Lung ultrasound imaging in avian influenza A (H7N9) respiratory failure

Background

Lung ultrasound has been shown to identify in real-time, various pathologies of the lung such as pneumonia, viral pneumonia, and acute respiratory distress syndrome (ARDS). Lung ultrasound maybe a first-line alternative to chest X-ray and CT scan in critically ill patients with respiratory failure. We describe the use of lung ultrasound imaging and findings in two cases of severe respiratory failure from avian influenza A (H7N9) infection.

Methods

Serial lung ultrasound images and video from two cases of H7N9 respiratory failure requiring mechanical ventilation and extracorporeal membrane oxygenation in a tertiary care intensive care unit were analyzed for characteristic lung ultrasound findings described previously for respiratory failure and infection. These findings were followed serially, correlated with clinical course and chest X-ray.

Results

In both patients, characteristic lung ultrasound findings have been observed as previously described in viral pulmonary infections: subpleural consolidations associated or not with local pleural effusion. In addition, numerous, confluent, or coalescing B-lines leading to ‘white lung’ with corresponding pleural line thickening are associated with ARDS. Extension or reduction of lesions observed with ultrasound was also correlated respectively with clinical worsening or improvement. Coexisting consolidated pneumonia with sonographic air bronchograms was noted in one patient who did not survive.

Conclusions

Clinicians with access to point-of-care ultrasonography may use these findings as an alternative to chest X-ray or CT scan. Lung ultrasound imaging may assist in the efficient allocation of intensive care for patients with respiratory failure from viral pulmonary infections, especially in resource scarce settings or situations such as future respiratory virus outbreaks or pandemics.     

In diagnosis of pleural effusion and pneumothorax in the intensive care unit patients: Can chest us replace bedside plain radiography?

Aim

To compare the role of chest US and bedside plain chest radiography in the evaluation of intensive care patients having pleural effusion and pneumothorax. Chest computed tomography has been used as an ideal standard.

Current practice of lung ultrasonography (LUS) in the diagnosis of pneumothorax: a survey of physician sonographers in Germany

Background

The purpose of this study was to survey the current practice of the use of lung ultrasonography (LUS) in the diagnosis of pneumothorax.

Methods

Physician sonographers, accredited for diagnostic ultrasonography in surgery, anaesthesia and medicine were studied. Questions addressed the frequency of exposure to patients with suspected pneumothorax, frequency of LUS use, preferences regarding technical aspects of LUS examination, assessment of diagnostic accuracy of LUS and involvement in teaching.

Results

Of the respondents, 55.1% used LUS ‘always’ or ‘frequently’ for suspected pneumothorax. Also, 35.5% of physicians rated LUS as ‘always reliable’ in ruling out pneumothorax, and 21.3% of respondents rated LUS as ‘always reliable’ in ruling in pneumothorax. The mode of performing LUS for pneumothorax was highly variable.Statistically significant differences were found regarding the likelihood of LUS usage, the combined use of M-Mode and B-mode scanning and the confidence to exclude pneumothorax based on LUS findings for physicians with frequent exposure to pneumothorax cases.

Conclusions

Physicians'' use of LUS in the diagnosis of pneumothorax is modest. Confidence in diagnostic accuracy is not comprehensive. Further research is required to establish the most efficient way of performing LUS in this scenario to achieve the highest possible diagnostic accuracy and reliable documentation of examination results.     

Sonography of Invasive Apocrine Carcinoma of the Breast in Five Cases

Objective

To evaluate the sonographic features of invasive apocrine carcinoma (IAC) of the breast.

Materials and Methods

This study included five pathologically proven cases of IAC, and their sonographic features were retrospectively analyzed according to the Breast Imaging Reporting and Data System (BI-RADS) lexicon.

Results

All five lesions involved the left breast and were seen as irregularly shaped masses. All lesions, except one, had a parallel orientation to the chest wall. All five lesions showed noncircumscribed margins and heterogeneous echotexture; however, they showed various posterior features. One lesion had edema as an associated feature. Sonographic assessments were classified as BI-RADS category 4 in all five cases.

Conclusion

Invasive apocrine carcinoma sonographic findings are difficult to differentiate from those of invasive ductal carcinoma of no special type.     

Ultrasound guided dry needling and autologous blood injection for patellar tendinosis

Objective

To evaluate the efficacy of ultrasound guided dry needling and autologous blood injection for the treatment of patellar tendinosis.

