Seth Koenig

Thoracic Ultrasonography for the Pulmonary Specialist

Thoracic ultrasonography is a noninvasive and readily available imaging modality that has important applications in pulmonary medicine outside of the ICU. It allows the clinician to diagnose a variety of thoracic disorders at the point of care. Ultrasonography is useful in imaging lung consolidation, pleural-based masses and effusions, pneumothorax, and diaphragmatic dysfunction. It can identify complex or loculated effusions and be useful in planning treatment. Identifying intrathoracic mass lesions can guide sampling by aspiration and biopsy. This article summarizes thoracic ultrasonography applications for the pulmonary specialist, related procedural codes, and reimbursement. The major concepts are illustrated with cases. These case summaries are enhanced with online supplemental videos and chest radiograph, chest CT scan, and ultrasound correlation.

Accuracy of Ultrasonography Performed by Critical Care Physicians for the Diagnosis of DVT

BACKGROUNDnDVT is common among critically ill patients. A rapid and accurate diagnosis is essential for patient care. We assessed the accuracy and timeliness of intensivist-performed compression ultrasonography studies (IP-CUS) for proximal lower extremity DVT (PLEDVT) by comparing results with the formal vascular study (FVS) performed by ultrasonography technicians and interpreted by radiologists.nnnMETHODSnWe conducted a multicenter, retrospective review of IP-CUS examinations performed in an ICU by pulmonary and critical care fellows and attending physicians. Patients suspected of having DVT underwent IP-CUS, using a standard two-dimensional compression ultrasonography protocol for the diagnosis of PLEDVT. The IP-CUS data were collected prospectively as part of a quality-improvement initiative. The IP-CUS interpretation was recorded and timed at the end of the examination on a standardized report form. An FVS was then ordered, and the FVS result was used as the criterion standard for calculating sensitivity and specificity. Time delays between the IP-CUS and FVS were recorded.nnnRESULTSnA total of 128 IP-CUS were compared with an FVS. Eighty-one percent of the IP-CUS were performed by fellows with <2 years of clinical ultrasonography experience. Prevalence of DVT was 20%. IP-CUS studies yielded a sensitivity of 86% and a specificity of 96% with a diagnostic accuracy of 95%. Median time delay between the ordering of FVS and the FVS result was 13.8 h.nnnCONCLUSIONSnRapid and accurate diagnosis of proximal lower extremity DVT can be achieved by intensivists performing compression ultrasonography at the bedside.

Video Laryngoscopy is Associated With Increased First Pass Success and Decreased Rate of Esophageal Intubations During Urgent Endotracheal Intubation in a Medical Intensive Care Unit When Compared to Direct Laryngoscopy

Background: To compare the complication rates of urgent endotracheal intubation (UEI) performed by pulmonary critical care medicine (PCCM) fellows and attending intensivists using a direct laryngoscope (DL) versus a video laryngoscope (VL) in a medical intensive care unit (MICU). Methods: We studied all UEIs performed from November 2008 through July 2012 in an 18-bed MICU in a university-affiliated hospital. All UEIs were performed by 15 PCCM fellows or attending intensivists using only the DL from November 2008 through February 2010 and the VL from March 2010 to July 2012. Throughout the entire study period, the UEI team leader recorded complications of the procedure using a standard data collection form immediately following the completion of the procedure. This permitted a comparison of complication rates between the DL and the VL. Results: A total of 140 UEIs were performed using the DL and 252 using the VL. Using the DL, the esophageal intubation rate was 19% and the difficult intubation rate was 22%; using the VL, the esophageal intubation rate was 0.4% and the difficult intubation rate was 7%. There was no significant difference in the rate of severe hypotension, severe desaturation, aspiration, dental injury, airway injury, or death between the 2 groups. Conclusion: The use of the VL for UEI performed by PCCM fellows is associated with a reduction in the rate of esophageal intubation and difficult endotracheal intubation when compared to the use of the DL.

Ultrasound Assessment of Pulmonary Embolism in Patients Receiving CT Pulmonary Angiography

BACKGROUNDnCT pulmonary angiography (CTPA) is considered the gold standard for the diagnosis of pulmonary embolism (PE) and is frequently performed in patients with cardiopulmonary complaints. However, indiscriminate use of CTPA results in significant exposure to ionizing radiation and contrast. We studied the accuracy of a bedside ultrasound protocol to predict the need for CTPA.nnnMETHODSnThis was an observational study performed by pulmonary/critical care physicians trained in critical care ultrasonography. Screening ultrasonography was performed when a CTPA was ordered to rule out PE. The ultrasound examination consisted of a limited ECG, thoracic ultrasonography, and lower extremity deep venous compression study. We predicted that CTPA would not be needed if either DVT was found or clear evidence of an alternative diagnosis was established. CTPA parenchymal and pleural findings, and, when available, formal DVT and ECG results, were compared with our screening ultrasound findings.nnnRESULTSnOf 96 subjects who underwent CTPA, 12 subjects (12.5%) were positive for PE. All 96 subjects had an ultrasound study; two subjects (2.1%) were positive for lower extremity DVT, and 54 subjects (56.2%) had an alternative diagnosis suggested by ultrasonography, such as alveolar consolidation consistent with pneumonia or pulmonary edema, which correlated with CTPA findings. In no patient did the CTPA add an additional diagnosis over the screening ultrasound study.nnnCONCLUSIONSnWe conclude that ultrasound examination indicated that CTPA was not needed in 56 of 96 patients (58.3%). A screening, point-of-care ultrasonography protocol may predict the need for CTPA. Furthermore, an alternative diagnosis can be established that correlates with CTPA. This study needs further verification, but it offers a possible approach to reduce the cost and radiation exposure that is associated with CTPA.

Utility of ultrasonography for detection of gastric fluid during urgent endotracheal intubation.

PurposeAspiration of gastric contents is a dangerous complication of urgent endotracheal intubation (UEI). Left upper quadrant (LUQ) ultrasonography may have the potential to decrease this complication by identifying patients with gastric fluid content, thereby allowing the UEI team to evacuate gastric contents prior to intubation.MethodsThis was an observational study of 80 UEIs where LUQ ultrasonography was performed in a medical intensive care unit of a tertiary care hospital. The subjects were 80 patients requiring UEI. Gastric fluid content was identified as an anechoic or hypoechoic space in the appropriate anatomic position. If potentially consequential fluid was identified, it was evacuated using a gastric tube. Repeat LUQ ultrasonography confirmed removal of gastric contents prior to induction.ResultsA total of 80 patients had LUQ ultrasonography performed; 19 (24%) had gastric fluid content identified and 13 (16%) had sufficient gastric fluid content such that the UEI team proceeded with gastric tube insertion. Following gastric fluid removal, repeat ultrasonography showed absence of gastric fluid. Gastric fluid volume removed was 553xa0±xa0290xa0ml (meanxa0±xa0standard deviation, SD). None of the 80 patients had a clinically consequential aspiration event. Performance of ultrasonography took fewer than 2xa0min. No patient had complication related to the ultrasonography or removal of gastric contents.ConclusionsUltrasonography is useful for the detection of gastric fluid. This technique may have utility in reducing risk of a clinically consequential aspiration event during UEI.

Plasma ghrelin and leptin in adult cystic fibrosis patients

BACKGROUNDnWeight loss in cystic fibrosis (CF) may be associated with altered levels of appetite stimulating peptide ghrelin and the appetite decreasing peptide leptin. However, prior data on leptin in CF are conflicting, while the data on ghrelin are scarce. We hypothesized that weight loss in CF is associated with low levels ghrelin and elevated levels of leptin.nnnMETHODSnPlasma ghrelin, leptin, TNF-alpha, IL-1 and IL-6, BMI, fat free mass (FFM), fat mass (FM) were measured in 74 CF adults and 20 controls. CF subjects were divided into 3 groups based on lung disease: mild (n=19), moderate (n=30) and severe (n=25).nnnRESULTSnSevere CF patients (% predicted FEV1 27+/-7; median BMI 21 kg/m2) had significantly elevated ghrelin and decreased leptin compared to controls and other CF subjects. Ghrelin correlated (r value, p value) with BMI (-0.35,<0.001), FFM (-0.22,<0.05), FM (-0.41,<0.0001), FEV1 (-0.62,<0.001), TNF-alpha (0.51,<0.0001), IL-1 (0.56,<0.0001), and IL-6 (0.33,<0.01). Leptin correlated (r value, p value) with BMI (0.40,<0.0001), FM (0.56,<0.0001), FEV1 (0.34,<0.05), IL-1 (-0.51,<0.05) and TNF-alpha (-0.43,<0.0001). BMI and FEV1 were independent predictors of ghrelin (-0.35,<0.05;-0.59,<0.001). FM was a predictor of leptin (0.56,<0.0001). Cytokines were elevated only in severe CF (severe CF vs. controls, pg/ml): TNF-alpha (3.4+/-0.6 vs. 1.2+/-0.4), IL-1 (3.5+/-1 vs. 0.2+/-0.1), IL-6 (17.4+/-4 vs. 2.4+/-2).nnnCONCLUSIONSnElevated ghrelin and decreased leptin levels are a consequence rather than a cause of weight loss in advanced CF.

