Time course of the Bioelectrical Impedance Vector Analysis and muscular ultrasound in critically ill patients

Prospective ultrasonographic evaluation of femoral and vastus intermedius muscles as predictors of ICU-acquired weakness in critically ill patients

PURPOSE

Intensive care unit-acquired weakness (ICU-AW) is associated with poor functional outcomes and increased healthcare costs. This study aimed to evaluate the diagnostic performance of muscular ultrasound (MUS) measurements in predicting ICU-AW and identify potential predictors.

METHODS

Forty-three surgical and medical ICU patients underwent serial MUS measurements of the femoral cross-sectional area (Fcsa) and femoral + vastus intermedius thickness (F + VIth) on days 1, 3 and 5 post-ICU admission. Patients were categorized as having ICU-AW (Medical Research Council (MRC) sum score < 48 at discharge) or not. Univariate and multivariate logistic regression analyses were performed to identify predictors of ICU-AW. The diagnostic performance of MUS measurements was assessed via receiver operating characteristic (ROC) curves. Clinical outcomes (ICU length of stay, ventilator days, extubation failure) were compared between the groups.

RESULTS

Patients with ICU-AW (n = 12, 28%) showed a significant reduction in the Fcsa from Day 1 to Day 5 (p < 0.001). Univariate analysis revealed significant associations between ICU-AW and the Apache II score (OR 1.12, p = 0.03), SOFA score (OR 1.32, p = 0.008), and Day 1 F + VIth score (OR 0.23, p = 0.05). Multivariate analysis confirmed a significant association with the SOFA score (OR 1.35, p = 0.04) and a trend toward an F + VIth score of Day 1 (OR 0.12, p = 0.09). The day 1 Fcsa and F + VIth demonstrated moderate predictive capabilities for ICU-AW (ROC-AUC values of 0.72 and 0.82, respectively). ICU-AW patients experienced longer ICU stays, more ventilator days, and higher extubation failure rates.

CONCLUSION

Preexisting low muscle mass, combined with a high SOFA score, may be a stronger predictor of ICU-acquired weakness than the degree of subsequent muscle loss.

Predicting early diagnosis of intensive care unit-acquired weakness in septic patients using critical ultrasound and biological markers

OBJECTIVE

Early diagnosis of intensive care unit-acquired weakness (ICUAW) is crucial for improving the outcomes of critically ill patients. Hence, this study was designed to identify predisposing factors for ICUAW and establish a predictive model for the early diagnosis of ICUAW.

METHODS

This prospective observational multicenter study included septic patients from the comprehensive ICUs of West China Hospital of Sichuan University and 10 other hospitals between September and November 2023. Inclusion criteria were as follows: age over 18 years; expected ICU stay longer than 3 days; and voluntary informed consent. Patients were classified into ICUAW (MRC score < 48) and non-ICUAW (MRC score ≥ 48) groups based on muscle strength assessments. The analyzed key predictive factors encompassed demographic data, SOFA and APACHE II scores, inflammatory markers (PCT, IL-6, and CRP), and ultrasound measurements of muscle thickness and cross-sectional area. Logistic regression analysis was conducted for variable selection and nomogram model construction.

RESULTS

A total of 116 septic patients were included, comprising 77 males and 39 females (mean age: 56.94 ± 19.90 years). A nomogram model predicting ICUAW probability was developed, which involved vastus intermedius diameter, rectus femoris cross-sectional area, IL-6, and CRP. The AUC of the composite diagnostic ROC curve was 0.966 (95%CI: 0.936 - 0.996), with a sensitivity of 88% and a specificity of 95.8%.

CONCLUSIONS

Conclusively, a nomogram model is constructed for diagnosing ICUAW in septic patients, which is simple and rapid and allows for visual representation, with excellent diagnostic capability.

