Acute Hypoventilation (Acute Ventilatory Failure, Acute Hypercapnic Respiratory Failure)

Definition

  • Acute Ventilatory Failure: exists when pCO2 increases enough (above the patient’s baseline pCO2) to produce a clinically significant decrease in pH (i.e. acidemia)
    • Note that the absolute pCO2 value alone does not necessarily indicate the presence of acute ventilatory failure (as increased pCO2 values can also be seen as part of physiologic respiratory compensation in metabolic alkalosis and in chronic hypoventilation)
    • The normal physiologic response to hypercapnia is renal reabsorption of bicarbonate (a process which usually takes a period of days)
    • Pre-Existing Chronic Hypoventilation: in the special clinical context of a patient with pre-existing chronic hypercapnia/chronic hypoventilation, the rise in pCO2 above the patient’s baseline must be large enough to produce a clinically significant decrease in pH to be considered concomitant acute ventilatory failure
      • In some patients with pre-existing chronic hypoventilation (with chronically elevated bicarbonate), an acute decrease in serum bicarbonate (due to an unrelated metabolic acidosis) may be sufficient to produce acidemia without technically being due to concomitant acute ventilatory failure -> in such cases, the clinical context of the combined acid-base disturbance is crucial to correctly interpret the respiratory component
        • Example: 50 y/o morbidly obese male with prior history of obstructive sleep apnea and associated chronic hypoventilation (baseline ABG: ph 7.40, pCO2 60 and serum bicarbonate: 36), now presents with superimposed diabetic ketoacidosis (current ABG: pH 7.22, pCO2 60, serum bicarbonate: 24) -> in this example, without a prior ABG (indicating the presence of chronic hypoventilation), the patient might be mistakenly interpreted to have acute ventilatory failure

Etiology: Summary

ACUTE HYPOVENT


Etiology: Disorders with Decreased Ventilatory Drive

Metabolic Alkalosis (see Metabolic Alkalosis, [[Metabolic Alkalosis]])

  • Elevated serum bicarbonate -> increased serum pH -> physiologic decrease in central respiratory drive

Chemosensitivity Disorders

  • Carotid Body Dysfunction (see Carotid Body Dysfunction, [[Carotid Body Dysfunction]]): may play a role in sudden infant death syndrome (SIDS)
  • Carotid Body Trauma: due to carotid endarterectomy, etc
  • Hypercapnia (“CO2 Narcosis”) (see Hypercapnia, [[Hypercapnia]]): worsens central hypoventilation
  • Hypothyroidism (see Hypothyroidism, [[Hypothyroidism]]): hypothyroidism-associated chronic hypoventilation is due to a combination of decreased central respiratory drive, phrenic neuropathy, and respiratory muscle myopathy

Acute Brainstem Disease

  • Autonomic Insufficiency Syndrome (Dysautonomia) (see Autonomic Insufficiency Syndrome, [[Autonomic Insufficiency Syndrome (Dysautonomia)]])
  • Brainstem Abscess (see Brain Abscess, [[Brain Abscess]])
  • Brainstem Encephalitis (see Encephalitis, [[Encephalitis]])
  • Brainstem Hemorrhage (see Intracerebral Hemorrhage, [[Intracerebral Hemorrhage]])
  • Brainstem Cerebrovascular Accident (CVA) (see Ischemic Cerebrovascular Accident, [[Ischemic Cerebrovascular Accident]])
  • Brainstem Multiple Sclerosis (see Multiple Sclerosis, [[Multiple Sclerosis]])
  • Brainstem Neoplasm
  • Brainstem Poliomyelitis (see Poliomyelitis, [[Poliomyelitis]])
  • Brainstem Sarcoidosis (see Sarcoidosis, [[Sarcoidosis]])
  • Hypogonadism with Testosterone Administration (see Hypogonadism, [[Hypogonadism]])
  • Obesity Hypoventilation Syndrome (see Obesity Hypoventilation Syndrome, [[Obesity Hypoventilation Syndrome]]): mechanism likely a combination of chest wall restriction + decreased central respiratory drive
  • Prader-Willi Syndrome (see Prader-Willi Syndrome, [[Prader-Willi Syndrome]]): impaired hypoxic/hypercapnic ventilatory drive
  • Primary Alveolar Hypoventilation Syndrome (Ondine’s Curse) (see Primary Alveolar Hypoventilation Syndrome, [[Primary Alveolar Hypoventilation Syndrome]])
  • Pharmacologic Central Respiratory Depression
    • Opiates (see Opiates, [[Opiates]])
    • Benzodiazepines (see Benzodiazepines, [[Benzodiazepines]])
    • Barbiturates (see Barbiturates, [[Barbiturates]])
    • Etomidate (Amidate) (see Etomidate, [[Etomidate]])
    • Intoxications
    • Ketamine (see Ketamine, [[Ketamine]]): respiratory depression may occur with rapid administration or overdosage
    • Propofol (Diprivan) (see Propofol, [[Propofol]])