Safety of Propofol as an Induction Agent for Urgent Endotracheal Intubation in the Medical Intensive Care Unit

Purpose: Propofol is known to provide excellent intubation conditions without the use of neuromuscular blocking agents. However, propofol has adverse effects that may limit its use in the critically ill patients, particularly in the hemodynamically unstable patient. We report on the safety and efficacy of propofol for use as an agent for urgent endotracheal intubation (UEI) in the critically ill patients. Methods: We reviewed the outcomes of 472 consecutive UEIs performed by a medical intensive care unit (ICU) team at a tertiary care hospital from November 2008 through November 2012. Outcome data were collected prospectively as part of an ongoing quality improvement project. Results: Propofol was used as the sole sedative agent in 409 (87%) of the 472 patients. In 18 (4%) of the 472 patients, other agents (midazolam, lorazepam, or etomidate) were used in addition to propofol. Of the 472, 10 (2%) intubations were performed with a sedative agent other than propofol, and 35 (7%) of the 472 intubations were performed without any sedating agent. Endotracheal tube insertion was successful in all 472 patients. Complications of UEI in those patients who received propofol were as follows: desaturation (Sao 2 < 80%) 30 (7%) of the 427, hypotension (systolic blood pressure < 70 mm Hg) 19 (4%) of the 427, difficult intubation (>2 attempts) 44 (10%) of the 427, esophageal intubation 24 (6%) of the 427, aspiration 6 (1%) of the 427, and oropharyngeal injury 4 (1%) of the 427. There were no deaths. Average dose of propofol was 99 mg (standard deviation 7.39) per person. Conclusions: Our results compare favorably with the complication rate of UEI reported in the critical care and anesthesiology literature and indicate that propofol is a useful agent for airway management in the ICU.

Potential Role of Endogenous Adenosine in Ticagrelor‐Induced Dyspnea

Ticagrelor, a recently approved platelet antagonist indicated for the reduction of thrombotic cardiovascular events in patients with acute coronary syndrome (ACS), has been reported to cause dyspnea in more than 13% of patients. Dyspnea is not a clinically relevant adverse event with other medications indicated for ACS. One suggested mechanism of ticagrelor‐induced dyspnea involves an increase in systemic adenosine concentrations through adenosine deaminase inhibition. Dyspnea, a subjective finding resulting from physiologic and sensory mechanisms, may be a consequence of increased systemic adenosine concentrations, leading to amplified and prolonged receptor activity. Current literature suggests, however, that pulmonary status is not compromised, with no reduction of efficacy seen in patients with ticagrelor‐induced dyspnea, thus allowing clinicians to continue therapy without reservation. Still, patients with a history of asthma and chronic obstructive pulmonary disease may be more susceptible to ticagrelor‐induced dyspnea, potentially leading to nonadherence and exacerbations of morbidity. Therefore, it is paramount that health care providers continually monitor these patients with the aims of maintaining medication therapy adherence and providing relevant options if dyspnea becomes intolerable.

Shock: A Case of Mistaken Identity

A 66-year-old woman had a brief syncopal episode after standing up from the toilet. She awoke in seconds and noted no chest pain or shortness of breath. On presentation to the ED, she had a BP of 90/60 mm Hg, a regular heart rate of 115 beats/min, temperature of 37.2°C, and a respiratory rate of 26 breaths/min. Her oxygen saturation on 4 L nasal cannula was 91%. The physical examination was otherwise unremarkable. Her chest radiograph was clear, and the ECG showed sinus tachycardia without other abnormality. Laboratory values were as follows: WBC count, 12.7 K/ m L; lactate, 3.4 mmol/L; and creatinine, 2.2 mg/dL; urinalysis results were 25 WBC per high-powered fi eld. She was given antibiotics for presumed septic shock with a urinary tract infection, and over the next few hours, per sepsis bundle protocol, she was given a total of 3 L of normal saline. The patient remained hypotensive. Norepinephrine was started at 0.5 m g/kg/min while fl uid resuscitation with normal saline was continued. The patient was admitted to the medical ICU with a diagnosis of septic shock. The intensivist performed an immediate bedside ultrasound examination to diagnose and guide management of her hypotension and hypoxemia (Videos 1-3).

The Use of M-Mode Ultrasonography to Differentiate the Causes of B Lines

BACKGROUND The presence of B lines on lung ultrasonography is a characteristic feature of both cardiogenic pulmonary edema (CPE) and noncardiogenic alveolar interstitial syndrome (NCAIS), so their presence does not allow the clinician to differentiate between the two entities. Our study used M‐mode ultrasonography of the pleura to differentiate CPE from NCAIS. METHODS A total of 43 subjects were enrolled in the study, and based on history, physical examination, and chart review, the patients were divided into three groups: an NCAIS group, a CPE group, and a control group. Three distinct pleural line morphologic categories were identified: a continuous pleural line, a fragmented pleural line, and a sinusoidal pleural line. In addition, two separate subpleural patterns were independently identified by the investigators: a horizontal pattern and a vertical pattern. These pleural and subpleural patterns were correlated with subject diagnoses. RESULTS A fragmented pleural line and a vertical subpleural pattern on M‐mode ultrasonography is associated with patients who have NCAIS. Most patients with CPE have a continuous pleural line and a vertical subpleural pattern on M‐mode ultrasonography. A sinusoidal pleural line on M‐mode ultrasonography is suggestive of the presence of a pleural effusion. CONCLUSIONS Our results indicate that M‐mode ultrasonography is useful to distinguish CPE from NCAIS based on the pleural and the subpleural morphologic features.