Advancing Nutritional Care Through Bioelectrical Impedance Analysis in Critical Patients

Nutritional support in critically ill patients has been acknowledged as a pillar of ICU care, playing a pivotal role in preserving muscle mass, supporting immune function, and promoting recovery during and after critical illness. Providing effective nutritional support requires adapting it to the patient's diagnosis, unique characteristics, and metabolic state to minimize the risks of overfeeding or underfeeding while mitigating muscle loss. This level of care requires a comprehensive nutritional assessment and the establishment of a nutrition-focused protocol. Regular, consistent and detailed nutritional evaluation can influence both therapeutic decisions and clinical interventions, thus ensuring that the specific needs of critically ill patients are met from the acute phase through their entire recovery process. Bioelectrical impedance analysis (BIA) is increasingly recognized as a valuable tool for enhancing nutritional care in critically ill patients. By delivering precise, real-time insights into key aspects of body composition, BIA is thought to provide clinicians with a more comprehensive understanding of the complex physiological changes that occur during critical illness. This narrative review highlights the potential of BIA in offering these precise assessments, facilitating the development of more accurate and personalized nutritional strategies for critically ill patients. If BIA can reliably assess dynamic shifts in hydration and tissue integrity, it holds the promise of further advancing individualized care and optimizing clinical outcomes in this vulnerable population.

Impact of COVID-19 on Diaphragmatic Function: Understanding Multiorgan Involvement and Long-Term Consequences

The COVID-19 pandemic has brought significant attention to the respiratory system, with much focus on lung-related disorders. However, the diaphragm, a crucial component of respiratory physiology, has not been adequately studied, especially in the context of long COVID. This review explores the multipotential role of the diaphragm in both respiratory health and disease, emphasizing its involvement in long-term complications following SARS-CoV-2 infection. The diaphragm's fundamental role in respiratory physiology and its impact on balance and posture control, breathing patterns, and autonomic nervous system regulation are discussed. This review examines complications arising from COVID-19, highlighting the diaphragm's involvement in neurological, musculoskeletal, and inflammatory responses. Particular attention is given to the neuroinvasive impact of SARS-CoV-2, the inflammatory response, and the direct viral effects on the diaphragm. The diaphragm's role in long COVID is explored, with a focus on specific symptoms such as voice disorders, pelvic floor dysfunction, and sleep disturbances. Diagnostic challenges, current methods for assessing diaphragmatic dysfunction, and the complexities of differentiating it from other conditions are also explored. This article is the first to comprehensively address diaphragmatic dysfunction resulting from COVID-19 and long COVID across various physiological and pathological aspects, offering a new perspective on its diagnosis and treatment within a multisystem context.

Methodologies and clinical applications of lower limb muscle ultrasound in critically ill patients: a systematic review and meta-analysis

BACKGROUND

Reduced muscle mass upon admission and development of muscle wasting are frequent in critically ill patients, and linked to unfavorable outcomes. Muscle ultrasound is a promising instrument for evaluating muscle mass. We summarized the findings of lower limb muscle ultrasound values and investigated how the muscle ultrasound parameters of the examination or the patient characteristics influence the results.

METHODS

Systematic review and meta-analysis of studies of lower limb ultrasound critically ill adults. PubMed, CINAHL, Embase, PEDro and Web of Science were searched. PRISMA guidelines were followed, and studies evaluated with the appropriate NIH quality assessment tool. A meta-analysis was conducted to compare the values at admission, short and long follow-up during ICU stay, and the association between baseline values and patient characteristics or ultrasound parameters was investigated with a meta-regression.

RESULTS

Sixty-six studies (3839 patients) were included. The main muscles investigated were rectus femoris cross-sectional area (RF-CSA, n = 33/66), quadriceps muscle layer thickness (n = 32/66), and rectus femoris thickness (n = 19/66). Significant differences were found in the anatomical landmark and ultrasound settings. At ICU admission, RF-CSA ranged from 1.1 [0.73-1.47] to 6.36 [5.45-7.27] cm2 (pooled average 2.83 [2.29-3.37] cm2) with high heterogeneity among studies (I2 = 98.43%). Higher age, higher BMI, more distal landmark and the use of probe compression were associated with lower baseline muscle mass.

CONCLUSIONS

Measurements of muscle mass using ultrasound varied with reference to patient characteristics, patient position, anatomical landmarks used for measurement, and the level of compression applied by the probe; this constrains the external validity of the results and highlights the need for standardization.

STUDY REGISTRATION

PROSPERO CRD42023420376.

