A Prospective Comparison of Supine Chest Radiography and Bedside Ultrasound for the Diagnosis of Traumatic Pneumothorax

Background: Supine anteroposterior (AP) chest radiography may not detect the presence of a small or medium pneumothorax (PTX) in trauma patients. Objectives: To compare the sensitivity and specificity of bedside ultrasound (US) in the emergency department (ED) with supine portable AP chest radiography for the detection of PTX in trauma patients, and to determine whether US can grade the size of the PTX. Methods: This was a prospective, single‐blinded study with convenience sampling, based on researcher availability, of blunt trauma patients at a Level 1 trauma center with an annual census of 75,000 patients. Enrollment criteria were adult trauma patients receiving computed tomography (CT) of the abdomen and pelvis (which includes lung windows at the authors' institution). Patients in whom the examination could not be completed were excluded. During the initial evaluation, attending emergency physicians performed bedside trauma US examinations to determine the presence of a sliding lung sign to rule out PTX. Portable, supine AP chest radiographs were evaluated by an attending trauma physician, blinded to the results of the thoracic US. The CT results (used as the criterion standard), or air release on chest tube placement, were compared with US and chest radiograph findings. Sensitivities and specificities with 95% confidence intervals (95% CIs) were calculated for US and AP chest radiography for the detection of PTX, and Spearman's rank correlation was used to evaluate for the ability of US to predict the size of the PTX on CT. Results: A total of 176 patients were enrolled in the study over an eight‐month period. Twelve patients had a chest tube placed prior to CT. Pneumothorax was detected in 53 (30%) patients by US, and 40 (23%) by chest radiography. There were 53 (30%) true positives by CT or on chest tube placement. The sensitivity for chest radiography was 75.5% (95% CI = 61.7% to 86.2%) and the specificity was 100% (95% CI = 97.1% to 100%). The sensitivity for US was 98.1% (95% CI = 89.9% to 99.9%) and the specificity was 99.2% (95% CI = 95.6% to 99.9%). The positive likelihood ratio for a PTX was 121. Spearman's rank correlation showed at ρ of 0.82. Conclusions: With CT as the criterion standard, US is more sensitive than flat AP chest radiography in the diagnosis of traumatic PTX. Furthermore, US allowed sonologists to differentiate between small, medium, and large PTXs with good agreement with CT results.     

Thoracic point-of-care ultrasound is an accurate diagnostic modality for clinically significant traumatic pneumothorax

Objective

There are conflicting data regarding the accuracy of thoracic point-of-care ultrasound (POCUS) in detecting traumatic pneumothorax (PTX). The purpose of our study was to determine the accuracy of thoracic POCUS performed by emergency physicians for the detection of clinically significant PTX in blunt and penetrating trauma patients.

Methods

We conducted a retrospective institutional review board–approved study of trauma patients 15 years or older presenting to our urban Level I academic trauma center from December 2021 to June 2022. All study patients were imaged with single-view chest radiography (CXR) and thoracic POCUS. The presence or absence of PTX was determined by multidetector computed tomography (CT) or CXR and ultrasound (US) with tube thoracostomy placement.

Results

A total of 846 patients were included, with 803 (95%) sustaining blunt trauma. POCUS identified 13/15 clinically significant PTXs (defined as ≥35 mm of pleural separation on a blinded overread or placement of a tube thoracostomy prior to CT) with a sensitivity of 87% (95% confidence interval [CI] 58–97), specificity of 100% (95% CI 99–100), positive predictive value of 81% (95% CI 54%–95%), and negative predictive value of 100% (95% CI 99%–100%). The positive likelihood ratio was 484 and the negative likelihood ratio was 0.1. CXR identified eight (53%) clinically significant PTXs, with a sensitivity of 53% (95% CI 27%–78%) and a specificity of 100%, when correlated with the CT. The most common reason for a missed PTX identified on expert-blinded overread was failure to recognize a lung point sign that was present on US.

Conclusions

Thoracic POCUS accurately identifies the majority of clinically significant PTXs in both blunt and penetrating trauma patients. Common themes for false-negative thoracic US in the expert-blinded overread process identified key gaps in training to inspire US education and medical education research.     