(Note: Ambien does not produce significant respiratory depression)


Etiology: Disorders with Decreased Ventilatory Output (Despite Increased Ventilatory Effort)

Acute Spinal Cord Disease

High Cervical (Above C3) or Low-Mid Cervical (C3-C8) Spinal Cord Disease (see Cervical Spinal Cord Disease, [[Cervical Spinal Cord Disease]])

  • Atlantoaxial Subluxation/Instability (see Atlantoaxial Instability, [[Atlantoaxial Instability]]): associated with rheumatoid arthritis
  • Cervical Disk Disease with Cord Compression
  • Cervical Osteoarthritis
  • Cervical Space-Occupying Lesions
  • Cervical Spinal Cord Infarction (see Spinal Cord Infarction, [[Spinal Cord Infarction]])
  • Cervical Spine Trauma with Cord Injury
  • Diastematomyelia: bony spur in spinal canal, which may compress cervical spinal cord
  • Post-Cervical Cordotomy: procedure done to achieve pain control may damage ascending and descending tracts
  • Spondylolisthesis/Cervical Spondylosis
  • Syringomelia (see Syringomelia, [[Syringomelia]]): cavitation of central cord
  • Thoracic Outlet Syndrome (see Thoracic Outlet Syndrome, [[Thoracic Outlet Syndrome]])
  • Transverse Myelitis (see Transverse Myelitis, [[Transverse Myelitis]])

Cervical Root Disease (see Cervical Root Disease, [[Cervical Root Disease]])

  • Cervical Osteoarthritis: with bilateral C3-C5 compression
  • Cervical Spine Manipulation: with bilateral C3-C5 compression
  • Cervical Mass Lesion: with bilateral C3-C5 compression
  • Herpes Zoster (see Varicella-Zoster Virus, [[Varicella-Zoster Virus]]): bilaterally involving C3-C5
  • Multiple Sclerosis (see Multiple Sclerosis, [[Multiple Sclerosis]]): bilaterally involving C3-C5
  • Neuralgic Amyotrophy: bilaterally involving C3-C5 (usually affects brachial plexus)

Acute Motor Neuron Disease

  • Amyotrophic Lateral Sclerosis (ALS) (see Amyotrophic Lateral Sclerosis, [[Amyotrophic Lateral Sclerosis]])
    • Upper and lower motor neuron disease
    • Acute ventilatory failure may be the initial presentation of ALS
  • Kennedy Disease: lower motor neuron disease due to androgen receptor mutation (X-linked) with age of onset from adolescence-old age in males
  • Poliomyelitis (see Poliomyelitis, [[Poliomyelitis]])
  • Post-Polio Syndrome (see Poliomyelitis, [[Poliomyelitis]])
  • Primary Lateral Sclerosis: upper motor neuron disease
  • Progressive Muscular Atrophy (PMA): lower motor neuron disease
  • Spinal Muscular Atrophies: lower motor neuron disease
  • Strychnine Intoxication (see Strychnine, [[Strychnine]])
  • Survival of Motor Neuron (SMN) Protein-Associated Spinal Muscular Atrophy (all involve gene defect of the Survival of Motor Neuron protein)
    • Werdnig-Hoffman Disease (Type 1): lower motor neuron disease with onset at 0-6 mo
    • Type 2 Survival of Motor Neuron Protein-Associated Spinal Muscular Atrophy: lower motor neuron disease with onset at 7-18 mo
    • Kugelberg-Welander Disease (Type 3): lower motor neuron disease with onset at >18 mo
    • Adult-Onset (Type 4) Survival of Motor Neuron Protein-Associated Spinal Muscular Atrophy: lower motor neuron disease with adult onset
  • Tetanus (see Tetanus, [[Tetanus]])
    • Mechanism: damaged upper motor neurons can no longer inhibit lower motor neurons

