Basic ultrasound head-to-toe skills for intensivists in the general and neuro intensive care unit population: consensus and expert recommendations of the European Society of Intensive Care Medicine

Ultrasonography Comparison of Diaphragm Morphological Structure and Function in Young and Middle-Aged Subjects with and without Non-Specific Chronic Low Back Pain: A Case-Control Study

Background

It is reported that impaired postural control in patients with non-specific chronic low back pain (NCLBP) was associated with "core" trunk muscle incoordination. However, as the diaphragm is an important component of the "core" deep trunk muscle group, we still know little about the potential relationship between diaphragm dysfunction and NCLBP.

Objectives

This case-control study is intended to investigate the changes of diaphragm morphological structure and function in young and middle-aged subjects with and without NCLBP by ultrasound evaluation and its possible validity in predicating the occurrence of NCLBP.

Methods

31 subjects with NCLBP (NCLBP group) and 32 matched healthy controls (HC group) were enrolled in this study. The diaphragm thickness at the end of inspiration (T ^ins) or expiration (T ^exp) during deep breathing was measured through B-mode ultrasound, and the diaphragm excursion (T ^exc) was estimated at deep breathing through M-mode ultrasound. The diaphragm thickness change rate (T ^rate) was calculated by the formula: T ^rate=(T ^ins - T ^exp)/T ^exp × 100%.

Results

Compared with the HC group, the NCLBP group had a significant smaller degree of T^ins (t = -3.90, P < 0.001), T ^exp (Z = -2.79, P=0.005), and T ^rate (t = -2.03, P=0.047). However, there was no statistical difference in T ^exc between the two groups (t = -1.42, P=0.161). The binary logistic regression analysis indicated that T ^rate (OR = 16.038, P=0.014) and T ^exp (OR = 7.714, P=0.004) were potential risk factors for the occurrence of NCLBP.

Conclusions

The diaphragm morphological structure and function were changed in young and middle-aged subjects with NCLBP, while the diaphragm thickness change rate (T ^rate) and diaphragm thickness at the end of expiration (T ^exp) may be conductive to the occurrence of NCLBP. Furthermore, these findings may suggest that abnormal diaphragm reeducation is necessary for the rehabilitation of patients with NCLBP.

Lung ultrasound response to awake prone positioning predicts the need for intubation in patients with COVID-19 induced acute hypoxemic respiratory failure: an observational study

Background

Awake prone positioning (APP) reduces the intubation rate in COVID-19 patients treated by high-flow nasal cannula (HFNC). However, the lung aeration response to APP has not been addressed. We aimed to explore the lung aeration response to APP by lung ultrasound (LUS).

Methods

This two-center, prospective, observational study enrolled patients with COVID-19-induced acute hypoxemic respiratory failure treated by HFNC and APP. LUS score was recorded 5–10 min before, 1 h after APP, and 5–10 min after supine in the first APP session within the first three days. The primary outcome was LUS score changes in the first three days. Secondary outcomes included changes in SpO₂/FiO₂ ratio, respiratory rate and ROX index (SpO₂/FiO₂/respiratory rate) related to APP, and the rate of treatment success (patients who avoided intubation).

Results

Seventy-one patients were enrolled. LUS score decreased from 20 (interquartile range [IQR] 19–24) to 19 (18–21) (p < 0.001) after the first APP session, and to 19 (18–21) (p < 0.001) after three days. Compared to patients with treatment failure (n = 20, 28%), LUS score reduction after the first three days in patients with treatment success (n = 51) was greater (− 2.6 [95% confidence intervals − 3.1 to − 2.0] vs 0 [− 1.2 to 1.2], p = 0.001). A decrease in dorsal LUS score > 1 after the first APP session was associated with decreased risk for intubation (Relative risk 0.25 [0.09–0.69]). APP daily duration was correlated with LUS score reduction in patients with treatment success, especially in dorsal lung zones (r =  − 0.76; p < 0.001).

Conclusions

In patients with acute hypoxemic respiratory failure due to COVID-19 and treated by HFNC, APP reduced LUS score. The reduction in dorsal LUS scores after APP was associated with treatment success. The longer duration on APP was correlated with greater lung aeration.

Trial registration This study was prospectively registered on clinicaltrials.gov on April 22, 2021. Identification number NCT04855162.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-04064-3.

A cross-sectional survey on the lung ultrasound training and practice of respiratory therapists in mainland China

Purpose

This national study aimed to investigate the lung ultrasound (LUS) training and practice of respiratory therapists (RTs) in mainland China.