Confirmation of endotracheal intubation by combined ultrasonographic methods in the emergency department

Objectives: The objective of the present study was to investigate whether the combined use of transcricothyroid membrane ultrasonography and ultrasonographic evaluation for pleural sliding is useful for verifying endotracheal intubation in the ED. Methods: We performed a prospective clinical trial in the ED from January to July 2008. All patients enrolled in the present study had been admitted to the ED owing to severe airway problems. A linear probe was placed horizontally over the cricothyroid membrane (dynamic phase) during the intubation process. Endotracheal intubation was confirmed by ultrasonographic lung sliding. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated. Results: Thirty patients (17 men, 13 women; mean age 59.6 ± 16.7 [SD] years) were enrolled in the study. Of the 30, 7 had a history of trauma. Four trauma patients were diagnosed with haemopneumothorax. The ratio of initial oesophageal‐to‐endotracheal intubation was 3:27. Sensitivity, specificity, PPV and NPV for endotracheal intubation were 96.3%, 100%, 100% and 75%, respectively. After verification by ultrasonographic lung sliding, sensitivity, specificity, PPV and NPV were each 100%. Conclusions: The combination of transcricothyroid membrane ultrasonography and ultrasonographic lung‐sliding evaluation could be useful in confirming endotracheal intubation in the ED.     

ABSCESS: Applied Bedside Sonography for Convenient Evaluation of Superficial Soft Tissue Infections

Objectives: Soft tissue infections are a common presenting complaint in the emergency department (ED). The authors sought to determine the utility of ED bedside ultrasonography (US) in detecting subcutaneous abscesses. Methods: Between August 2003 and November 2004, a prospective, convenience sample of adult patients with a chief complaint suggestive of cellulitis and/or abscess was enrolled. US was performed by attending physicians or residents who had attended a 30‐minute training session in soft tissue US. The treating physician recorded a yes/no assessment of whether he or she believed an abscess was present before and after the US examination. Incision and drainage (I + D) was the criterion standard when performed, while resolution on seven‐day follow‐up was the criterion standard when I + D was not performed. Results: Sixty‐four of 107 patients had I + D–proven abscess, 17 of 107 had negative I + D, and 26 of 107 improved with antibiotic therapy alone. The sensitivity of clinical examination for abscesses was 86% (95% confidence interval [CI] = 76% to 93%), and the specificity was 70% (95% CI = 55% to 82%). The positive predictive value was 81% (95% CI = 70% to 90%), and the negative predictive value was 77% (95% CI = 62% to 88%). The sensitivity of US for abscess was 98% (95% CI = 93% to 100%), and the specificity was 88% (95% CI = 76% to 96%). The positive predictive value was 93% (95% CI = 84% to 97%), and the negative predictive value was 97% (95% CI = 88% to 100%). Of 18 cases in which US disagreed with the clinical examination, US was correct in 17 (94% of cases with disagreement, χ²= 14.2, p = 0.0002). Conclusions: ED bedside US improves accuracy in detection of superficial abscesses.     

Comparison of the Medical Priority Dispatch System to an Out-of-hospital Patient Acuity Score

Background: Although the Medical Priority Dispatch System (MPDS) is widely used by emergency medical services (EMS) dispatchers to determine dispatch priority, there is little evidence that it reflects patient acuity. The Canadian Triage and Acuity Scale (CTAS) is a standard patient acuity scale widely used by Canadian emergency departments and EMS systems to prioritize patient care requirements. Objectives: To determine the relationship between MPDS dispatch priority and out‐of‐hospital CTAS. Methods: All emergency calls on a large urban EMS communications database for a one‐year period were obtained. Duplicate calls, nonemergency transfers, and canceled calls were excluded. Sensitivity and specificity to detect high‐acuity illness, as well as positive predictive value (PPV) and negative predictive value (NPV), were calculated for all protocols. Results: Of 197,882 calls, 102,582 met inclusion criteria. The overall sensitivity of MPDS was 68.2% (95% confidence interval [CI] = 67.8% to 68.5%), with a specificity of 66.2% (95% CI = 65.7% to 66.7%). The most sensitive protocol for detecting high acuity of illness was the breathing‐problem protocol, with a sensitivity of 100.0% (95% CI = 99.9% to 100.0%), whereas the most specific protocol was the one for psychiatric problems, with a specificity of 98.1% (95% CI = 97.5% to 98.7%). The cardiac‐arrest protocol had the highest PPV (92.6%, 95% CI = 90.3% to 94.3%), whereas the convulsions protocol had the highest NPV (85.9%, 95% CI = 84.5% to 87.2%). The best‐performing protocol overall was the cardiac‐arrest protocol, and the protocol with the overall poorest performance was the one for unknown problems. Sixteen of the 32 protocols performed no better than chance alone at identifying high‐acuity patients. Conclusions: The Medical Priority Dispatch System exhibits at least moderate sensitivity and specificity for detecting high acuity of illness or injury. This performance analysis may be used to identify target protocols for future improvements.     