Design

Prospective cohort study.

Setting

Hospital/clinic based.

Patients

47 knees in 44 patients (40 men, 7 women, mean age 34.5 years, age range 17 to 54 years) with refractory tendinosis underwent sonographic examination of the patellar tendon following referral with a clinical diagnosis of patellar tendinosis (mean symptom duration 12.9 months).

Interventions

Ultrasound guided dry needling and injection of autologous blood into the site of patellar tendinosis was performed on two occasions four weeks apart.

Main outcome measures

Pre‐ and post‐procedure Victorian Institute of Sport Assessment scores (VISA) were collected to assess patient response to treatment. Follow up ultrasound examination was done in 21 patients (22 knees).

Results

Therapeutic intervention led to a significant improvement in VISA score: mean pre‐procedure score = 39.8 (range 8 to 72) v mean post procedure score = 74.3 (range 29 to 100), p<0.001; mean follow up 14.8 months (range 6 to 22 months). Patients were able to return to their sporting interests. Follow up sonographic assessment showed a reduction in overall tendon thickness and in the size of the area of tendinosis (hypoechoic/anechoic areas within the proximal patellar tendon). A reduction was identified in interstitial tears within the tendon substance. Neovascularity did not reduce significantly or even increased.

Conclusions

Dry needling and autologous blood injection under ultrasound guidance shows promise as a treatment for patients with patellar tendinosis.     

Efficacy of an opposite position aspiration on resolution of pneumothorax following CT-guided lung biopsy

Objective:

To evaluate the efficacy of aspiration in an opposite position to deal with pneumothorax after CT-guided lung biopsy.

Methods:

A retrospective study was developed involving 210 patients with pneumothorax who had undergone CT-guided percutaneous core biopsies from January 2012 to March 2014 for various pulmonary lesions. Asymptomatic patients with minimal pneumothorax were treated conservatively. Simple manual aspiration was performed for symptomatic patients with minimal pneumothorax and for all patients with moderate to large pneumothorax. An opposite position aspiration was performed when simple manual aspiration failed. The efficacy of simple manual aspiration and the opposite position aspiration was observed.

Results:

Among 210 patients with pneumothorax, 128 (61.0%) asymptomatic patients with minimal pneumothorax were treated conservatively. The remaining 82 were treated with attempted simple manual aspiration. Out of these 82 patients, simple manual aspiration was successful in 58 (70.7%, 58/82) cases. The complete and partial regression rates were 17.2% (10/58) and 82.8% (48/58), respectively. In the other 24 patients (29.3%, 24/82), simple aspiration technique was ineffective. An opposite position (from prone to supine or vice versa) was applied, and a new biopsy puncture site was chosen for reaspiration. This procedure was successful in 22 patients but not in 2 patients who had to have a chest tube insertion. The complete and partial regression rates were 25.0% (6/24) and 66.7% (16/24), respectively. Applying the new method, the total effective rate of aspiration improved significantly from 70.7% (58/82) to 97.6% (80/82).

Conclusion:

The opposite position aspiration can be safe, effective and minimally invasive treatment for CT-guided lung biopsy-induced pneumothorax thus reducing the use of chest tube significantly.

Advances in knowledge:

(1) Opposite position aspiration can elevate the success rate of aspiration significantly (from 70.7% to 97.6% in our study); (2) this procedure is a safe, effective and minimally invasive treatment for pneumothorax caused by biopsy; and (3) opposite position aspiration is a useful technique to reduce the use of chest tube, which has clinical significance.CT-guided transthoracic needle biopsy is an established and safe technique for the diagnosis of lung lesions. Pneumothorax is the most frequent complication of this technique.^1–4 Chest tube placement is associated with higher levels of pain and anxiety, and opioid pre-medication and local anaesthesia is required.⁵ The infection risk and in-patient stay increased significantly. Numerous modifications to the technique have been evaluated in an attempt to manage biopsy-induced pneumothorax and to reduce the number of cases that require chest tube placement. The purpose of this study was to evaluate the efficacy of changing the posture and/or puncture site in the treatment of pneumothorax following CT-guided lung biopsies.     

Medial epicondylitis: is ultrasound guided autologous blood injection an effective treatment?

Objective

To assess if ultrasound guided autologous blood injection is an effective treatment for medial epicondylitis.