Methods

A cross-sectional multicenter survey was conducted from May 22, 2021 to August 12, 2021, through online platforms. This survey included RTs in mainland China. The survey was divided into four sections: (1) demographic characteristics and basic information; (2) basic information about LUS training and practice; (3) LUS practice details; and (4) Other ultrasound training and practice.

Results

A total of 514 responses were received, and 494 valid responses were included in the analysis. 81.2% (401/494) participants’ highest degree of education was a bachelor’s degree, and 43.1% (213/494) participants were at level II in terms of job ranking. 99.2%(490/494) participants agreed that the RTs needed to learn lung ultrasound, but only 12.3% (61/494) participants had received a LUS training course. Further, 66.2% (327/494) experienced participants responded to Sect. 3. Most of RTs used LUS when the patient had hypoxia (265/327, 81%) or dyspnea (260/317, 79.5%); they also used it during spontaneous breathing trial(SBT) (191/327, 58.4%) or in prone position (177/327, 54.1%). The A-line (302/327, 92.4%), B-line (299/327, 91.4%), lung slide (263/327, 80.4%), and bat sign (259/327, 79.2%) were well known as LUS signs. Also, 30.6% (100/327) participants did not use the LUS protocol in their clinical practice, and only 25.4%(83/327) participants said they had used LUS scores. Moreover, 55.7% (182/327) participants frequently changed the respiratory therapy strategy according to LUS results.

Conclusions

We should improve the number and workplace of RTs in mainland China in the future. We should also standardize the application of LUS practice and training for RTs in mainland China and establish corresponding certification pathways.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-02213-6.

Pathophysiology of fluid administration in critically ill patients

Fluid administration is a cornerstone of treatment of critically ill patients. The aim of this review is to reappraise the pathophysiology of fluid therapy, considering the mechanisms related to the interplay of flow and pressure variables, the systemic response to the shock syndrome, the effects of different types of fluids administered and the concept of preload dependency responsiveness. In this context, the relationship between preload, stroke volume (SV) and fluid administration is that the volume infused has to be large enough to increase the driving pressure for venous return, and that the resulting increase in end-diastolic volume produces an increase in SV only if both ventricles are operating on the steep part of the curve. As a consequence, fluids should be given as drugs and, accordingly, the dose and the rate of administration impact on the final outcome. Titrating fluid therapy in terms of overall volume infused but also considering the type of fluid used is a key component of fluid resuscitation. A single, reliable, and feasible physiological or biochemical parameter to define the balance between the changes in SV and oxygen delivery (i.e., coupling “macro” and “micro” circulation) is still not available, making the diagnosis of acute circulatory dysfunction primarily clinical.

Fluids are drugs used in patients with shock to increase the cardiac output with the aim to improve oxygen delivery to the cells. The response to fluid administration is determined by the physiological interaction of cardiac function and venous return. In septic shock, the beneficial clinical response of fluid administration is rapidly reduced after few hours and fluid titration is crucial to avoid detrimental fluid overload. The fluid challenge is a fluid bolus given at a defined quantity and rate to assess fluid responsiveness.

The ideal fluid for critically ill patients does not exist; however, crystalloids should be used as first choice. Balanced crystalloid solutions may be associated with better outcomes but the evidence is still low. Albumin infusion may have a role in already fluid resuscitated patients at risk of fluid overload.

Fluid administration is integrated into the complex management of pressure and flow “macro” hemodynamic variables, coupled to the “micro” local tissue flow distribution and regional metabolism. Macro-variables are managed by measuring systemic blood pressure and evaluating the global cardiac function. The critical threshold of oxygen delivery to the cells is difficult to estimate, however, several indexes and clinical signs may be considered as surrogate of that, and integrated in a decision-making process at the bedside.

Comparison of ultrasound-guided internal jugular vein and supraclavicular subclavian vein catheterization in critically ill patients: a prospective, randomized clinical trial

Background

The aim of this study was to compare the effectiveness and safety of ultrasound-guided out-of-plane internal jugular vein (OOP-IJV) and in-plane supraclavicular subclavian vein (IP-SSCV) catheterization in adult intensive care unit.

Methods

A total of 250 consecutive patients requiring central venous catheterization, were randomly assigned to undergo either ultrasound-guided OOP-IJV or IP-SSCV cannulation. All catheterizations were carried out by three physicians. The primary outcome was the first attempt success rate. Ultrasound scanning time, venous puncture time, insertion time, overall access time, number of puncture attempts, number of needle redirections, success rate, guidewire advancing difficulties, venous collapse and adverse events were also documented.