Ultrasonography to Evaluate Adults for Appendicitis: Decision Making Based on Meta-analysis and Probabilistic Reasoning

Objectives: To review ultrasonography (US) test performance and to develop recommendations for the use of US to aid in the evaluation of potential appendicitis.
Methods: A meta-analysis was conducted using all English-language articles published since 1986 (17 studies; 3,358 patients) to ascertain sensitivity and specificity of US for diagnosing appendicitis in adults and teenagers. Calculation of the predictive value of US was performed for three groups of patients: group I—usually operated on (prevalence of appendicitis = 80%); group II—usually observed in hospital (prevalence = 40%); and group III—usually released home (prevalence 2%).
Results: Overall sensitivity was 84.7% (95% CI: 81.0–87.8%), and specificity 92.1% (88.0–95.2). The accuracy and usefulness of US were related to the likelihood of appendicitis. In group I, a positive test was accurate [positive predictive value (PPV) = 97.6%], but a negative study could not rule out appendicitis [negative predictive value (NPV) = 59.5%]. The converse was true for group III patients (PPV = 19.5%, NPV = 99.7%). Test performance accuracy was balanced only for group II patients (PPV = 87.3%, NPV = 89.9%).
Conclusions: 1) US should not be used to exclude appendicitis for patients who have "classic" signs/symptoms, due to the underlying high false-negative rate. 2) US is most useful for patients who have an indeterminate probability of disease after the initial evaluation—if US is positive, the patient should have an operation; otherwise, he or she should be observed. 3) US is not recommended for screening patients who have a low probability of appendicitis, due to the low prevalence of disease and high false-positive rate in this group.     

Short-axis versus Long-axis Approaches for Teaching Ultrasound-guided Vascular Access on a New Inanimate Model

OBJECTIVES: To determine whether a short-axis (SA) or long-axis (LA) ultrasound (US) approach to guidance for line placement results in faster vascular access for novice US users. Also, to assess if there was a difference in the number of skin penetrations and needle redirections between the two guidance techniques. METHODS: This was a prospective, randomized, observational study of emergency medicine (EM) residents at a Level I trauma center. A gelatin dessert and dietary fiber supplement mixture, providing a realistic US image, were placed inside a synthetic arm skin that is used for training phlebotomists and contains a rubber vein filled with red fluid at a depth of 1.5 cm. After a 30-minute tutorial on US-guided vascular access, EM residents were randomized to one of two groups. Group one attempted SA first and then the LA. Group two tried LA first followed by the SA. Time from skin break to vein cannulation, number of skin breaks and needle redirections, and difficulty of access on a 10-point Likert scale as reported by residents were recorded. Statistical analysis included paired Student's t-test with 95% confidence intervals (95% CIs). RESULTS: Seventeen EM residents participated. The mean times to vein cannulation in SA and LA were 2.36 minutes (95% CI = 1.15 to 3.58) and 5.02 minutes (95% CI = 2.90 to 7.13), respectively (p = 0.03). The mean numbers of skin breaks for SA and LA were 4.18 (95% CI = 1.18 to 7.17) and 5.76 (95% CI = 1.83 to 9.69), respectively (p = 0.49). The mean numbers of needle redirections in the SA and LA were 13.71 (95% CI = 4.51 to 22.89) and 18.17 (95% CI = 7.95 to 28.40), respectively (p = 0.51). The mean difficulty scores for SA and LA were 3.99 (95% CI = 2.42 to 5.67) and 5.86 (95% CI = 4.32 to 7.40), respectively (p = 0.17). CONCLUSIONS: Novice US users obtain vascular access faster with an SA approach on an inanimate model.     

