Clinical review: airway hygiene in the intensive care unit

Appropriateness of respiratory physiotherapy positioning for acute lobar collapse

BACKGROUND

Positioning is an important physiotherapy treatment modality for the management of aeration loss associated with acute lobar atelectasis (ALA). Physiotherapists typically rely on lung auscultation and interpretation of chest x-ray (CXR) to inform treatment selection. These tools lack diagnostic accuracy, which could limit the ability of a physiotherapist to locate ALA and select an appropriate treatment position.

OBJECTIVES

The objectives of this study were to determine the number of clinical physiotherapist treatment positions found to be in agreement with lung ultrasound (LUS)-identified aeration loss and to determine the diagnostic accuracy of CXR and lung auscultation against LUS as the reference standard for locating aeration loss in mechanically ventilated patients with ALA.

METHODS

A prospective cohort study was conducted in a tertiary teaching hospital in Sydney. Mechanically ventilated adult patients in critical care with ALA were included. Physiotherapist-selected positions were compared against location of aeration loss based on LUS results to determine appropriateness. Location of aeration loss as identified by CXR results and lung auscultation was compared against LUS as the reference standard to determine diagnostic accuracy.

RESULTS

Forty-three participants were included in this study. Four out of 43 patients (9.3%) were positioned appropriately. The rate of true positives for CXR and auscultation in locating aeration loss were highest in the lower lobes. Lung auscultation had higher sensitivities (16.7%-97.4%) than CXR (0%-59.5%) in a majority of lobes when detecting location of aeration loss. CXR had higher specificities (16.7%-100%) than lung auscultation (0%-64.9%) in a majority of lobes when detecting location of aeration loss.

CONCLUSIONS

Physiotherapists did not deliver appropriate positioning in a majority of cases. Overall, the diagnostic accuracy of lung auscultation and CXR in detecting location of ALA was low. Correctly locating lung aeration loss is imperative to ensure appropriate respiratory physiotherapy positions are selected. Physiotherapists should consider additional assessment tools such as LUS to increase their diagnostic ability.

Development of a Cost-Effective 3D-Printed Airway Suction Simulator for Respiratory Therapy Students

BACKGROUND

Three-dimensional (3D)-printed models are cost-effective and can be customized by trainers. This study designed a 3D-printed airway suction simulator for use by respiratory therapy (RT) students. The objective was to demonstrate the cost-effectiveness and application of 3D-printed models in respiratory care training, aiming to enhance the educational experience for RT students.

METHODS

This study developed a 3D-printed airway suction simulator that was cost-effective. A randomized controlled trial was conducted involving RT students to compare effectiveness in a 3D-model group and a control group. Skill assessments and written examinations were used to evaluate the participants' knowledge and skills.

RESULTS

A total of 38 second-year RT students were randomly assigned to either the 3D-model group (n = 19) or the control group (n = 19). One participant in the 3D-model group was lost to follow-up during the planned direct observation of procedural skills (DOPS) assessment and satisfaction questionnaire completion. The posttest written examination scores were significantly higher in the 3D-model group than in the control group (100% vs 80%, P = .02). The scores from the DOPS and satisfaction questionnaire were comparable in the 2 groups.

CONCLUSIONS

This study demonstrated that 3D printing can be used to create a safe and cost-effective airway suction simulator for use by RT students, with potential to enhance training methods. Further research is necessary.

Is atelectasis related to the development of postoperative pneumonia? a retrospective single center study

BACKGROUND

Atelectasis may play a substantial role in the development of pneumonia. However, pneumonia has never been evaluated as an outcome of atelectasis in surgical patients. We aimed to determine whether atelectasis is related to an increased risk of postoperative pneumonia, intensive care unit (ICU) admission and hospital length of stay (LOS).

METHODS

The electronic medical records of adult patients who underwent elective non-cardiothoracic surgery under general anesthesia between October 2019 and August 2020 were reviewed. They were divided into two groups: one who developed postoperative atelectasis (atelectasis group) and the other who did not (non-atelectasis group). The primary outcome was the incidence of pneumonia within 30 days after the surgery. The secondary outcomes were ICU admission rate and postoperative LOS.

RESULTS

Patients in the atelectasis group were more likely to have risk factors for postoperative pneumonia including age, body mass index, a history of hypertension or diabetes mellitus and duration of surgery, compared with those in the non-atelectasis. Among 1,941 patients, 63 (3.2%) developed postoperative pneumonia; 5.1% in the atelectasis group and 2.8% in the non-atelectasis (P = 0.025). In multivariable analysis, atelectasis was associated with an increased risk of pneumonia (adjusted odds ratio, 2.33; 95% CI: 1.24 - 4.38; P = 0.008). Median postoperative LOS was significantly longer in the atelectasis group (7 [interquartile range: 5-10 days]) than in the non-atelectasis (6 [3-8] days) (P < 0.001). Adjusted median duration was also 2.19 days longer in the atelectasis group (β, 2.19; 95% CI: 0.821 - 2.834; P < 0.001). ICU admission rate was higher in the atelectasis group (12.1% vs. 6.5%; P < 0.001), but it did not differ between the groups after adjustment for confounders (adjusted odds ratio, 1.52; 95% CI: 0.88 - 2.62; P = 0.134).

CONCLUSION

Among patients undergoing elective non-cardiothoracic surgery, patients with postoperative atelectasis were associated with a 2.33-fold higher incidence of pneumonia and a longer LOS than those without atelectasis. This finding alerts the need for careful management of perioperative atelectasis to prevent or reduce the adverse events including pneumonia and the burden of hospitalizations.

TRIAL REGISTRATION

None.

New horizons in understanding oral health and swallowing function within the context of frailty

Frailty is a complex and multidimensional condition wherein declines in physiologic reserve and function place individuals in a state of heightened vulnerability and decreased resiliency. There has been growing interest in both research and clinical settings to understand how to best define, assess and characterise frailty in older adults. To this end, various models and clinical assessment tools have been used to define and measure frailty. While differences exist among these models and tools, a common unifying theme is a focus on physical function and activity. Notably absent across many available conceptual models and clinical tools are items directly related to oral and swallowing function. This is an important oversight as widespread changes to both oral and swallowing function are evident in older adults. Indeed, emerging evidence suggests many of the functional domains affected in frail older adults, such as nutrition and sarcopenia, have cyclical relationships with impairments in oral (oral hypofunction) and swallowing function (dysphagia) as well. The increasing appreciation for the interrelationships among oral hypofunction, dysphagia and frailty provides an opportunity for refinement of frailty assessment and characterisation in older adults to incorporate metrics specific to oral and swallowing function.

