Untitled Quiz

Ventilation & Suctioning - FTP 303

• Topics covered include Introduction to ICU, Ventilation, Suctioning, Evaluation of ICU patients, Haemodynamic monitoring, Different ICU settings, and Rehabilitation and CPR.

Objectives

• Describe various ventilation modes.
• Interpret ventilator settings.
• List and explain ventilation complications.
• Explain weaning and physiotherapy's role.
• Detail indications for suctioning.
• List adverse reactions for suctioning.
• Describe and perform suctioning procedures.

Pressure Relationships

• Atmospheric pressure is balanced by transpulmonary and intrapleural pressures.
• Transpulmonary pressure is 4 mmHg.
• Intrapleural pressure is -4 mmHg.
• Intrapulmonary/Alveolar pressure is 0 mmHg.

Respiratory Cycle

• Tidal volume (VT) is the amount of air moved in and out of the lungs during a respiratory cycle.
• Intrapulmonary pressure equals atmospheric pressure during the respiratory cycle.
• Volume increases in the thoracic cavity during inhalation.
• Intrapleural pressure decreases during inhalation.
• Intrapulmonary pressure decreases to -1 mmHg, then rises as air flows into the lungs.
• Transpulmonary pressure is 4 mmHg.
• Intrapleural pressure is -4 mmHg.
• Intrapulmonary/Alveolar pressure is 0 mmHg.

Mechanical Ventilation

• Temporarily replaces or supports spontaneous breathing.
• Goals include maintaining alveolar ventilation, optimizing O2 delivery, optimizing work of breathing, minimizing toxicity, and ensuring favorable cardio-respiratory interaction.

Indications for Intubation

• Problems with breathing (e.g., rib fractures, muscle paralysis, during/after surgery, airway obstruction).
• Oxygenation defects (e.g., ARDS, pulmonary edema, lung contusion).
• Cardiac failure.
• Respiratory failure.
• Neuromuscular disease or head injury.
• Decrease ICP due to hyperventilation – vasoconstriction.
• Postoperatively.

Methods of Intubation

• Endotracheal tube: Most common, inserted through the mouth or nose into the airway.
• Oropharyngeal: From mouth to airway.
• Nasopharyngeal: From nose to airway.
• Tracheostomy: Opening in the trachea for long-term ventilation.

Ventilator Settings (Graphical examples shown)

• Various modes of ventilation (e.g., CPAP, PSV, SIMV, AC) and their corresponding ventilator parameters (e.g., FiO2, Rate, PEEP, PSV) are discussed.

Modes of Ventilation

• Various modes of ventilation are identified and defined (example: Pressure Support Ventilation, Continuous Positive Airway Pressure, Synchronized Intermittent Mandatory Ventilation, Assist Control)

PEEP (Positive End Expiratory Pressure)

• Alveolar pressure at the end of expiration is above atmospheric pressure.
• Open collapsed alveoli, increase surface area for oxygenation.
• Too much PEEP can injure capillaries.

Pressure Support Ventilation (PSV)

• Patient triggers breaths, ventilator supports with positive pressure.
• Airway pressure held at a pre-set level throughout inspiration.
• Pre-set pressure level selected to maintain tidal volume of 6–8 ml/kg.
• Often used with SIMV.
• Decreases work of breathing.
• Decreases respiratory failure.
• Increases patient comfort.

Continuous Positive Airway Pressure (CPAP)

• Positive pressure maintained throughout respiratory cycle.
• Patient is not generating negative airway pressure to receive oxygen.
• Maintains functional residual capacity and good oxygenation in spontaneously breathing patients.

Synchronized Intermittent Mandatory Ventilation (SIMV)

• Ventilator delivers gas at a pre-set rate.
• Volume controlled (6-8 ml/kg) / Pressure conttrolled.
• Allows spontaneous breaths from the patient.
• Used often after surgery.
• Maintains breathing during surgery/sedation.
• Can be used as a weaning mode.

Assist Control (AC)

• Patient sedated and paralysed.
• No spontaneous breaths.
• Ventilated at a pre-set rate.
• Pre-set Peak inspiratory airway pressure cannot be exceeded.
• Tidal volume uncontrolled – depends primarily on lung compliance.
• Recruit collapsed alveoli.
• Limiting PIP may decrease barotrauma.
• As compliance improves, tidal volume increases.

Other Ventilation Methods

• High-frequency oscillatory ventilation (HFOV)
• Extracorporeal membrane oxygenation (ECMO)
• Extracorporeal carbon dioxide removal (ECCO2R)

Criteria for Weaning Trial

• Reversal of intubation reason.
• Cardiovascular stability (HR, SBP).
• Minimal inotropic support.
• Stable metabolic status.
• Adequate cough.
• Absence of excessive secretions.
• FiO2, PEEP, RR, PaO2, PaO2/FiO2 ratio, and RSBI values within specific ranges.