Acute Peripheral Neuropathy (see Phrenic Neuropathy, [[Phrenic Neuropathy]])

Infection/Toxin

Other

  • Acute Intermittent Porphyria (see Acute Intermittent Porphyria, [[Acute Intermittent Porphyria]])
  • Chronic Inflammatory Demyelinating Polyneuropathy (see Chronic Inflammatory Demyelinating Polyneuropathy, [[Chronic Inflammatory Demyelinating Polyneuropathy]])
  • Critical Illness Polyneuropathy (see ICU-Acquired Weakness, [[ICU-Acquired Weakness]])
  • Diabetic Neuropathy (see Diabetic Neuropathy, [[Diabetic Neuropathy]])
  • Guillain-Barre Syndrome (see Guillain-Barre Syndrome, [[Guillain-Barre Syndrome]]): most common etiology of acute paralysis and neuromuscular ventlatory failure presenting to acute care hospitals
    • 33% of cases develop acute ventilatory failure
    • May be acute or subacute
    • Ascending paralysis (similar to tick paralysis)
  • Hypothyroidism (see Hypothyroidism, [[Hypothyroidism]]): hypothyroidism-associated chronic hypoventilation is due to a combination of decreased central respiratory drive, phrenic neuropathy, and respiratory muscle myopathy
  • Idiopathic Peripheral Neuropathy
  • Mediastinal/Esophageal Surgical Injury or Traumatic Injury of Bilateral Phrenic Nerves
    • Phrenic nerve injury occurs in 2-20% of open heart surgery cases
    • L>R sided injury
    • Mechanisms: cold cardioplegia, dissection of LIMA, and/or stretching of phrenic nerve
  • Multiple Sclerosis (see Multiple Sclerosis, [[Multiple Sclerosis]])
  • Neurofibromatosis (see Neurofibromatosis, [[Neurofibromatosis]]): case report of bilateral diaphragmatic paralysis
  • Systemic Lupus Erythematosus (SLE) (see Systemic Lupus Erythematosus, [[Systemic Lupus Erythematosus]]): neuropathy with vasculitis of phrenic nerves + myopathy

Acute Neuromuscular Junction Disease (Involving Respiratory Muscles)

