Diaphragm protection: what should we target?

Recovery and Survival of Patients After Out-of-Hospital Cardiac Arrest: A Literature Review Showcasing the Big Picture of Intensive Care Unit-Related Factors

As an important public health issue, out-of-hospital cardiac arrest (OHCA) requires several stages of high quality medical care, both on-field and after hospital admission. Post-cardiac arrest shock can lead to severe neurological injury, resulting in poor recovery outcome and increased risk of death. These characteristics make this condition one of the most important issues to deal with in post-OHCA patients hospitalized in intensive care units (ICUs). Also, the majority of initial post-resuscitation survivors have underlying coronary diseases making revascularization procedure another crucial step in early management of these patients. Besides keeping myocardial blood flow at a satisfactory level, other tissues must not be neglected as well, and maintaining mean arterial pressure within optimal range is also preferable. All these procedures can be simplified to a certain level along with using targeted temperature management methods in order to decrease metabolic demands in ICU-hospitalized post-OHCA patients. Additionally, withdrawal of life-sustaining therapy as a controversial ethical topic is under constant re-evaluation due to its possible influence on overall mortality rates in patients initially surviving OHCA. Focusing on all of these important points in process of managing ICU patients is an imperative towards better survival and complete recovery rates.

Perioperative Diaphragm Dysfunction

Diaphragm Dysfunction (DD) is a respiratory disorder with multiple causes. Although both unilateral and bilateral DD could ultimately lead to respiratory failure, the former is more common. Increasing research has recently delved into perioperative diaphragm protection. It has been established that DD promotes atelectasis development by affecting lung and chest wall mechanics. Diaphragm function must be specifically assessed for clinicians to optimally select an anesthetic approach, prepare for adequate monitoring, and implement the perioperative plan. Recent technological advancements, including dynamic MRI, ultrasound, and esophageal manometry, have critically aided disease diagnosis and management. In this context, it is noteworthy that therapeutic approaches for DD vary depending on its etiology and include various interventions, either noninvasive or invasive, aimed at promoting diaphragm recruitment. This review aims to unravel alternative anesthetic and operative strategies that minimize postoperative dysfunction by elucidating the identification of patients at a higher risk of DD and procedures that could cause postoperative DD, facilitating the recognition and avoidance of anesthetic and surgical interventions likely to impair diaphragmatic function.

Effects of transcutaneous electrical diaphragmatic stimulation in critically ill elderly patients: a randomized controlled trial

BACKGROUND

Elderly patients under invasive mechanical ventilation (IMV) are more susceptible to muscle weakness. In the out-of-hospital environment, there are benefits to transcutaneous electrical diaphragmatic stimulation (TEDS), which is an easy-to-apply and low-cost technique.

OBJECTIVE

To evaluate the effect of TEDS on respiratory muscle strength, diaphragm thickness (DT), and IMV time in critically ill elderly patients.

METHODS

This was a randomized controlled trial in which patients were divided into an experimental group (EG) and a control group (CG). TEDS started 24 h after orotracheal intubation and lasted until the end of weaning. Both groups underwent the following assessments during the spontaneous breathing test after weaning from mechanical ventilation (MV): measurement of respiratory muscle strength by pressure gauge, analysis of DT by lung ultrasound, and extubation failure prevention checklist.

RESULTS

There were 23 participants in the EG and 21 in the CG. The median age was 66 (60-79) years. The mean values of the diaphragmatic thickening index in the EG and CG participants were 99.13 ± 26.75 and 66.88 ± 31.77, respectively (p = .001, Cohen's d = 1.094). The mean values of maximum inspiratory pressure in the EG and CG were 22.04 ± 3.41 and 19.34 ± 4.23 cmH2O, respectively (p = .005, Cohen's d = 0.698). The Tobin index and the integrative weaning index were similar between groups (p = .584 and p = .102, respectively). The duration of MV in the EG and CG was 6.28 ± 2.68 and 9.21 ± 2.76 days, respectively (p = .001, Cohen's d = -1.075).

CONCLUSION

Critically ill elderly patients receiving TEDS had shorter MV time, greater inspiratory muscle strength, and greater diaphragmatic contraction capacity according to their thickness fraction.