Methods

Twenty patients (13 men, 7 women) with refractory medial epicondylitis with symptom duration of 12 months underwent sonographic evaluation. Tendinosis was confirmed according to three sonographic criteria: echo texture, interstitial tears and neovascularity. The tendon was then dry needled and autologous blood was injected. Patients were reviewed at 4 weeks and at 10 months. VAS scores and modified Nirschl scores were assessed pre‐procedure and post‐procedure.

Results

There was significant reduction in VAS pain score between pre‐procedure and 10 months post‐procedure when it had a median (IQR) of 1.00 (1–1.75), range 0–7. The median (IQR) Nirschl score, which at pre‐procedure was 6.00 (5–7), range 4–7, had decreased at 4 weeks to 4.00 (2.25–5), range 2–7, and at 10 months to 1.00 (1–1.75), range 0–7, revealing a significant decrease (z = 3.763, p<0.001). The hypo‐echoic change in the flexor tendon significantly decreased between pre‐procedure, when there was a mean (SD) of 6.45 (1.47), and at 10 months, when it was 3.85 (2.37) (p<0.001). Doppler ultrasound showed that neovascularity decreased between pre‐procedure, when there was a mean (SD) of 6.10 (1.62), range 4–9, and at 10 months, when it was 3.60 (2.56), range 0–9 (p<0.001).

Discussion

The combined action of dry needling and autologous blood injection under ultrasound guidance appears to be an effective treatment for refractory medial epicondylitis as demonstrated by a significant decrease in VAS pain and a fall in the modified Nirschl scores.     

Transcranial ultrasound analysis of cerebral blood flow during induced hypertension in acute ischemic stroke - a case series

Background

Current recommendations of stroke treatment favour a moderately elevated blood pressure in the acute phase, based on the concept of an improved cerebral perfusion. Here, cerebral blood flow was assessed in a case series of patients with acute hemodynamic stroke by means of transcranial colour-coded sonography (TCCS) to study the effects of pharmacologically induced hypertension.

Findings

We investigated six patients with acute hemodynamic stroke and blood pressure-dependent clinical fluctuation of neurological symptoms. TCCS was performed during the initiation phase of catecholamine-induced controlled hypertension. A blood pressure-dependent increase of flow velocity in the ipsilesional middle and the posterior cerebral artery was found in all patients (mean increase 0.80% and 0.65% per mmHg, respectively).

Conclusions

Catecholamine-induced hypertension in severe hemodynamic stroke leads to an ultrasound-detectable rise of cerebral blood flow. This finding gives ‘proof-of-principle’ evidence, supporting active blood pressure management in this selected group of stroke patients. Outcome-related questions of target blood pressure, treatment duration or applicability to other forms of stroke, however, remain to be studied. In this, transcranial ultrasound may be a valuable tool for patient selection and subsequent bedside monitoring.     

Contrast-Enhanced Harmonic Ultrasonography for the Assessment of Prostate Cancer Aggressiveness: a Preliminary Study

Objective

To determine whether contrast-enhanced harmonic ultrasonography can be used to predict the aggressiveness of prostate cancer.

Materials and Methods

Contrast-enhanced harmonic ultrasonography was performed in 103 patients suspected of prostate cancer before biopsy. Time intensity curves were reconstructed for systematic biopsy sites and sonographic abnormalities. The characteristics of the curves were described using hemodynamic indices including arrival time (AT), time-to-peak (TTP), and peak intensity (PI). The differences of hemodynamic indices between high-grade and low-grade cancer were analyzed and the correlations between the hemodynamic indices and biopsy Gleason score were studied.

Results

Prostate cancer was detected in 41 of 103 patients and there were significant differences in the hemodynamic indices between the biopsy sites of the non-malignant patients and prostate cancer lesions (p < 0.05). The prostate biopsies revealed 154 prostate cancer lesions, including 31 low-grade lesions and 123 high-grade lesions. The hemodynamic indices AT and TTP of high-grade tumors were significantly shorter than those of low-grade tumors (p = 0.001, 0.002). In addition, high-grade peripheral zone (PZ) tumors had higher PI than low-grade PZ tumors (p = 0.009). The PZ prostate cancer Gleason score correlated with PI, AT and TTP, with Spearman correlation coefficients of 0.223, -0.335, and -0.351, respectively (p = 0.013, < 0.001 and < 0.001).

Conclusion

Contrast-enhanced ultrasound measurements of hemodynamic indices correlate with the prostate cancer Gleason score.     