Results

The first attempt success rate was significantly higher in IP-SSCV group (83.2%) compared to OOP-IJV group (63.2%) (p = 0.001). The IP-SSCV group was associated with a longer ultrasound scanning time (16.54 ± 13.51 vs. 5.26 ± 4.05 s; p < 0.001) and a shorter insertion time (43.98 ± 26.77 vs. 53.12 ± 40.21 s; p = 0.038). In the IP-SCCV group, we recorded a fewer number of puncture attempts (1.16 ± 0.39 vs. 1.47 ± 0.71; p < 0.001), needle redirections (0.69 ± 0.58 vs. 1.17 ± 0.95; p < 0.001), difficulties in guidewire advancement (2.4% vs. 27.4%; p < 0.001), venous collapse (2.4%, vs. 18.4%; p < 0.001) and adverse events (8.8% vs. 13.6%; p = 0.22).

Conclusions

The IP-SSCV approach is an effective and a safe alternative to the classic OOP-IJV catheterization in critical adult patients.

Trial registration: Clinicaltrials.gov, NCT03879954. Registered March 19, 2019—Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT03879954.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-022-01065-x.

Effects of Unilateral Intermediate Cervical Plexus Block on the Diaphragmatic Function in Patients Undergoing Unilateral Thyroidectomy: A Randomized Controlled Study

Background and Purpose

Although unilateral intermediate cervical plexus block (ICPB) can be used for perioperative analgesia in neck surgery, its effect on diaphragm function remains controversial. This prospective study aimed to examine whether unilateral ICPB with different concentrations of ropivacaine resulted in the diaphragmatic dysfunction in unilateral thyroidectomy.

Methods

A total of 54 patients scheduled to undergo unilateral thyroidectomy under general anesthesia were randomly allocated to receive either 10 mL of 0.3% (Group L) or 0.5% (Group H) ropivacaine for ICPB. General anesthesia was then administered for surgery. The diaphragm thickness and diaphragmatic excursion were measured at three different times: before the ICPB, at 40 min and 4 h after the block. The primary outcome was the incidence of diaphragmatic dysfunction of the block side at 40 min and 4 h after ICPB. Secondary outcomes included the maximum pain score within 24 h after the surgery, rescue analgesics within 24 h after the surgery, and time to first ambulation.

Results

The incidence of diaphragmatic dysfunction on the block side of Group H was higher than that of Group L at 40 min after block (58% vs 29%, P = 0.01). However, the incidence of diaphragmatic dysfunction was comparable between Group H and Group L (65% vs 46%) at 4 h after block placement. Within 24 h after the operation, the maximum VAS pain score of Group H was significantly lower than Group L (P = 0.04), and fewer patients in Group H required rescue analgesics (P < 0.01).

Conclusion

The ICPB with different concentrations of ropivacaine can induce the ipsilateral diaphragmatic dysfunction. The high concentration of ropivacaine results in higher incidence of diaphragmatic dysfunction at 40 min, but comparable incidence at 4 h after block compared with lower concentration of ropivacaine.

Chinese Clinical Trial Registry

ChiCTR2000029348.

Diaphragm Evaluation and Lung Ultrasound Score during Weaning

How to cite this article: Blanco JB, Esquinas A. Diaphragm Evaluation and Lung Ultrasound Score during Weaning. Indian J Crit Care Med 2022;26(9):1054–1055.

Point-of-care ultrasound training for residents in anaesthesia and critical care: results of a national survey comparing residents and training program directors' perspectives

BACKGROUND

Point-of-care ultrasound (POCUS) has become an essential tool for anaesthesia and critical care physicians and dedicated training is mandatory. This survey describes the current state of Italian residency training programs through the comparison of residents' and directors' perspective.

METHODS

Observational prospective cross-sectional study: 12-question national e-survey sent to Italian directors of anaesthesia and critical care residency programs (N = 40) and residents (N = 3000). Questions focused on POCUS teaching (vascular access, transthoracic echocardiography, focused assessment for trauma, transcranial Doppler, regional anaesthesia, lung and diaphragm ultrasound), organization (dedicated hours, teaching tools, mentors), perceived adequacy/importance of the training and limiting factors.