Effects of usual yoga practice on the diaphragmatic contractility: A cross-sectional controlled study

Objectives

The aim of this study is to observe and compare the effects of regular yoga practice on the main inspiratory muscle, the diaphragm, by analyzing its thickness, excursion, velocity and contraction time, using ultrasound.

Design

A Cross-Sectional Controlled Study.

Participants

80 healthy subjects (40 habitual yoga practitioners and 40 non-practitioners), without previous respiratory pathology participated in this study. During maximum diaphragmatic breathing, the diaphragmatic thickness (at rest and after maximum inspiration), excursion, velocity and contraction time were measured by ultrasound.

Results

in the experimental group, practicing yoga, statistically significant differences (p < 0.001) were observed compared to the control group, not practicing, in the thickness of the diaphragm at rest (0.26 ± 0.02 vs 0.22 ± 0.01 cm); the diaphragmatic thickness in maximum inspiration (0.34 ± 0.03 vs 0.28 ± 0.03 cm); contraction velocity (1.54 ± 0.54 vs 2.23 ± 0.86 cm/s), contraction time (3.28 ± 0.45 vs 2.58 ± 0.49 s) and Borg scale of perceived exertion (1.05 ± 1.6 vs 1.70 ± 1.34), p = 0.05. However, the diaphragmatic excursion was greater in the control group (5.45 ± 1.42 vs 4.87 ± 1.33 cm) with no statistically significant differences (p = 0.06).

Conclusions

the regular practice of yoga improves the parameters of diaphragm thickness, speed and contraction time measured in ultrasound and the sensation of perceived exertion during a maximum inspiration. So it can be considered as another method for training the inspiratory muscles in clinical practice.

Diaphragm Ultrasound in Critically Ill Patients on Mechanical Ventilation—Evolving Concepts

Mechanical ventilation (MV) is a life-saving respiratory support therapy, but MV can lead to diaphragm muscle injury (myotrauma) and induce diaphragmatic dysfunction (DD). DD is relevant because it is highly prevalent and associated with significant adverse outcomes, including prolonged ventilation, weaning failures, and mortality. The main mechanisms involved in the occurrence of myotrauma are associated with inadequate MV support in adapting to the patient’s respiratory effort (over- and under-assistance) and as a result of patient-ventilator asynchrony (PVA). The recognition of these mechanisms associated with myotrauma forced the development of myotrauma prevention strategies (MV with diaphragm protection), mainly based on titration of appropriate levels of inspiratory effort (to avoid over- and under-assistance) and to avoid PVA. Protecting the diaphragm during MV therefore requires the use of tools to monitor diaphragmatic effort and detect PVA. Diaphragm ultrasound is a non-invasive technique that can be used to monitor diaphragm function, to assess PVA, and potentially help to define diaphragmatic effort with protective ventilation. This review aims to provide clinicians with an overview of the relevance of DD and the main mechanisms underlying myotrauma, as well as the most current strategies aimed at minimizing the occurrence of myotrauma with special emphasis on the role of ultrasound in monitoring diaphragm function.