High-Resolution CT Findings of Re-Expansion Pulmonary Edema

Objective

To describe the high-resolution CT (HRCT) findings of re-expansion pulmonary edema (REPE) following a thoracentesis for a spontaneous pneumothorax.

Materials and Methods

HRCT scans from 43 patients who developed REPE immediately after a thoracentesis for treatment of pneumothorax were retrospectively analyzed. The study group consisted of 41 men and two women with a mean age of 34 years. The average time interval between insertion of the drainage tube and HRCT was 8.5 hours (range, 1-24 hours). The patterns and distribution of the lung lesions were analyzed and were assigned one of the following classifications: consolidation, ground-glass opacity (GGO), intralobular interstitial thickening, interlobular septal thickening, thickening of bronchovascular bundles, and nodules. The presence of pleural effusion and contralateral lung involvement was also assessed.

Results

Patchy areas of GGO were observed in all 43 patients examined. Consolidation was noted in 22 patients (51%). The geographic distribution of GGO and consolidation was noted in 25 patients (58%). Interlobular septal thickening and intralobular interstitial thickening was noted in 28 patients (65%), respectively. Bronchovascular bundle thickening was seen in 13 patients (30%), whereas ill-defined centrilobular GGO nodules were observed in five patients (12%). The lesions were predominantly peripheral in 38 patients (88%). Of these lesions, gravity-dependent distribution was noted in 23 cases (53%). Bilateral lung involvement was noted in four patients (9%), and a small amount of pleural effusion was seen in seven patients (16%).

Conclusion

The HRCT findings of REPE were peripheral patchy areas of GGO that were frequently combined with consolidation as well as interlobular septal and intralobular interstitial thickening.     

Ultrasound assessment of spleen size in collegiate athletes

Objectives

To determine normal spleen dimensions in a healthy collegiate athletic population.

Methods

631 Division I collegiate athletes from one university participated in the study. During pre‐participation examinations, demographic data collected were collected from volunteer athletes including sex, race, measurement of height and weight, and age. Subjects also completed a medical history form to determine any history of mononucleosis infection, platelet disorder, sickle cell disease (or trait), thalassaemia, or recent viral symptoms. Subjects then underwent a limited abdominal ultrasound examination, where splenic length and width were recorded.

Results

Mean (SD) splenic length was 10.65 (1.55) cm and width, 5.16 (1.21) cm. Men had larger spleens than women (p<0.001). White subjects had larger spleens than African‐American subjects (p<0.001). A previous history of infectious mononucleosis or the presence of recent cold symptoms had no significant affect on spleen size. In more than 7% of athletes, baseline spleen size met current criteria for splenomegaly.

Conclusions

There is a wide range of normal spleen size among collegiate athletes. Average spleen size was larger in men and white athletes than in women and black athletes. A single ultrasound examination for determination of splenomegaly is of limited value in this population.     

Ultrasonographic evaluation of oral submucous fibrosis in habitual areca nut chewers

Objectives:

To characterize the sonographic features of the buccal mucosa in patients with oral submucous fibrosis (OSF).

Methods:

Three groups (controls with areca-related habits, controls without areca-related habits and clinically diagnosed OSF cases), each comprising 30 subjects, were included in the study. After a thorough clinical examination, transcutaneous B-mode ultrasonography was performed with a multifrequency linear transducer (5–10 MHz) for anterior and posterior buccal mucosa bilaterally. Both clinical and ultrasound findings were recorded by three independent observers. One-way analysis of variance and Tukey''s honestly significant difference post-hoc tests were used for statistical comparisons between groups and Pearson χ² tests to compare the proportions. Kappa statistics was used to determine the interobserver agreement.

Results:

The submucosa that appeared hypoechoic in the control groups had significantly increased echogenicity in the case group (hypo- to isoechoic in 46.7% and isoechoic in 53.3%). The differentiation between the submucosa and the muscle layer appeared distinct in the control groups while it was not clear in the case group (indistinct in 50% and completely lost in 50%). The number of sites found positive on the ultrasound was significantly greater than the number of clinically positive sites. There was a very good interobserver consistency in clinical and ultrasound findings.

Conclusions:

Ultrasonography of the buccal mucosa demonstrates increased submucosal echogenicity and reduced echo differentiation between submucosa and muscle layer in OSF cases. Hence, it can be used as a non-invasive imaging modality to assess the disease extent and severity across the entire buccal mucosa to supplement clinical evaluation.     