Transtracheal ultrasonographic confirmation of endotracheal intubation using I-gel and an endotracheal tube introducer

BackgroundThis study aimed to investigate the efficacy of transtracheal ultrasonography in confirming the placement of an endotracheal tube introducer during endotracheal intubation using the I-gel supraglottic airway as a guide.MethodsIn this prospective study, endotracheal intubation using an endotracheal tube introducer through the I-gel was performed in patients with return of spontaneous circulation after I-gel insertion for out-of-hospital cardiac arrest. The introducer placement was assessed by the occurrence of hyperechoic artifacts within the trachea or esophagus in transtracheal ultrasonography. Results of ultrasonography were confirmed by waveform capnography in the case of tracheal artifacts and direct visualization by laryngoscopy in the case of esophageal artifacts.ResultsOne hundred and six patients were enrolled in this study. In transtracheal ultrasonography, artifacts of introducer in the trachea and esophagus were observed in 80 (75.5%) and 26 (24.5%) patients, respectively. Transtracheal ultrasonography in identifying the placement of introducers revealed a sensitivity of 100% (95% CI 95.4 to 100), specificity of 96.3% (95% CI 81.0 to 99.9), a PPV of 98.7% (95% CI 92.0 to 99.8), and a NPV of 100% (95% CI 94.8 to 99.9).ConclusionTranstracheal ultrasonography is an accurate method for identifying introducer placement during endotracheal intubation using an endotracheal tube introducer through the I-gel.     

Impact of endotracheal tube twisting on the diagnostic accuracy of ultrasound for intubation confirmation

IntroductionUltrasound is a readily-available technique used to identify accurate placement of an endotracheal tube (ETT) after an intubation attempt. There is limited research on using manipulation of the ETT to improve the diagnostic accuracy of ETT location confirmation. Our study sought to directly assess whether ETT twisting during the standard grayscale technique influenced the accuracy of intubation confirmation by ultrasound.MethodsThe study was performed using two different fresh cadavers. During each trial, the cadavers were randomized to either tracheal or esophageal intubation. Three blinded, ultrasound fellowship-trained sonographers assessed the location of the ETT post-intubation alternating between using either a technique with no ETT movement or a technique with ETT twisting. In the latter technique, the sonographers manipulated the ETT in using a side-to-side, twisting motion while performing the ultrasound exam. The study measured the accuracy of ETT location identification, time to identification, and sonographer confidence.Results540 assessments were performed with equal numbers of tracheal and esophageal intubations. The accuracy of ultrasound using the static technique was 97.8% (95% CI 95.2% to 99.0%) and the accuracy using the ETT twisting technique was 100% (95% CI 98.6% to 100%). The ETT twisting group showed a faster time to identification with a mean time to identification of 4.97 s (95% CI 4.36 to 5.57 s) compared to 6.87 s (95% CI 6.30 to 7.44 s) for the static ETT group. Operator confidence was also higher in the ETT twisting group at 4.84/5.0 (95% CI 4.79 to 4.90) compared to 4.71/5.0 (95% CI 4.63 to 4.78) in the static ETT group.ConclusionThere was no statistically significant difference in the accuracy of ETT location identification between the two groups. However, utilizing the ETT twisting technique showed a statistically significant improvement in the time to identification and sonographer confidence.     

Diagnostic performance of exercise bicycle testing and single-photon emission computed tomography: comparison with 64-slice computed tomography coronary angiography

To conduct a comparison of the diagnostic performance of exercise bicycle testing and single-photon emission computed tomography (SPECT) with computed tomography coronary angiography (CTCA) for the detection of obstructive coronary artery disease (CAD) in patients with stable angina. 376 symptomatic patients (254 men, 122 women, mean age 60.4 ± 10.0 years) referred for noninvasive stress testing (exercise bicycle test and/or SPECT) and invasive coronary angiography were included. All patients underwent additional 64-slice CTCA. The diagnostic performance of exercise bicycle testing (ST segment depression), SPECT (reversible perfusion defect) and CTCA (≥50% lumen diameter reduction) was presented as sensitivity, specificity, positive and negative predictive value (PPV and NPV) to detect or rule out obstructive CAD with quantitative coronary angiography as reference standard. Comparisons of exercise bicycle testing versus CTCA (n = 334), and SPECT versus CTCA (n = 61) were performed. The diagnostic performance of exercise bicycle testing was significantly (P value < 0.001) lower compared to CTCA: sensitivity of 76% (95% CI, 71–82) vs. 100% (95% CI, 97–100); specificity of 47% (95% CI, 36–58) vs. 74% (95% CI, 63–82). We observed a PPV of 70% (95% CI, 65–75) vs. 91% (95% CI, 87-94); and NPV of 30% (95%, 25–35) vs. 99% (95%, 90–100). There was a statistically significant difference in sensitivity (P value < 0.05) between SPECT and CTCA: 89% (95% CI, 75–96) vs. 98% (95% CI, 87–100); but not in specificity (P value > 0.05): 77% (95% CI, 50–92) vs. 82% (95% CI, 56–95). We observed a PPV of 91% (95% CI, 77–97) vs. 93% (95% CI, 81–98); and NPV of 72% (95%, 46–89) vs. 93% (95%, 66–100). SPECT and CTCA yielded higher diagnostic performance compared to traditional exercise bicycle testing for the detection and rule out of obstructive CAD in patients with stable angina.     

