pulmonary disease (r = 0.80), multiple trauma (r = 0.64), severe pneumonia (r = 0.60), gastrointestinal surgery (r = 0.57), and cerebrovascular diseases (r = 0.53), PETCO2 and PaCO2 were positively correlated. For oxygenation index <200 mm Hg, correlation coefficient r = 0.69, P < .001; oxygenation index ≥200, r = 0.73, P < .001. Under different oxygenation indexes, there was no statistically significant difference between the 2 correlation coefficients. Among 116 pairs of data with oxygenation index <200 mm Hg, the difference of PaCO2-PETCO2 ≥10 mm Hg was found in 25 pairs (21.55%); in 182 pairs of data with oxygenation index ≥200 mm Hg, the difference of PaCO2-PETCO2 ≥10 mm Hg was found in 26 pairsIn patients on invasive mechanical ventilation, there was a good correlation between PETCO2 and PaCO2 in different ventilator modes, different disease types, and different oxygenation indexes, especially in synchronized intermittent mandatory ventilation mode and chronic obstructive pulmonary disease patients.

Jugular venous catheter-associated thrombosis and fatal pulmonary embolism: A case report.

INTRODUCTION: Central venous catheters related thrombosis (CRT) insertion has been shown to increase the risk of venous thromboembolism, particularly pulmonary embolism (PE). Nevertheless, deaths cased due to PE have been rarely reported. PATIENT CONCERNS: A central venous catheter was introduced through the right jugular vein during the operation due to severe septic shock from a 57-year-old male patient. Two days after surgery, the hemodynamics was stable. On the 7th day, and low molecular weight heparin calcium (4100 units, once a day) was added for anticoagulation to prevent venous thromboembolism. On the 15th day, during the process of central venous catheter removal, the patient suddenly lost consciousness, suffered cardiac arrest, and received emergency cardiopulmonary resuscitation. DIAGNOSIS: Jugular venous catheter-associated thrombosis and fatal PE. An acute bedside ultrasound showed a thrombus drifting with the blood stream in the right jugular vein. The lower section of the xiphoid process by echocardiography showed decreased systolic amplitude of the right atrium and right ventricle, widened and fixed inferior vena cava, and no variation with respiration. Para-sternal left ventricular long axis section showed that the right ventricular outflow tract was significantly extended, and the contraction amplitude of the anterior and posterior walls of the left ventricle decreased. Left ventricular short axis section indicated a right ventricle enlargement and ventricular septum deviation of left ventricle, showing "D" sign. Apical 4-chamber view showed that the right ventricular ratio increased and the contractile capacity decreased. INTERVENTIONS: One and a half million units of urokinase were immediately given trough intravenous drip. OUTCOMES: Twenty minutes after thrombolysis, the patient's autonomic heart rhythm was recovered, but continued to suffer from hypotension and coma, followed by multiple organ failure, and died 50 hours later. CONCLUSION: Recent clinical practice guidelines recommend against the routine use of any anticoagulant thromboprophylaxis in patients with central venous catheters, but for patients at particularly high risk for CRT, consideration can be given to using higher doses of anticoagulant as prophylaxis, although there are virtually no data to support this approach.

Procalcitonin, C-reactive protein, PaCO2, and noninvasive mechanical ventilation failure in chronic obstructive pulmonary disease exacerbation.

It is unclear whether procalcitonin (PCT) is correlated with noninvasive ventilation (NIV) failure. This retrospective case-control study aimed to compare PCT levels, C-reactive protein (CRP) levels, and PaCO2 in patients (05/2014-03/2015 at the Harrison International Peace Hospital, China) with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) and NIV failure/success.This was a retrospective case-control study of patients with AECOPD who required NIV between May 2014 and March 2015. All consecutive patients with AECOPD admitted at the Department of Critical Care Medicine and transferred from the general ward were included in the study. Hemogram, PCT, erythrocyte sedimentation rate (ESR), arterial blood gas (ABG), and CRP levels were measured ≤1 hour before NIV was used. NIV was considered to have failed if at least one of the following criteria was met: cardiac arrest or severe hemodynamic instability; respiratory arrest or gasping; mask intolerance; difficulty in clearing bronchial secretions; or worsening of ABGs or sensorium level during NIV. The factors associated with NIV failure were determined.A total of 376 patients were included: 286 with successful NIV and 90 wither NIV failure. The multivariate analysis showed that PCT (OR = 2.0, 95%CI: 1.2-3.2, P = .006), CRP (OR = 1.2, 95%CI: 1.1-1.3, P < .001), and PaCO2 (OR = 1.1, 95%CI: 1.1-1.2, P < .001) ≤1 hour before NIV were independently associated with NIV failure. The optimal cutoff were 0.31 ng/mL for PCT (sensitivity, 83.3%; specificity, 83.7%), 15.0 mg/mL for CRP (sensitivity, 75.6%; specificity, 93.0%), and 73.5 mm Hg for PaCO2 (sensitivity, 71.1%; specificity, 100%). The area under the curve (AUC) was 0.854 for PCT, 0.849 for CRP, and 0.828 for PaCO2. PCT, CRP, and PaCO2 were used to obtain a combined prediction factor, which achieved an AUC of 0.978 (95%CI: 0.961-0.995).High serum PCT, CRP, and PaCO2 levels predict NIV failure for patients with AECOPD. The combination of these three parameters might enable even more accurate prediction.