Broncho-Pleural Fistula with Hydropneumothorax at CT: Diagnostic Implications in Mycobacterium avium Complex Lung Disease with Pleural Involvement

Objective

To determine the patho-mechanism of pleural effusion or hydropneumothorax in Mycobacterium avium complex (MAC) lung disease through the computed tomographic (CT) findings.

Materials and Methods

We retrospectively collected data from 5 patients who had pleural fluid samples that were culture-positive for MAC between January 2001 and December 2013. The clinical findings were investigated and the radiological findings on chest CT were reviewed by 2 radiologists.

Results

The 5 patients were all male with a median age of 77 and all had underlying comorbid conditions. Pleural fluid analysis revealed a wide range of white blood cell counts (410–100690/µL). The causative microorganisms were determined as Mycobacterium avium and Mycobacterium intracellulare in 1 and 4 patients, respectively. Radiologically, the peripheral portion of the involved lung demonstrated fibro-bullous changes or cavitary lesions causing lung destruction, reflecting the chronic, insidious nature of MAC lung disease. All patients had broncho-pleural fistulas (BPFs) and pneumothorax was accompanied with pleural effusion.

Conclusion

In patients with underlying MAC lung disease who present with pleural effusion, the presence of BPFs and pleural air on CT imaging are indicative that spread of MAC infection is the cause of the effusion.     

Integrated medical school ultrasound: development of an ultrasound vertical curriculum

Background

Physician-performed focused ultrasonography is a rapidly growing field with numerous clinical applications. Focused ultrasound is a clinically useful tool with relevant applications across most specialties. Ultrasound technology has outpaced the education, necessitating an early introduction to the technology within the medical education system. There are many challenges to integrating ultrasound into medical education including identifying appropriately trained faculty, access to adequate resources, and appropriate integration into existing medical education curricula. As focused ultrasonography increasingly penetrates academic and community practices, access to ultrasound equipment and trained faculty is improving. However, there has remained the major challenge of determining at which level is integrating ultrasound training within the medical training paradigm most appropriate.

Methods

The Ohio State University College of Medicine has developed a novel vertical curriculum for focused ultrasonography which is concordant with the 4-year medical school curriculum. Given current evidenced-based practices, a curriculum was developed which provides medical students an exposure in focused ultrasonography. The curriculum utilizes focused ultrasonography as a teaching aid for students to gain a more thorough understanding of basic and clinical science within the medical school curriculum. The objectives of the course are to develop student understanding in indications for use, acquisition of images, interpretation of an ultrasound examination, and appropriate decision-making of ultrasound findings.

Results

Preliminary data indicate that a vertical ultrasound curriculum is a feasible and effective means of teaching focused ultrasonography. The foreseeable limitations include faculty skill level and training, initial cost of equipment, and incorporating additional information into an already saturated medical school curriculum.

Conclusions

Focused ultrasonography is an evolving concept in medicine. It has been shown to improve education and patient care. The indications for and implementation of focused ultrasound is rapidly expanding in all levels of medicine. The ideal method for teaching ultrasound has yet to be established. The vertical curriculum in ultrasound at The Ohio State University College of Medicine is a novel evidenced-based training regimen at the medical school level which integrates ultrasound training into medical education and serves as a model for future integrated ultrasound curricula.     

The feasibility of nurse practitioner-performed,telementored lung telesonography with remote physician guidance - ‘a remote virtual mentor’

Background

Point-of-care ultrasound (POC-US) use is increasingly common as equipment costs decrease and availability increases. Despite the utility of POC-US in trained hands, there are many situations wherein patients could benefit from the added safety of POC-US guidance, yet trained users are unavailable. We therefore hypothesized that currently available and economic ‘off-the-shelf’ technologies could facilitate remote mentoring of a nurse practitioner (NP) to assess for recurrent pneumothoraces (PTXs) after chest tube removal.

Methods

The simple remote telementored ultrasound system consisted of a handheld ultrasound machine, head-mounted video camera, microphone, and software on a laptop computer. The video output of the handheld ultrasound machine and a macroscopic view of the NP''s hands were displayed to a remote trauma surgeon mentor. The mentor instructed the NP on probe position and US machine settings and provided real-time guidance and image interpretation via encrypted video conferencing software using an Internet service provider. Thirteen pleural exams after chest tube removal were conducted.

