A protocolized approach to pulmonary failure and the role of intermittent prone positioning

Prone during pandemic: development and implementation of a quality-based protocol for proning severe COVID-19 hypoxic lung failure patients in situationally or historically low resource hospitals

Background

Intermittent Prone Positioning (IPP) for Acute Respiratory Distress Syndrome (ARDS) decreases mortality. We present a program for IPP using expedient materials for settings of significant limitations in both overwhelmed established ICUs and particularly in low- and middle-income countries (LMICs) treating ARDS due to COVID-19 caused by SARS CoV-2.

Methods

The proning program evolved based on the principles of High Reliability Organizations (HROs) and Crew Resource Management (CRM). Patients with severe ARDS [PaO₂:FiO₂ ratio (PFr) ≤ 150 on FiO₂ ≥ 0.6 and PEEP ≥ 5 cm H₂O] received IPP. Patients were placed prone 16 h each day. When PFr was ≥ 200 for > 8 h supine IPP ceased. IPP used available materials without requiring additional work from the bedside team. Changes in PFr, PaCO₂, and the SaO₂:FiO₂ ratio (SaFr) positionally were evaluated using t-statistics and ANOVA with Bonferroni correction (p < 0.017).

Results

Between 14APR2020 and 09MAY2020, at the peak of deaths in New York, there were 202 IPPs in 29 patients. Patients were 58.5 ± 1.7 years of age (37, 73), 76% male and had a body mass index (BMI) of 27.8 ± 0.8 (21, 38). Pressor agents were used in 76% and 17% received dialysis. The PFr prior to IPP was 107.5 ± 5.6 and 1 h after IPP was 155.7 ± 11.2 (p < 0.001 compared to pre-prone). PFr after the patients were placed supine was 131.5 ± 9.1 (p = 0.02). Pre-prone PaCO₂ was 60.0 ± 2.5 and the 1-h post-prone PaCO₂ was 67.2 ± 3.1 (p = 0.02). Supine PaCO₂ after IPP was 60.4 ± 3.4 (p = 0.90). The SaFr prior to IPP was 121.3 ± 4.2 and the SaFr 1 h after positioning was 131.5 ± 5.1 (p = 0.03). The post-IPP supine SaFr was 139.7 ± 5.9 (p < 0.001). With ANOVA and Bonferroni correction there were statistically significant changes in PFr (p < 0.001) and SaFr (p < 0.001) and no significant changes in PaCO₂ over the four time points measured. Using regression coefficients, the SaFrs predicted by PFrs of 150 and 200 at baseline are 133.2 and 147.3, respectively.

Conclusions

An IPP program for patients with COVID-19 ARDS can be instituted rapidly, safely, and effectively during an overwhelming mass casualty scenario. This approach may be equally applicable in both traditionally austere environments in LMICs and in otherwise capable centers facing situational resource limitations.

A practical approach to the use of prone therapy in acute respiratory distress syndrome

In this article we propose a practical approach to the use of prone therapy for acute respiratory distress syndrome (ARDS). We have attempted to provide information to improve the understanding and implementation of prone therapy based on the literature available and our own experience. We review the basic physiology behind ARDS and the theoretical mechanism by which prone therapy can be of benefit. The findings of the most significant studies regarding prone therapy in ARDS as they pertain to its implementation are summarized. Also provided is a discussion of the nuances of utilizing prone therapy, including potential pitfalls, complications, and contraindications. The specific considerations of prone therapy in open abdomens and traumatic brain injuries are discussed as well. Finally, we supply suggested protocols for the implementation of prone therapy discussing criteria for initiation and cessation of therapy as well as addressing issues such as the use of neuromuscular blockade and nutritional supplementation.

Pandemic flu and the sudden demand for ECMO resources: a mature trauma program can provide surge capacity in acute critical care crises

BACKGROUND

Patients with severe H1N1 pneumonia created a sudden demand for extracorporeal membrane oxygenation (ECMO) capacity. In a single referral center, the established procedures, protocols, and staff of the Level I trauma service were adapted to help manage this nontrauma critical care crisis.