  • Myasthenia Gravis (see Myasthenia Gravis, [[Myasthenia Gravis]]): acute ventilatory failure may be the initial presentation of myasthenia gravis
  • Lambert-Eaton Myasthenic Syndrome (LEMS) (see Lambert-Eaton Myasthenic Syndrome, [[Lambert-Eaton Myasthenic Syndrome]])
  • Botulism (see Botulism, [[Botulism]]): botulinum toxin blocks acetylcholine release at neuromuscular junction
    • Descending paralysis (similar to paralytic-neurotoxic shellfish poisoning)
  • Tick Paralysis (see Tick Paralysis, [[Tick Paralysis]]): toxin probably impairs acetylcholine mobilization at motor nerve terminal
    • Ascending paralysis (similar to Guillian-Barre syndrome)
  • Snake Bite: due to various types of neurotoxins in venom
    • Mojave Rattlesnake (Crotalus scutulatus) (see Rattlesnake Bite, [[Rattlesnake Bite]]): Fasciculin toxin (destroys acetylcholinesterase, resulting in tetany)
    • Cobra/King Cobra: α-neurotoxins (inhibition at acetylcholine receptor)
    • Sea Snake: α-neurotoxins (inhibition at acetylcholine receptor)
    • Mamba: Fasciculin toxin (destroys acetylcholinesterase, resulting in tetany) and Dendrotoxin (blocks ion channels -> blocks nerve transmission)
  • Organophosphate Intoxication (see Organophosphates, [[Organophosphates]]) [MEDLINE]
  • Carbamate Intoxication (see Carbamates, [[Carbamates]]) [MEDLINE]
  • VX Nerve Agent (see VX Nerve Agent, [[VX Nerve Agent]])
  • Pharmacologic Neuromuscular Junction Antagonists
    • Aminoglycosides (see Aminoglycosides, [[Aminoglycosides]]): usually clinically relevant only in the presence of other NM disease
    • Fluoroquinolones (see Fluoroquinolones, [[Fluoroquinolones]]): usually clinically relevant only in the presence of other neuromuscular disease
    • Anti-Cholinergics: usually clinically relevant only in the presence of other neuromuscular disease
    • Procainamide (see Procainamide, [[Procainamide]]): usually clinically relevant only in the presence of other neuromuscular disease
    • Polymyxin B (see Polymyxins, [[Polymyxins]]): usually clinically relevant only in the presence of other neuromuscular disease
    • Sodium Colistimethate (aka Colistin, Polymyxin E) (see Polymyxins, [[Polymyxins]]): usually clinically relevant only in the presence of other neuromuscular disease
    • Paralytics: Succinylcholine, Aminosteroid Non-Depolarizing Blockers (Pancuronium, Vecuronium, etc), Benzylisoquinolone Non-Depolarizing Blockers (Atracurium, etc)

Acute Myopathy (Involving Respiratory Muscles)/Muscle Dysfunction (see Myopathy, [[Myopathy]])

Periodic Paralysis Syndromes

Rheumatologic

Electrolyte-Related

Other

  • Bilateral Diaphragmatic Paralysis (see Bilateral Diaphragmatic Paralysis, [[Bilateral Diaphragmatic Paralysis]])
  • Critical Illness Polymyopathy (see ICU-Acquired Weakness, [[ICU-Acquired Weakness]])
    • Necrotizing Myopathy from Steroids + Neuromuscular Junction Antagonists
  • Hyperthyroidism (see Hyperthyroidism, [[Hyperthyroidism]])
    • Proximal and distal myopathy -> manifests as both inspiratory and expiratory muscle weakness
  • Hypothyroidism (see Hypothyroidism, [[Hypothyroidism]]): hypothyroidism-associated chronic hypoventilation is due to a combination of decreased central respiratory drive, phrenic neuropathy, and respiratory muscle myopathy
    • Manifests as both inspiratory and expiratory muscle weakness

Acute Upper Airway Obstruction (with Increased Work of Breathing) (see Obstructive Lung Disease, [[Obstructive Lung Disease]])

Bilateral Vocal Fold Immobility (BVFI) (see Bilateral Vocal Fold Immobility, [[Bilateral Vocal Fold Immobility]])

  • Cricoarytenoid Arthritis (see Cricoarytenoid Arthritis, [[Cricoarytenoid Arthritis]])
  • Laryngeal Inflammation
  • Laryngospasm (see Laryngospasm, [[Laryngospasm]])
  • Neurologic Disease/Dysfunction Involving the Vocal Folds (Vocal Cord Paralysis)
  • Developmental Abnormality or Neoplasm the Involving Vocal Folds
  • Intubation Injury to Vocal Folds
  • Mechanical/Iatrogenic Injury to Vocal Folds
  • Surgical Injury to Vocal Folds

Other Upper Airway Disease (see Obstructive Lung Disease, [[Obstructive Lung Disease]])