Results

Thirteen patients (26 lung fields) were examined. The remote exam was possible in all cases with good connectivity including one trans-Atlantic interpretation. Compared to the subsequent upright chest radiograph, there were 4 true-positive remotely diagnosed PTXs, 2 false-negative diagnoses, and 20 true-negative diagnoses for 66% sensitivity, 100% specificity, and 92% accuracy for remotely guided chest examination.

Conclusions

Remotely guiding a NP to perform thoracic ultrasound examinations after tube thoracostomy removal can be simply and effectively performed over encrypted commercial software using low-cost hardware. As informatics constantly improves, mentored remote examinations may further empower clinical care providers in austere settings.     

Detection of soft tissue foreign bodies by nurse practitioner-performed ultrasound

Background

This study aimed to evaluate the accuracy of emergency nurse practitioner (NP)-performed point-of-care ultrasound (POCUS) for the detection of soft tissue foreign bodies (FBs).

Methods

Following a 2-h training session, ten NPs were assessed on their ability to detect various FBs in an experimental model. FBs (wood, metal and plastic) were inserted randomly into eight experimental models (uncooked chicken thighs) by an independent observer. Control experimental models had no FB inserted, but all had a 1-cm incision made on their surface. NPs, blinded to the type of model, were then assessed on their ability to detect the FBs by ultrasound examination using high-frequency linear transducers (Toshiba Nemio). Models were also scanned by two experienced emergency physicians (EPs) as a further control.

Results

Overall, NP-performed POCUS detected 47 of the 60 foreign bodies with a sensitivity, specificity, positive predictive value and negative predictive value of 78.3%, 50%, 82% and 43%, respectively, compared with 83.3%, 75%, 90.9% and 60% for EPs. Sensitivity for detecting specific types of FB was 95%, 85% and 50% for wood, metal and plastic, respectively, for NP-performed POCUS, compared with 100%, 100% and 50% in the EP group.

Conclusions

NPs with no previous ultrasound experience can detect soft tissue FBs with accuracy comparable to that of EPs in an experimental model. Test sensitivity was high for wood and metal foreign bodies. Specificity was generally low.     

A prospective study of three diagnostic sonographic methods in differentiation between benign and malignant salivary gland tumours

Objective

The aim of this study was to evaluate the role of three diagnostic sonographic methods, greyscale sonography (GSS), colour Doppler sonography (CDS) and spectral Doppler (SPD), in differentiating between benign and malignant salivary gland (SG) tumours.

Methods

44 patients with SG masses were examined using GSS, CDS and SPD. The morphological features of each tumour were evaluated using GSS, the distribution and number of detected blood vessels were assessed using CDS, and peak systolic velocity (PSV), resistive index (RI) and pulsatility index (PI) were measured on SPD. All cases underwent excisional biopsy and a definite tissue diagnosis was obtained.

Results

Histopathological examination revealed that 28 of the 44 tumours were benign and 16 were malignant. GSS showed that malignant SG tumours had a significantly higher incidence of ill-defined borders and lymph node involvement than benign tumours, but there was no significant difference between benign and malignant SG tumours regarding echogenicity, homogeneity or sonographic shape. CDS demonstrated malignant tumours with significantly higher vascularity and a scattered distribution. Using SPD, malignant tumours had significantly higher PSV, RI and PI compared with benign tumours.

Conclusion

RI values above 0.7, PI values above 1.2, PSV values above 44.3 cm s^–1, ill-defined borders, lymph node involvement, Grade 2 or 3 vascularity and hilar distribution of blood vessels should alert the clinician to suspect a malignant SG tumour. After consensus on the threshold values of PSV, RI and PI in differentiating benign from malignant SG tumours, these numbers should be incorporated into the software of ultrasound machines to guide the sonographer in his or her analysis.     

A feasibility study on bedside upper airway ultrasonography compared to waveform capnography for verifying endotracheal tube location after intubation

Background

In emergency settings, verification of endotracheal tube (ETT) location is important for critically ill patients. Ignorance of oesophageal intubation can be disastrous. Many methods are used for verification of the endotracheal tube location; none are ideal. Quantitative waveform capnography is considered the standard of care for this purpose but is not always available and is expensive. Therefore, this feasibility study is conducted to compare a cheaper alternative, bedside upper airway ultrasonography to waveform capnography, for verification of endotracheal tube location after intubation.