Diyafram ultrasonografisinin weaning başarısını tahmin etmedeki gücü

Amaç: Bu çalışmada amaç; diyafram kalınlığının weaning üzerine etkilerini ultrasonografi (USG) ile değerlendirmektir. Gereç ve Yöntem: Prospektif olarak yapılan bu çalışmada; hastaların demografik özellikleri, yoğun bakıma yatış ve mekanik ventilasyon endikasyonları, ek hastalıkları, diyafram kalınlığı, Sıralı Organ Yetmezliği Değerlendirmesi (SOFA) skoru ve Basitleştirilmiş Akut Fizyoloji Skoru (SAPS) II, mortalite oranı, periferik oksijen satürasyonu (SpO2), IMV süresi, dakika hacmi, solunum sayısı (RR), ekspiratuar hacimleri, RSBI değerleri kaydedildi.Hastalar invaziv mekanik ventilatör (IMV) basınç desteği (PS) modunda 30 dakika boyunca spontan olarak ventile edildi . Diyafram kalınlığı (DT), B moduna ayarlanmış 7-10 MHz lineer ultrason probu kullanılarak ölçüldü. Sağ hemidiyafram, 8. ve 10. interkostal boşluklar arasındaki midaksiller çizgide diyafram ve göğüs kafesinin birleştiği bölgede görüntülendi. Ölçümler sonrasında hastalar stabil hale geldikten sonra 1 saat boyunca T-tüpe alındı. T-tüpte spontan solunum denemeleri (SBT)'ni başarıyla tamamlayan hastalar ekstübe edildi. Hastalar başarılı ve başarısız weaning olmak üzere 2 gruba ayrıldı. Bulgular: Toplam 72 hasta çalışmaya dahil edilme kriterlerini sağlayarak değerlendirilmeye alındı. Hastaların 4 tanesi 24 saatten daha kısa süre IMV desteği aldığı için çalışma dışı bırakıldı. Diyafram kalınlık indeksi (DTI) ve diyafram kalınlaşma fraksiyonu (DTF) oranlarında gruplar arasında bir farklılık gözlenmedi. İnspirasyon sonunu diyafram kalınlığı (DTV) ve ekspirasyon sonunu diyafram kalınlığı (DFRV) olarak tanımlanan diyaframın kalınlık ölçümleri başarılı weaning grubunda daha yüksekti. Weaning başarısını tahmin etmek için DTV'nin en iyi eşik değeri 0.72, DFRV değeri 0.669 olarak bulundu. Sonuç: Weaning başarısı diyafram fonksiyonları, diyafram kalınlık parametreleri ve akciğer kapasiteleri ile yakından ilişkilidir. USG, diyaframı değerlendirmek için kullanılabilecek pratik, hasta başı uygulanabilen, noninvaziv bir yöntemdir. DTV ve DFRV weaning sürecinde başarıyı tahmin edebilecek parametreler arasındadır. DTF ve DTI weaning başarısını öngörmede yetersiz bulundu.

The Main Role of Diaphragm Muscle as a Mechanism of Hypopressive Abdominal Gymnastics to Improve Non-Specific Chronic Low Back Pain: A Randomized Controlled Trial

Background: Chronic low back pain (LBP) has been stated as one of the main health concerns in the XXI century due to its high incidence. Objective: The objective of this study was to determine the effects of an 8-week program of hypopressive abdominal gymnastics (HAG) on inspiratory muscle strength, diaphragm thickness, disability and pain in patients suffering from non-specific chronic LBP. Methods: A total of 40 patients with chronic LBP were randomly divided into two groups. The experimental group carried out an 8-week supervised program of HAG (two sessions/week), whereas the control group did not receive any treatment. Outcomes were measured before and after the intervention, comprising diaphragm thickness during relaxed respiratory activity, maximal inspiratory pressure (PI_max), pain intensity (NRS), pressure pain threshold and responses to four questionnaires: Physical Activity Questionnaire (PAQ), Roland–Morris Disability Questionnaire (RMQ), Central Sensitization Inventory (CSI) and Tampa Scale of Kinesiophobia-11 Items (TSK-11). Results: Statistically significant differences (p < 0.05) were observed for greater thickness of the left and right hemi-diaphragms at inspiration, as well as higher PI_max and decreased NRS, CSI and RMQ scores in the intervention group. After treatment, the increases in the thickness of the left and right hemi-diaphragms at inspiration and PI_max, as well as the decrease in the NRS and RMQ scores, were only predicted by the proposed intervention (R² = 0.118–0.552). Conclusions: An 8-week HAG intervention seemed to show beneficial effects and predicted an increase in diaphragm thickness and strength during inspiration, as well as a reduction in pain intensity, central sensitization and disability, in patients suffering from chronic non-specific LBP with respect to non-intervention.

Determinants of diaphragm inspiratory motion, diaphragm thickening, and its performance for predicting respiratory restrictive pattern in Duchenne muscular dystrophy

INTRODUCTION/AIMS

Respiratory status is a key determinant of prognosis in patients with Duchenne muscular dystrophy (DMD). We aimed to evaluate the determinants of diaphragm ultrasound and its performance in predicting restrictive respiratory patterns in DMD.

