Changes in peak inspiratory flow rate and peak airway pressure with endotracheal tube size during chest compression / 世界急诊医学杂志（英文）

@#BACKGROUND: Adequate airway management plays an important role in high-quality cardiopulmonary resuscitation (CPR). Airway management is usually performed using an endotracheal tube (ETT) during CPR. However, no study has assessed the effect of ETT size on the flow rate and airway pressure during CPR. METHODS: We measured changes in peak inspiratory flow rate (PIFR), peak airway pressure (Ppeak), and mean airway pressure (Pmean) according to changes in ETT size (internal diameter 6.0, 7.0, and 8.0 mm) and with or without CPR. A tidal volume of 500 mL was supplied at a rate of 10 times per minute using a mechanical ventilator. Chest compressions were maintained at a constant compression depth and speed using a mechanical chest compression device (LUCAS2, mode: active continuous, chest compression rate: 102±2/minute, chest compression depth 2–2.5 inches). RESULTS: The median of several respiratory physiological parameters during CPR was significantly different according to the diameter of each ETT (6.0 vs. 8.0 mm): PIFR (32.1 L/min [30.5–35.3] vs. 28.9 L/min [27.5–30.8], P<0.001), Ppeak (48.84 cmH2O [27.46–52.11] vs. 27.45 cmH2O [22.53–52.57], P<0.001), and Pmean (18.34 cmH2O [14.61–21.66] vs.13.66 cmH2O [8.41–19.24], P<0.001). CONCLUSION: The changes in PIFR, Ppeak, and Pmean were related to the internal diameter of ETT, and these values tended to decrease with an increase in ETT size. Higher airway pressures were measured in the CPR group than in the no CPR group.

Does the direction of J-tip of the guide-wire influence the misplacement of subclavian catheterization?

OBJECTIVE: Central venous catheter (CVC) misplacement can result in incorrect readings of the central venous pressure, vascular erosion, and intravascular thrombosis. Several studies have examined the correlation between the guidewire J-tip direction and misplacement rate. This study examined whether the guidewire J-tip direction (cephalad vs. caudad) affects the misplacement rate in right subclavian venous catheterization. METHODS: This prospective randomized controlled study was conducted between February 2016 and February 2017. The subjects were divided into two groups (cephalad group vs. caudad group) and the misplacement rate was compared according to guidewire J-tip direction in each group. RESULTS: Of 100 patients, the cephalad and caudad groups contained 50 patients each. The age, sex, and operator experience were similar in the two groups. In the cephalad group, misplacement of CVC insertion into the ipsilateral internal jugular vein occurred in two cases. In the caudad group, misplacement of CVC insertion into the contralateral subclavian vein occurred in one case, with loop formation in the brachiocephalic trunk in one case. Guidewire J-tip direction showed no significant correlation with CVC misplacement. CONCLUSION: The guidewire J-tip direction does not influence the rate of misplacement.

The influence of the decision making time by using point-of-care creatinine in patients with acute abdomen

OBJECTIVE: Radio-contrast abdomino-pelvic computed tomography (APCT) is considered the gold standard diagnostic tool for an acute abdomen in the emergency department. On the other hand, APCT has a risk of contrast-induced nephropathy. Emergency physicians evaluate the creatinine (Cr) level prior to taking a APCT for the above reason but it takes time to evaluation the serum Cr level. This study hypothesized that Cr measured by a point-of-care test (POCT) can shorten the time to making clinically important decisions for patients with an acute abdomen. METHODS: This prospective randomized study was conducted between March 2017 and October 2017. The subjects were divided into two groups (Cr measured by laboratory vs. Cr measured by POCT). To analyze the clinical acceptability for creatinine, agreement was demonstrated graphically by Bland-Altman plots. This study compared the time to make a clinically important decision by physicians and the length of stay at the emergency department in both groups. RESULTS: A total of 76 patients were eligible for the study, 38 patients were assigned to each group. There was no statistically significant difference in the time to the first medical examination (P=0.222) and emergency department stay time (P=0.802). On the other hand, the time to recognition of the Cr level (P < 0.001), time to performing APCT (P < 0.001), time to decision making (P < 0.001), and time to initiation of treatment (P < 0.001) were shortened significantly in the point-of-care creatinine group. CONCLUSION: In this study, the POCT for creatinine can allow rapid decision making by shortening the time to performing the radio-contrast APCT than the laboratory for patients with an acute abdomen.

