Subjective Perceptions and Physiological Variables During Weaning From Mechanical Ventilation

Dyspnoea in acutely ill mechanically ventilated adult patients: an ERS/ESICM statement

This statement outlines a review of the literature and current practice concerning the prevalence, clinical significance, diagnosis and management of dyspnoea in critically ill, mechanically ventilated adult patients. It covers the definition, pathophysiology, epidemiology, short- and middle-term impact, detection and quantification, and prevention and treatment of dyspnoea. It represents a collaboration of the European Respiratory Society and the European Society of Intensive Care Medicine. Dyspnoea ranks among the most distressing experiences that human beings can endure. Approximately 40% of patients undergoing invasive mechanical ventilation in the intensive care unit (ICU) report dyspnoea, with an average intensity of 45 mm on a visual analogue scale from 0 to 100 mm. Although it shares many similarities with pain, dyspnoea can be far worse than pain in that it summons a primal fear response. As such, it merits universal and specific consideration. Dyspnoea must be identified, prevented and relieved in every patient. In the ICU, mechanically ventilated patients are at high risk of experiencing breathing difficulties because of their physiological status and, in some instances, because of mechanical ventilation itself. At the same time, mechanically ventilated patients have barriers to signalling their distress. Addressing this major clinical challenge mandates teaching and training, and involves ICU caregivers and patients. This is even more important because, as opposed to pain which has become a universal healthcare concern, very little attention has been paid to the identification and management of respiratory suffering in mechanically ventilated ICU patients.

Dyspnoea in acutely ill mechanically ventilated adult patients: an ERS/ESICM statement

This statement outlines a review of the literature and current practice concerning the prevalence, clinical significance, diagnosis and management of dyspnoea in critically ill, mechanically ventilated adult patients. It covers the definition, pathophysiology, epidemiology, short- and middle-term impact, detection and quantification, and prevention and treatment of dyspnoea. It represents a collaboration of the European Respiratory Society (ERS) and the European Society of Intensive Care Medicine (ESICM). Dyspnoea ranks among the most distressing experiences that human beings can endure. Approximately 40% of patients undergoing invasive mechanical ventilation in the intensive care unit (ICU) report dyspnoea, with an average intensity of 45 mm on a visual analogue scale from 0 to 100 mm. Although it shares many similarities with pain, dyspnoea can be far worse than pain in that it summons a primal fear response. As such, it merits universal and specific consideration. Dyspnoea must be identified, prevented and relieved in every patient. In the ICU, mechanically ventilated patients are at high risk of experiencing breathing difficulties because of their physiological status and, in some instances, because of mechanical ventilation itself. At the same time, mechanically ventilated patients have barriers to signalling their distress. Addressing this major clinical challenge mandates teaching and training, and involves ICU caregivers and patients. This is even more important because, as opposed to pain which has become a universal healthcare concern, very little attention has been paid to the identification and management of respiratory suffering in mechanically ventilated ICU patients.

Dyspnea and the electromyographic activity of inspiratory muscles during weaning from mechanical ventilation

Rationale

Dyspnea, a key symptom of acute respiratory failure, is not among the criteria for spontaneous breathing trial (SBT) failure. Here, we sought (1) to determine whether dyspnea is a reliable failure criterion for SBT failure; (2) to quantify the relationship between dyspnea and the respective electromyographic activity of the diaphragm (EMGdi), the parasternal (EMGpa) and the Alae nasi (EMGan).

Methods

Mechanically ventilated patients undergoing an SBT were included. Dyspnea intensity was measured by the Dyspnea-Visual Analogic Scale (Dyspnea-VAS) at the initiation and end of the SBT. During the 30-min SBT or until SBT failure, the EMGdi was continuously measured with a multi-electrode nasogastric catheter and the EMGan and EMGpa with surface electrodes.

