Acute and Chronic Respiratory Failure in Patients With Obesity-Hypoventilation Syndrome: A New Challenge for Noninvasive Ventilation

Abstract

The increased prevalence of adult obesity has been one of the most striking epidemiologic phenomenon in most countries around the world during these last 100 years. It is also a matter of great concern in children 5 to 12 years old in whom the prevalence of obesity has been multiplied by three in the United States and by four in France between 1960 and 2000.1Molarius A Seidell JC Sans S et al.Educational level, relative body weight, and changes in their association over 10 years: an international perspective from the WHO MONICA Project.Am J Public Health. 2000; 90: 1260-1268Crossref PubMed Scopus (284) Google ScholarBecause adult obesity is a risk factor for obstructive sleep apnea syndrome (OSAS), obesity-hypoventilation syndrome (OHS), acute hypercapnic respiratory failure (AHRF), and higher incidence of respiratory postsurgical complications, it is not surprising to see that obesity is now considered as an emerging cause of chronic respiratory failure (CRF) requiring domiciliary ventilatory assistance.2Janssens JP Derivaz S Breitenstein E et al.Changing patterns in long-term noninvasive ventilation: a 7-year prospective study in the Geneva Lake area.Chest. 2003; 123: 67-79Abstract Full Text Full Text PDF PubMed Scopus (237) Google Scholar CRF in obese patients is a frequent issue in clinical practice and is usually diagnosed either in the context of an AHRF in the emergency department or when investigating a potential diagnosis of OSAS or even during a preoperative evaluation. Approximately 10% of patients with OSAS have daytime hypercapnia, often associated with pulmonary hypertension.3Kessler R Chaouat A Schinkewitch P et al.The obesity-hypoventilation syndrome revisited: a prospective study of 34 consecutive cases.Chest. 2001; 120: 369-376Abstract Full Text Full Text PDF PubMed Scopus (318) Google Scholar Obstructive airways disease may be associated in some of these patients and constitutes the so-called overlap syndrome.4Flenley DC Sleep in chronic obstructive lung disease.Clin Chest Med. 1985; 6: 651-661Abstract Full Text PDF PubMed Google Scholar, 5Chaouat A Weitzenblum E Krieger J et al.Association of chronic obstructive pulmonary disease and sleep apnea syndrome.Am J Respir Crit Care Med. 1995; 151: 82-86Crossref PubMed Scopus (381) Google Scholar, 6Sanders MH Newman AB Haggerty CL et al.Sleep and sleep-disordered breathing in adults with predominantly mild obstructive airway disease.Am J Respir Crit Care Med. 2003; 167: 7-14Crossref PubMed Scopus (325) Google Scholar Another clinical picture of CRF in obese patients is OHS,3Kessler R Chaouat A Schinkewitch P et al.The obesity-hypoventilation syndrome revisited: a prospective study of 34 consecutive cases.Chest. 2001; 120: 369-376Abstract Full Text Full Text PDF PubMed Scopus (318) Google Scholar previously called the Pickwickian syndrome,7Bickelmann AG Burwell CS Robin ED et al.Extreme obesity associated with alveolar hypoventilation: a Pickwickian syndrome.Am J Med. 1956; 21: 811-818Abstract Full Text PDF PubMed Scopus (535) Google Scholar which is associated with a range of different sleep respiratory patterns such as hypoventilation, obstructive apneas, central apneas, or a combination of these.Noninvasive ventilation (NIV) using a nasal or facial mask has been proposed to alleviate respiratory failure of various origins.8Hill NS Noninvasive ventilation: does it work, for whom, and how?.Am Rev Respir Dis. 1993; 147: 1050-1055Crossref PubMed Scopus (192) Google Scholar In obese patients, mechanisms of action probably include unloading of respiratory muscles,9Pankow W Hijjeh N Schuttler F et al.Influence of noninvasive positive pressure ventilation on inspiratory muscle activity in obese subjects.Eur Respir J. 1997; 10: 2847-2852Crossref PubMed Scopus (96) Google Scholar correction of nocturnal hypoventilation and resetting of the respiratory centers.8Hill NS Noninvasive ventilation: does it work, for whom, and how?.Am Rev Respir Dis. 1993; 147: 1050-1055Crossref PubMed Scopus (192) Google Scholar However, the data are limited, and we need to better understand the physiologic effects of NIV in these patients. Surprisingly, very few articles or chapters have focused on the issue of obese patients treated by NIV in the acute10Shivaram U Cash ME Beal A Nasal continuous positive airway pressure in decompensated hypercapnic respiratory failure as a complication of sleep apnea.Chest. 