Effect of rigorous fluid management using monitoring of ECW ratio by bioelectrical impedance analysis in critically ill postoperative patients: A prospective, single-blind, randomized controlled study

BACKGROUND & AIMS

Precise assessment of postoperative volume status is important to administrate optimal fluid management. Bioelectrical impedance analysis (BIA) which measures the body composition using electric character. Extracellular water (ECW) ratio by BIA represented as the ratio of ECW to total body water (TBW) and is known to reflect the hydration status. Based on this, we aimed to determine whether aggressive fluid control using ECW ratio could improve clinical outcomes through a single blind, randomized controlled trial.

METHODS

From November 2021 to December 2022, intensive care unit (ICU) patients admitted after surgery were randomly assigned to an intervention group or a control group whether postoperative fluid management was controlled via BIA. Among patients in the intervention group, dehydrated patients received a bolus infusion with crystalloid fluid whereas diuretics were administrated to overhydrated patients until the value of ECW ratio fell within its normal setting range (0.390-0.406). Contrarily, BIA was performed once a day for the control group. Patients in the control group received traditional fluid treatment regardless of BIA results. Primary outcome was in-hospital mortality in two groups. The secondary outcomes were postoperative morbidities, 28-day mortality.

RESULTS

77 patients of the intervention group and 90 patients of the control group were finally analyzed. The in-hospital mortality (0 in intervention, 4.4% in control, p = 0.125) and 28-day mortality (1.3% in intervention, 14.4% in control, p = 0.002) showed lower incidence in the intervention group than in the control group. In multivariate analysis, the overhydrated status whose ECW ratio exceeding 0.406 [odds ratio (OR): 2.731, 95% confidence interval (CI): 1.001-7.663, p = 0.049] and high capillary leak index (CLI) value at ICU admission (OR: 1.024, 95% CI: 1.008-1.039, p = 0.002) were risk factors of postoperative morbidities. Regarding the 28-day mortality, high CLI value (OR: 1.025, 95% CI: 1.002-1.050, p = 0.037) and traditional strategy without BIA monitoring (OR: 9.903, 95% CI: 1.095-89.566, p = 0.041) were the significant predisposing factors.

CONCLUSION

Our results revealed the rigorous fluid treatment with volume control based on ECW ratio by BIA failed to achieve significant improvement in in-hospital mortality, but it could reduce 28-day mortality of ICU patients. Monitoring of ECW ratio may help establish optimal fluid treatment strategies for postoperative ICU patients who are susceptible to fluid imbalances with fluid overload.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT06097923, retrospectively registered on October 16, 2023, https://clinicaltrials.gov/study/NCT06097923?term=NCT06097923&rank=1.

The effect of protein administration during critical illness depends on body composition: A secondary analysis of a prospective, observational study

BACKGROUND & AIMS

The most adequate amount of protein that should be administered to critically ill patients is still debated and diverging findings are recently accumulating. We hypothesized that the effect of protein administration might depend on the amount of muscle mass.

METHODS

A secondary analysis of a single-centre prospective observational study of body composition in critically ill patients. Mechanically-ventilated subjects with an expected intensive care unit (ICU) stay >72 h were enrolled. Within 24 h from ICU admission, bioimpedance-derived muscle mass (BIA MM) and rectus femoris cross-sectional area (RF CSA) were measured. The amount of proteins and calories administered on the 7th ICU day was recorded.

RESULTS

We enrolled 94 subjects (65 males, actual body weight 72.9 ± 14.4 Kg, BMI 26.0 ± 4.8 kg/m2). Actual body weight was only weakly related to BIA MM (R = 0.478, p < 0.001) and not related to RF CSA (R = 0.114, p = 0.276). A higher protein intake was associated with a reduced mortality in the highest quartile of BIA MM (OR 0.68 [0.46; 0.99] per each 10 g of proteins administered) and in the third (OR 0.74 [0.57; 0.98]) and highest quartile of RF CSA (OR 0.68 [0.48; 0.96]).

CONCLUSION

A higher protein intake was associated with lower ICU mortality only in patients admitted with a higher muscle mass, as either assessed by BIA or muscle ultrasound.