S100A8/A9: A Potential New Diagnostic Aid for Acute Appendicitis

Objectives: Diagnosing acute appendicitis is a daunting clinical challenge, as there is no single test that reliably distinguishes acute appendicitis from other etiologies of acute abdominal pain. In this study, the authors examined whether circulating levels of S100A8/A9 could be useful as a marker to aid in the diagnosis of acute appendicitis. Methods: Plasma samples from emergency department (ED) patients with acute abdominal pain (n = 181) were tested using an immunoassay for S100A8/A9. Results: The sensitivity and specificity for S100A8/A9 in diagnosing acute appendicitis were estimated to be 93% (95% confidence interval [CI] = 81% to 97%) and 54% (95% CI = 45% to 62%), respectively. Negative predictive value (NPV) was 96% (95% CI = 89% to 99%), and positive predictive value (PPV) was 37% (95% CI = 28% to 47%). Performance characteristics of elevated white blood cell (WBC) count were also estimated: sensitivity 63% (95% CI = 47% to 76%), specificity 67% (95% CI = 59% to 75%), NPV 86% (95% CI = 78% to 91%), and PPV 36% (95% CI = 26% to 47%). Conclusions: This is the first report exploring the relationship between circulating S100A8/A9 and acute appendicitis and establishes proof of concept for this biomarker as a diagnostic test for acute appendicitis. Further studies are indicated to optimize the use of this biomarker, in conjunction with other established approaches. ACADEMIC EMERGENCY MEDICINE 2010; 17:333–336 © 2010 by the Society for Academic Emergency Medicine     

Ultrasound Image Quality Comparison between an Inexpensive Handheld Emergency Department (ED) Ultrasound Machine and a Large Mobile ED Ultrasound System

Questions have been raised regarding image quality (IQ) provided by portable ultrasound (US) machines. OBJECTIVES: To determine if a difference exists between images obtained with a common portable US machine and those obtained with a more expensive, larger US machine when comparing typical views used by emergency physicians. METHODS: The authors performed a cross-sectional, blinded comparison of images from similar sonographic windows obtained on healthy models using a SonoSite 180 Plus and a General Electric (GE) 400 US machine. Both machines were optimized by company representatives. Images obtained included typical abdominal and vascular applications using the abdominal and linear transducers on each machine. All images were printed on identical high-resolution printers and then digitized using a bitmap format at 300 dots-per-inch resolution (RES). Images were then cropped, masked, and placed into random order comparing each view per model by a commercial Web design company (loracs.com). Three credentialed emergency physician sonologists, blinded to machine type, rated each image pair for RES, detail (DET), and total IQ as previously defined in the literature using a ten-point Likert scale; 10 was the best rating for each category. Paired t-test, 95% confidence intervals (95% CIs), and interobserver correlation were calculated. RESULTS: A total of 49 image pairs were evaluated. Mean GE 400 RES, DET, and IQ scores were 6.8, 6.8, and 6.6, respectively. Corresponding SonoSite means were 6.3, 6.3, and 6.0, respectively. The difference of 0.5 (95% CI = 0.13 to 1.1) for DET was not statistically significant (p = 0.06). The differences of 0.5 (95% CI = 0.1 to 1.1) and 0.6 (95% CI = 0.2 to 1.2) for RES and IQ were statistically significant, with p = 0.01 and 0.01. There was good interobserver agreement (kappa = 0.71; 95% CI = 0.67 to 0.78). CONCLUSIONS: A statistically significant difference was seen between GE 400 and SonoSite in IQ and RES, but not DET.     

Comparative study of transvaginal ultrasonography and CA 125 in the preoperative evaluation of myometrial invasion in endometrial carcinoma.