Benefits of secretion clearance with high frequency percussive ventilation in tracheostomized critically ill patients: a pilot study

Clearance of secretions remains a challenge in ventilated patients. Despite high-frequency percussive ventilation (HFPV) showing benefits in patients with cystic fibrosis and neuromuscular disorders, very little is known about its effects on other patient categories. Therefore, we designed a physiological pilot study investigating the effects on lung aeration and gas exchange of short HFPV cycles in tracheostomized patients undergoing mechanical ventilation. Electrical impedance tomography (EIT) was recorded at baseline (T0) by a belt wrapped around the patient's chest, followed by the HFPV cycle lasting 10 min. EIT data was collected again after the HFPV cycle (T1) as well as after 1 h (T2) and 3 h (T3) from T0. Variation from baseline of end-expiratory lung impedance (∆EELI), tidal variation (TIV) and global inhomogeneity index (GI) were computed. Arterial blood was also taken for gas analysis. HFPV cycle significantly improved the ∆EELI at T1, T2 and T3 when compared to baseline (p < 0.05 for all comparisons). The ratio between arterial partial pressure and inspired fraction of oxygen (PaO₂/FiO₂) also increased after the treatment (p < 0.001 for all comparison) whereas TIV (p = 0.132) and GI (p = 0.114) remained unchanged. Short cycles of HFPV superimposed to mechanical ventilation promoted alveolar recruitment, as suggested by improved ∆EELI, and improved oxygenation in tracheostomized patients with high load of secretion.Trial Registration Prospectively registered on www.clinicaltrials.gov (NCT05200507; dated 6th January 2022).

Quantification of changes in lung aeration associated with physiotherapy using lung ultrasound in mechanically ventilated patients: a prospective cohort study

BACKGROUND

Lung ultrasound (LUS) is a novel and emerging tool for physiotherapists in ICU and may provide a way of monitoring lung aeration change in response to respiratory physiotherapy treatment during a patient's ICU stay.

OBJECTIVE

To measure change in the LUS score associated with a respiratory physiotherapy treatment; to determine whether change in LUS score correlates with other physiological measures.

DESIGN AND SETTING

A single-centre prospective cohort study was undertaken in a tertiary teaching hospital in Sydney, Australia.

PATIENTS

Adult mechanically ventilated patients in ICU with suspicion of atelectasis.

MEASUREMENTS

Primary outcome: pre-post difference in LUS score.

SECONDARY OUTCOMES

PaO₂/FiO₂ (PF) ratio, tidal volume (V_T), lung auscultation score, driving pressure (DP) and the modified radiological atelectasis score (mRAS) on CXR.

RESULTS

43 patients were included. There was a mean improvement in total LUS score after physiotherapy treatment of - 2.9 (95%CI -4.4, -1.4), and a mean improvement in LUS of the right and left lungs of - 1.6 (-2.5, -0.7) and - 1.3 (-2.5, -0.1) respectively. There was a mean improvement in PF ratio, V_T and auscultation score of 10.4 (-11.89, 32.7), 19 (-7.4, 44.5) and - 1.8 (-2.6, -1.0) respectively. There was no improvement in mRAS or DP. There was a weak correlation between change in LUS score compared with change in mRAS score.

LIMITATIONS

Limitations included the prospective cohort single site design and the small sample size.

CONCLUSIONS

The LUS score can be used to detect changes in lung aeration associated with respiratory physiotherapy treatment for acute lobar atelectasis in mechanically ventilated patients. Australian and New Zealand Clinical Trials Registry Number: ACTRN12619000783123. CONTRIBUTION OF THE PAPER.

Bronchoscopy in Patients With Known or Suspected COVID-19: Results From the Global Pandemic SARS-CoV-2 Bronchoscopy Database (GPS-BD)

BACKGROUND

Amid the Coronavirus Disease 2019 (COVID-19) pandemic, the benefits and risks of bronchoscopy remain uncertain. This study was designed to characterize bronchoscopy-related practice patterns, diagnostic yields, and adverse events involving patients with known or suspected COVID-19.

METHODS

An online survey tool retrospectively queried bronchoscopists about their experiences with patients with known or suspected COVID-19 between March 20 and August 20, 2020. Collected data comprised the Global Pandemic SARS-CoV-2 Bronchoscopy Database (GPS-BD). All bronchoscopists and patients were anonymous with no direct investigator-to-respondent contact.

RESULTS

Bronchoscopy procedures involving 289 patients from 26 countries were analyzed. One-half of patients had known COVID-19. Most (82%) had at least 1 pre-existing comorbidity, 80% had at least 1 organ failure, 51% were critically ill, and 37% were intubated at the time of the procedure. Bronchoscopy was performed with diagnostic intent in 166 (57%) patients, yielding a diagnosis in 86 (52%). and management changes in 80 (48%). Bronchoscopy was performed with therapeutic intent in 71 (25%) patients, mostly for secretion clearance (87%). Complications attributed to bronchoscopy or significant clinical decline within 12 hours of the procedure occurred in 24 (8%) cases, with 1 death.

CONCLUSION

Results from this international database provide a widely generalizable characterization of the benefits and risks of bronchoscopy in patients with known or suspected COVID-19. Bronchoscopy in this setting has reasonable clinical benefit, with diagnosis and/or management change resulting from about half of the diagnostic cases. However, it is not without risk, especially in patients with limited physiological reserve.