Bioimpedance-assessed muscle wasting and its relation to nutritional intake during the first week of ICU: a pre-planned secondary analysis of Nutriti Study

BACKGROUND

Muscle mass evaluation in ICU is crucial since its loss is related with long term complications, including physical impairment. However, quantifying muscle wasting with available bedside tools (ultrasound and bioimpedance analysis) must be more primarily understood. Bioimpedance analysis (BIA) provides estimates of muscle mass and phase angle (PA). The primary aim of this study was to evaluate muscle mass changes with bioimpedance analysis during the first 7 days after ICU admission. Secondary aims searched for correlations between muscular loss and caloric and protein debt.

METHODS

Patients with an expected ICU-stay ≥ 72 h and the need for artificial nutritional support were evaluated for study inclusion. BIA evaluation of muscle mass and phase angle were performed at ICU admission and after 7 days. Considering the difference between ideal caloric and protein targets, with adequate nutritional macronutrients delivered, we calculated the caloric and protein debt. We analyzed the potential correlation between caloric and protein debt and changes in muscle mass and phase angle.

RESULTS

72 patients from September 1st to October 30th, 2019 and from August 1st to October 30th, 2021 were included in the final statistical analysis. Median age was 68 [59-77] years, mainly men (72%) admitted due to respiratory failure (25%), and requiring invasive mechanical ventilation for 7 [4-10] days. Median ICU stay was 8 [6-12] days. Bioimpedance data at ICU admission and after 7 days showed that MM and PA resulted significantly reduced after 7 days of critically illness, 34.3 kg vs 30.6 kg (p < 0.0001) and 4.90° vs 4.35° (p = 0.0004) respectively. Mean muscle loss was 3.84 ± 6.7 kg, accounting for 8.4% [1-14] MM reduction. Correlation between caloric debt (r = 0.14, p = 0.13) and protein debt (r = 0.18, p = 0.13) with change in MM was absent. Similarly, no correlation was found between caloric debt (r = -0.057, p = 0.631) and protein debt (r = -0.095, p = 0.424) with changes in PA.

CONCLUSIONS

bioimpedance analysis demonstrated that muscle mass and phase angle were significantly lower after 7 days in ICU. The total amount of calories and proteins does not correlate with changes in muscle mass and phase angle.

Ultrasound for measurement of skeletal muscle mass quantity and muscle composition/architecture in critically ill patients: A scoping review on studies' aims, methods, and findings

AIMS

This scoping review aimed to identify, explore, and map the objectives, methodological aspects, and results of studies that used ultrasound (US) to assess skeletal muscle (SM) in critically ill patients.

METHODS

A scoping review was conducted according to the Joanna Briggs Institute's methodology. All studies that evaluated SM parameters from the US in patients admitted to the intensive care unit (ICU) were considered eligible. We categorized muscle thickness and cross-sectional area as parameters for assessing SM quantity, while echogenicity, fascicle length, and pennation angle analysis were used to evaluate muscle "quality" (composition/architecture). A literature search was conducted using four databases for articles published until December 2022. Independent reviewers selected the studies and extracted data. Descriptive statistics were calculated to present the results.

RESULTS

A total of 107 studies were included, the majority of which were prospective cohort studies (59.8 %) conducted in general ICUs (49.5 %). The most frequent objective of the studies was to evaluate SM quantity depletion during the ICU stay (25.2 %), followed by determining whether a specific intervention would modify SM (21.5 %). Most studies performed serial SM evaluations (76.1 %). The rectus femoris muscle thickness was evaluated in most studies (67.9 %), followed by the rectus femoris cross-sectional area (54.3 %) and the vastus intermedius muscle thickness (40.2 %). The studies demonstrated the feasibility and reproducibility of US for SM evaluation, especially related to quantitative parameters. Most studies (70.3 %) reported significant SM quantity depletion during hospitalization. However, the accuracy of the US in measuring SM varied across the studies.

CONCLUSIONS

The lack of detailed description and standardization in the protocols adopted by the studies included in this scoping review precludes the translation of the evidence related to US for SM assessment into clinical practice.

