Mechanical ventilation invasive

Noninvasive positive-pressure ventilation (NPPV) provides ventilatory support with oxygen and pressurized airflow using a face or nasal mask with a tight seal but without endotracheal intubation. In patients with acute respiratory failure due to COPD exacerbations, NPPV was associated with lower mortality, lower intubation rates, shorter hospital stays, and greater improvements in serum pH in 1 hour compared with usual care. Use of NPPV reduces the complications that often arise with invasive mechanical ventilation. NPPV is not appropriate for patients with altered mental status, severe acidosis, respiratory arrest, or cardiovascular instability. 

Nevins ML, Epstein SK. Predictors of outcome for patients with COPD requiting invasive mechanical ventilation. Chest 2001 119(6) 1840-1849. 

A three-month prospective cohort study of 26 Italian RICUs reported on 756 patients (14). Of all patients receiving invasive mechanical ventilation, 61% were tracheotomized and therefore considered ventilator dependent. According to the Acute Physiology and Chronic Health Evaluation II (APACHE II) score, the predicted mortality was 22%, while the actual mortality rate was 16%. The results indicate that units with a level of care below ICU can successfiilly manage patients with acute-on-chronic respiratory failure. 

Abbreviations IV, invasive mechanical ventilation NIV, noninvasive mechanical ventilation ABGA, arterial blood gas analysis. 

Criner GJ. Care of the patient requiring invasive mechanical ventilation. Respir Care Clin N Am 2002 8 575-592. 

Elliott MW, Steven MH, Phillips GD, et al. Non-invasive mechanical ventilation for acute respiratory failure. BMJ 1990 300 358-360. 

The number of VAIs has fluctuated from decade to decade. As the need for LTMV for polio patients declined, the number of patients with spinal cord injuries or progressive neuromuscular disease (NMD) increased due to better acute care. Therefore, the number of patients administered LTMV has progressively increased, due both to advances in medical care and to the more widespread application of invasive mechanical ventilation in the acute setting. The increasing number of VAIs can be documented by comparing surveys performed in the last two decades. Regional surveys carried out in Minnesota, United States, in 1986 and 1992, documented that the prevalence of ventilatory assistance rose from 2.4/100,000 in 1986 to 4.9/100,000 in 1992 (2). Extrapolation of these data would suggest that in the United States, the potential number of VAIs rose from 5777 in 1986 to 12,279 in 1992 (4). 

Nava S, Ambrosino N, Bruschi C, et al. Physiological effects of flow and pressure triggering during non-invasive mechanical ventilation in patients with chronic obstructive pulmonary disease. Thorax 1997 52 249-254. 

Van Der Schans C, Bach J, Rubin B. Chest physical therapy mucous mobilising techniques. In Bach J, ed. Non-invasive Mechanical Ventilation. Philadelphia Hanley and Belfus Publications, 2002 259-284. 

Schonhofer B, Sortor-Eeger. Equipment needs for non-invasive mechanical ventilation. Eur Respir J 2002 20 1029-1036. 

A relevant example is of Miss B (11), a woman who was deemed to be eompetent, was receiving long-term invasive mechanical ventilation, and requested the clinical staff to remove her from the ventilator. Although the staff refused, the courts decided that to continue mechanical ventilation against her wishes was unlawful and that she was competent to refuse this treatment, even if it led to her death. There was legal acceptance that it was permissible to allow her to end her life and that to continue with a treatment against her wishes was an assault. This has been described as legally sanctioned ethical homicide, assisted suicide, and active euthanasia. 

General indications for tracheostomy placement include (i) upper airway obstruction, (ii) invasive mechanical ventilation (IV), (Hi) airway clearance, (iv) airway protection, and rarely (v) obstructive sleep apnea. Engoren et al. (1) demonstrated that those able to wean from tracheostomy support, whether during or after hospital admission, had an improved survival rate. Whether this is a reflection of a less severe underlying condition or whether the tracheostomy itself portends a worse outcome is uncertain. Tracheostomy weaning is often conducted outside of acute care hospitals and therefore this skill is not limited to those who work in intensive care settings. 

American Association of Respiratory Care. AARC clinical practice guideline. Long term invasive mechanical ventilation in the home. Respir Care 1995 40(12) 1313-1320. 

In a study of 91 ventilator users with DMD, 51 went on to require continuous NIPPV for 6.3 4.6 (range to 25) years. None of the 34 full-time NIPPV users who had access to MAC died from respiratory complications, whereas three died from severe cardiomyopathy. Five patients with no breathing capacity were extubated or decannulated to continuous NIPPV and five became continuously dependent on NIPPV for one year or more without ever being hospitalized (15). It has previously been reported that DMD patients undergoing tracheostomy tend to have a prolongation of survival of about seven years but also have a tendency to die from complications related to invasive mechanical ventilation (IMV) (24). 

The general point of view is that NPPV is preferred over invasive mechanical ventilation as the first therapy of chronic respiratory failure. However, NPPV is inadequate in some circumstances, which are listed in Table 2. The inability to correct the alveolar hypoventilation... 

Fauroux B, Lofaso F. Non-invasive mechanical ventilation when to start for what benefit Thorax 2005 60 979-980. 

NIV is not always preferred to tracheostomy ventilation. If patients lose their ability to protect their airway or if they develop vocal cord paralysis, invasive mechanical ventilation may be preferred, although some patients with severe impairment of speech and swallowing still respond favorably to NIV (32). Some patients feel more secure with invasive ventilation because of direct access for secretion clearance (4). Both approaches require skilled and dedicated caregivers, hut many patients requiring continuous ventilatory support elect for tracheostomy ventilation unless they are closely managed by a highly skilled team, staffed and experienced in NTV for patients with no ventilator-free time. 

NICOLINO AMBROSINO is Director of Respiratory Unit, Cardio-Thoracic Department, University Hospital of Pisa, Italy, Director of Pulmonary Rehabilitation and Weaning Center, Volterra, Italy and is or was Professor at the Universities of Pisa, Pavia, Florence, and Trieste, Italy. Professor Ambrosino s research and clinical activity has been devoted to Respiratory Critical Care, Pulmonary Rehabilitation and Home Respiratory Care. He contributed to the development of the use of non-invasive mechanical ventilation techniques in acute and chronic respiratory failure, with several clinical trials and original experimental studies. Results of his studies have been published in more than 155 peer-reviewed international journals. The former Head of Pulmonary Rehabilitation Working Croup of the European Respiratory Society (ERS), Dr. Ambrosino is a member of various editorial boards of several international journals, has written over 60 books and chapters, 200 articles, and has spoken at over 100 international conferences. 

---