Perioperative Pulmonary Atelectasis: Part II. Clinical Implications

The development of pulmonary atelectasis is common in the surgical patient. Pulmonary atelectasis can cause various degrees of gas exchange and respiratory mechanics impairment during and after surgery. In its most serious presentations, lung collapse could contribute to postoperative respiratory insufficiency, pneumonia, and worse overall clinical outcomes. A specific risk assessment is critical to allow clinicians to optimally choose the anesthetic technique, prepare appropriate monitoring, adapt the perioperative plan, and ensure the patient's safety. Bedside diagnosis and management have benefited from recent imaging advancements such as lung ultrasound and electrical impedance tomography, and monitoring such as esophageal manometry. Therapeutic management includes a broad range of interventions aimed at promoting lung recruitment. During general anesthesia, these strategies have consistently demonstrated their effectiveness in improving intraoperative oxygenation and respiratory compliance. Yet these same intraoperative strategies may fail to affect additional postoperative pulmonary outcomes. Specific attention to the postoperative period may be key for such outcome impact of lung expansion. Interventions such as noninvasive positive pressure ventilatory support may be beneficial in specific patients at high risk for pulmonary atelectasis (e.g., obese) or those with clinical presentations consistent with lung collapse (e.g., postoperative hypoxemia after abdominal and cardiothoracic surgeries). Preoperative interventions may open new opportunities to minimize perioperative lung collapse and prevent pulmonary complications. Knowledge of pathophysiologic mechanisms of atelectasis and their consequences in the healthy and diseased lung should provide the basis for current practice and help to stratify and match the intensity of selected interventions to clinical conditions.

Shock due to an Obstructed Endotracheal Tube

Endotracheal tube obstruction by a mucus plug causing a ball-valve effect is a rare but significant complication. The inability to pass a suction catheter through the endotracheal tube with high peak and plateau pressure differences are classical features of an endotracheal tube obstruction. A case is described of endotracheal tube obstruction from a mucus plug that compounded severe respiratory acidosis and hypotension in a patient who simultaneously had abdominal compartment syndrome. The mucus plug was not identified until a bronchoscopic assessment of the airway was performed. Due to the absence of classical signs, the delayed identification of the obstructing mucus plug exacerbated diagnostic confusion. It resulted in various treatments being trialed whilst the patient continued to deteriorate from the evasive offending culprit. We suggest that earlier and more routine use of bronchoscopy should be employed in an intensive care unit, especially as a definitive way to rule out endotracheal obstruction.

Peak Expiratory Flow During Mechanical Insufflation-Exsufflation: Endotracheal Tube Versus Face Mask

BACKGROUND

Mechanical insufflation-exsufflation (MI-E) applied through the endotracheal tube (ETT) can effectively eliminate airway secretions in intubated patients. However, the effect of the interface (ETT vs face mask) on expiratory air flow generated by MI-E has not been investigated. This study aimed to investigate the effect of the ETT on peak expiratory flow (PEF) along with other associated factors that could influence PEF generated by MI-E.

METHODS

Intubated participants received 2 sessions of MI-E via ETT therapy per d for 2 consecutive days. One MI-E session consisted of 5 sets of either constant (+40/-40 cm H₂O) or incremental (+30/-30 to +50/-50 cm H₂O) pressure applications. Following extubation, MI-E sessions were repeated using face mask. Expiratory air flow during MI-E therapy was continuously measured, and every PEF during each application was analyzed using linear mixed-effect and generalized linear mixed models.

RESULTS

A total of 12 participants (9 [75.0%] men; mean [SD] age, 74.0 [10.2] y) completed all MI-E sessions with both ETT and face mask interfaces. The PEF generated during MI-E treatment was influenced by the interface (ETT vs face mask), pressure gradient, and number of session repetitions. Adjusted mean PEF values for MI-E via ETT and face mask at +40/-40 cm H₂O were -2.521 and -3.114 L/s, respectively, and -2.956 and -3.364 L/s at +50/-50 cm H₂O, respectively. At a pressure gradient of +40/-40 cm H₂O, only 172 of 528 MI-E trials via ETT (32.6%) achieved a PEF faster than -2.7 L/s, whereas 304 of 343 MI-E trials via face mask (88.6%) exceeded PEF < -2.7 L/s.

CONCLUSIONS

MI-E via ETT generated slower PEF than via face mask, suggesting that a higher-pressure protocol should be prescribed for intubated patients. An insufflation-exsufflation pressure up to +50/-50 cm H₂O could be considered to produce a PEF faster than 2.7 L/s, and the applications were safe and feasible for subjects on invasive mechanical ventilation.

Effect of intrapulmonary percussive ventilation on intensive care unit length of stay, the incidence of pneumonia and gas exchange in critically ill patients: A systematic review

Background

Pulmonary complications such as pneumonia, pulmonary atelectasis, and subsequent respiratory failure leading to ventilatory support are a common occurrence in critically ill patients. Intrapulmonary percussive ventilation (IPV) is used to improve gas exchange and promote airway clearance in these patients. The current evidence regarding the effectiveness of intrapulmonary percussive ventilation in critical care settings remains unclear. This systematic review aims to summarise the evidence of the effectiveness of intrapulmonary percussive ventilation on intensive care unit length of stay (ICU-LOS) and respiratory outcomes in critically ill patients.

Research question

In critically ill patients, is intrapulmonary percussive ventilation effective in improving respiratory outcomes and reducing intensive care unit length of stay.

Methods

A systematic search of intrapulmonary percussive ventilation in intensive care unit (ICU) was performed on five databases from 1979 to 2021. Studies were considered for inclusion if they evaluated the effectiveness of IPV in patients aged ≥16 years receiving invasive or non-invasive ventilation or breathing spontaneously in critical care or high dependency units. Study titles and abstracts were screened, followed by data extraction by a full-text review. Due to a small number of studies and observed heterogeneities in the study methodology and patient population, a meta-analysis could not be included in this review. Outcomes of interest were summarised narratively.

Results

Out of 306 identified abstracts, seven studies (630 patients) met the eligibility criteria. Results of the included studies provide weak evidence to support the effectiveness of intrapulmonary percussive ventilation in reducing ICU-LOS, improving gas exchange, and reducing respiratory rate.

Interpretation

Based on the findings of this review, the evidence to support the role of IPV in reducing ICU-LOS, improving gas exchange, and reducing respiratory rate is weak. The therapeutic value of IPV in airway clearance, preventing pneumonia, and treating pulmonary atelectasis requires further investigation.

Investigating the effect of materials and structures for negative pressure ventilators suitable for pandemic situation

The onset of the corona virus disease 2019 (COVID-19) pandemic caused shortages in mechanical ventilators (MVs) essential for the intensive care unit (ICU) in the hospitals. The increasing crisis prompted the investigation of ventilators which is low cost and offers lower health complications. Many researchers are revisiting the use of negative pressure ventilators (NPVs), due to the cost and complications of positive pressure ventilators (PPVs). This paper summarizes the evolution of the MVs, highlighting the limitations of popular positive and negative pressure ventilators and how NPV can be a cost-effective and lower health complication solution. This paper also provides a detailed investigation of the structure and material for the patient enclosure that can be used for a cost-effective NPV system using ANSYS simulations. The simulation results can confirm the selection and also help in developing a low cost while based on readily available materials. This can help the manufacturer to develop low-cost NPV and reduce the pressure on the healthcare system for any pandemic situation similar to COVID-19.

N-acetylcysteine and coronavirus disease 2019: May it work as a beneficial preventive and adjuvant therapy? A comprehensive review study

BACKGROUND

Coronaviruses are major pathogens of respiratory system causing different disorders, including the common cold, Middle East respiratory syndrome, and severe acute respiratory syndrome. Today's global pandemic coronavirus disease 2019 (COVID-19) has high mortality rate, with an approximate of 20% in some studies, and is 30-60 times more fatal than the common annual influenza, However, there is still no gold standard treatment for it. N-acetylcysteine (NAC) is a well-known multi-potential drug with hypothetically probable acceptable effect on COVID-related consequences, which we completely focused in this comprehensive review.

MATERIALS AND METHODS

PubMed, Scopus, Science Direct, and Google Scholar have been searched. Study eligibility criteria: efficacy of NAC in various subclasses of pathogenic events which may occur during COVID-19 infection. Efficacy of NAC for managing inflammatory or any symptoms similar to symptoms of COVID-19 was reviewed and symptom improvements were assessed.

RESULTS

Randomized clinical trials introduced NAC as an antioxidant glutathione analog and detoxifying agent promoted for different medical conditions and pulmonary disorders to alleviate influenza and reduce mortality by 50% in influenza-infected animals. The beneficial effects of NAC on viral disorders, including Epstein-Barr virus, HIV and hepatitis, and well-known vital organ damages were also exist and reported.

CONCLUSION

We classified the probable effects of NAC as oxidative-regulatory and apoptotic-regulatory roles, antiviral activities, anti-inflammatory roles, preventive and therapeutic roles in lung disorders and better oxygenation functions, supportive roles in intensive care unit admitted patients and in sepsis, positive role in other comorbidities and nonpulmonary end-organ damages or failures and even in primary COVID-associated cutaneous manifestations. Based on different beneficial effects of NAC, it could be administered as a potential adjuvant therapy for COVID-19 considering patient status, contraindications, and possible drug-related adverse events.

Airway Hygiene in COVID-19 Pneumonia: Treatment Responses of 3 Critically Ill Cruise Ship Employees

BACKGROUND COVID-19, the disease entity caused by the novel severe acute respiratory coronavirus 2 (SARS-CoV-2), continues to pose a major therapeutic challenge for clinicians. At present, an effective treatment regimen and vaccination has not been established. Many patients develop severe symptoms requiring endotracheal intubation and a prolonged stay in the Intensive Care Unit (ICU). In early postmortem examinations of COVID-19 patients, profuse viscous secretions were observed throughout the respiratory tract. Thus, oxygen supplementation without aggressive pulmonary hygiene management may be suboptimal. In the present case series, pulmonary hygiene management encompassed mucolytics, bronchodilators, and tracheal suctioning. We report 3 severe cases of COVID-19 pneumonia in cruise ship employees who were admitted to the ICU and responded to supportive mechanical ventilation and pulmonary hygiene management. CASE REPORT Three cruise ship employees with COVID-19 underwent endotracheal intubation and were admitted to the ICU for acute hypoxemic respiratory failure. Initial chest X-rays suggested multifocal pneumonia with superimposed acute respiratory distress syndrome (ARDS). A regimen of hydroxychloroquine, azithromycin, and dexamethasone was initiated on admission in all cases. Additionally, medications used for pulmonary hygiene were administered through a metered-dose inhaler (MDI) in line with the ventilator circuit. Endotracheal suctioning was performed prior to medication administration. The duration from endotracheal intubation to extubation ranged from 9 to 24 days. All 3 patients reached 30-day survival. CONCLUSIONS The cases reported highlight the importance of the use of airway hygiene with mucolytics, bronchodilators, and tracheal suctioning for patients with COVID-19 pneumonia requiring ventilatory support.

Chest physiotherapy improves lung aeration in hypersecretive critically ill patients: a pilot randomized physiological study

Background

Besides airway suctioning, patients undergoing invasive mechanical ventilation (iMV) benefit of different combinations of chest physiotherapy techniques, to improve mucus removal. To date, little is known about the clearance effects of oscillating devices on patients with acute respiratory failure undergoing iMV. This study aimed to assess (1) the effects of high-frequency chest wall oscillation (HFCWO) on lung aeration and ventilation distribution, as assessed by electrical impedance tomography (EIT), and (2) the effect of the association of HFCWO with recruitment manoeuvres (RM).

Methods

Sixty critically ill patients, 30 classified as normosecretive and 30 as hypersecretive, who received ≥ 48 h of iMV, underwent HFCWO; patients from both subgroups were randomized to receive RM or not, according to two separated randomization sequences. We therefore obtained four arms of 15 patients each. After baseline record (T0), HFCWO was applied for 10 min. At the end of the treatment (T1) or after 1 (T2) and 3 h (T3), EIT data were recorded. At the beginning of each step, closed tracheobronchial suctioning was performed. In the RM subgroup, tracheobronchial suctioning was followed by application of 30 cmH₂O to the patient’s airway for 30 s. At each step, we assessed the change in end-expiratory lung impedance (ΔEELI) and in tidal impedance variation (ΔTIV), and the center of gravity (COG) through EIT. We also analysed arterial blood gases (ABGs).

Results

ΔTIV and COG did not differ between normosecretive and hypersecretive patients. Compared to T0, ΔEELI significantly increased in hypersecretive patients at T2 and T3, irrespective of the RM; on the contrary, no differences were observed in normosecretive patients. No differences of ABGs were recorded.

Conclusions

In hypersecretive patients, HFCWO significantly improved aeration of the dorsal lung region, without affecting ABGs. The application of RM did not provide any further improvements.

Trial registration

Prospectively registered at the Australian New Zealand Clinical Trial Registry (www.anzctr.org.au; number of registration: ACTRN12615001257550; date of registration: 17th November 2015).

Closed-suction System for Intubated COVID-19 Patients with the Use of an Ultrasound Probe Cover

Supplemental Digital Content is available in the text.

Part I. SARS-CoV-2 triggered 'PANIC' attack in severe COVID-19

The coronavirus disease 2019 (COVID-19) pandemic has produced a world-wide collapse of social and economic infrastructure, as well as constrained our freedom of movement. This respiratory tract infection is nefarious in how it targets the most distal and highly vulnerable aspect of the human bronchopulmonary tree, specifically, the delicate yet irreplaceable alveoli that are responsible for the loading of oxygen upon red cell hemoglobin for use by all of the body's tissues.

In most symptomatic individuals, the disease is a mild immune-mediated syndrome, with limited damage to the lung tissues. About 20% of those affected experience a disease course characterized by a cataclysmic set of immune activation responses that can culminate in the diffuse and irreversible obliteration of the distal alveoli, leading to a virtual collapse of the gas-exchange apparatus.

Here, in Part I of a duology on the characterization and potential treatment for COVID-19, we define severe COVID-19 as a consequence of the ability of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to trigger what we now designate for the first time as a ‘Prolific Activation of a Network-Immune-Inflammatory Crisis’, or ‘PANIC’ Attack, in the alveolar tree. In Part II we describe an immunotherapeutic hypothesis worthy of the organization of a randomized clinical trial in order to ascertain whether a repurposed, generic, inexpensive, and widely available agent is capable of abolishing ‘PANIC’; thereby preventing or mitigating severe COVID-19, with monumental ramifications for world health, and the global pandemic that continues to threaten it.

Mucoactive agent use in adult UK Critical Care Units: a survey of health care professionals' perception, pharmacists' description of practice, and point prevalence of mucoactive use in invasively mechanically ventilated patients

Background

Mechanical ventilation for acute respiratory failure is one of the most common indications for admission to intensive care units (ICUs). Airway mucus clearance is impaired in these patients medication, impaired mucociliary motility, increased mucus production etc. and mucoactive agents have the potential to improve outcomes. However, studies to date have provided inconclusive results. Despite this uncertainty, mucoactives are used in adult ICUs, although the extent of use and perceptions about place in therapy are not known.

Aims and Objectives

We aim to describe the use of mucoactive agents in mechanically ventilated patients in UK adult critical care units. Specifically, our objectives are to describe clinicians perceptions about the use of mucoactive agents, understand the indications and anticipated benefits, and describe the prevalence and type of mucoactive agents in use.

Methods

We conducted three surveys. Firstly, a practitioner-level survey aimed at nurses, physiotherapists and doctors to elucidate individual practitioners perceptions about the use of mucoactive agents. Secondly, a critical care unit-level survey aimed at pharmacists to understand how these perceptions translate into practice. Thirdly, a point prevalence survey to describe the extent of prescribing and range of products in use. The practitioner-level survey was disseminated through the UK Intensive Care Society for completion by a multi-professional membership. The unit-level and point prevalence surveys were disseminated cthrough the UK Clinical Pharmacy Association for completion by pharmacists.

Results

The individual practitioners survey ranked ‘thick secretions’ as the main reason for commencing mucoactive agents determined using clinical assessment. The highest ranked perceived benefit for patient centred outcomes was the duration of ventilation. Of these respondents, 79% stated that further research was important and 87% expressed support for a clinical trial. The unit-level survey found that mucoactive agents were used in 83% of units. The most highly ranked indication was again ‘thick secretions’ and the most highly ranked expected patient centred clinical benefit being improved gas exchange and reduced ventilation time. Only five critical care units provided guidelines to direct the use of mucoactive agents (4%). In the point prevalence survey, 411/993 (41%) of mechanically ventilated patients received at least one mucoactive agent. The most commonly administered mucoactives were inhaled sodium chloride 0.9% (235/993, 24%), systemic carbocisteine (161/993, 16%) and inhaled hypertonic sodium cloride (127/993, 13%).

Conclusions

Mucoactive agents are used extensively in mechanically ventilated adult patients in UK ICUs to manage ‘thick secretions’, with a key aim to reduce the duration of ventilation. There is widespread support for clinical trials to determine the optimal use of mucoactive agent therapy in this patient population.

Effects of ventilation mode and manual chest compression on flow bias during the positive end- and zero end-expiratory pressure manoeuvre in mechanically ventilated patients: a randomised crossover trial

OBJECTIVES

To investigate the effects of ventilation mode and manual chest compression (MCC) application on the flow bias generated during positive end-expiratory pressure-zero end-expiratory pressure (PEEP-ZEEP) in mechanically ventilated patients. PEEP-ZEEP is an airway clearance manoeuvre with the potential to exceed the flow bias required to remove secretions. However, the ventilation mode applied during the manoeuvre has not been standardised.

DESIGN

Randomised crossover trial.

PARTICIPANTS

Nineteen mechanically ventilated patients.

INTERVENTIONS

Patients were randomised to receive PEEP-ZEEP in volume-controlled and pressure-controlled modes, and with or without MCC.

MAIN OUTCOME MEASURES

The difference in flow bias - assessed by the peak expiratory flow (PEF) and peak inspiratory flow (PIF) ratio and difference - between PEEP-ZEEP applied in both ventilation modes, and with and without MCC.

RESULTS

The expiratory flow bias was significantly higher in the volume-controlled mode than the pressure-controlled mode. This result was caused by a lower PIF in the volume-controlled mode. PEEP-ZEEP applied in the pressure-controlled mode did not achieve the PEF-PIF difference threshold to clear mucus. Moreover, in the majority of cycles of PEEP-ZEEP applied in the pressure-controlled mode, an inspiratory flow bias was generated, which might embed mucus. PEF was 8l/minute higher with MCC compared with without MCC, which increased the PEF-PIF difference by the same amount. No haemodynamic or respiratory adverse effects were found.