METHODS

When airway pressure release ventilation and high-frequency oscillator ventilation failed, we used standard ECMO circuits and the VDR-4 critical care ventilator. We cannulated patients percutaneously in the intensive care unit and transported them on ECMO. Trauma service resources included a mobile surgical transport team, direct to OR resuscitations, massive transfusion protocols, trauma performance improvement processes, trauma resuscitation nurses, in-house attending doctors, and experienced staff familiar with protocol-driven care.

RESULTS

During an 84-day period, 15 patients with severe H1N1 pneumonia were treated with ECMO. All patients were referred; 10 were transported on ECMO. Patients were aged 34.4 ± 4.1 years (6-58 years); 47% were male, and they had been ventilated 3.5 ± 0.8 days. Pre-ECMO PaO2/FIO2 ratios were 62.3 ± 6.1; ECMO duration was 9.4 ± 1.3 days for survivors; and post-ECMO PaO2/FIO2 ratio was 295.0 ± 35.1. Recovery occurred in 67% and 60% survived to discharge. No patient died of lung failure. Surviving patients were discharged at their neurologic baseline.

CONCLUSION

H1N1 created a severe public health challenge for referral centers with ECMO capability. The resources of our trauma service were adapted to this nontrauma critical care crisis without disruption of other hospital services. These H1N1 patients treated with ECMO had a 67% recovery rate and a 60% survival rate. All survivors were discharged to home.

LEVEL OF EVIDENCE

Therapeutic/epidemiologic study, level V.

Prone positioning in trauma patients: nursing roles and responsibilities

One of the leading causes of mortality in the intensive care unit is Acute Respiratory Distress Syndrome (ARDS). Acute Respiratory Distress Syndrome can occur as a result from multiorgan dysfunction syndrome and sepsis. In the trauma population, ARDS accounts for an increase in mortality as well as morbidity and disability. Nurses have an essential role in the care of the trauma patients with ARDS or acute lung injury patients. Respiratory treatments such as airway pressure release ventilation and chest physiotherapy are utilized often for ARDS treatment. A lesser used therapy, intermittent prone positioning has also been found to be effective in increasing the pulmonary gas exchange in trauma patients. This article will explain the nursing roles and responsibilities in the initiation, continuation, and cessation of intermittent prone positioning.

Outcomes of acute respiratory distress syndrome (ARDS) in elderly patients

BACKGROUND

Elderly patients have become an increasingly prevalent proportion of the intensive care unit population. Outcomes of patients with acute respiratory distress syndrome (ARDS) have been improving in recent years, but studies of ARDS rarely include substantial numbers of elderly patients. Historically, the mortality rate for ARDS has been 69% to 80% among elderly patients. We reviewed our experience with ARDS to determine whether outcomes were improving over time, and in particular whether outcomes were equally favorable among our elderly patients aged 65 years or older.

METHODS

Patients who developed ARDS in a university surgical intensive care unit from 1993 to 2003 were identified and their data were collected prospectively. Data collected included age, gender, cause of ARDS, Acute Physiology and Chronic Health Evaluation (APACHE) III score (AIII), initial Pao2:FIO2, lung injury score (LIS), maximum positive end-expiratory pressure, multiple organ dysfunction pulmonary and nonpulmonary organ dysfunction scores (MODnp), vasopressor dependence, and development of ventilator-associated pneumonia. Outcomes of patients >65 years old with ARDS were compared with those of patients <65 years old.