Results

Thirty-one patients were included, SAPS 2 (median [interquartile range]) 53 (37‒74), mechanically ventilated for 6 (3‒10) days. Seventeen patients (45%) failed the SBT. The increase in Dyspnea-VAS along the SBT was higher in patients who failed (6 [4‒8] cm) than in those who passed (0 [0‒1] cm, p = 0.01). The area under the receiver operating characteristics curve for Dyspnea-VAS was 0.909 (0.786–1.032). The increase in Dyspnea-VAS was significantly correlated to the increase in EMGan (Rho = 0.42 [0.04‒0.70], p < 0.05), but not to the increase in EMGpa (Rho = − 0.121 [− 0.495 to − 0.290], p = 0.555) and EMGdi (Rho = − 0.26 [− 0.68 to 0.28], p = 0.289).

Conclusion

Dyspnea is a reliable criterion of SBT failure, suggesting that Dyspnea-VAS could be used as a monitoring tool of the SBT. In addition, dyspnea seems to be more closely related to the electromyographic activity of the Alae nasi than of the diaphragm.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-022-01025-5.

Factors associated with time to successful weaning in mechanically ventilated organophosphate poisoned patients

We designed this study to identify the factors associated with time to successful weaning in mechanically ventilated organophosphate (OP)-poisoned patients as the primary outcomes while duration of mechanical ventilation (MV) support, intensive care unit (ICU), and hospital length of stay (LOS) and in-hospital mortality as the secondary outcomes. We conducted a retrospective study of mechanically ventilated OP-poisoned patients admitted to the ICU of Poison Control Center of Ain Shams, Cairo, Egypt, starting from January 2019 to December 2019. Weaning was considered successful if the patient succeeded in the first spontaneous breathing trial of weaning and did not need reinstitution of MV. We used Cox proportional hazards regression models to identify factors associated with time to successful weaning in the studied patients. A total of 55 patients were enrolled in the study. Thirty-eight patients were weaned successfully. Lower initial red cell distribution width (RDW) levels [adjusted hazard ratio (HR), 0.299, 95% confidence interval (CI) (0.184-0.486)] and lower initial doses of atropine [adjusted HR, 0.97, 95% CI (0.935-0.999)] were independently associated with shorter time to achieve successful weaning. Successfully weaned patients had significantly longer hospital LOS (p = 0.019) and no reported in-hospital mortality (p < 0.001) compared with patients who failed to wean. We concluded that initial RDW and initial doses of atropine were found to be the strongest factors associated with time to successful weaning in mechanically ventilated OP-poisoned patients. RDW and atropine can be used as simple risk assessment tools in OP poisoning.

Detection and management of dyspnea in mechanically ventilated patients

PURPOSE OF REVIEW

In ICU patients, dyspnea is one of the most prominent and distressing symptom. We sought to summarize current data on the prevalence and prognostic influence of dyspnea in the ICU setting and to provide concise and useful information for dyspnea detection and management.

RECENT FINDINGS

As opposed to pain, dyspnea has been a neglected symptom with regard to detection and management. Many factors contribute to the pathogenesis of dyspnea. Among them, ventilator settings seem to play a major role. Dyspnea affects half of mechanically ventilated patient and causes immediate intense suffering [median dyspnea visual analog scale of 5 (4-7)]. In addition, it is associated with delayed extubation and with an increased risk of intubation and mortality in those receiving noninvasive ventilation. However, one-third of critically ill patients are noncommunicative, and therefore, at high risk of misdiagnosis. Heteroevaluation scales based on physical and behavioral signs of respiratory discomfort are reliable and promising alternatives to self-report.

SUMMARY

Dyspnea is frequent and severe in critically ill patients. Implementation of observational scale will help physicians to access to noncommunicative patient's respiratory suffering and tailor its treatment. Further studies on the prognostic impact and management strategies are needed.