CONCLUSIONS

If applied in the volume-controlled mode, PEEP-ZEEP can achieve the flow bias needed to expel pulmonary secretions. However, this is not the case in the pressure-controlled mode. MCC can augment the flow bias generated by PEEP-ZEEP, but its application may be dispensable.

CLINICAL TRIAL REGISTRATION

http://www.ensaiosclinicos.gov.br/rg/RBR-223xv8/.

Therapeutic bronchoscopy vs. standard of care in acute respiratory failure: a systematic review

BACKGROUND

We aimed to assess patient-important benefits and harms of therapeutic bronchoscopy vs. standard of care (no bronchoscopy) in critically ill patients with acute respiratory failure (ARF).

METHODS

We conducted a systematic review with meta-analysis and trial sequential analysis (TSA) according to the Cochrane Handbook and GRADE methodology, including a predefined protocol (PROSPERO no. CRD42016046235). We included randomized clinical trials (RCTs) comparing therapeutic bronchoscopy to standard of care in critically ill patients with ARF. Two reviewers independently assessed trials for inclusion, extracted data and assessed risk of bias. Risk ratios (RR) with 95% confidence intervals (CI) were estimated by conventional meta-analysis. The risk of random errors was assessed by TSA. Exclusively patient-important outcomes were evaluated.

RESULTS

We included five trials (n = 212); all were judged as having high risk of bias. There was no difference in all-cause mortality between therapeutic bronchoscopy and standard of care (TSA adjusted RR 0.39; 95% CI 0.14 to 1.07; I² 0%), and only 3% of the required information size had been accrued. There was no difference in ICU length of stay. A shorter duration of mechanical ventilation was suggested by conventional meta-analysis, however TSA highlighted that only 42% of the required information size had been accrued, indicating high risk of random errors. No trials reported data on adverse events, hospital length of stay, quality of life or performance status.

CONCLUSIONS

The quantity and quality of evidence supporting therapeutic bronchoscopy in critically ill patients with ARF is very low with no firm evidence for benefit or harm.

The role of mucoactive agents in the mechanically ventilated patient: a review of the literature

INTRODUCTION

The management of airway secretions in the mechanically ventilated patient is a routine task throughout all intensive care units. The current treatment strategies are primarily based on anecdotal experiences rather than statistical evidence. Areas covered: This review article evaluates the data from published trials surrounding mucoactive agents and their use in the critically ill patient population. We completed an extensive search through PUBMED and CINAHL via EBSCO, along with the Cochran library to find all trials using mucoactive agents in the critically ill patient population. Expert commentary: Overall, the role of mucoactive agents in the intensive care unit is a field within pulmonary critical care that is in need of evidence-based recommendations. We feel that there is great opportunity for investigators to evaluate different mucoactive therapies in this patient population and to determine their effect on clinical outcomes.

Fundamentals of aerosol therapy in critical care

Drug dosing in critically ill patients is challenging due to the altered drug pharmacokinetics–pharmacodynamics associated with systemic therapies. For many drug therapies, there is potential to use the respiratory system as an alternative route for drug delivery. Aerosol drug delivery can provide many advantages over conventional therapy. Given that respiratory diseases are the commonest causes of critical illness, use of aerosol therapy to provide high local drug concentrations with minimal systemic side effects makes this route an attractive option. To date, limited evidence has restricted its wider application. The efficacy of aerosol drug therapy depends on drug-related factors (particle size, molecular weight), device factors, patient-related factors (airway anatomy, inhalation patterns) and mechanical ventilation-related factors (humidification, airway). This review identifies the relevant factors which require attention for optimization of aerosol drug delivery that can achieve better drug concentrations at the target sites and potentially improve clinical outcomes.

Brazilian recommendations of mechanical ventilation 2013. Part 2

Perspectives on invasive and noninvasive ventilatory support for critically ill patients are evolving, as much evidence indicates that ventilation may have positive effects on patient survival and the quality of the care provided in intensive care units in Brazil. For those reasons, the Brazilian Association of Intensive Care Medicine (Associação de Medicina Intensiva Brasileira - AMIB) and the Brazilian Thoracic Society (Sociedade Brasileira de Pneumologia e Tisiologia - SBPT), represented by the Mechanical Ventilation Committee and the Commission of Intensive Therapy, respectively, decided to review the literature and draft recommendations for mechanical ventilation with the goal of creating a document for bedside guidance as to the best practices on mechanical ventilation available to their members. The document was based on the available evidence regarding 29 subtopics selected as the most relevant for the subject of interest. The project was developed in several stages, during which the selected topics were distributed among experts recommended by both societies with recent publications on the subject of interest and/or significant teaching and research activity in the field of mechanical ventilation in Brazil. The experts were divided into pairs that were charged with performing a thorough review of the international literature on each topic. All the experts met at the Forum on Mechanical Ventilation, which was held at the headquarters of AMIB in São Paulo on August 3 and 4, 2013, to collaboratively draft the final text corresponding to each sub-topic, which was presented to, appraised, discussed and approved in a plenary session that included all 58 participants and aimed to create the final document.

Lung hyperinflation by mechanical ventilation versus isolated tracheal aspiration in the bronchial hygiene of patients undergoing mechanical ventilation

OBJECTIVE

To determine the efficacy of lung hyperinflation maneuvers via a mechanical ventilator compared to isolated tracheal aspiration for removing secretions, normalizing hemodynamics and improving lung mechanics in patients on mechanical ventilation.

METHODS

This was a randomized crossover clinical trial including patients admitted to the intensive care unit and on mechanical ventilation for more than 48 hours. Patients were randomized to receive either isolated tracheal aspiration (Control Group) or lung hyperinflation by mechanical ventilator (MVH Group). Hemodynamic and mechanical respiratory parameters were measured along with the amount of aspirated secretions.

RESULTS

A total of 50 patients were included. The mean age of the patients was 44.7 ± 21.6 years, and 31 were male. Compared to the Control Group, the MVH Group showed greater aspirated secretion amount (3.9g versus 6.4g, p = 0.0001), variation in mean dynamic compliance (-1.3 ± 2.3 versus -2.9 ± 2.3; p = 0.008), and expired tidal volume (-0.7 ± 0.0 versus -54.1 ± 38.8, p = 0.0001) as well as a significant decrease in peak inspiratory pressure (0.2 ± 0.1 versus 2.5 ± 0.1; p = 0.001).