Temporal evolution of diaphragm thickness and diaphragm excursion among subjects hospitalized with COVID-19: A prospective observational study

BACKGROUND

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has an affinity for the angiotensin-converting enzyme 2 (ACE2) receptors, which are present abundantly on the diaphragm. This study aims to describe temporal changes in diaphragmatic thickness and excursion using ultrasonography in subjects with acute COVID-19.

METHODS

This prospective observational study included adults hospitalized with COVID-19 in the past 48 hours. The diaphragm thickness at end-expiration (DTE), diaphragm thickening fraction (DTF), and diaphragm excursion during tidal breathing (DE) and maximal inspiration (DEmax) were measured using ultrasonography daily for 5 days. The changes in DTE, DTF, DE, and Demax from day 1 to day 5 were assessed.

RESULTS

This study included 64 adults (62.5% male) with a mean (SD) age of 50.2 (17.5) years. A majority (91%) of the participants had mild or moderate illness. The median (IQR) DTE, DTF (%), DE and Demax on day 1 were 2.2 (1.9, 3.0) mm, 21.5% (14.2, 31.0), 19.2 (16.5, 24.0) mm, and 26.7 (22.0, 30.2) mm, respectively. On day 5, there was a significant reduction in the DTE (p=0.002) with a median (IQR) percentage change of -15.7% (-21.0, 0.0). The DTF significantly increased on day 5 with a median (IQR) percentage change of 25.0% (-19.2, 98.4), p=0.03. There was no significant change in DE and Demax from day 1 to day 5, with a median (IQR) percentage change of 3.6% (-5.2, 15) and 0% (-6.7, 5.9), respectively.

CONCLUSIONS

Non-intubated patients with COVID-19 exhibited a temporal decline in diaphragm thickness with increase in thickening fraction over 5 days of hospital admission. Further research is warranted to assess the impact of COVID-19 pneumonia on diaphragmatic function.

Ultrasonographic Assessment of Diaphragmatic Function and Its Clinical Application in the Management of Patients with Acute Respiratory Failure

Acute respiratory failure (ARF) is a common life-threatening medical condition, with multiple underlying etiologies. In these cases, many factors related to systemic inflammation, prolonged use of steroids, and lung mechanical abnormalities (such as hyperinflation or increased elastic recoil due to pulmonary oedema or fibrosis) may act as synergic mechanisms leading to diaphragm dysfunction. The assessment of diaphragm function with ultrasound has been increasingly investigated in the emergency department and during hospital stay as a valuable tool for providing additional anatomical and functional information in many acute respiratory diseases. The diaphragmatic ultrasound is a noninvasive and repeatable bedside tool, has no contraindications, and allows the physician to rapidly assess the presence of diaphragmatic dysfunction; this evaluation may help in estimating the need for mechanical ventilation (and the risk of weaning failure), as well as the risk of longer hospital stay and higher mortality rate. This study presents an overview of the recent evidence regarding the evaluation of diaphragmatic function with bedside ultrasound and its clinical applications, including a discussion of real-life clinical cases.

Rectus Femoris Muscle and Phase Angle as Prognostic Factor for 12-Month Mortality in a Longitudinal Cohort of Patients with Cancer (AnyVida Trial)

BACKGROUND

Cancer-related malnutrition is still unrecognized and undertreated in clinical practice. The morphofunctional assessment of disease-related malnutrition (DRM) is a new approach that focuses on evaluating changes in body composition and function. The aim of this study is to evaluate the prognostic value of classic and emerging assessment of malnutrition at 12-months survival in cancer patients.

METHODS

We conducted a prospective study on cancer outpatients. Bioelectrical impedance with phase angle (PhA), nutritional ultrasound by rectus femoris cross-sectional area (RFCSA), hand grip strength, and "Timed Up and Go Test" (TUG) were evaluated as predictors of mortality.

