Yogic agnisara increases blood flow in the superior mesenteric artery.

OBJECTIVES: Medieval yoga texts claim that a special exercise of the muscles of the anterior abdominal wall, called agnisara, improves digestive function. Main objective of the study was to demonstrate change in the blood flow through superior mesenteric artery (if any) after performance of agnisara. METHODS: Ultrasound examination of the linear and volumetric indicators of blood flow in the superior mesenteric artery (SMA) before and after performing the agnisara yoga exercise 100 times was carried out in 12 healthy volunteers of both sexes (8 of them women). RESULTS: A significant increase in the diameter of the SMA, peak systolic and diastolic velocities, and blood flow in the superior mesenteric artery after performing the agnisara exercise 100 times was found, which contrasts with the established data on a decrease in splanchnic blood flow in humans in response to normal physical activity. CONCLUSION: Properly performed agnisara increases blood flow to the splanchnic region, registered by the SMA, which should contribute to adequate blood supply to the gastrointestinal tract for successful performance of digestive function.

Protocol Failure Detection: The Conflation of Acute Respiratory Distress Syndrome, SARS-CoV-2 Pneumonia and Respiratory Dysfunction.

In medicine, protocols are applied to assure the provision of the treatment with the greatest probability of success. However, the development of protocols is based on the determination of the best intervention for the group. If the group is heterogeneous, there will always be a subset of patients for which the protocol will fail. Furthermore, over time, heterogeneity of the group may not be stable, so the percentage of patients for which a given protocol may fail may change depending on the dynamic patient mix in the group. This was thrown into stark focus during the severe acute respiratory syndrome-2 coronavirus (SARS-CoV-2) pandemic. When a COVID-19 patient presented meeting SIRS or the Berlin Criteria, these patients met the criteria for entry into the sepsis protocol and/or acute respiratory distress syndrome (ARDS) protocol, respectively and were treated accordingly. This was perceived to be the correct response because these patients met the criteria for the "group" definitions of sepsis and/or ARDS. However, the application of these protocols to patients with SARS-CoV-2 infection had never been studied. Initially, poor outcomes were blamed on protocol noncompliance or some unknown patient factor. This initial perception is not surprising as these protocols are standards and were perceived as comprising the best possible evidence-based care. While the academic response to the pandemic was robust, recognition that existing protocols were failing might have been detected sooner if protocol failure detection had been integrated with the protocols themselves. In this review, we propose that, while protocols are necessary to ensure that minimum standards of care are met, protocols need an additional feature, integrated protocol failure detection, which provides an output responsive to protocol failure in real time so other treatment options can be considered and research efforts rapidly focused.

Headstand (Sirshasana) Does Not Increase the Blood Flow to the Brain.

Objectives: Most yoga practitioners believe that headstand (Sirshasana) results in increased cerebral perfusion. This, however, is not consistent with autoregulation of the cerebral blood flow. The intent of this study was to demonstrate the effect of Sirshasana on the blood flow to the brain through ultrasound examination of the internal carotid artery (ICA). Design, location, and subjects: The ICA blood flow was measured with pulsed Doppler in 20 men and women aged 10 to 59 years (median 43) while performing the headstand (Sirshasana). Seventeen subjects were studied in 2018 in Spain at the altitude of 2,000 m, whereas the other three females were studied at sea level. Results: Although the diameter of the artery under examination during the headstand remained almost unchanged, the decrease in peak flow velocities in systole and diastole caused a significant decrease in arterial blood flow to the brain, followed by return to baseline values immediately after the antiorthostatic postural effect, likely due to the expected consequences of the cerebral blood flow autoregulation of the cerebral blood supply as well as the intracranial pressure. Conclusions: Contrary to popular belief, Sirshasana does not increase blood flow to the brain through the ICA, but results in predictable reduction in cerebral blood delivery in compliance with known mechanisms of autoregulation of cerebral blood flow. Moreover, increased ICA blood flow while performing the headstand is likely to be a contraindication to this exercise.

Guidelines for the Appropriate Use of Bedside General and Cardiac Ultrasonography in the Evaluation of Critically Ill Patients-Part II: Cardiac Ultrasonography.