CONCLUSION

In the studied sample, the MVH technique led to a greater amount of aspirated secretions, significant increases in dynamic compliance and expired tidal volume and a significant reduction in peak inspiratory pressure.

Open and Closed Endotracheal Suctioning and Arterial Blood Gas Values: A Single-Blind Crossover Randomized Clinical Trial

Aim. This study was aimed at comparing the effects of the open and closed suctioning techniques on the arterial blood gas values in patients undergoing open-heart surgery. Methods. In a clinical trial, we recruited 42 patients after open-heart surgery in an educational hospital. Each patient randomly underwent both open and closed suctioning. ABGs, PaO2, SaO2, PaCO2, were analyzed before and one, five, and fifteen minutes after each suctioning episode. Results. At first the pressure of oxygen in arterial blood increased; however, this increase in the open technique was greater than that of the closed system (P < 0.001). The pressure of oxygen decreased five and fifteen minutes after both suctioning techniques (P < 0.05). The trends of carbon dioxide variations after the open and closed techniques were upward and downward, respectively. Moreover, the decrease in the level of oxygen saturation five and fifteen minutes after the open suctioning was greater than that of the closed suctioning technique (P < 0.05).  Conclusion. Arterial blood gas disturbances in the closed suctioning technique were less than those of the open technique. Therefore, to eliminate the unwanted effects of endotracheal suctioning on the arterial blood gases, the closed suctioning technique is recommended.

Preventive nebulization of mucolytic agents and bronchodilating drugs in invasively ventilated intensive care unit patients (NEBULAE): study protocol for a randomized controlled trial

Background

Preventive nebulization of mucolytic agents and bronchodilating drugs is a strategy aimed at the prevention of sputum plugging, and therefore atelectasis and pneumonia, in intubated and ventilated intensive care unit (ICU) patients. The present trial aims to compare a strategy using the preventive nebulization of acetylcysteine and salbutamol with nebulization on indication in intubated and ventilated ICU patients.

Methods/Design

The preventive nebulization of mucolytic agents and bronchodilating drugs in invasively ventilated intensive care unit patients (NEBULAE) trial is a national multicenter open-label, two-armed, randomized controlled non-inferiority trial in the Netherlands. Nine hundred and fifty intubated and ventilated ICU patients with an anticipated duration of invasive ventilation of more than 24 hours will be randomly assigned to receive either a strategy consisting of preventive nebulization of acetylcysteine and salbutamol or a strategy consisting of nebulization of acetylcysteine and/or salbutamol on indication. The primary endpoint is the number of ventilator-free days and surviving on day 28. Secondary endpoints include ICU and hospital length of stay, ICU and hospital mortality, the occurrence of predefined pulmonary complications (acute respiratory distress syndrome, pneumonia, large atelectasis and pneumothorax), and the occurrence of predefined side effects of the intervention. Related healthcare costs will be estimated in a cost-benefit and budget-impact analysis.

Discussion

The NEBULAE trial is the first randomized controlled trial powered to investigate whether preventive nebulization of acetylcysteine and salbutamol shortens the duration of ventilation in critically ill patients.

Trial registration

NCT02159196, registered on 6 June 2014.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-015-0865-0) contains supplementary material, which is available to authorized users.

Evaluation of the Effect of Nebulized N-Acetylcysteine on Respiratory Secretions in Mechanically Ventilated Patients: Randomized Clinical Trial

BACKGROUND

The purpose of our study was to evaluate an inexpensive and available method to reduce mucous impactions in mechanically ventilated patients.

METHODS

This randomized clinical trial was conducted on 40 mechanically ventilated patients aged 15-90 years. The patients were randomly allocated into two arms; 20 cases and 20 controls. The cases received N-acetylcysteine via their nebulizers, and the control group received normal saline three times a day for one day. We measured the density of respiratory secretion, plateau and peak airway pressures, and O2 saturation at baseline, 12 and 24 hours later.

RESULTS

Although the mean secretion density was significantly lower in the NAC group (F (1, 38)=8.61, P=0.006), but a repeated measures ANOVA with a Greenhouse-Geisser correction determined that the effect of NAC on mean secretion density did not differ significantly between time points (F (1, 38)=3.08, P=0.087). NAC increased O2 saturation significantly between time points (F (1.92, 73.1)=4.6, P=0.014). The plateau airway pressures were relatively stable throughout the study in the normal saline and NAC groups (F (1.95, 37.1)=0.67, P=0.513). The peak airway pressure did not change significantly during the study in the normal saline and NAC groups (F (1.52, 56.4)=0.91, P=0.384).

CONCLUSION

Considering the limitations of the study, nebulized NAC in mechanically ventilated patients was not effective more than normal saline nebulization in reducing the density of mucous plugs. The peak and plateau airway pressures were relatively stable throughout the study in both groups.

TRIAL REGISTRATION NUMBER

IRCT201104276312N1.

Impact of bedside bronchoscopy in critically ill lung transplant recipients

BACKGROUND

Over 32,000 lung transplants have been performed worldwide for a variety of end-stage lung diseases (http://www.ishlt.org/). Flexible bronchoscopy (FB) is frequently used as a bedside-tool for diagnosis and management of respiratory failure among critically ill lung transplant recipients (LTRs). We study the indications, results, therapeutic impact, and complications of FB in LTRs admitted to medical intensive care unit (MICU).

METHODS

Retrospective chart review was performed for all critically ill LTRs undergoing FB while admitted to MICU at the Cleveland Clinic Foundation between 2009 and 2011. ICD-9 codes for bronchoscopy were used to identify patients. The procedures were categorized as: (i) airway examination and interventions, (ii) microbiological, and (iii) histopathologic diagnosis. SAS version 9.2 was used for analysis.