OBJECTIVE: To compare the ability of transvaginal sonography and serum CA 125 levels to predict myometrial invasion in patients with endometrial carcinoma. DESIGN AND METHODS: Prospective study in 50 consecutive patients (mean age 60 years, SD 10.5, range 29-77 years) diagnosed as having endometrial cancer and scheduled for surgical staging. All patients were evaluated by transvaginal ultrasonography. Endometrial thickness was measured in all cases and myometrial invasion was estimated as < 50% or > or = 50%. Serum CA 125 level was determined in each patient. A cut-off level of > or = 35 IU/ml was considered to predict myometrial invasion of > or = 50%. All patients underwent surgical staging, and definitive histopathological findings regarding myometrial invasion were used as the 'gold standard'. Sensitivity, specificity and positive predictive value (PPV) and negative predictive value (NPV) were calculated for transvaginal ultrasonography and CA 125 and compared. RESULTS: On histopathological analysis, myometrial invasion was found to be < 50% in 35 (70%) cases and > or = 50% in 15 cases (30%). Mean endometrial thickness in patients with superficial invasion was significantly lower than in those with deep invasion (13.4 mm (95% CI 11.2-15.7) vs. 18.7 mm (95% CI 15.0-22.3), respectively; p = 0.014). Median CA 125 was significantly higher in patients with deep invasion than in those with superficial invasion (30 IU/ml, interquartile range (IQR) 46.0 vs. 16.9 IU/ml, IQR 13.9, respectively; p = 0.002). The sensitivity, specificity, PPV and NPV for transvaginal ultrasonography were 86.7% (95% CI 59.5-98.3), 94.3% (95% CI 80.8-99.3), 86.7% (95% CI 59.5-98.3) and 94.3% (95% CI 80.8-99.3), respectively. The sensitivity, specificity, PPV and NPV for CA 125 were 40% (95% CI 16.3-67.7), 91.4% (95% CI 76.9-98.2), 66.7% (95% CI 29.9-92.5) and 78% (95% CI 63.4-89.5), respectively. The sensitivity of transvaginal ultrasonography was significantly higher than that of CA 125 (p = 0.008). No differences were found in terms of specificity, PPV or NPV. CONCLUSION: Our results indicate that transvaginal ultrasonography is more sensitive than CA 125 in predicting myometrial invasion in endometrial cancer.     

The Potential Role of Ultrasound in the Work-up of Appendicitis in the Emergency Department

Background

Acute appendicitis is common in the adult emergency department (ED). Computed tomography (CT) scan is frequently used to diagnose this condition, but ultrasound (US)—commonly used in pediatric diagnosis—may also have a role.

Proper Depth of Placement of Oral Endotracheal Tubes in Adults Prior to Radiographic Confirmation

Objective: To determine whether a certain distance measurement on the oral endotracheal tube (ETT) at the corner of the mouth could reasonably ensure proper depth of placement in critically ill patients, without the immediate need for a confirming chest x-ray (CXR).
Methods: A prospective observational cross-sectional design was used to compare ETT mark distance and radiographic location of the ETT tip. The measurement marking on the ETT at the level of the corner of the mouth was noted at the time of intubation. The relationship of the tip of the ETT to the tracheal carina on the postintubation CXR was then determined. The ETT placement was deemed correct if the tip was at least 2 cm cephalad to the carina on the CXR.
Results: Of 83 intubated patients assessed, 52 were men and 31 women. The mean measurement on the ETT at the corner of the mouth was 22.2 cm for the women and 23.1 cm for the men. The mean distance from the tip of the ETT to the carina was 3.45 cm for the women and 4.13 cm for the men. Seventy-five of the 83 patients (90.4%; 95% CI 81.9–95.7%) had correct ETT positions on the initial CXR. If the ETT position had been adjusted at the corner of the mouth to 21 cm for the women and 23 cm for the men, the ETT would have been in correct position for 81 of the 83 patients (97.6%; 95% CI 89.6–99.7%). This represents a significant improvement in tube placement (p < 0.025; the McNemar chi-square).
Conclusion: Proper depth of ETT placement in the critically ill adult patient can be estimated by the technique of this study. In this adult patient population, corner-of-the-mouth placement of the ETT using the 21-cm tube mark for the women and the 23-cm mark for the men would have led to proper placement for most patients.     