Predictors of Successful Extubation

• Spontaneous breathing trial (SBT).
• Maximum inspiratory pressure (MIP).
• Rapid shallow breathing index (RSBI).
• Ratio of respiratory rate and spontaneous tidal volume.
• Cough strength, hand-grip strength, heart rate variability.
• All used in combination

Signs of Failed Weaning

• Respiratory rate > 35 breaths/min.
• SpO2 <90%.
• Heart rate > 130 beats/min.
• Clinical signs of respiratory distress.
• Sweating.
• Agitation.
• Depressed mental status.

Failed Extubation

• Need for re-intubation within 48-72 hours.
• Increased mortality rate (25–50%).
• Reasons include:
  • Ineffective cough.
  • Airway secretions.
  • Obstruction.
  • New onset sepsis.
• Results in increased need for tracheostomy, risk of nosocomial pneumonia, ICU stay, and mortality.
• High-flow nasal cannula (HFNC) or non-invasive positive pressure ventilation (NIPPV).

Prolonged Mechanical Ventilation

• Ventilation for more than 48 hours is detrimental.
• Increased risk of nosocomial infections, ICU length of stay, hospital length of stay, financial expenditures, critical illness myopathy/neuropathy, reduced functional ability, and quality of life are observed.

Extubation

• Original reason for intubation is resolved.
• Weaning criteria are met.
• Effects of anaesthesia and other respiratory depressants are no longer present.
• Patient can maintain the airway independently.
• Patient can cough and is awake.

Suctioning

• Indications:
  • Remove retained secretions.
  • Crepitations on auscultation.
  • Visible secretions in airway.
  • Inability to cough effectively.
  • Suspected aspiration of gastric/upper airway secretions.
  • Deterioration in ABG's.
  • X-ray changes.
  • Increase WOB (work of breathing).
  • Obtain sputum specimen & Luki.
• Prevention is better than cure, - routine suctioning is discouraged.

Suction Parameters to Monitor

• SpO2 (pulse oximetry).
• Respiratory rate and pattern.
• Pulse.
• Blood pressure.
• Sputum characteristics.
• Cough effort.
• Intracranial Pressure (if indicated).
• Ventilator parameters (RR, PIP, VT).

Suction Adverse Reactions

• Hypoxaemia: Principle complication, reduced by pre-oxygenation.
• Mucosal damage/atelectasis/bleeding: From excessive negative pressure.
• Cardiac arrhythmias: Stimulation of vagus nerve can cause cardiac arrest.
• Increased ICP: Possible complication.
• Loss of PIP/PEEP: Reduced pressure support and positive end-expiratory pressure.

Relative Contraindications

• Hypoxaemia/Hypoxia.
• Mucosal trauma.
• Cardiac/Respiratory arrest.
• Uncontrolled cardiac arrhythmias.
• Bronchospasm not relieved with nebulization.
• Frank haemoptysis.
• Increased ICP.
• Interruption of high PEEP levels.
• Increased blood pressure greater than 20% of baseline.

Effect Post Suctioning

• Improved breath sounds during auscultation.
• Decreased PIP (positive inspiratory pressure).
• Increased tidal volume.
• Elevated SpO2 (oxygen saturation).
• Improved oxygenation seen in ABG (artery blood gas values) results.
• Removal of secretions.

Suction: Catheter Size

• Children: No more than 1½ times the diameter of the endotracheal tube (ETT).
• Adults: No more than ⅔ times the diameter of the ETT.
• Specific sizes for different age groups are given.

Nasopharyngeal Suction

• Indications: Weakness, semi-consciousness, similar to those for intubated patients.
• Precautions: Stridor, CSF leak/skull fracture (increased ICP and infection), clotting disorders, pulmonary edema, and bronchospasm.
• Other considerations: Recent pneumonectomy and oesophagectomy.

Suction Equipment

• Correct-sized catheter.
• Saline (10 ml in syringe).
• Sterile water for rinsing the suction catheter.
• Sterile gauze for cleaning the catheter.
• Goggles and mask for protection.
• Sterile alcohol swabs.
• Clean gloves.
• Suction device.
• Yankauer.

Suction Procedure

• Explain the procedure to the patient.
• Sterilize the equipment.
• Use protective sheath for the catheter.
• Oxygenation before and after suction.
• Catheter insertion depth adjustments based on eliciting cough reflex.
• Suctioning duration (10-15 seconds).
• Removal of catheter by rolling between fingers.
• Technique variations for ET/trach, nose, or mouth procedures.

Questions

• Questions remain outstanding.

References

• Citations of relevant articles, books, and websites are listed.