1993; 104: 770-774Abstract Full Text Full Text PDF PubMed Scopus (65) Google Scholar, 11Sturani C Galavotti V Scarduelli C et al.Acute respiratory failure due to severe obstructive sleep apnea syndrome, managed with nasal positive pressure ventilation.Monaldi Arch Chest Dis. 1994; 49: 558-560PubMed Google Scholar, 12Ordronneau J Chollet S Nogues B et al.Le syndrome d’apnée du sommeil en Réanimation.Rev Mal Respir. 1994; 11: 51-55PubMed Google Scholar or the chronic setting,13Piper AJ Sullivan CE Effects of short-term NIPPV in the treatment of patients with severe obstructive sleep apnea and hypercapnia.Chest. 1994; 105: 434-440Abstract Full Text Full Text PDF PubMed Scopus (148) Google Scholar, 14Waldhorn RE Nocturnal nasal intermittent positive pressure ventilation with bi-level positive airway pressure (BiPAP) in respiratory failure.Chest. 1992; 101: 516-521Abstract Full Text Full Text PDF PubMed Scopus (107) Google Scholar, 15Rabec C Merati M Baudouin N et al.Prise en charge de l’obèse en décompensation respiratoire. Intérêt de la ventilation nasale à double niveau de pression.Rev Mal Respir. 1998; 15: 269-278PubMed Google Scholar, 16Masa JF Celli BR Riesco JA et al.The obesity hypoventilation syndrome can be treated with noninvasive mechanical ventilation.Chest. 2001; 119: 1102-1107Abstract Full Text Full Text PDF PubMed Scopus (144) Google Scholar and only included a limited number of patients with short follow-up. Waiting for a clinical assessment like in acute COPD, NIV should be today considered early in the management of an obese patient with AHRF (when endotracheal intubation is not immediately required) in order to prevent the risk from endotracheal intubation, to reduce hospital stay and to correct the underlying sleep respiratory disorders. Domiciliary NIV should be also considered when daytime hypercapnia and nocturnal hypoventilation are present. In this situation, precursory clinical signs often associate morning headaches, impaired cognitive function, or reduced daytime vigilance (the “obese sleepy patient” as described by Claman et al 17Claman DM Piper A Sanders MH et al.Nocturnal noninvasive positive pressure ventilatory assistance.Chest. 1996; 110: 1581-1588Abstract Full Text Full Text PDF PubMed Scopus (33) Google Scholar), but diagnoses may also be made much later withcor pulmonaleand/or nocturnal arrhythmias.In this issue ofCHEST(see page 587) De Llano et al describe a large group of 54 obese patients treated by NIV for hypercapnic respiratory failure and followed up at least during 1 year (50 ± 25 months [± SD]). NIV was initiated electively in 20 patients and in the immediate outcome of an AHRF episode in the remaining 34 patients. Most of the patients improved under bilevel positive pressure ventilation adapted according to night oximetry and daytime arterial blood gas (ABG) analysis, and were discharged home with nocturnal NIV and additional oxygen. The authors show that NIV is efficient either in acute as in chronic setting with a reduction of daytime sleepiness, a sustained improvement of ABG values on a long-term basis, and a low mortality rate. However, NIV was not accepted by 15 of the 69 initially screened patients, and this situation was associated with a significant risk of death (four of seven in ARF and three of eight in CRF). Another point emphasized by De Llano et al is the primary role of polysomnographic (PSG) recordings during follow-up, when patients achieve a stable clinical condition: 13% of patients were free of associated OSAS, and the remaining received a diagnosis of OSAS with an apnea-hypopnea index of 43.3 ± 25.6. In 31 patients, this PSG recording attested that a simple continuous positive airway pressure (CPAP) device was sufficient to prevent from further recurrence of respiratory failure. Moreover, a significant proportion of patients were allowed to stop additional oxygen therapy.Therefore, a new sphere of activity is opening for respiratory physicians, especially those working in intermediate care units where a significant number of obese patients with daytime hypercapnia are managed, either in the acute or the chronic setting. At hospital admission for AHRF and otherwise contraindicated, NIV should be the first-line treatment using bilevel positive pressure ventilators and sometimes flow-preset ventilators in case of primary failure. Domiciliary NIV allows to correct the underlying sleep respiratory disorders and may prevent from the risk of recurrent AHRF episodes. PSG studies may help to titrate NIV during initiation and also to evaluate a further shift of the ventilatory assistance (with or without oxygen) to a CPAP device alone. The increased prevalence of adult obesity has been one of the most striking epidemiologic phenomenon in most countries around the world during these last 100 years. It is also a matter of great concern in children 5 to 12 years old in whom the prevalence of obesity has been multiplied by three in the United States and by four in France between 1960 and 2000.1Molarius A Seidell JC Sans S et al.Educational level, relative body weight, and changes in their association over 10 years: an international perspective from the WHO MONICA Project.Am J Public Health. 2000; 90: 1260-1268Crossref PubMed Scopus (284) Google Scholar Because adult obesity is a risk factor for obstructive sleep apnea syndrome (OSAS), obesity-hypoventilation syndrome (OHS), acute hypercapnic respiratory failure (AHRF), and higher incidence of respiratory postsurgical complications, it is not surprising to see that obesity is now considered as an emerging cause of chronic respiratory failure (CRF) requiring domiciliary ventilatory assistance.2Janssens JP Derivaz S Breitenstein E et al.Changing patterns in long-term noninvasive ventilation: a 7-year prospective study in the Geneva Lake area.Chest. 2003; 123: 67-79Abstract Full Text Full Text PDF PubMed Scopus (237) Google Scholar CRF in obese patients is a frequent issue in clinical practice and is usually diagnosed either in the context of an AHRF in the emergency department or when investigating a potential diagnosis of OSAS or even during a preoperative evaluation. Approximately 10% of patients with OSAS have daytime hypercapnia, often associated with pulmonary hypertension.3Kessler R Chaouat A Schinkewitch P et al.The obesity-hypoventilation syndrome revisited: a prospective study of 34 consecutive cases.Chest. 2001; 120: 369-376Abstract Full Text Full Text PDF PubMed Scopus (318) Google Scholar Obstructive airways disease may be associated in some of these patients and constitutes the so-called overlap syndrome.4Flenley DC Sleep in chronic obstructive lung disease.Clin Chest Med. 1985; 6: 651-661Abstract Full Text PDF PubMed Google Scholar, 5Chaouat A Weitzenblum E Krieger J et al.Association of chronic obstructive pulmonary disease and sleep apnea syndrome.Am J Respir Crit Care Med. 1995; 151: 82-86Crossref PubMed Scopus (381) Google Scholar, 6Sanders MH Newman AB Haggerty CL et al.Sleep and sleep-disordered breathing in adults with predominantly mild obstructive airway disease.Am J Respir Crit Care Med. 2003; 167: 7-14Crossref PubMed Scopus (325) Google Scholar Another clinical picture of CRF in obese patients is OHS,3Kessler R Chaouat A Schinkewitch P et al.The obesity-hypoventilation syndrome revisited: a prospective study of 34 consecutive cases.Chest. 2001; 120: 369-376Abstract Full Text Full Text PDF PubMed Scopus (318) Google Scholar previously called the Pickwickian syndrome,7Bickelmann AG Burwell CS Robin ED et al.Extreme obesity associated with alveolar hypoventilation: a Pickwickian syndrome.Am J Med. 1956; 21: 811-818Abstract Full Text PDF PubMed Scopus (535) Google Scholar which is associated with a range of different sleep respiratory patterns such as hypoventilation, obstructive apneas, central apneas, or a combination of these. Noninvasive ventilation (NIV) using a nasal or facial mask has been proposed to alleviate respiratory failure of various origins.8Hill NS Noninvasive ventilation: does it work, for whom, and how?.Am Rev Respir Dis. 1993; 147: 1050-1055Crossref PubMed Scopus (192) Google Scholar In obese patients, mechanisms of action probably include unloading of respiratory muscles,9Pankow W Hijjeh N Schuttler F et al.Influence of noninvasive positive pressure ventilation on inspiratory muscle activity in obese subjects.Eur Respir J. 1997; 10: 2847-2852Crossref PubMed Scopus (96) Google Scholar correction of nocturnal hypoventilation and resetting of the respiratory centers.8Hill NS Noninvasive ventilation: does it work, for whom, and how?.Am Rev Respir Dis. 1993; 147: 1050-1055Crossref PubMed Scopus (192) Google Scholar However, the data are limited, and we need to better understand the physiologic effects of NIV in these patients. Surprisingly, very few articles or chapters have focused on the issue of obese patients treated by NIV in the acute10Shivaram U Cash ME Beal A Nasal continuous positive airway pressure in decompensated hypercapnic respiratory failure as a complication of sleep apnea.Chest. 