OBJECTIVE: To establish evidence-based guidelines for the use of bedside cardiac ultrasound, echocardiography, in the ICU and equivalent care sites. METHODS: Grading of Recommendations, Assessment, Development and Evaluation system was used to rank the "levels" of quality of evidence into high (A), moderate (B), or low (C) and to determine the "strength" of recommendations as either strong (strength class 1) or conditional/weak (strength class 2), thus generating six "grades" of recommendations (1A-1B-1C-2A-2B-2C). Grading of Recommendations, Assessment, Development and Evaluation was used for all questions with clinically relevant outcomes. RAND Appropriateness Method, incorporating the modified Delphi technique, was used in formulating recommendations related to terminology or definitions or in those based purely on expert consensus. The process was conducted by teleconference and electronic-based discussion, following clear rules for establishing consensus and agreement/disagreement. Individual panel members provided full disclosure and were judged to be free of any commercial bias. RESULTS: Forty-five statements were considered. Among these statements, six did not achieve agreement based on RAND appropriateness method rules (majority of at least 70%). Fifteen statements were approved as conditional recommendations (strength class 2). The rest (24 statements) were approved as strong recommendations (strength class 1). Each recommendation was also linked to its level of quality of evidence and the required level of echo expertise of the intensivist. Key recommendations, listed by category, included the use of cardiac ultrasonography to assess preload responsiveness in mechanically ventilated (1B) patients, left ventricular (LV) systolic (1C) and diastolic (2C) function, acute cor pulmonale (ACP) (1C), pulmonary hypertension (1B), symptomatic pulmonary embolism (PE) (1C), right ventricular (RV) infarct (1C), the efficacy of fluid resuscitation (1C) and inotropic therapy (2C), presence of RV dysfunction (2C) in septic shock, the reason for cardiac arrest to assist in cardiopulmonary resuscitation (1B-2C depending on rhythm), status in acute coronary syndromes (ACS) (1C), the presence of pericardial effusion (1C), cardiac tamponade (1B), valvular dysfunction (1C), endocarditis in native (2C) or mechanical valves (1B), great vessel disease and injury (2C), penetrating chest trauma (1C) and for use of contrast (1B-2C depending on indication). Finally, several recommendations were made regarding the use of bedside cardiac ultrasound in pediatric patients ranging from 1B for preload responsiveness to no recommendation for RV dysfunction. CONCLUSIONS: There was strong agreement among a large cohort of international experts regarding several class 1 recommendations for the use of bedside cardiac ultrasound, echocardiography, in the ICU. Evidence-based recommendations regarding the appropriate use of this technology are a step toward improving patient outcomes in relevant patients and guiding appropriate integration of ultrasound into critical care practice.

Guidelines for the Appropriate Use of Bedside General and Cardiac Ultrasonography in the Evaluation of Critically Ill Patients-Part I: General Ultrasonography.

OBJECTIVE: To establish evidence-based guidelines for the use of bedside ultrasound by intensivists and specialists in the ICU and equivalent care sites for diagnostic and therapeutic purposes for organs of the chest, abdomen, pelvis, neck, and extremities. METHODS: The Grading of Recommendations, Assessment, Development and Evaluation system was used to determine the strength of recommendations as either strong or conditional/weak and to rank the "levels" of quality of evidence into high (A), moderate (B), or low (C) and thus generating six "grades" of recommendation (1A-1B-1C-2A-2B-2C). Grading of Recommendations, Assessment, Development and Evaluation (GRADE) was used for all questions with clinically relevant outcomes. RAND appropriateness method, incorporating modified Delphi technique, was used in steps of GRADE that required panel judgment and for those based purely on expert consensus. The process was conducted by teleconference and electronic-based discussion, following clear rules for establishing consensus and agreement/disagreement. Individual panel members provided full disclosure and were judged to be free of any commercial bias. The process was conducted independent of industry funding. RESULTS: Twenty-four statements regarding the use of ultrasound were considered-three did not achieve agreement and nine were approved as conditional recommendations (strength class 2). The remaining 12 statements were approved as strong recommendations (strength class 1). Each recommendation was also linked to its level of quality of evidence. Key strong recommendations included the use of ultrasonography for ruling-in pleural effusion and assisting its drainage, ascites drainage, ruling-in pneumothorax, central venous cannulation, particularly for internal jugular and femoral sites, and for diagnosis of deep venous thrombosis. Conditional recommendations were given to the use of ultrasound by the intensivist for diagnosis of acalculous cholecystitis, renal failure, and interstitial and parenchymal lung diseases. No recommendations were made regarding static (vs dynamic) ultrasound guidance of vascular access or the use of needle guide devices. CONCLUSIONS: There was strong agreement among a large cohort of international experts regarding several recommendations for the use of ultrasound in the ICU. Evidence-based recommendations regarding the appropriate use of this technology are a step toward improving patient outcomes in relevant patients.

Shear wave elastography for evaluation of liver fibrosis.

The prognosis and management of chronic viral hepatitis mainly depend on the extent of liver fibrosis, particularly in chronic hepatitis C. Liver histologic analysis is still considered the reference standard in the assessment of liver fibrosis despite the interobserver and interobserver variability in staging and some morbidity and mortality risks. Thus, noninvasive methods for assessing liver fibrosis are of great clinical interest. In the last decade, ultrasound-based techniques to estimate the stage of liver fibrosis have become commercially available. They all have the capability to noninvasively evaluate differences in the elastic properties of soft tissues by measuring tissue behavior when a mechanical stress is applied. Shear wave elastography relies on the generation of shear waves determined by the displacement of tissues induced by the force of a focused ultrasound beam or by an external push. This article reviews the results that have been obtained with shear wave elastography for assessment of liver fibrosis.

Neonatal incubators: a toxic sound environment for the preterm infant?*.