Methods

This was a prospective, single-centre, observational study, conducted at the HRPB, Ipoh. It included patients who were intubated in the emergency department from 28 March 2012 to 17 August 2012. A waiver of consent had been obtained from the Medical Research Ethics Committee. Bedside upper airway ultrasonography was performed after intubation and compared to waveform capnography. Specificity, sensitivity, positive and negative predictive value and likelihood ratio are calculated.

Results

A sample of 107 patients were analysed, and 6 (5.6%) had oesophageal intubations. The overall accuracy of bedside upper airway ultrasonography was 98.1% (95% confidence interval (CI) 93.0% to 100.0%). The kappa value (Κ) was 0.85, indicating a very good agreement between the bedside upper airway ultrasonography and waveform capnography. Thus, bedside upper airway ultrasonography is in concordance with waveform capnography. The sensitivity, specificity, positive predictive value and negative predictive value of bedside upper airway ultrasonography were 98.0% (95% CI 93.0% to 99.8%), 100% (95% CI 54.1% to 100.0%), 100% (95% CI 96.3% to 100.0%) and 75.0% (95% CI 34.9% to 96.8%). The likelihood ratio of a positive test is infinite and the likelihood ratio of a negative test is 0.0198 (95% CI 0.005 to 0.0781). The mean confirmation time by ultrasound is 16.4 s. No adverse effects were recorded.

Conclusions

Our study shows that ultrasonography can replace waveform capnography in confirming ETT placement in centres without capnography. This can reduce incidence of unrecognised oesophageal intubation and prevent morbidity and mortality.

Trial registration

National Medical Research Register NMRR11100810230.     

Saline-Enhanced Radiofrequency Thermal Ablation of the Lung: A Feasibility Study in Rabbits

Objective

To assess the feasibility and safety of CT-guided percutaneous transthoracic radiofrequency ablation (RFA) with saline infusion of pulmonary tissue in rabbits.

Materials and Methods

Twenty-eight New Zealand White rabbits were divided into two groups: an RFA group (n=10) and a saline-enhanced RFA (SRFA) group (n=18). In the RFA group, percutaneous RFA of the lung was performed under CT guidance and using a 17-gauge internally cooled electrode. In the SRFA group, 1.5 ml of 0.9% saline was infused slowly through a 21-gauge, polyteflon-coated Chiba needle prior to and during RFA. Lesion size and the healing process were studied in rabbits sacrificed at times from the day following treatment to three weeks after, and any complications were noted.

Results

In the SRFA group, the mean diameter (12.5 ± 1.6 mm) of acute RF lesions was greater than that of RFA lesions (8.5 ± 1.4 mm) (p < .05). The complications arising in 12 cases were pneumothorax (n=8), thermal injury to the chest wall (n=2), hemothorax (n=1), and lung abscess (n=1). Although procedure-related complications tended to occur more frequently in the SRFA group (55.6%) than in the RFA group (20%), the difference was not statistically significant (p = .11).

Conclusion

Saline-enhanced RFA of pulmonary tissue in rabbits produces more extensive coagulation necrosis than conventional RFA procedures, without adding substantial risk of serious complications.     

Will the presence of radiological signs of tension pneumothorax affect the clinical presentation of primary spontaneous pneumothorax?

Introduction

Patients with primary spontaneous pneumothorax (PSP) rarely presented with radiological signs of tension pneumothorax on their presenting chest X-ray. Even though, those patients may not develop the hemodynamic instability that is seen in tension pneumothorax. The aim of this study is to elaborate whether the presence of radiological signs of tension pneumothorax in patients with PSP will affect their clinical presentation.

Methods

Retrospective study of all cases of PSP over a period from January 2007 to December 2014. The cases were divided into two groups; tension group includes cases who have radiological signs of tension pneumothorax and non-tension group who do not have those signs. The main outcome was a comparison of the hemodynamic status of both groups.

Results

A total of 151 cases of PSP were included in the study. Radiologic signs of tension pneumothorax were identified in 13 cases of the sample. Only one case of the tension group developed hemodynamic instability in the form of desaturation to below 92% with no statistical difference between the two groups in maintaining the hemodynamic status.

Conclusion

In spite that PSP can be presented with radiological signs of tension pneumothorax, those patients usually maintained their hemodynamic stability. Tension pneumothorax rarely presented as consequence of PSP.