  • Infection
    • Coccidioidomycosis (see Coccidioidomycosis, [[Coccidioidomycosis]]): typically mild upper airway obstruction
    • Croup (see Croup, [[Croup]]): typically acute
    • Cryptococcosis (see Cryptococcosis, [[Cryptococcosis]]): typically mild upper airway obstruction
    • Deep Neck Infection (see Deep Neck Infection, [[Deep Neck Infection]]): typically acute
      • Peritonsillar Abscess (see Peritonsillar Abscess, [[Peritonsillar Abscess]]): involving peritonsillar space
      • Pretracheal Abscess (see Pretracheal Abscess, [[Pretracheal Abscess]]): involving pretracheal space
      • Retropharyngeal Abscess (see Retropharyngeal Abscess, [[Retropharyngeal Abscess]]): involving retropharyngeal space
      • Submandibular Space Abscess/Ludwig’s Angina (see Ludwig’s Angina, [[Ludwigs Angina]]): involving submandibular space
    • Diphtheria (see Diphtheria, [[Diphtheria]]): typically acute
    • Epiglottitis (see Epiglottitis, [[Epiglottitis]]): typically acute
    • Histoplasmosis (see Histoplasmosis, [[Histoplasmosis]]): typically mild upper airway obstruction
    • Syphilis (see Syphilis, [[Syphilis]])
  • Neurologic
    • Altered Mental Status with Inability to Protect Upper Airway: typically acute
    • Essential Tremor (see Essential Tremor, [[Essential Tremor]]): typically mild upper airway obstruction
    • Parkinson’s Disease (see Parkinson’s Disease, [[Parkinsons Disease]]): may cause acute upper airway obstruction in the post-operative setting or progressive upper airway dysfunction
  • Miscellaneous
    • Ammonia Inhalation (see Ammonia, [[Ammonia]]): typically acute
    • Anaphylaxis (see Anaphylaxis, [[Anaphylaxis]]): typically acute
    • Congenital Small Cricoid Cartilage: typically progressive
    • Eosinophilic Granuloma (see Eosinophilic Granuloma, [[Eosinophilic Granuloma]]): typically mild upper airway obstruction
    • Esophageal Foreign Body: extrinsic compression of upper airway, typically progressive
    • Laryngeal Cyst/Laryngocele: typically mild upper airway obstruction
    • Laryngeal Rheumatoid Nodule (see Rheumatoid Arthritis, [[Rheumatoid Arthritis]]): typically progressive
    • Macroglossia: typically mild upper airway obstruction
    • Nasal Polyps (see Nasal Polyps, [[Nasal Polyps]]): typically mild upper airway obstruction
    • Obstructive Sleep Apnea (OSA) (see Obstructive Sleep Apnea, [[Obstructive Sleep Apnea]]): may cause acute upper airway obstruction in the post-operative setting
    • Thermal Injury/Burns of Upper Airway (see Smoke Inhalation, [[Smoke Inhalation]]): thermal injury is usually supraglottic (typically, laryngeal injury) and may be acute
    • Thyromegaly/Goiter (see Goiter, [[Goiter]]): typically progressive
    • Tracheal Cyst: typically progressive
    • Tracheomalacia (see Tracheomalacia, [[Tracheomalacia]]): typically progressive
    • Tonsillar/Adenoid Enlargement: typically progressive
    • Unilateral Vocal Cord Paralysis (see Unilateral Vocal Fold Immobility, [[Unilateral Vocal Fold Immobility]]): typically mild upper airway obstruction
    • Upper Airway Foreign Body (see Foreign Body, [[Foreign Body]]): typically acute
    • Urticaria-Angioedema Syndrome (see Urticaria-Angioedema, [[Urticaria-Angioedema]]): typically acute

Acute Obstructive Airway Disease (with Increased Work of Breathing) (see Obstructive Lung Disease, [[Obstructive Lung Disease]])