BACKGROUND: High sound pressure levels may be harmful to the maturing newborn. Current guidelines suggest that the sound pressure levels within a neonatal intensive care unit should not exceed 45 dB(A). It is likely that environmental noise as well as the noise generated by the incubator fan and respiratory equipment may contribute to the total sound pressure levels. Knowledge of the contribution of each component and source is important to develop effective strategies to reduce noise within the incubator. AIMS: The objectives of this study were to determine the sound levels, sound spectra, and major sources of sound within a modern neonatal incubator (Giraffe Omnibed; GE Healthcare, Helsinki, Finland) using a sound simulation study to replicate the conditions of a preterm infant undergoing high-frequency jet ventilation (Life Pulse, Bunnell, UT). METHODS: Using advanced sound data acquisition and signal processing equipment, we measured and analyzed the sound level at a dummy infant's ear and at the head level outside the enclosure. The sound data time histories were digitally acquired and processed using a digital Fast Fourier Transform algorithm to provide spectra of the sound and cumulative sound pressure levels (dBA). The simulation was done with the incubator cooling fan and ventilator switched on or off. In addition, tests were carried out with the enclosure sides closed and hood down and then with the enclosure sides open and the hood up to determine the importance of interior incubator reverberance on the interior sound levels RESULTS: With all the equipment off and the hood down, the sound pressure levels were 53 dB(A) inside the incubator. The sound pressure levels increased to 68 dB(A) with all equipment switched on (approximately 10 times louder than recommended). The sound intensity was 6.0 × 10(-8) watts/m(2); this sound level is roughly comparable with that generated by a kitchen exhaust fan on high. Turning the ventilator off reduced the overall sound pressure levels to 64 dB(A) and the sound pressure levels in the low-frequency band of 0 to 100 Hz were reduced by 10 dB(A). The incubator fan generated tones at 200, 400, and 600 Hz that raised the sound level by approximately 2 dB(A)-3 dB(A). Opening the enclosure (with all equipment turned on) reduced the sound levels above 50 Hz by reducing the revereberance within the enclosure. CONCLUSION: The sound levels, especially at low frequencies, within a modern incubator may reach levels that are likely to be harmful to the developing newborn. Much of the noise is at low frequencies and thus difficult to reduce by conventional means. Therefore, advanced forms of noise control are needed to address this issue.

Inhaled nitric oxide as salvage therapy in massive pulmonary embolism: a case series.

Inhaled nitric oxide (INO) has been shown to preferentially lower resistance in the pulmonary vasculature. The relative selectiveness of INO in accomplishing this effect makes it an attractive drug to administer as salvage therapy in patients with acute right ventricular failure secondary to pulmonary embolism. We describe 4 cases in which INO was used as a temporizing agent to decrease right ventricular after-load following massive near-fatal pulmonary embolism. All 4 patients survived to hospital discharge.

Echocardiographic assessment of preload responsiveness in critically ill patients.

Fluid challenges are considered the cornerstone of resuscitation in critically ill patients. However, clinical studies have demonstrated that only about 50% of hemodynamically unstable patients are volume responsive. Furthermore, increasing evidence suggests that excess fluid resuscitation is associated with increased mortality. It therefore becomes vital to assess a patient's fluid responsiveness prior to embarking on fluid loading. Static pressure (CVP, PAOP) and echocardiographic (IVC diameter, LVEDA) parameters fails to predict volume responsiveness. However, a number of dynamic echocardiographic parameters which are based on changes in vena-caval dimensions or cardiac function induce by positive pressure ventilation or passive leg raising appear to be highly predictive of volume responsiveness.

Detection of subcutaneous and intramuscular air with sonography: a sensitive and specific modality.

OBJECTIVES: Soft tissue air may raise suspicion for several life-threatening illnesses. Physical examination has limited sensitivity in detecting air, and computed tomography and magnetic resonance imaging are time-consuming and expensive. Sonography can show soft tissue air, but the sensitivity and specificity in this setting are currently unknown. Therefore, the purpose of this study was to assess the performance characteristics of sonography in depicting the presence, amount, and affected tissue plane in a cadaver model of soft tissue air. METHODS: We conducted a single-blinded observational cadaver study. Cutaneous sites were selected and marked (≈4 or 5 sites on each of 6 cadavers). An examiner injected air at some sites, recording both the depth (plane) and volume. A second examiner, who was blinded to the injection procedure, examined each site with sonography and recorded the presence or absence of air and the plane (subcutaneous or intramuscular). The results were compared, and statistical analysis was performed. RESULTS: Twenty-eight sites on 6 cadavers were used. Sites were not used if they were damaged or were within 10 cm of previous dissection. Air was injected in 20 of 28 sites; the remaining 8 were sham injections. Sonography showed air in all of the 20 sites with air injected. No air was detected in 7 of the 8 remaining sham sites, yielding 1 false-positive case. The plane was accurately assessed in all cases. Sensitivity for detection was 100%, and specificity was 87.5%. CONCLUSIONS: Sonography accurately showed the presence, amount, and anatomic plane of soft tissue air in cadavers with sensitivity of 100%. It warrants investigation as a screening test in patients at high risk for subcutaneous air from conditions such as necrotizing fasciitis and gas gangrene.