RESULTS

Fifty-seven patients were included. The non-survivors had lower PhA values than the survivors (4.7° vs. 5.4°; p < 0.001), and we had the same results with RFCSA 2.98 cm2/m2 vs. 4.27 cm2/m2 (p = 0.03). Cut-off points were identified using the ROC (receiver operating characteristic) curves for PhA (≤5.6° cancer patients, ≤5.9° men, ≤5.3° women), RFCSA (≤4.47 cm2/m2 cancer patients, ≤4.47° men, ≤2.73° women) and rectus femoris-Y-axis (RF-Y-axis; ≤1.3 cm cancer patients, ≤1.06 men, ≤1 women). In multivariate logistic regression analysis, we found that high PhA was significantly associated with a lower mortality hazard ratio (HR: 0.42 95% CI: 0.21-0.84, p = 0.014). Likewise, high RFCSA was associated with a decrease in mortality risk in the crude model (HR: 0.61 95% CI: 0.39-0.96, p = 0.031). This trend was also maintained in the adjusted models by the confounding variables.

CONCLUSIONS

Low PhA and RFCSA values are significant independent predictors of mortality in cancer patients. These cut-off points are clinical data that can be used for nutritional assessment and the prediction of clinical outcomes.

Prognostic role of bioelectrical impedance phase angle for critically ill patients: A systemic review and meta-analysis

Objective

Bioelectrical impedance-derived phase angle (PA) has exhibited good prognostic values in several non-critical illnesses. However, its predictive value for critically ill patients remains unclear. Thus, we aimed to perform a systematic review and meta-analysis to investigate the relationship between PA and survival in such a patient population.

Materials and methods

We searched for relevant studies in PubMed, Embase, and the Cochrane database up to Jan 20, 2022. Meta-analyses were performed to determine the association between the baseline PA after admission with survival. We further conducted subgroup analyses and sensitivity analyses to explore the sources of heterogeneity.

Results

We included 20 studies with 3,770 patients. Patients with low PA were associated with a significantly higher mortality risk than those with normal PA (OR 2.45, 95% CI 1.97-3.05, P < 0.00001). Compared to survivors, non-survivors had lower PA values (MD 0.82°, 95% CI 0.66-0.98; P < 0.00001). Similar results were also found when pooling studies reported regression analyses of PA as continuous (OR = 0.64; 95% CI 0.52-0.79, P < 0.00001) or categorical variable (OR = 2.42; 95% CI 1.76-3.34; P < 0.00001). These results were further confirmed in subgroup analyses and sensitivity analyses.

Conclusion

Our results indicated that PA may be an important prognostic factor of survival in critically ill patients and can nicely complement the deficiencies of other severity scoring systems in the ICU setting.

Prognostic value of phase angle and bioelectrical impedance vector in critically ill patients: A systematic review and meta-analysis of observational studies

BACKGROUND AND AIMS

Assessment of the raw parameters derived from bioelectrical impedance analysis (BIA) has gained emphasis in critically ill patients. The phase angle (PhA) reflects the integrity of the cell membrane, and bioelectrical impedance vector analysis (BIVA) is indicative of patients' hydration status. The aim of this study was to investigate whether these parameters are associated with clinical outcomes in the intensive care unit (ICU) setting.

METHODS

We conducted a systematic review with meta-analysis. We searched PubMed, Embase, Scopus and Web of Science for all published observational studies without language restrictions up to April 2022. Two reviewers independently performed study selection and data extraction. We judged the risk of bias by the Newcastle-Ottawa Scale and the certainty of evidence by the GRADE approach. Mortality was the primary outcome. Secondary outcomes included ICU length of stay, hospital length of stay, duration of mechanical ventilation, nutritional risk, and malnutrition. A meta-analysis with a random-effect model was performed to combine data on R version 3.6.2.

RESULTS

Twenty-seven studies were included in the systematic review (4872 participants). Pooled analysis revealed that patients with low PhA had a higher risk of death (14 studies; RR = 1.82, 95% CI 1.46 to 2.26; I² = 42%) and spent more days in ICU (6 studies; MD = 1.79, 95% CI 0.33 to 3.24, I² = 69%) in comparison to patients with normal PhA. The pooled analysis also showed higher PhA values in survivors compared to non-survivor patients (12 studies; MD = 0.75°, 95% CI 0.60° to 0.91°, I² = 31%). Overhydration defined by BIVA was not a predictor of mortality (4 studies; RR = 1.01, 95% CI 0.70 to 1.46; I² = 0%). More than 40% of primary studies were classified with a high risk of bias, and the quality of evidence ranged from low to very low.