  • COPD Exacerbation (see Chronic Obstructive Pulmonary Disease, [[Chronic Obstructive Pulmonary Disease]])
  • Asthma Exacerbation (see Asthma, [[Asthma]])
  • Cystic Fibrosis Exacerbation (see Cystic Fibrosis, [[Cystic Fibrosis]])
  • Bronchiectasis Exacerbation (see Bronchiectasis, [[Bronchiectasis]])
  • Acute Tracheobronchial Obstruction
    • Tracheobronchial Infection
    • Tracheobronchial Neoplasm
      • Primary Tracheobronchial Tumor
      • Endobronchial Metastases
    • Extrinsic Tracheobronchial Compression
    • Other Tracheobronchial Obstructive Process

Acute Parenchymal Lung Disease (with Increased Work of Breathing)

  • Acute Lung Injury-ARDS (see Acute Lung Injury-ARDS, [[Acute Lung Injury-ARDS]])
  • Aspiration Pneumonia (see Aspiration Pneumonia, [[Aspiration Pneumonia]])
  • Cardiogenic Pulmonary Edema (see Congestive Heart Failure, [[Congestive Heart Failure]])
  • Diffuse Alveolar Hemorrhage (see Diffuse Alveolar Hemorrhage, [[Diffuse Alveolar Hemorrhage]])
  • Idiopathic Pulmonary Fibrosis (IPF) (see Idiopathic Pulmonary Fibrosis, [[Idiopathic Pulmonary Fibrosis]]: acute ventilatory failure may be manifested as the end-stage of the IPF or more commonly, in conjunction with pneumonia, surgery, or other illness
    • In end-stage IPF requiring mechanical ventilation, lung compliance has been noted to be significantly decreased
  • Pneumonia (see Pneumonia, [[Pneumonia]])

Acute Pleural or Chest Wall Disease (with Increased Work of Breathing)

Increased Dead Space Ventilation (Increased VD/VT Ratio)

  • Acute Lung Injury-ARDS (see Acute Lung Injury-ARDS, [[Acute Lung Injury-ARDS]]): very low V/Q and/or intrapulmonary shunt
  • Acute Pulmonary Embolism (see Acute Pulmonary Embolism, [[Acute Pulmonary Embolism]]): localized pulmonary hypoperfusion
  • Air Embolism (see Air Embolism, [[Air Embolism]]): venous air ambolism -> localized pulmonary hypoperfusion
  • Cardiogenic Shock (see Cardiogenic Shock, [[Cardiogenic Shock]]): generalized pulmonary hypoperfusion
  • COPD Exacerbation (see Chronic Obstructive Pulmonary Disease, [[Chronic Obstructive Pulmonary Disease]]): very high V/Q
  • Hypovolemic Shock (see Hypovolemic Shock, [[Hypovolemic Shock]]): generalized pulmonary hypoperfusion
  • Pulmonary Hyperinflation (Excessive Exogenous PEEP or Auto-PEEP): generalized pulmonary hypoperfusion
  • Sickle Cell Acute Chest Syndrome (see Sickle Cell Disease, [[Sickle Cell Disease]])
  • Ventilation During Cardiopulmonary Resuscitation (CPR) (see Cardiopulmonary Resuscitation, [[Cardiopulmonary Resuscitation]]): generalized pulmonary hypoperfusion

Increased CO2 Production

Inflammation/Hypermetabolism

  • Fever (see Fever, [[Fever]])
  • Burns (see Burns, [[Burns]])
  • Sepsis (see Sepsis, [[Sepsis]])
  • Severe Trauma

Muscle Activity

Excessive Caloric Intake

  • Excessive Caloric Intake: especially carbohydrates (which generate more CO2 per calorie than fats)