RESULTS

In the study period, 343 patients developed ARDS, 210 of whom were >65 years old. Overall, age was 65.2 +/- 0.2 years, with a mean APACHE III score of 83.4 +/- 2.0 points. Sixty-six percent were men. The initial Pao2:FIO2 for the entire group was 104.3 +/- 4.1, and was less in younger patients. Maximum positive end-expiratory pressure was 15.6 +/- 0.5 cm H2O, and mean LIS was 3.3 +/- 0.6 points; these values did not differ between cohorts. Elderly patients had a mortality of 51.9% when compared with 41.7% for younger patients (p = not significant). By logistic regression analysis, factors predicting mortality included APACHE III score (each point, odds ratio [OR], 1.022; 95% confidence interval [CI], 1.008-1.035; p < 0.01) and nonpulmonary multiple organ dysfunction score (each point, OR, 1.366; 95% CI, 1.223-1.526; p < 0.0001), but neither age (p = 0.37), LIS (p = 0.49), multiple organ dysfunction pulmonary (p = 0.90), nor year of treatment (p = 0.74) had any effect on mortality.

CONCLUSIONS

The mortality rate for elderly patients with ARDS is lower in our experience when compared with historical series, even though illness severity may be higher, and comparable to that of other patients. Careful hemodynamic monitoring and resuscitation combined with other strategies to ameliorate nonpulmonary organ dysfunction achieved good outcomes in high-risk patients and could contribute in the future to further improved outcomes of elderly patients with ARDS.

Mechanical ventilation strategies in massive chest trauma

Patients in extremis because of trauma-related massive chest injury require expedient evaluation and prompt intervention. The initial pathophysiology relates to the significant intrapulmonary shunting caused by disruption of pulmonary capillaries and extravasation into the alveolar spaces. Disproportionate or unilateral lung involvement needs measures more technical than general supportive care. Independent lung ventilation (mostly with unilateral lung involvement) and other strategies like inhaled nitric oxide, prone positioning, partial liquid ventilation, and extracorporeal membrane oxygenation (ECMO) have had good results. Intensivists confronted with this clinical subset may consider using these strategies as alternative/adjunctive options for optimizing respiratory and hemodynamic status in the supportive management of trauma-related acute lung injury (ALI) and adult respiratory distress syndrome (ARDS).

[The prone position in acute respiratory distress syndrome: a critical systematic review]

OBJECTIVE

To do a critical systematic review regarding effects of prone positioning (PP) in patients with acute respiratory distress syndrome (ARDS).

METHODS

A systematic review (Highwire, Medline, Cochrane Library from 1976 to 2004), using the keywords: prone position, acute respiratory distress syndrome, allowed us to include the human studies on PP in ARDS patients, independantly of their objectives or their type of protocol. To appreciate the studies validity, we scored the quality evidence of the studies in order to grade our conclusions.

RESULTS AND CONCLUSION

The qualitative analysis of the 58 included studies (1,500 patients returned prone, 4,000 episodes of PP) led to the following main conclusions: 1) the PP improves oxygenation in the majority of ARDS patients (level of evidence I); 2) the PP improves the pulmonary haemodynamics without altering the systemic haemodynamics (level of evidence III); 3) the PP enhances the recruitment maneuvers (level of evidence III); 4) because there are no formal predictive criteria for response to the PP, a "trial of PP" or better two PP trials are necessary to look for the responders; 5) the PP should be performed as early as possible in the course of severe ARDS; 6) the optimal duration of PP is 18 to 23 hours daily, and it should be continued until improvement of arterial oxygenation, or loss of the positive effect of PP on arterial oxygenation or evidently patient's death.

Body positioning and its effect on oxygenation--a literature review

Evidence-based health care has become a priority in the National Health Service (NHS), with increased emphasis on clinical practices that are grounded in quality evidence rather than those that persist because of tradition. Turning and positioning of patients are well-accepted nursing activities. Appropriate positioning of the critically ill patient can dramatically improve gas exchange, resulting in a shorter stay in the critical care unit and an improved outcome. This study reviews the current published literature on the subject of positioning and gas exchange, with emphasis on oxygenation. Conclusions made from this study are that nurses need to be aware of how different positions can affect patients' oxygenation. Further research on exploring patients' experience of positioning within the critical care environment and nurses' understanding of positioning and oxygenation is needed.

Prone positioning improves oxygenation in post-traumatic lung injury--a prospective randomized trial

BACKGROUND

In a prospective randomized trial the effect of prone positioning on the duration of mechanical ventilation was evaluated in multiple trauma patients and was compared with patients ventilated in supine position.

METHOD

Multiple trauma patients of the intensive care units of two university hospitals were considered eligible if they met the criteria for acute lung injury or the acute respiratory distress syndrome. Patients in the prone group (N = 21) were kept prone for at least eight hours and a maximum of 23 hours per day. Prone positioning was continued until a PaO2:FiO2 ratio of more than 300 was present in prone as well as supine position over a period of 48 hours. Patients in the supine group (N = 19) were positioned according to standard care guidelines.

RESULTS

The duration of ventilatory support did not differ significantly (30 +/- 17 days in the prone group and 33 +/- 23 days in the supine group). Worst case analysis (death and deterioration of gas exchange) displayed ventilatory support for 41 +/- 29 days in the prone group and 61 +/- 35 days in the supine group (p = 0.06). The PaO2:FiO2 ratio increased significantly more in the prone group in the first four days (p = 0.03). The prevalence of Acute Respiratory Distress Syndrome (ARDS) following acute lung injury (p = 0.03) and the prevalence of pneumonia (p = 0.048) were reduced also. One patient in the prone and three patients in the supine group died due to multi organ failure (p = 0.27).

CONCLUSIONS

Intermittent prone positioning was not able to reduce the duration of mechanical ventilation in this limited number of patients. However the oxygenation improved significantly over the first four days of treatment, and the prevalence of ARDS and pneumonia were reduced.

Prone positioning in the patient who has acute respiratory distress syndrome: the art and science

Acute respiratory distress syndrome (ARDS) remains a significant contributor to the morbidity and mortality of patients in the ICU. A variety of treatments are used to support the lung of the patient who has ARDS and improve gas exchange during the acute injury phase. It seems, however, that the simple, safe, and noninvasive act of prone positioning of the critically ill patient who has ARDS may improve gas exchange while preventing potential complications of high positive end-expiratory pressure, volutrauma, and oxygen toxicity. This article provides the critical care nurse with the physiologic rationale for use of the prone position, indications and contraindications for use, safe strategies for prone positioning, and care techniques and monitoring methods of the patient who is in the prone position.

Acute respiratory distress syndrome criteria in trauma patients: why the definitions do not work

BACKGROUND

The international consensus definitions for acute respiratory distress syndrome (ARDS) have formed the basis for recruitment into randomized, controlled trials and, more recently, standardized the protocols for ventilatory treatment of acute lung injury. Although possibly appropriate for sepsis-induced ARDS, these criteria may not be appropriate for posttraumatic ARDS if the disease patterns are widely divergent. This study tests the hypothesis that standard ARDS criteria applied to the trauma population will capture widely disparate forms of acute lung injury and are too nonspecific to identify a population at risk for prolonged respiratory failure and associated complications.

METHODS

Patients with and Injury Severity Score > or = 16 ventilated for > 12 hours were prospectively enrolled. Clinical data, including elements of cardiovascular, renal, hepatic, hematologic, neurologic, and pulmonary function, were collected daily. Two hundred fifty-four patients were enrolled over a 36-month period, of whom 70 met the consensus definitions of ARDS. Patients from whom support was withdrawn within 48 hours were excluded. The remaining 61 patients were stratified into two groups on the basis of intubation (n = 12) days.

RESULTS

There was considerable disparity in severity and clinical course. A mild, limited form of ARDS was characterized by earlier onset (group 1, 2 days; group 2, 4 days; p = 0.002), fewer intubation days (7 days vs. 28 days; p < 0.001), and less severe derangements in lung mechanics. A significant difference between the two groups was also seen in systemic inflammatory response syndrome score, incidence of sepsis, and incidence of multiple organ failure.