CONCLUSIONS

This meta-analysis revealed, with limited evidence, that low PhA was associated with higher mortality and ICU length of stay, while overhydration identified by BIVA was not a predictor of death in critically ill patients.

Nutrition support for critically ill patients during the COVID-19 pandemic: the Italian SIAARTI survey

BACKGROUND

Critically ill, COVID-19 patients are characterized by a hypermetabolic state and a reduced food intake and are at high risk of malnutrition and lean body mass loss. An appropriate metabolic-nutritional intervention aims to reduce complications and improve the clinical outcomes. We conducted a cross-sectional, multicenter, observational, nationwide online survey involving Italian Intensivists to assess the nutritional practices in critically ill patients with COVID-19.

RESULTS

A group of experts in nutrition of the Italian Society of Anaesthesia Analgesia Resuscitation and Intensive Care (SIAARTI) developed a 24-item questionnaire; the 9000 members of the Society were invited to participate through emails and social networks. Data was collected from June 1 to August 1, 2021. A total of 545 responses were collected: 56% in northern, 25% in central, and 20% in southern Italy. Artificial nutrition support is directly handled by intensivists in > 90 of the cases; the nutritional status is assessed as suggested by the guidelines in more than 70% of the cases, and a form of nutrition support is started within the first 48 h from ICU admission by > 90% of the respondents. Nutritional targets are reached in 4-7 days in > 75% of the cases, mainly by the enteral route. Indirect calorimetry, muscle ultrasound, and bioimpedance analysis are used by a limited part of the interviewees. Only about a half of the respondents reported the nutritional issues in the ICU discharge summary.

CONCLUSIONS

This survey among Italian Intensivists during the COVID-19 epidemic showed how the beginning, progression, and route of nutritional support adhere to international recommendations, while recommendations on the tools to set the target and monitor the efficacy of the metabolic support are less followed.

Severe but reversible impaired diaphragm function in septic mechanically ventilated patients

Background

Whether sepsis-associated diaphragm dysfunction may improve despite the exposure of mechanical ventilation in critically ill patients is unclear. This study aims at describing the diaphragm function time course of septic and non-septic mechanically ventilated patients.

Methods

Secondary analysis of two prospective observational studies of mechanically ventilated patients in whom diaphragm function was assessed twice: within the 24 h after intubation and when patients were switched to pressure support mode, by measuring the endotracheal pressure in response to bilateral anterior magnetic phrenic nerve stimulation (Ptr,stim). Change in diaphragm function was expressed as the difference between Ptr,stim measured under pressure support mode and Ptr,stim measured within the 24 h after intubation. Sepsis was defined according to the Sepsis-3 international guidelines upon inclusion. In a sub-group of patients, the right hemidiaphragm thickness was measured by ultrasound.

Results

Ninety-two patients were enrolled in the study. Sepsis upon intubation was present in 51 (55%) patients. In septic patients, primary reason for ventilation was acute respiratory failure related to pneumonia (37/51; 73%). In non-septic patients, main reasons for ventilation were acute respiratory failure not related to pneumonia (16/41; 39%), coma (13/41; 32%) and cardiac arrest (6/41; 15%). Ptr,stim within 24 h after intubation was lower in septic patients as compared to non-septic patients: 6.3 (4.9–8.7) cmH₂O vs. 9.8 (7.0–14.2) cmH₂O (p = 0.004), respectively. The median (interquartile) duration of mechanical ventilation between first and second diaphragm evaluation was 4 (2–6) days in septic patients and 3 (2–4) days in non-septic patients (p = 0.073). Between first and second measurements, the change in Ptr,stim was + 19% (− 13–61) in septic patients and − 7% (− 40–12) in non-septic patients (p = 0.005). In the sub-group of patients with ultrasound measurements, end-expiratory diaphragm thickness decreased in both, septic and non-septic patients. The 28-day mortality was higher in patients with decrease or no change in diaphragm function.

Conclusion

Septic patients were associated with a more severe but reversible impaired diaphragm function as compared to non-septic patients. Increase in diaphragm function was associated with a better survival.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-022-01005-9.