Exogenous CO2 Inhalation

  • Industrial/Laboratory Accident
  • CO2 Rebreathing

Clinical

Upper Airway/Proximal Tracheal Airway Obstruction

  • Characteristics of Upper Airway/Tracheal Obstruction
    • Role of Airway Diameter: progressive/gradual airway obstruction can be tolerated until upper airway/tracheal diameter reaches approximately 5-6 mm
    • Role of the Location of Airway Obstruction: impacts whether inspiratory and/or expiratory flows are more adversely affected by the obstructing lesion
      • Variable Extrathoracic Upper Airway Obstruction: adversely affects predominantly inspiratory flow (as inspiratory negative intraluminal pressures exacerbate the inspiratory airway narrowing, while expiratory positive intraluminal pressures splints the obstruction open)
        • Example: vocal cord paralysis -> inspiratory stridor with no expiratory obstruction
      • Variable Intrathoracic Upper Airway Obstruction: adversely affects predominantly expiratory flow (as inspiratory negative pressures decrease the inspiratory airway narrowing, while expiratory positive intrapleural pressures exacerbate the airway obstruction)
        • Example: tracheomalacia -> expiratory worsening of airway obstruction
      • Fixed Upper Airway Obstruction: adversely affects both inspiratory and espiratory flows
    • Complication by Negative Pressure Pulmonary Edema: negative pressure pulmonary edema may occur in cases with critical, acute upper airway obstruction (such as laryngospasm)

Clinical Manifestations of Inspiratory Muscle Fatigue

  • In a study of 12 patients with post-extubation respiratory failure (patients with intact ventilatory drive, but decreased ventilatory output), 6 patients manifested EMG evidence of inspiratory muscle fatigue characterized by a defined sequence of clinical stages [MEDLINE]
    • Note that the stages were of variable duration (with some patients skipping stages): however, this study suggests that the occurrence of respiratory arrest is typically heralded by preceding clinical events

INSPFATIGUE


Treatment

General Management

  • Acute Non-Invasive Positive Pressure Ventilation (NIPPV) (see Noninvasive Positive-Pressure Ventilation, [[Noninvasive Positive-Pressure Ventilation]])
    • Clinical Indications
      • Neuromuscular Disease
      • Congestive Heart Failure (CHF)
      • COPD Exacerbation
  • Mechanical Ventilation (see Mechanical Ventilation, [[Mechanical Ventilation]]): may be indicated for cases unresponsive or not amenable to NIPPV (especially cases with airway compromise, secretions, and/or aspiration risk)

Specific Management

  • Specific Management of Hypothyroidism (see Hypothyroidism, [[Hypothyroidism]])
    • Hormone Replacement
    • Evaluation/Treatment of Concomitant Sleep-Disordered Breathing/Obstructive Sleep Apnea (OSA)
    • Evaluation/Treatment of Concomitant Congestive Heart Failure (CHF): if present
  • Specific Management of Obesity-Hypoventilation Syndrome (see Obesity Hypoventilation Syndrome, [[Obesity Hypoventilation Syndrome]])
    • Evaluation/Treatment of Concomitant Sleep-Disordered Breathing/Obstructive Sleep Apnea (OSA): if present
    • Evaluation/Treatment of Concomitant Congestive Heart Failure (CHF): if present
    • In retrospective study of 54 morbidly obese patients (mean BMI: 44), 87% of whom had concomitant OSA, chronic nocturnal nasal NIPPV improved gas exchange, dyspnea, and sleepiness [MEDLINE]
    • Weight Loss
  • Management of Chest Trauma
    • In subset of patients with persistent hypoxemia, NIPPV has been demonstrated to decrease the need for intubation and shorten hospital length of stay [MEDLINE]

References

  • Clinical manifestations of inspiratory muscle fatigue. Am J Med. 1982 Sep;73(3):308-16 [MEDLINE]
  • The spectrum of intermediate syndrome following acute organophosphate poisoning: a prospective cohort study from Sri Lanka. PLoS Med. 2008 Jul 15;5(7):e147. doi: 10.1371/journal.pmed.0050147 [MEDLINE]
  • Short-term and long-term effects of nasal intermittent positive pressure ventilation in patients with obesity-hypoventilation syndrome. Chest. 2005 Aug;128(2):587-94 [MEDLINE]
  • Noninvasive ventilation reduces intubation in chest trauma-related hypoxemia: a randomized clinical trial. Chest. 2010 Jan;137(1):74-80. doi: 10.1378/chest.09-1114. Epub 2009 Sep 11 [MEDLINE]