METHODS

This was a retrospective study of DMD patients followed in our center and admitted for an annual checkup from 2015 to 2018. We included DMD patients who underwent diaphragm ultrasound and pulmonary functional tests.

RESULTS

This study included 74 patients with DMD. The right diaphragm thickening fraction (TF) was significantly associated with age (P = .001), Walton score (P = .012), inspiratory capacity (IC) (P = .004), upright forced vital capacity (FVC) (P < .0001), supine FVC (P = .038), and maximal inspiratory pressure (MIP) (P = .002). Right diaphragm excursion was significantly associated with age (P < .0001), steroid use (P = .008), history of spinal fusion (P < .0001), body mass index (BMI) (P = .002), Walton score (P < .0001), IC (P < .0001), upright FVC (P < .0001), supine FVC (P < .0001), and MIP (P < .0001). A right diaphragm TF >28% and a right diaphragm excursion>25.4 mm were associated with an FVC >50% with, respectively, an area under the curve (AUC) of 0.95 (P = .001) and 0.93 (P < .001). A left diaphragm TF >26.8% and a left diaphragm excursion >21.5 mm were associated with an FVC >50% with, respectively, an AUC of 0.95 (P = .011) and 0.97 (P < .001).

DISCUSSION

Diaphragm excursion and diaphragm TF can predict restrictive pulmonary insufficiency in DMD.

Early rehabilitation relieves diaphragm dysfunction induced by prolonged mechanical ventilation: a randomised control study

BACKGROUND

Prolonged mechanical ventilation (MV) induces diaphragm dysfunction in patients in the intensive care units (ICUs). Our study aimed to explore the therapeutic efficacy of early rehabilitation therapy in patients with prolonged MV in the ICU.

METHODS

Eighty eligible patients who underwent MV for > 72 h in the ICU from June 2019 to March 2020 were enrolled in this prospective randomised controlled trial. The patients were randomly divided into a rehabilitation group (n = 39) and a control group (n = 41). Rehabilitation therapy included six levels of rehabilitation exercises. Diaphragm function was determined using ultrasound (US).

RESULTS

Diaphragmatic excursion (DE) and diaphragm thickening fraction (DTF) were significantly decreased in all patients in both groups after prolonged MV (p < 0.001). The rehabilitation group had significantly higher DTF (p = 0.008) and a smaller decrease in DTF (p = 0.026) than the control group after 3 days of rehabilitation training. The ventilator duration and intubation duration were significantly shorter in the rehabilitation group than in the control group (p = 0.045 and p = 0.037, respectively). There were no significant differences in the duration of ICU stay, proportion of patients undergoing tracheotomy, and proportion of recovered patients between the two groups.

CONCLUSIONS

Early rehabilitation is feasible and beneficial to ameliorate diaphragm dysfunction induced by prolonged MV and advance withdrawal from the ventilator and extubation in patients with MV. Diaphragm US is suggested for mechanically ventilated patients in the ICU. Trial registration Chinese Clinical Trial Registry, ID: ChiCTR1900024046, registered on 2019/06/23.

PREVENTION OF RESPIRATORY MUSCLE DYSFUNCTION DUE TO DIAPHRAGM ATROPHY IN CHILDREN WITH RESPIRATORY FAILURE

The aim of the study was to determine whether diaphragm-protective mechanical ventilation can prevent diaphragm atrophy in children with respiratory failure. Materials and methods. We complete the prospective single-center cohort study. Data analysis included 82 patients 1 month - 18 years old, divided into I group (lung-protective MV) and II group (diaphragm-protective in addition to lung-protective MV). Patients were divided into age subgroups. Stages of the study: 1st day (d1), 3rd (d3), 5th (d5), 7th (d7), 9th (d9), 28th (d28). We studied changes in diaphragm thickness at the end of exhalation and compared them with these indicators at patient`s admission to the study (baseline). Primary endpoint was length of stay in ICU, secondary endpoints were complications (prolonged MV). Results are described as arithmetic mean (X) and standard deviation (σ) with level of significance p. Results. There were significant differences in length of stay in ICU among patients of the 1st and 5th age subgroups: in 1st age subgroup this data was in 1.3 times lower in II group, compared with I group (p <0,05); in 5th age subgroup the situation was the opposite - length of stay in ICU was in 1.4 times higher in II group, compared with I group (p<0.05). There were no patients who required lifelong mechanical ventilation in any of the groups. Changes in the thickness of the diaphragm, which indicate its atrophy, were the most significant among patients of the first, second, third and fourth age subgroups and the severity of atrophy was higher among patients of group I, compared with patients of group II. Conclusions. Diaphragm-protective mechanical ventilation significantly prevents diaphragm atrophy in children with respiratory failure in 2nd, 4th, and 5th age subgroups. Providing goal-directed diaphragm-protective MV might reduce the length of stay in ICU among patients of 1st and 5th age subgroups. There were no observed complications like lifelong mechanical ventilation in both patient`s group.

