Acute ventilatory failure.ppt

Acute ventilatory failure or (type ii hypercapnic respiratory failure ) : 

Acute ventilatory failure or (type ii hypercapnic respiratory failure ) Conducted by: Ms.Monika

Introduction : 

Introduction Ventilatory failure, characterized by increased arterial tension of carbon dioxide occurs in acute conditions in which retained pulmonary secretions cause increased airway resistance and decreased lung compliance.

Definition : 

Definition It is also known as Type II or Hypercapnic (PaCO2 >45 mm hg ): Failure to exchange or remove carbon dioxide So Ventilatory failure is a rise in Paco2 (hypercapnia) that occurs when the respiratory loadcan no longer be supported by the strength or activity of the respiratory system It leads to the inability of the chest wall & muscles to mechanically move air in & out of the lungs. The hallmark of ventilator failure is an elevated co2 level.

Etiology : 

Etiology acute exacerbations of asthma and COPD. conditions that cause respiratory muscle weakness (eg, Guillain- Barré syndrome, myasthenia gravis, botulism). overdoses of drugs that suppressventilatory drive conditions that resist in moving air in & out of the lungs.

Risk factors for acute ventilatory failure : 

Risk factors for acute ventilatory failure

Pathophysiology : 

Pathophysiology Alveolar ventilation is maintained by the CNS acting through nerves & the muscles of respiration to drive breathing. Failure of alveolar ventilation leads to a ventilation/perfusion ( v/Q) mismatch It results in hypercapnia ( rising co2 levels) Hypercapnia occurs when alveolar ventilation either falls or fails to rise adequately inresponse to increased CO2 production Left untreated acute ventilatory failure leads to death.

Diagnostic evaluation : 

Diagnostic evaluation Patients suspected of having ventilatory failure should have ABG analysis continuouspulse oximetry Chest x-ray. Respiratory acidosis on the ABG (eg, pH < 7.35 andPco2 > 50) confirms the diagnosis. Patients with chronic ventilatory failure often havequite elevated Pco2 (eg, 60 to 90 mm Hg) history is suggestive; sudden onsetof tachypnea and hypotension after surgery suggests pulmonary embolism. Neuromuscular competencemay be assessed through measurement of inspiratory muscle strength

Clinical manifestation : 

Clinical manifestation The predominant symptom is dyspnea. Signs include vigorous use of accessoryventilatory muscles tachypnea (respiratory rates > 28 to 30/min) , tachycardia diaphoresis, anxiety, declining tidal volume, irregular breathing patterns. paradoxical abdominal motion. CNS manifestations range from subtle personality changes to marked confusion,obtundation, or coma cyanosis,

Medical management : 

Medical management - Medical management is directed at: reversing bronchospasm Maintaining the oxygenation Treating the underlying problem Providing mechanical ventilation (Mechanical ventilation is not used until other methods of maintaining ventilation have been tried)

1) Reverse bronchospasm : 

1) Reverse bronchospasm Bronchospasm should be reversed by the use of : Bronchodilators are used to treat obstruction to airflow in COPD &asthma. Theophylline ,albuterol & corticosteroids . If infection is the underlying cause ,broad spectrum antibiotics are used.

2) Maintain oxygenation : 

2) Maintain oxygenation Oxygen by mask may be adequate to support oxygenation. Noninvasive positive pressure ventilation (NIPPV) can immediately reduce the work of breathing. After an explanation of its benefit, patients hold the mask against their face while modest amounts of pressure are applied (continuous positiveairway pressure [CPAP] 3 to 5 mm). Once tolerated, the mask is strapped in placewhile pressures are increased to patient comfort and reduced work of breathing asassessed by respiratory rate and accessory muscle use

3) To manage the underlying problem : 

3) To manage the underlying problem There are many systemic causes for the VRF: CNS ,PNS ,Musculoskeletal ,airways ,lungs & non pulmonary conditions Some of these causes can be quickly managed. Supportive therapies are used to reverse or control the underlying cause.

4) Maintain ventilation : 

4) Maintain ventilation NPPV should be used if client is alert & can maintain the mask over the nose & mouth without becoming claustrophobic. NPPV keeps small airways open & improve gas exchange with the goal being to keep oxygen saturation above 90%. Frequent ABG readings may need to be taken to ensure that adequate oxygenation is being achieved. If NPPV is not successful ,mechanical ventilation is required & helps to minimize the work of breathing while effectively to promote gas exchange.

Cont………….d : 

Cont………….d The client requires an artificial airway usually by ET intubation & the use of positive pressure ventilation (ppv). If prolonged intubation is required ,the ET tube is replaced with a tracheostomy.

5) Endotracheal intubation : 

5) Endotracheal intubation Conventional mechanical ventilation via endotracheal intubation is indicated forimpending respiratory failure as indicated clinically by obtundation, monosyllabicspeech, slumped posture, and shallow breathing Oral intubation is preferred over nasal because it allowsuse of a larger endotracheal tube, which decreases airway resistance and permits easiersuctioning.

6) Continuous mechanical ventilation : 

6) Continuous mechanical ventilation mechanical ventilation is a method to mechanically assist or replace spontaneous breathing. This may involve a machine called a ventilator or the breathing may be assisted by a physician or other suitable person compressing a bag or Traditionally divided into negative-pressure ventilation, where air is essentially sucked into the lungs, or positive pressure ventilation, where air (or another gas mix) is pushed into the trachea.

Nursing management : 

Nursing management

NURSING ASSESSMENT : 

NURSING ASSESSMENT ASSESS RESPIRATIONS FOR : rate, pattern, depth, and breathing effort. Both rapid, shallow breathing patterns and hypoventilation can be due to the reduce lung volume and decrease ventilation. Assess lung sounds and the presence of adventitious sounds. Assess for signs and symptoms of hypoxemia: tachycardia, restlessness, diaphoresis, headache, lethargy, and confusion. Assess for signs and symptoms of atelectasis: diminished chest excursion, limited diaphragm excursion, bronchial or tubular breath sounds, Assess for signs or symptoms of pulmonary infarction: cough, hemoptysis, pleuritic pain, consolidation, pleural effusion, bronchial breathing,fever.

Nursing intervention : 

Nursing intervention Use pulse oximetry to monitor oxygen saturation and pulse rate. Pulse oximetry is a useful tool to detect changes in oxygenation. Oxygen saturation should be maintained at 90% or greater. Maintain oxygen administration device as ordered, attempting to maintain oxygen saturation at 90% or greater. This provides for adequate oxygenation. Change patient’s position every 2 hours. This facilitates secretion movement and drainage. Suction as needed. Suction clears secretions if the patient is unable to effectively clear the airway. Encourage deep breathing, using incentive spirometer as indicated. This reduces alveolar collapse

Cont…………..d : 

Cont…………..d Administer medications as prescribed. The type depends on the etiological factors of the problem (e.g., antibiotics for pneumonia, bronchodilators for COPD, anticoagulants/ thrombolytics for pulmonary embolus, analgesics for thoracic pain).