Use of ultrasound to facilitate accurate femoral nerve block in the emergency department

Objective: To compare the accuracy of ultrasound (US)‐assisted femoral nerve blocks (FNB) with the fascial pop (FP) technique, examining the rates of success and complications. Methods: This is a prospective unblinded pseudo‐randomized controlled trial of US‐assisted versus FP FNB techniques. The primary outcome measure was nerve block stratified to level of blockade (intact, partial or complete) with FNB assessed by skin sensation. Participants were assessed at 15 and 60 min post nerve block. Results: Sixty‐seven patients were enrolled. Thirty‐four (50.7% [95% CI 44.7–56.8]) underwent the US‐assisted technique whereas thirty‐three (49.2% [95% CI 43.4–55.2]) underwent the FP technique. At 15 min, FNB using US was intact, partial or complete for 9 (26.5% [95% CI 22.5–30.4]), 15 (44.1% [95% CI 36.8–51.5]) and 10 (29.4% [95% CI 24.9–33.9]) patients, respectively, compared with 14 (42.4% [95% CI 35.3–49.6]), 17 (51.5% [95% CI 42.7–60.3]) and 2 (6.1% [95% CI 5.6–6.6]) patients, respectively (P = 0.038). There was no difference at 60 min. Complete block at 15 min was achieved in 10/34 patients (29% [95% CI 14.1–44.7]) in the US group and 2/33 patients (6% [95% CI ?2.1–14.2]) in the FP group (P = 0.029); no difference was seen at 60 min. No complications were recorded in either group. Conclusions: A more complete blockade is achieved earlier using the US‐assisted technique. The US‐assisted technique will become the technique of choice for FNB in this department.     

Tissue Harmonic Imaging Improves Organ Visualization in Trauma Ultrasound When Compared with Standard Ultrasound Mode

The focused abdominal sonography for trauma (FAST) examination is complicated by brightly lit trauma bays, limited time, and body habitus. Recently, new ultrasound (US) technology has become available that improves organ visualization in abdominal scans. OBJECTIVE: The hypothesis was that a new US mode, tissue harmonic (TH) imaging, improves visualization of critical organ relationships in the FAST examination by making use of previously unused frequencies. The authors performed a blind, prospective observational study to compare the images obtained in typical FAST views with those obtained in standard US and TH modes. METHODS: Blunt trauma patients presenting to a level I trauma center between April and September 2000 were enrolled on a convenience basis. Typical FAST views were obtained in standard and TH modes. The emergency ultrasonographer (EU) switched between modes for each view, optimizing the gain each time. Multiple digital still images were made with all indications of the mode used disguised. For each view on a patient, the best image in each mode was selected in a blinded fashion. Three experienced EUs, blinded to the mode used, rated each image pair for resolution, detail, and total image quality as previously defined on a ten-point Likert scale, 10 being the best for each category. Wilcoxon signed-ranks test, 95% confidence intervals (95% CIs), and interobserver correlation were calculated. RESULTS: A total of 76 image groups (39 of Morison's pouch, 20 splenorenal, and 17 bladder) from 52 patients were rated. Tissue harmonics produced improved resolution, detail, and quality when compared with the standard US mode, with median scores of 6.7 vs. 6.0, 6.7 vs. 6.0, and 6.3 vs. 6.0, respectively. The differences of 0.7 (95% CI = 0.4 to 0.93), 0.7 (95% CI = 0.4 to 0.93), and 0.33 (95% CI = 0.17 to 0.67) were statistically significant, with p = 0.0001, 0.0001, and 0.0003, respectively. There was good interobserver agreement (kappa = 0.74; 95% CI = 0.68 to 0.79). CONCLUSIONS: Tissue harmonics produced FAST images higher in detail, resolution, and total image quality than standard-mode US images.     

Using color flow detection of air insufflation to improve accuracy in verifying nasogastric tube position

Objectives

Previous studies have shown that ultrasonography (USG), as an alternative to radiography, has a good accuracy in confirming nasogastric tube (NGT) position. Color flow detection of air insufflation is a novel approach in verifying NGT position. In our study, we aimed at evaluating its sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy in confirming the NGT position, as compared with 2-dimensional (2D) USG.

A Modified Lung and Cardiac Ultrasound Protocol Saves Time and Rules in the Diagnosis of Acute Heart Failure

Background

Multiorgan ultrasound (US), which includes evaluation of the lungs and heart, is an accurate method that outperforms clinical gestalt for diagnosing acutely decompensated heart failure (ADHF). A known barrier to ultrasound use is the time needed to perform these examinations.