RESULTS

Five hundred seventy-one residents and 22 directors completed the survey. Bedside teaching (59.4-93.2%) and classroom lessons (29.7-54.4%) were the most frequent teaching tools. Directors reported higher participation in research projects (p < 0.05 for all techniques but focused assessment for trauma) and simulation (p < 0.05 for all techniques but transthoracic echocardiography). Use of online teaching was limited (< 10%); however, 87.4% of residents used additional web-based tools. Consultants were the most frequent mentors, with different perspectives between residents (72.0%) and directors (95.5%; p = 0.013). Residents reported self-training more frequently (48.5 vs. 9.1%; p < 0.001). Evaluation was mainly performed at the bedside; a certification was not available in most cases (< 10%). Most residents perceived POCUS techniques as extremely important. Residents underestimated the relevance given by directors to ultrasound skills in their evaluation and the minimal number of exams required to achieve basic competency. Overall, the training was considered adequate for vascular access only (62.2%). Directors mainly agreed on the need of ultrasound teaching improvement in all fields. Main limitations were the absence of a standardized curriculum for residents and limited mentors' time/expertise for directors.

CONCLUSION

POCUS education is present in Italian anaesthesia and critical care residency programs, although with potential for improvement. Significant discrepancies between residents' and directors' perspectives were identified.

Treadmill Exercise Decreases Inflammation Via Modulating IL-6 Expression in the Rat Model of Middle Cerebral Artery Occlusion

BACKGROUND

Long-term bed rest in neurointensive care (NIC) patients leads to skeletal muscle atrophy and cognitive dysfunction, which seriously affects the physical fitness and final prognosis of critically ill patients. Exercise therapy plays an increasingly important role in the treatment and rehabilitation of patients with sarcopenia. However, the therapeutic effect and mechanism of exercise therapy for patients with neurological impairment remain unclear.

METHODS

Serum samples of NIC patients before and after exercise therapy and normal people were collected to detect interleukin-6 (IL-6) and interleukin-1β levels by enzyme-linked immunosorbent assay (ELISA). Middle cerebral artery occlusion (MCAO) was used for the construction of a rat model. The Morris water maze test, exploration test, and open-field test were used to assess neurological function in rats. Western blot and quantitative real-time polymerase chain reaction were performed to evaluate the activation of IL-6/adenosine-monophosphate-activated protein kinase (AMPK) signaling.

RESULTS

Exercise therapy attenuated IL-6 expression in NIC patients. Exercise therapy alleviated cognitive dysfunctions and decreased IL-6 expression in MCAO rats. Exercise therapy alleviated gastrocnemius muscle injury in rats after MCAO by modulating IL-6/AMPK signaling.

CONCLUSIONS

Treadmill exercise decreases inflammation in MCAO rats via modulating IL-6/AMPK signaling.

Calculated left ventricular outflow tract diameter for critically ill patients

A fast and reliable left ventricular outflow diameter (LVOTd) estimation may aid in quickly estimating cardiac output. However, obtaining a correct LVOTd can be difficult in intensive care patients, potentially leading to errors and a cardiac output deviation. In this study, the measured LVOTd was compared with the expected LVOTd when estimated using an existing formula in 1177 critically ill patients. We show that estimated LVOTd based on baseline data can aid when obtaining LVOTd is difficult or impossible and simplified estimation based on a formula may allow for more reliable and accessible measurement of cardiac output.

Echocardiography in Prone Positioned Critically Ill Patients: A Wealth of Information from a Single View

In critically ill patients, standard transthoracic echocardiography (TTE) generally does not facilitate good image quality during mechanical ventilation. We propose a prone-TTE in prone positioned patients, which allows clinicians to obtain a complete apical four-chamber (A-4-C) view. A basic cardiac assessment can be performed in order to evaluate right ventricle function and left ventricle performance, even measuring objective parameters, i.e., tricuspid annular plane systolic excursion (TAPSE); pulmonary artery systolic pressure (PAP), from the tricuspid regurgitation peak Doppler velocity; RV end-diastolic diameter and its ratio to left ventricular end-diastolic diameter; the S’ wave peak velocity with tissue Doppler imaging; the ejection fraction (EF); the mitral annular plane systolic excursion (MAPSE); diastolic function evaluation by the mitral valve; and annular Doppler velocities. Furthermore, by tilting the probe, we can obtain the apical-five-chamber (A-5-C) view, which facilitates the analysis of blood flow at the level of the output tract of the left ventricle (LVOT) and then the estimation of stroke volume. Useful applications of this technique are hemodynamic assessment, titration of fluids, vasoactive drugs therapy, and evaluation of the impact of prone positioning on right ventricle performance and right pulmonary resistances. We believe that considerable information can be drawn from a single view and hope this may be helpful to emergency and critical care clinicians whenever invasive hemodynamic monitoring tools are not available or are simply inconvenient due to clinical reasons.