DIAPHRAGMATIC MYOTRAUMA IN CHILDREN WITH ACUTE RESPIRATORY FAILURE

The aim of the study was to establish the prevalence of diaphragmatic dysfunction (DD), depending on the strategy of mechanical ventilation (MV). Materials and methods. We completed the prospective single-center cohort study. Data analysis included 82 patients (1 month – 18 years old), divided into I group (lung-protective MV) and II group (diaphragm-protective in addition to lung-protective MV). Patients were divided into age subgroups. Stages of the study: 1st day (d1), 3rd (d3), 5th (d5), 7th (d7), 9th (d9), 14th (d14), 28th (d28). We studied amplitude of diaphragm movement; thickening fraction, parameters of acid-base balance and MV. Results are described as median [IQR - interquartile range] with level of significance p. Results. In patients of the 1st age subgroup in I group there were episodes with under-assist during MV, while in II group diaphragm overload was registered only on d5. In patients of 2nd subgroup in I group we found over-assist of MV with excessive work of the right hemidiaphragm and low contractions of left dome at all stages of study, while in II group – the only episode of diaphragmatic weakness on d3 due to under-assist of MV. In the 3rd subgroup the proper diaphragmatic activity in I group was restored significantly later than in II group. In 4th subgroup of I group there was episode of high work of diaphragm on d5, whereas in II group – all data were within the recommended parameters for diaphragm-protective strategy of MV. In 5th subgroup of I group excessive work of both right and left domes of diaphragm was significantly more often registered than in II group, however, in II group there were found episodes of both type changes – diaphragmatic weakness and excessive work. Conclusion: The prevalence and variety of manifestations of DD depend on the strategy of MV. Low incidence of DD was associated with lower duration of MV: in 1st age subgroup in 1.5 times; in 2nd age subgroup – in 2.4 times; in 4th age subgroup – in 1.75 times; in 5th age subgroup – in 4.25 times.

Clinical study of Dysfunctional Ventilatory Weaning Response in critically ill patients

Objective:

to clinically validate the nursing diagnosis of Dysfunctional Ventilatory Weaning Response in adult patients admitted to Intensive Care Units.

Method:

a concurrent cohort performed with 93 patients admitted to Intensive Care Units. The incidence and incidence density of the diagnosis were estimated, its related factors were identified based on bivariate analysis and clinical indicators for determining its occurrence, according to the global and temporal presentation.

Results:

the overall incidence of the diagnosis was 44.09% and the incidence density was 14.49 occurrences for every 100 extubations/day. The factors related to the diagnosis were the following: age, clinical severity, fluid balance, oliguria, hemodialysis, edema in upper/lower limbs, anasarca, number of antibiotics, hypothermia, hyperthermia, amount of secretion, muscle retraction, anxiety score, heart rate, use of vasopressors and non-invasive ventilation after extubation. The clinical indicators most frequently identified for determining the diagnosis were the following: tachypnea, drop of saturation and tachycardia. Temporal progression in the severity of these manifestations was found.

Conclusion:

the Dysfunctional Ventilatory Weaning Response is a common finding in critically ill patients. Some components of the diagnosis of the NANDA-International (2018) version could be clinically validated. It is noteworthy that there are variables not yet described in the taxonomy, demonstrating the need to review this nursing diagnosis.