The method to reduce the malposition rate via reposition of guidewire with ultrasound guidance in the central venous catheterization

OBJECTIVE: Malposition of central venous catheterization (CVC) may cause vascular related complications and catheter dysfunctions. The aim of this study was to reduce the malposition rate of CVC by repositioning the malposition after confirming the location of the guide-wire with ultrasound (US) guidance. METHODS: This research assessed the before study (group A) from January to December 2016 and after study (group B) from January to December 2017 in the emergency department. CVCs were performed using the anatomical landmark technique (group A) and US guided technique (group B). In group B, if the guided-wire was misplaced, it was drawn back and repositioned under US guidance. The final location of the catheter tip was confirmed by chest X-ray. The rate of malposition before and after repositioning of the two groups was compared. RESULTS: The subjects were group A (694 cases) and group B (619 cases) with a total of 1,313 patients. The rate of malposition before repositioning of the two groups were 16 cases (2.3%) and 13 cases (2.1%), respectively, and no statistically significant difference was observed (P>0.05). In group B, there were 10 cases (1.6%) of guidewire malposition that was identified and three cases (0.5%) of catheter malposition could not be identified under US examination. The malpositioned guidewires were all corrected by repositioning under ultrasound guidance. The rate of malposition after repositioning of the two groups were 2.3% (n=16) and 0.5% (n=3), respectively, and a statistically significant difference was observed (P=0.009). CONCLUSION: With US guidance, confirming the location and repositioning CVC guidewire can reduce the malposition rate in CVCs.

Vasopressor requirement during targeted temperature management for out-of-hospital cardiac arrest caused by acute myocardial infarction without cardiogenic shock

OBJECTIVE: We investigated whether patients with out-of-hospital cardiac arrest (OHCA) due to an acute myocardial infarction without cardiogenic shock required higher doses of vasopressors with low targeted temperature management (TTM) after return of spontaneous circulation. METHODS: We included consecutive comatose patients resuscitated from OHCA between January 2011 and December 2013. Patients with return of spontaneous circulation, regional wall motion abnormality on echocardiography, and coronary artery stenosis of ≥70% on percutaneous coronary artery angiography were enrolled. These patients received 36°C TTM or 33°C TTM following approval of TTM by patients’ next-of-kin (36°C and 33°C TTM groups, respectively). The cumulative vasopressor index was compared between groups. RESULTS: During induction phase, dose of vasopressors did not differ between groups. In the maintenance phase, the norepinephrine dose was 0.37±0.57 and 0.26±0.91 µg·kg⁻¹·min⁻¹ in the 33°C and 36°C TTM groups, respectively (P<0.01). During the rewarming phase, the norepinephrine and dopamine doses were 0.49±0.60 and 9.67±9.60 mcg·kg⁻¹·min⁻¹ in the 33°C TTM group and 0.14±0.46 and 3.13±7.19 mcg·kg⁻¹·min⁻¹ in the 36°C TTM group, respectively (P<0.01). The median cumulative vasopressor index was 8 (interquartile range, 3 to 8) and 4 (interquartile range, 0 to 8) in the 33°C and 36°C TTM groups, respectively (P=0.03). CONCLUSION: In this study, patients with OHCA due to acute myocardial infarction without cardiogenic shock had an elevated vasopressor requirement with 33°C TTM compared to 36°C TTM during the maintenance and rewarming phases.

How to Decrease the Malposition Rate of Central Venous Catheterization: Real-Time Ultrasound-Guided Reposition / 대한구급학회지

BACKGROUND: The purpose of this retrospective and prospective study is to evaluate the efficiency of ultrasound (US) guidance as a method of decreasing the malposition rate of central venous catheterization (CVC) in the emergency department (ED). METHODS: We retrospectively enrolled 379 patients who underwent landmark-guided CVC (Group A) and prospectively enrolled 411 patients who underwent US-guided CVC (Group B) in the ED of a tertiary hospital. Malposition of the CVC tip is identified when the tip is not located in the superior vena cava (SVC). In Group B, we performed US-guided intravascular guide-wire repositioning and then confirmed the location of the CVC tip with chest radiography when the guide-wire was visible in any three other vessels rather than in the approached vessel. In the case of a guide-wire inserted into the right subclavian vein (SCV), the left SCV and both internal jugular veins (IJV) were referred to as the three other vessels. The two subject groups were compared in terms of the malposition rate using Fisher's exact test (significance = p < 0.05). RESULTS: There were 38 malposition cases out of a total of 790 CVCs. The malposition rates of Groups A and B were 5.5% (21) and 4.1% (17), respectively, and no statistically significant difference in malposition rate between the two groups was found. In Group B, the malposition rate was decreased from 4.1% (17) to 1.2% (5) after the guide-wire was repositioned with US guidance, which led to a statistically significant difference in malposition rate (p < 0.01). CONCLUSIONS: The authors concluded that repositioning the guide-wire with US guidance increased correct placement of central venous catheters toward the SVC.