Prognostic Value of Initial Assessment of Residual Hypoventilation Using Nocturnal Capnography in Mechanically Ventilated Neuromuscular Patients: A 5-Year Follow-up Study.
BACKGROUND
Restrictive respiratory failure is a major cause of morbidity and mortality in neuromuscular diseases (NMD). Home mechanical ventilation (HMV) is used to treat hypoventilation, and its efficiency is mostly assessed by daytime blood gases or nocturnal oxygen saturation monitoring (SpO2). Non-invasive transcutaneous measure of CO2 (TcCO2) allows to directly assess nocturnal hypercapnia and to detect residual hypoventilation with a higher sensitivity than SpO2. We aimed to compare the prognostic value of nocturnal SpO2 and TcCO2 in ventilated adult NMD patients.


METHODS
All consecutive capno-oximetries performed between 2010 and 2011 in ventilated adult NMD patients were analyzed retrospectively. Concomitant blood gas analysis and lung function data were collected. Patients on oxygen therapy were excluded. Nocturnal hypoxemia and hypercapnia (using four different definitions) at baseline were compared in their ability to predict mortality and respiratory events requiring ICU admission during follow-up.


RESULTS
Data from 55 patients were analyzed (median age 28 [interquartile range: 25-36.5] years; 71% Duchenne muscular dystrophy; vital capacity 12 [7-27]% of predicted; 51% tracheostomy). Capno-oxymetry showed hypoxemia in 14.5% and hypercapnia in 12.7-41.8%, according to the used definition. Over a follow-up lasting up to 5 years (median 4.0 [3.6-4.5] years), we observed 12 deaths and 20 respiratory events requiring ICU admission. Hypercapnia was significantly associated with the study outcomes, with TcCO2 > 49 mmHg during ≥10% of the time being the best definition, while hypoxemia was not.


CONCLUSIONS
Our data show for the first time that residual hypoventilation, assessed by capnometry, is significantly associated with negative outcomes in adult ventilated NMD patients, while oximetry is not. Accordingly, we suggest capnometry to be included in the systematic assessment of HMV efficiency in NMD patients.


BACKGROUND
NCT02551406.
Service de Réanimation médicale et unité de ventilation à domicile, AP-HP, Hôpital Raymond Poincaré , Garches , France.
Adam
A
Ogna
Service de Physiologie-Explorations Fonctionnelles, AP-HP, Hôpital Raymond Poincaré , Garches , France.
Julie
J
Nardi
Service de Physiologie-Explorations Fonctionnelles, AP-HP, Hôpital Raymond Poincaré , Garches , France.
Helene
H
Prigent
Unité du Sommeil, AP-HP, Hôpital Raymond Poincaré , Garches , France.
Maria-Antonia
MA
Quera Salva
Département de Biostatistique et Informatique Médicale, Hôpital Saint Louis , Paris , France.
Cendrine
C
Chaffaut
Service de Réanimation médicale et unité de ventilation à domicile, AP-HP, Hôpital Raymond Poincaré , Garches , France.
Laure
L
Lamothe
Département de Biostatistique et Informatique Médicale, Hôpital Saint Louis , Paris , France.
Sylvie
S
Chevret
Service de Réanimation médicale et unité de ventilation à domicile, AP-HP, Hôpital Raymond Poincaré , Garches , France.
Djillali
D
Annane
Service de Réanimation médicale et unité de ventilation à domicile, AP-HP, Hôpital Raymond Poincaré, Garches, France; INSERM CIC 14.29, AP-HP, Hôpital Raymond Poincaré, Garches, France.
David
D
Orlikowski
Service de Physiologie-Explorations Fonctionnelles, AP-HP, Hôpital Raymond Poincaré, Garches, France; Unité du Sommeil, AP-HP, Hôpital Raymond Poincaré, Garches, France.
Frederic
F
Lofaso
home mechanical ventilation; neuromuscular disease; nocturnal hypoventilation; prognosis; restrictive respiratory failure; transcutaneous capno-oximetry
Thorax. 2005 Sep;60(9):754-60
15939731
Eur Respir Rev. 2013 Sep 1;22(129):325-32
23997060
Lancet. 1994 Jun 25;343(8913):1600-4
7911921
J Neurol Sci. 2001 Oct 15;191(1-2):75-8
11676995
Respir Med. 2016 Mar;112:112-8
26874895
Thorax. 2011 May;66(5):438-45
20971980
Neurology. 2007 Nov 13;69(20):1931-6
17998484
Am Rev Respir Dis. 1991 Aug;144(2):401-5
1859067
Neuromuscul Disord. 2002 Dec;12(10):926-9
12467747
Chest. 1987 Mar;91(3):316
3816308
Lancet Neurol. 2006 Feb;5(2):140-7
16426990
Cochrane Database Syst Rev. 2014 Dec 13;(12):CD001941
25503955
Thorax. 1998 Nov;53(11):949-52
10193393
J Clin Sleep Med. 2012 Oct 15;8(5):597-619
23066376
Muscle Nerve. 2002 May;25(5):709-14
11994965
Thorax. 2005 Dec;60(12):1019-24
16299118
Respir Care. 2012 Sep;57(9):1425-30
22348449
J Clin Sleep Med. 2010 Oct 15;6(5):491-509
20957853
Respir Med. 2016 Aug;117:7-13
27492508
Chest. 1999 Aug;116(2):521-34
10453883
Am J Phys Med Rehabil. 2013 Mar;92(3):267-77
23051760
J Neurol Sci. 1995 May;129 Suppl:19-26
7595610
Sleep Breath. 2016 May;20(2):575-81
26338464
Intensive Care Med. 2009 Jun;35(6):1068-74
19172246
Tohoku J Exp Med. 1989 Sep;159(1):57-68
2815076