Davide Chiumello (ed.)Practical Issues Updates in Anesthesia and Intensive Care10.1007/978-3-319-18066-3_10

10. Noninvasive Ventilation Outside the Critical Care Unit

Cesare Gregoretti¹, Alessio Mattei² and Annalisa Carlucci³

(1)

Department of Anesthesia Emergency, Citta’ della Salute e della Scienza, C.so Bramante 88, Torino, 10126, Italy

(2)

Cardiothoracic Department, Citta’ della Salute e della Scienza, C.so Bramante 88, Torino, 10126, Italy

(3)

Respiratory Intensive Care Unit, Fondazione S. Maugeri, IRCCS, Via Salvatore Maugeri, 4, Pavia, 27100, Italy

Cesare Gregoretti (Corresponding author)

Email: c.gregoretti@gmail.com

Alessio Mattei

Email: mattei.alessio@virgilio.it

Annalisa Carlucci

Email: annalisa.carlucci@fsm.it

Keywords

Noninvasive ventilationGeneral wardMaskIntensive care unitOutside

10.1 Introduction

Noninvasive ventilation (NIV) refers to the noninvasive delivery of mechanical ventilation or continuous positive airway pressure (CPAP) through the patient’s mouth, nose, or both via different external interfaces. Differently from conventional invasive mechanical ventilation (IMV) delivered via endotracheal tube or tracheostomy, NIV does not impair patient’s native upper airway, and overall it does not impair glottis function. As a matter of fact, it is able to reduce work of breathing and improve gas exchange while preserving the ability to cough, swallow, and speak. Furthermore, NIV averts iatrogenic complications associated with endotracheal intubation and reduces the risk of ventilator-associated pneumonia (VAP) [1, 2]. NIV includes both noninvasive positive pressure ventilation (NPPV) and CPAP. During CPAP the pressure applied to the respiratory system is generated exclusively by the patient’s respiratory muscles. Consequently, the indications of this technique are limited to patients who, despite an alteration of the ventilation-perfusion (VA/Q), still have a muscular activity sufficient to maintain a spontaneous breath (absence of signs of severe fatigue of the respiratory muscles and ability to develop muscle strength in the face of an increased impedance of the respiratory system). Clinical indications to CPAP are therefore hypoxemia with alterations of the ratio VA/Q without hypercapnia and signs of respiratory distress. Unlike CPAP, during NPPV the inspiratory flow generated in the respiratory system is variably generated by the respiratory muscles and the pressure applied by the ventilator (partial support) or completely generated by the ventilator (total support). Consequently, the possible indications for this technique are patients who have hypoxemia and/or signs of fatigue of the respiratory muscles, paradoxical breathing, or simply insufficient muscular activity to maintain a correct spontaneous breathing and alveolar ventilation.

Noninvasive ventilation (NIV) has found a wide application both in home care and in the hospital setting. However, most of the studies on the acute application of NIV were carried out in the intensive care unit (ICU), emergency room, or in step-down units. These locations represent an “ideal” environment for the safe treatment of patients with moderate to severe acute respiratory failure (potentially with need of airway intubation) for the expertise of the staff and careful monitoring [1].

10.2 NIV Outside the Critical Area: Myth or Reality

Landoni et al. [1] in a recent monograph reported that over the last 15 years, there has been a steady increase in the number of publications on the use of NIV in departments that do not belong to the critical care area. Plant et al. [3] at the beginning of the present century demonstrated the efficacy of NIV in noncritical area during exacerbations of chronic obstructive pulmonary disease (COPD). In a study [4] where all the doctors could order the NIV for patients with acute respiratory failure, the authors reported that 41 % of cases were treated in noncritical departments without having a worse outcome. Surveys in Canada have shown that NIV was applied in departments outside of the critical area^.[5].

In the United States in a survey [6] conducted in 82 hospitals, 18 % of NIV treatments were initiated in noncritical departments. In a subsequent survey, which involved physicians and respiratory therapists of 63 hospitals, Bierer and Soo Hoo [7] reported that 40 % of respondents claimed the use of NIV in the departments. Interestingly 42 % of them reported of any restriction on the place of use.

Schettino et al. [8], in a single-center prospective observational study, reported that among 449 treated patients, NIV was introduced in noncritical departments in 33 % of cases. In addition, 35 % of the NIV treatments (some of which started in the critical area) were then run in noncritical units. The outcome of these patients led to a rate of intubation of 27.3 %; out of them 14.9 % died.

The effectiveness and feasibility of positive results have also been reported in other countries [9–14]. Carlucci et al. [9] reported that with the acquisition of a greater confidence to the use of NIV, there was a greater tendency to treat more severe acute exacerbation of COPD patients in a noncritical area. Cabrini et al. [10] reported, in a survey carried out in Italy and specifically related to the use of NIV outside the ICU, that 65 % of respondents claimed that NIV was applied in general wards and 28 % has allowed the use of NIV in every ward.