CONCLUSION

The criteria for ARDS, when applied to the trauma population, capture a widely disparate group and has poor specificity for identifying patients at risk. Recruitment of trauma patients for ARDS studies or preemptive ventilatory management based solely on these criteria may be ill-advised.

Extracorporeal life support for severe acute respiratory distress syndrome in adults

OBJECTIVE

Severe acute respiratory distress syndrome (ARDS) is associated with a high level of mortality. Extracorporeal life support (ECLS) during severe ARDS maintains oxygen and carbon dioxide gas exchange while providing an optimal environment for recovery of pulmonary function. Since 1989, we have used a protocol-driven algorithm for treatment of severe ARDS, which includes the use of ECLS when standard therapy fails. The objective of this study was to evaluate our experience with ECLS in adult patients with severe ARDS with respect to mortality and morbidity.

METHODS

We reviewed our complete experience with ELCS in adults from January 1, 1989, through December 31, 2003. Severe ARDS was defined as acute onset pulmonary failure, with bilateral infiltrates on chest x-ray, and PaO2/fraction of inspired oxygen (FiO2) ratio < or =100 or A-aDO2 >600 mm Hg despite maximal ventilator settings. The indication for ECLS was acute severe ARDS unresponsive to optimal conventional treatment. The technique of ECLS included veno-venous or veno-arterial vascular access, lung "rest" at low FiO2 and inspiratory pressure, minimal anticoagulation, and optimization of systemic oxygen delivery.

RESULTS

During the study period, ECLS was used for 405 adult patients age 17 or older. Of these 405 patients, 255 were placed on ECLS for severe ARDS refractory to all other treatment. Sixty-seven percent were weaned off ECLS, and 52% survived to hospital discharge. Multivariate logistic regression analysis identified the following pre-ELCS variables as significant independent predictors of survival: (1) age (P = 0.01); (2) gender (P = 0.048); (3) pH < or =7.10 (P = 0.01); (4) PaO2/FiO2 ratio (P = 0.03); and (5) days of mechanical ventilation (P < 0.001). None of the patients who survived required permanent mechanical ventilation or supplemental oxygen therapy.

CONCLUSION

Extracorporeal life support for severe ARDS in adults is a successful therapeutic option in those patients who do not respond to conventional mechanical ventilator strategies.

Management of post traumatic respiratory failure

Acute respiratory distress syndrome (ARDS) is a severe and common complication of major trauma. The most important early management principle is to identify the inciting event and remove the ongoing insult aggressively. It is important to immediately resuscitate the patients and prepare them for a complex and difficult hospitalization. Avoiding secondary insults is the cornerstone of supportive care, and this is based primarily on aggressive immune surveillance, full nutrition, and unrelenting oxygen delivery. The use of aggressive immune surveillance, nutritional support, and fluid management is critical to support ventilator management for oxygenation and ventilation. In general, although essential, the ventilator has great potential for harm in patients who are compromised seriously with ARDS. Physicians must establish reasonable therapeutic goals based on oxygen delivery rather than arbitrary normal values of blood gas measurement. The impact of the ventilator should be limited with regard to aspiratory pressure, tidal volume, inspired oxygen, and levels of expiratory end expiratory pressure. Use of pulmonary toilet, including therapeutic bronchoscopy; patient positioning, including intermittent prone positioning, and recruitment maneuvers are useful therapeutic complements for maintaining functional residual capacity and decreasing shunt. Overall, ARDS represents a clear indication that the patient is failing to meet the demands of their stress and without prompt attention likely will die. It is a challenge and an opportunity to identify the underlying situation and to manage the patient while not causing additional harm as the patient's intrinsic resources can bring about the healing necessary to recover from the situation of extremis.