1993; 104: 770-774Abstract Full Text Full Text PDF PubMed Scopus (65) Google Scholar, 11Sturani C Galavotti V Scarduelli C et al.Acute respiratory failure due to severe obstructive sleep apnea syndrome, managed with nasal positive pressure ventilation.Monaldi Arch Chest Dis. 1994; 49: 558-560PubMed Google Scholar, 12Ordronneau J Chollet S Nogues B et al.Le syndrome d’apnée du sommeil en Réanimation.Rev Mal Respir. 1994; 11: 51-55PubMed Google Scholar or the chronic setting,13Piper AJ Sullivan CE Effects of short-term NIPPV in the treatment of patients with severe obstructive sleep apnea and hypercapnia.Chest. 1994; 105: 434-440Abstract Full Text Full Text PDF PubMed Scopus (148) Google Scholar, 14Waldhorn RE Nocturnal nasal intermittent positive pressure ventilation with bi-level positive airway pressure (BiPAP) in respiratory failure.Chest. 1992; 101: 516-521Abstract Full Text Full Text PDF PubMed Scopus (107) Google Scholar, 15Rabec C Merati M Baudouin N et al.Prise en charge de l’obèse en décompensation respiratoire. Intérêt de la ventilation nasale à double niveau de pression.Rev Mal Respir. 1998; 15: 269-278PubMed Google Scholar, 16Masa JF Celli BR Riesco JA et al.The obesity hypoventilation syndrome can be treated with noninvasive mechanical ventilation.Chest. 2001; 119: 1102-1107Abstract Full Text Full Text PDF PubMed Scopus (144) Google Scholar and only included a limited number of patients with short follow-up. Waiting for a clinical assessment like in acute COPD, NIV should be today considered early in the management of an obese patient with AHRF (when endotracheal intubation is not immediately required) in order to prevent the risk from endotracheal intubation, to reduce hospital stay and to correct the underlying sleep respiratory disorders. Domiciliary NIV should be also considered when daytime hypercapnia and nocturnal hypoventilation are present. In this situation, precursory clinical signs often associate morning headaches, impaired cognitive function, or reduced daytime vigilance (the “obese sleepy patient” as described by Claman et al 17Claman DM Piper A Sanders MH et al.Nocturnal noninvasive positive pressure ventilatory assistance.Chest. 1996; 110: 1581-1588Abstract Full Text Full Text PDF PubMed Scopus (33) Google Scholar), but diagnoses may also be made much later withcor pulmonaleand/or nocturnal arrhythmias. In this issue ofCHEST(see page 587) De Llano et al describe a large group of 54 obese patients treated by NIV for hypercapnic respiratory failure and followed up at least during 1 year (50 ± 25 months [± SD]). NIV was initiated electively in 20 patients and in the immediate outcome of an AHRF episode in the remaining 34 patients. Most of the patients improved under bilevel positive pressure ventilation adapted according to night oximetry and daytime arterial blood gas (ABG) analysis, and were discharged home with nocturnal NIV and additional oxygen. The authors show that NIV is efficient either in acute as in chronic setting with a reduction of daytime sleepiness, a sustained improvement of ABG values on a long-term basis, and a low mortality rate. However, NIV was not accepted by 15 of the 69 initially screened patients, and this situation was associated with a significant risk of death (four of seven in ARF and three of eight in CRF). Another point emphasized by De Llano et al is the primary role of polysomnographic (PSG) recordings during follow-up, when patients achieve a stable clinical condition: 13% of patients were free of associated OSAS, and the remaining received a diagnosis of OSAS with an apnea-hypopnea index of 43.3 ± 25.6. In 31 patients, this PSG recording attested that a simple continuous positive airway pressure (CPAP) device was sufficient to prevent from further recurrence of respiratory failure. Moreover, a significant proportion of patients were allowed to stop additional oxygen therapy. Therefore, a new sphere of activity is opening for respiratory physicians, especially those working in intermediate care units where a significant number of obese patients with daytime hypercapnia are managed, either in the acute or the chronic setting. At hospital admission for AHRF and otherwise contraindicated, NIV should be the first-line treatment using bilevel positive pressure ventilators and sometimes flow-preset ventilators in case of primary failure. Domiciliary NIV allows to correct the underlying sleep respiratory disorders and may prevent from the risk of recurrent AHRF episodes. PSG studies may help to titrate NIV during initiation and also to evaluate a further shift of the ventilatory assistance (with or without oxygen) to a CPAP device alone.