RESULTS

A cohort of 76 LTRs accounted for 93 hospital admissions, 101 MICU admissions, and 129 bronchoscopies. FB was helpful in evaluation and management of airway complications [secretion clearance (18% bronchoscopy procedures), stenosis/dehiscence (8% patients)] and optimizing management of lower respiratory tract infections. Isolation of resistant gram-negative organisms, community-acquired respiratory viruses, and fungi commonly led to modification in antimicrobial therapy (35% microbiological samples). Nonspecific finding of acute lung injury was the most commonly seen histopathology (70%) on transbronchial biopsy. Twenty percent (4/20) of transbronchial biopsies showed acute cellular rejection, with 1 episode contributing to respiratory failure. Occasional hypoxia and hypotension, but no deaths, were noted due to FB during the ICU admission.

CONCLUSIONS

Use of FB modified clinical management in one third of airway evaluation and microbiological sampling procedures for critically ill LTRs. No fatalities were attributed to bronchoscopy in this critically ill population.

Brazilian recommendations of mechanical ventilation 2013. Part 2

Perspectives on invasive and noninvasive ventilatory support for critically ill patients are evolving, as much evidence indicates that ventilation may have positive effects on patient survival and the quality of the care provided in intensive care units in Brazil. For those reasons, the Brazilian Association of Intensive Care Medicine (Associação de Medicina Intensiva Brasileira - AMIB) and the Brazilian Thoracic Society (Sociedade Brasileira de Pneumologia e Tisiologia - SBPT), represented by the Mechanical Ventilation Committee and the Commission of Intensive Therapy, respectively, decided to review the literature and draft recommendations for mechanical ventilation with the goal of creating a document for bedside guidance as to the best practices on mechanical ventilation available to their members. The document was based on the available evidence regarding 29 subtopics selected as the most relevant for the subject of interest. The project was developed in several stages, during which the selected topics were distributed among experts recommended by both societies with recent publications on the subject of interest and/or significant teaching and research activity in the field of mechanical ventilation in Brazil. The experts were divided into pairs that were charged with performing a thorough review of the international literature on each topic. All the experts met at the Forum on Mechanical Ventilation, which was held at the headquarters of AMIB in São Paulo on August 3 and 4, 2013, to collaboratively draft the final text corresponding to each sub-topic, which was presented to, appraised, discussed and approved in a plenary session that included all 58 participants and aimed to create the final document.

Intensive care nurses' opinions and practice for oral care of mechanically ventilated patients

Context:

Oral care is an essential aspect of critical care nursing. However, no study has been published on oral care practice of Iranian and Asian nurses. The majority of published studies were conducted in western and European countries.

Aims:

This study aimed to evaluate the nurses’ opinions and practice about oral care in patients under mechanical ventilation.

Settings and Design:

A cross-sectional study was conducted on 130 intensive care nurses from 6 intensive care units in the university hospitals of Iran.

Materials and Methods:

A questionnaire was used to gather the data and charts of 45 patients were evaluated.

Statistical analysis:

Descriptive statistical analysis are presented.

Results:

Oral care obtained the 7^th rank in prority and a mean score of 5.7 on a scale of 1-10. More than 21% of subjects did not perform oral care in their usual duties. High load of writing tasks and personnel shortages were the major barriers to oral care. Only 20% of the patients’ charts contained a report on oral care.

Conclusions:

Nurses did not consider oral care in intensive care patients as a high priority. This result highlights the need to continue education programs on oral care for improving the knowledge and attitude of intensive care nurses with respect to oral care.

The validation of a clinical algorithm for the prevention and management of pulmonary dysfunction in intubated adults--a synthesis of evidence and expert opinion

BACKGROUND

Pulmonary dysfunction (PDF) in intubated patients remains a serious and costly complication of intensive care unit care. Optimal cardiopulmonary therapy strategies to prevent and manage PDF need clarification to reduce practice variability. The purpose of this paper is to report on the content validation of an evidence-based clinical management algorithm (EBCMA) aimed at the prevention, identification and management of PDF in critically ill patients.

METHODS

Forty-four draft algorithm statements extracted from the extant literature by the primary research team were verified and rated by research clinicians (n = 7) in an electronic three-round Delphi process. Statements which reached a priori defined consensus [semi-interquartile range (SIQR) <0.5] were collated into the EBCMA.

RESULTS

One hundred per cent response rate. Forty-four statements were added after round one. Consensus was reached on rating of 83% (73/88) statements. Differences in interpretation of the existing evidence base, and variations in accepted clinical practice were identified. Four themes were identified where panel failed to reach consensus.

CONCLUSION

The internationally agreed hierarchical framework of current available evidence and clinical expertise developed through this Delphi process provides clinicians with a tool to inform clinical practice. This tool has the potential to reduce practice variability thereby maximizing safety and treatment outcome. The clinical utility of the EBCMA requires further evaluation.

Effect of multimodality chest physiotherapy in prevention of ventilator-associated pneumonia: A randomized clinical trial

Background:

Despite remarkable progress that has been achieved in the recent years in the diagnosis, prevention, and therapy for ventilator-associated pneumonia (VAP), this disease continues to create complication during the course of treatment in a significant proportion of patients while receiving mechanical ventilation.

Objective:

This study was designed to evaluate the effect of multimodality chest physiotherapy in intubated and mechanically ventilated patients undergoing treatment in the intensive care units (ICUs) for prevention of VAP.

Patients and Methods:

A total of 101 adult intubated and mechanically ventilated patients were included in this study. Manual hyperinflation (MH) and suctioning were administered to patients in the control group (n = 51), and positioning and chest wall vibrations in addition to MH plus suctioning (multimodality chest physiotherapy) were administered to patients in the study group (n = 50) till they were extubated. Both the groups were subjected to treatment twice a day. Standard care in the form of routine nursing care, pharmacological therapy, inhalation therapy, as advised by the concerned physician/surgeon was strictly implemented throughout the intervention period.

Results:

Data were analyzed using SPSS window version 9.0. The Clinical Pulmonary infection Score (CPIS) Score showed significant decrease at the end of extubation/successful outcome or discharge in both the groups (P = 0.00). In addition, significant decrease in mortality rate was noted in the study group (24%) as compared to the control group (49%) (P = 0.007).

Conclusions:

It was observed in this study that twice-daily multimodality chest physiotherapy was associated with a significant decrease in the CPIS Scores in the study group as compared to the control group suggesting a decrease in the occurrence of VAP. There was also a significant reduction in the mortality rates with the use of multimodality chest physiotherapy in mechanically ventilated patients.