Dyspnoea in patients receiving noninvasive ventilation for acute respiratory failure: prevalence, risk factors and prognostic impact: A prospective observational study

Dyspnoea is a frequent and intense symptom in intubated patients, but little attention has been paid to dyspnoea during noninvasive mechanical ventilation in the intensive care unit (ICU).The objectives of this study were to quantify the prevalence, intensity and prognostic impact of dyspnoea in patients receiving noninvasive ventilation (NIV) for acute respiratory failure (ARF) based on secondary analysis of a prospective observational cohort study in patients who received ventilatory support for ARF in 54 ICUs in France and Belgium. Dyspnoea was measured by a modified Borg scale.Among the 426 patients included, the median (interquartile range) dyspnoea score was 4 (3-5) on admission and 3 (2-4) after the first NIV session (p=0.001). Dyspnoea intensity ≥4 after the first NIV session was associated with the Sequential Organ Failure Assessment Score (odds ratio (OR) 1.12, p=0.001), respiratory rate (OR 1.03, p=0.032), anxiety (OR 1.92, p=0.006), leaks (OR 2.5, p=0.002) and arterial carbon dioxide tension (OR 0.98, p=0.025). Dyspnoea intensity ≥4 was independently associated with NIV failure (OR 2.41, p=0.001) and mortality (OR 2.11, p=0.009), but not with higher post-ICU burden and altered quality of life.Dyspnoea is frequent and intense in patients receiving NIV for ARF and is associated with a higher risk of NIV failure and poorer outcome.

Predictive Associations of Music, Anxiety, and Sedative Exposure on Mechanical Ventilation Weaning Trials

BACKGROUND

Weaning from mechanical ventilation requires increased respiratory effort, which can heighten anxiety and later prolong the need for mechanical ventilation.

OBJECTIVES

To examine the predictive associations of music intervention, anxiety, sedative exposure, and patients' characteristics on time to initiation and duration of weaning trials of patients receiving mechanical ventilation.

METHODS

A descriptive, correlational design was used for a secondary analysis of data from a randomized trial. Music listening was defined as self-initiated, patient-directed music via headphones. Anxiety was measured daily with a visual analog scale. Sedative exposure was operationalized as a daily sedation intensity score and a sedative dose frequency. Analyses consisted of descriptive statistics, graphing, survival analysis, Cox proportional hazards regression, and linear regression.

RESULTS

Of 307 patients, 52% were women and 86% were white. Mean age was 59.3 (SD, 14.4) years, mean Acute Physiology and Chronic Health Evaluation III score was 62.9 (SD, 21.6), mean duration of ventilatory support was 8 (range, 1-52) days, and mean stay in the intensive care unit was 18 (range, 2-71) days. Music listening, anxiety levels, and sedative exposure did not influence time to initial weaning trial or duration of trials. Clinical factors of illness severity, days of weaning trials, and tracheostomy placement influenced weaning patterns in this sample.

CONCLUSIONS

Prospective studies of music intervention and other psychophysiological factors during weaning from mechanical ventilation are needed to better understand factors that promote successful weaning.

Patients' experience during weaning of invasive mechanical ventilation: A review of the literature

OBJECTIVE

Weaning from invasive mechanical ventilation (IMV) is influenced by physiological and psychological factors, the latter being the least studied. The aim was to identify, through the literature, patients' experiences during weaning from IMV and report its influencing factors.

METHOD

The literature search was conducted using the Pubmed, CINAHL and PsycINFO databases. The search terms were: "patient", "experience" and "ventilator weaning". The research limits were: age (>19years) and language (English, Spanish and Finnish).

RESULTS

Fifteen publications were analysed. The main results were grouped into three main categories according to patient's perceptions, feelings and experiences, influence of professionals' attention and determinants for successful weaning. Patients remember IMV weaning as a stressful process where they experience anxiety, frustration, despair or uncertainty. Nurses have a key role in improving communication with patients and foreseeing their needs. Family support and the care provided by the caregivers were shown as essential during the process. The patient's self-determination, self-motivation and confidence are identified as important factors to achieve successful IMV weaning.

CONCLUSIONS

Psychological care, in addition to physical and technical care, is important at providing holistic care. Interventional studies are needed to improve the care during the weaning experience.

Levine’s Framework in Long-Term Ventilated Patients During the Weaning Course

Within the context of Levine’s conceptual framework, this study evaluated fatigue and protein calorie malnutrition affecting adult, long-term ventilated patients during the weaning process. Levine’s principles of energy and structural integrity provided the basis for an evaluation of the fatigue and prealbumin levels for 11 patients. During the weaning process (1 to 4 weeks), fatigue data were collected at multiple points while prealbumin levels were collected weekly. Statistically significant findings revealed that long-term ventilated patients had distinctive fatigue trends in addition to trends associated with low prealbumin levels, which can affect the patient’s weaning ability.

Prolonged Ventilator Dependence

The purpose of this qualitative inquiry was to examine the meaning of prolonged mechanical ventilation from the perspective of the patient with a diagnosis of chronic obstructive pulmonary disease (COPD). Interviews were conducted with four individuals with a diagnosis of COPD who had experienced long-term ventilator dependence. Participants were asked to reflect on their experiences while they were ventilator dependent, and their narratives were utilized as text for hermeneutical analysis. The study's findings describe three distinct phases experienced by the participants, beginning with intubation and lasting until well after discharge from the hospital. The support of nurses was an important aspect of maintaining hope for the participants. The study revealed that prolonged mechanical ventilation had a profound impact on COPD patients and their sense of self. Postdischarge psychological support and follow-up with survivors of this experience is warranted.

The influence of music during mechanical ventilation and weaning from mechanical ventilation: A review

Mechanical ventilation (MV) causes many distressing symptoms. Weaning, the gradual decrease in ventilator assistance leading to termination of MV, increases respiratory effort, which may exacerbate symptoms and prolong MV. Music, a non-pharmacological intervention without side effects may benefit patients during weaning from mechanical ventilatory support. A narrative review of OVID Medline, PsychINFO, and CINAHL databases was conducted to examine the evidence for the use of music intervention in MV and MV weaning. Music intervention had a positive impact on ventilated patients; 16 quantitative and 2 qualitative studies were identified. Quantitative studies included randomized clinical trials (10), case controls (3), pilot studies (2) and a feasibility study. Evidence supports music as an effective intervention that can lesson symptoms related to MV and promote effective weaning. It has potential to reduce costs and increase patient satisfaction. However, more studies are needed to establish its use during MV weaning.

Unrecognized suffering in the ICU: addressing dyspnea in mechanically ventilated patients

BACKGROUND

Intensive care unit (ICU) patients are exposed to many sources of discomfort. Although increasing attention is being given to the detection and treatment of pain, very little is given to the detection and treatment of dyspnea (defined as "breathing discomfort").

METHODS

Published information on the prevalence, mechanisms, and potential negative impacts of dyspnea in mechanically ventilated patients are reviewed. The most appropriate tools to detect and quantify dyspnea in ICU patients are also assessed.

RESULTS/CONCLUSIONS

Growing evidence suggests that dyspnea is a frequent issue in mechanically ventilated ICU patients, is highly associated with anxiety and pain, and is improved in many patients by altering the ventilator settings.

CONCLUSIONS

Future studies are needed to better delineate the impact of dyspnea in the ICU and to define diagnostic, monitoring and therapeutic protocols.

The factors which influence nurses when weaning patients from mechanical ventilation: findings from a qualitative study

The aim of the study was to describe the factors that influence critical care nurses when deciding to wean patients from mechanical ventilation. The study adopted a qualitative methodology, using semi-structured interviews and a vignette. An invited sample of critical care nurses (n=24) from one Irish intensive care unit was employed. Each nurse was interviewed once and a vignette was used to structure the interview questioning. The findings were analysed using thematic content analysis. Six major themes influencing nurses' decision to wean emerged, as follows: physiological influences; clinical reassessment and decision making; the nurse's experience, confidence and education; the patient's medical history and current ventilation; the intensive care working environment; and use of protocols. The findings highlight the complex nature of weaning patients from mechanical ventilation and the major role of the nurse in this process.

Value of the PaO₂:FiO₂ ratio and Rapid Shallow Breathing Index in predicting successful extubation in hypoxemic respiratory failure

PURPOSE

We sought to determine the predictive value of the PaO₂:FiO₂ ratio (PFR), both independently and in combination with the standard Rapid Shallow Breathing Index (RSBI), for successful extubations in patients with primary hypoxemic respiratory failure (HRF).

MATERIALS AND METHODS

A retrospective chart review of 154 patients with HRF requiring mechanical ventilation for ≥24 hours was performed. The primary outcome was reintubation within 48 hours.

RESULTS

142 (92%) patients were successfully extubated. Pre-extubation PFR and RSBI values among reintubated and successfully extubated patients were similar. The areas under the curve of the receiver operating characteristic curves using RSBI and PFR were .5 and .62, respectively. A PFR < 200 or RSBI ≥ 70 when the PFR was ≥200 indicated a higher risk of reintubation, with .7 sensitivity and .56 specificity (area under the curve, .69), using a classification and regression tree model.

CONCLUSIONS

Neither the PFR independently nor the PFR in combination with the RSBI in a classification and regression tree model accurately predicted successful extubation in patients with HRF.

Patients' prediction of extubation success

PURPOSE

The spontaneous breathing trial (SBT)-relying on objective criteria assessed by the clinician-is the major diagnostic tool to determine if patients can be successfully extubated. However, little is known regarding the patient's subjective perception of autonomous breathing.

METHODS

We performed a prospective observational study in 211 mechanically ventilated adult patients successfully completing a SBT. Patients were randomly assigned to be interviewed during this trial regarding their prediction of extubation success. We compared post-extubation outcomes in three patient groups: patients confident (confidents; n = 115) or not (non-confidents; n = 38) of their extubation success and patients not subjected to interview (control group; n = 58).

RESULTS

Extubation success was more frequent in confidents than in non-confidents (90 vs. 45%; p < 0.001/positive likelihood ratio = 2.00) or in the control group (90 vs. 78%; p = 0.04). On the contrary, extubation failure was more common in non-confidents than in confidents (55 vs. 10%; p < 0.001/negative likelihood ratio = 0.19). Logistic regression analysis showed that extubation success was associated with patient's prediction [OR (95% CI): 9.2 (3.74-22.42) for confidents vs.non-confidents] as well as to age [0.72 (0.66-0.78) for age 75 vs. 65 and 1.31 (1.28-1.51) for age 55 vs. 65].

CONCLUSIONS

Our data suggest that at the end of a sustained SBT, extubation success might be correlated to the patients' subjective perception of autonomous breathing. The results of this study should be confirmed by a large multicenter trial.

Successful mechanical ventilation weaning experiences at respiratory care centers

A phenomenological qualitative study was conducted on the experiences of patients who had been successfully weaned from mechanical ventilation, including essential elements of the patient support system during the weaning process. In-depth interviews were conducted with 20 participants who had been recruited through purposive sampling from three respiratory care centers in Taiwan. The experiences of participants who had been successfully weaned from mechanical ventilation could be categorized into five themes, which were (a) dealing with the unfamiliar context presented by the weaning program, (b) experiencing various psychological responses and self-endurance ambiguity, (c) being tortured by helplessness, (d) wondering whether to continue or give up, (e) and release from self-breathing. Findings were intended to give nurses an increased understanding of patient experiences and help in raising their competence in managing patient emotional reactions that arise during the weaning process. As patient conditions gradually improve, nurses should assess the criteria for mechanical ventilation weaning and provide preparatory information and clarify patient questions to avoid potential negative responses during the process. Participants also reported that the professionalism of nurses and concern from family members were essential sources of support for successful weaning. Nurses can apply recommendations to develop effective patient support systems that encourage family members to accompany patients at critical times during the weaning process. Therefore, the results of this study may assist healthcare personnel to develop strategies to ensure successful weaning from mechanical ventilation.