Monitoring Lung Injury Severity and Ventilation Intensity during Mechanical Ventilation

Acute respiratory distress syndrome (ARDS) is a severe form of respiratory failure burden by high hospital mortality. No specific pharmacologic treatment is currently available and its ventilatory management is a key strategy to allow reparative and regenerative lung tissue processes. Unfortunately, a poor management of mechanical ventilation can induce ventilation induced lung injury (VILI) caused by physical and biological forces which are at play. Different parameters have been described over the years to assess lung injury severity and facilitate optimization of mechanical ventilation. Indices of lung injury severity include variables related to gas exchange abnormalities, ventilatory setting and respiratory mechanics, ventilation intensity, and the presence of lung hyperinflation versus derecruitment. Recently, specific indexes have been proposed to quantify the stress and the strain released over time using more comprehensive algorithms of calculation such as the mechanical power, and the interaction between driving pressure (DP) and respiratory rate (RR) in the novel DP multiplied by four plus RR [(4 × DP) + RR] index. These new parameters introduce the concept of ventilation intensity as contributing factor of VILI. Ventilation intensity should be taken into account to optimize protective mechanical ventilation strategies, with the aim to reduce intensity to the lowest level required to maintain gas exchange to reduce the potential for VILI. This is further gaining relevance in the current era of phenotyping and enrichment strategies in ARDS.

The weaning from mechanical ventilation: a comprehensive ultrasound approach

PURPOSE OF REVIEW

Due to heart, lung and diaphragm interactions during weaning from mechanical ventilation, an ultrasound integrated approach may be useful in the detection of dysfunctions potentially leading to weaning failure. In this review, we will summarize the most recent advances concerning the ultrasound applications relevant to the weaning from mechanical ventilation.

RECENT FINDINGS

The role of ultrasonographic examination of heart, lung and diaphragm has been deeply investigated over the years. Most recent findings concern the ability of lung ultrasound in detecting weaning induced pulmonary edema during spontaneous breathing trial. Furthermore, in patients at high risk of cardiac impairments, global and anterolateral lung ultrasound scores have been correlated with weaning and extubation failure, whereas echocardiographic indexes were not. For diaphragmatic ultrasound evaluation, new indexes have been proposed for the evaluation of diaphragm performance during weaning, but further studies are needed to validate these results.

SUMMARY

The present review summarizes the potential role of ultrasonography in the weaning process. A multimodal integrated approach allows the clinician to comprehend the pathophysiological processes of weaning failure.

Ten Good Reasons to Practice Neuroultrasound in Critical Care Setting

In the beginning, cerebral ultrasound (US) was not considered feasible because the intact skull was a seemingly impenetrable obstacle. For this reason, obtaining a clear image resolution had been a challenge since the first use of neuroultrasound (NUS) for the assessment of small deep brain structures. However, the improvements in transducer technologies and advances in signal processing have refined the image resolution, and the role of NUS has evolved as an imaging modality for the brain parenchyma within multiple pathologies. This article summarizes ten crucial applications of cerebral ultrasonography for the evaluation and management of neurocritical patients, whose transfer from and to intensive care units poses a real problem to medical care staff. This also encompasses ease of use, low cost, wide acceptance by patients, no radiation risk, and relative independence from movement artifacts. Bedsides, availability and reliability raised the interest of critical care intensivists in using it with increasing frequency. In this mini-review, the usefulness and the advantages of US in the neurocritical care setting are discussed regarding ten aspects to encourage the intensivist physician to practice this important tool.

Head to toe ultrasound: a narrative review of experts’ recommendations of methodological approaches

Critical care ultrasonography (US) is widely used by intensivists managing critically ill patients to accurately and rapidly assess different clinical scenarios, which include pneumothorax, pleural effusion, pulmonary edema, hydronephrosis, hemoperitoneum, and deep vein thrombosis. Basic and advanced critical care ultrasonographic skills are routinely used to supplement physical examination of critically ill patients, to determine the etiology of critical illness and to guide subsequent therapy. European guidelines now recommend the use of US for a number of practical procedures commonly performed in critical care. Full training and competence acquisition are essential before significant therapeutic decisions are made based on the US assessment. However, there are no universally accepted learning pathways and methodological standards for the acquisition of these skills.

Therefore, in this review, we aim to provide a methodological approach of the head to toe ultrasonographic evaluation of critically ill patients considering different districts and clinical applications.