An observational study in a single center on 129 consecutive patients treated with the medical emergency team (MET) [1, 15–18] service in the medical and surgical wards has shown a high success rate, with only a few minor complications. However, the workload related to the NIV for a medical emergency team demonstrated to be intense with a high commitment in terms of time [17].

Recently, there have been published reports of centers with a medical emergency team similar to that managed by nonmedical health personnel (CCOT) [18].

In a randomized controlled trial, an NIV service managed by a medical emergency team in a hematology department was associated with a reduced risk of death [19].

10.3 Rational Use of NIV Outside the Critical Care Area

The intensive care unit is considered to be the safest environment to deliver NIV in a hypoxemic patient especially if suffering from “de novo acute respiratory failure” [20].

The failure of NIV in such patients seems linked to increased mortality rate. The critical area provides monitoring, experienced staff, and a high nurse-patients ratio [21], in the face of high costs. However, if the use of NIV is only allowed in the ICU, you run the risk of its underuse [1, 22].

The use of NIV outside the critical area as in general wards may allow certain categories of patients (e.g., COPD and neuromuscular patients) to be treated at an early stage. This is less cost-effective, and patients present a lower risk of problems as “posttraumatic distress disorders” [23]. NIV in general wards has been used in “not to intubate” patients. Interestingly, approximately 50 % of patients survive acute events [21, 24].

In patients with terminal disease, NIV may be indicated to relieve the symptom of dyspnea that can be compared to pain or as a therapeutic option to allow you to save time and allow the patient to consent to diagnostic or therapeutic procedures [25].

There is also a general consensus that the effectiveness of NIV is greatest when treatment is started at the beginning of deterioration of pulmonary function to avoid the need for endotracheal intubation [1, 19, 21, 26–31]. This is particularly true in acute hypoxemic patients [20]. Paus-Jenssen et al. [4], in a prospective study in which NIV was introduced in all hospital wards without a formal protocol and with no prior training in response to financial constraints and limitations of beds, concluded that “patients in whom NIV was introduced outside the ICU did not seem to have worse outcomes” compared to similar patients treated in intensive care.

There is no doubt that the use of NIV outside the critical area should theoretically lead to greater cost-effectiveness as demonstrated in two studies [3, 9]. Plant et al. [3], in a prospective randomized study of 118 patients (NIV vs standard therapy) performed in “general ward,” showed that the introduction of an NIV service for the treatment of mild exacerbations of COPD has saved about 70,000 euro. In addition the mortality rate in the group treated with NIV was halved.

Carlucci et al. [9] observed a daily reduction of 90 € for each NIV treatment (comparing patients treated in critical vs noncritical area) over a period of 8 years. The savings according to the authors was due to a greater percentage of patients treated in noncritical area. So, provided that the safety of the patient and the effectiveness of the technique are retained, the use of NIV outside the critical area could also reduce the costs [1].

As mentioned earlier the use of NIV outside of departments of critical care [3, 4, 9] allows to anticipate the medical act and to improve the cost-effectiveness. It must be stressed, however, that the concept of intubation delay remains valid especially in the hypoxemic patient. In COPD patients, it has been shown that delaying intubation did not increase mortality in patients who failed NIV [32].

Squadrone and Coll [33] have shown that the early use of CPAP in “general ward” may decrease the incidence of tracheal intubation and other complications in patients who develop respiratory failure after major abdominal surgery. The same author [19] demonstrated that in hematologic patients undergoing helmet CPAP in the hematologic department, the setup of NIV by a dedicated service team had a lower need for ICU admission (4 vs 16 patients, P = 0.0002). The CPAP reduced the relative risk of intubation 0.46 (95 % confidence interval 0.27–0.78). This study suggests that the early use of a “simple” CPAP in a noncritical area in this patient population can reduce the rate of intubation.

10.4 NIV Relationship Between Training and Results

The training and experience of the staff are considered the most important factors that determine the effectiveness of the NIV [25] beyond the choice of a proper setting on where to start it. Although many centers have applied the NIV outside the ICU, without any education program [1, 4, 10], “noncritical” health-care personnel may not have specific experiences on acute respiratory failure and NIV [1].

Training on NIV should be considered mandatory before introducing this technique in medical wards [1, 6, 34, 35] to achieve maximum effectiveness while maintaining patient safety. Although the NIV can be easily applied, its success is highly dependent on many factors. Patient’s intolerance to the treatment is a common reason for the NIV failure [36]. In particular, the ward staff should be able to recognize promptly the failure of the technique without delaying tracheal intubation especially in hypoxemic patients [20].

It is clear that if the department staff cannot reach the required level of knowledge and experience in optimizing the effectiveness of NIV, a lower efficacy can be expected compared to the treatment of the patient in the critical care area. In addition, a periodic retraining of personnel should be carried out in particular, if one considers the often high staff turnover [1, 5, 31].

The requirements of basic training should include [1, 25, 34, 35]: