NURS 4540 Module 5 ALG Annotated

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Intrapulmonary Shunting

• Alveoli receive perfusion but no ventilation, hindering gas exchange.
• This causes blood to return to the left side of the heart unoxygenated.

Dead Space

• Alveoli receive ventilation but no perfusion, so it hinders gas exchange.
• This situation is called alveolar dead space.

Oxyhemoglobin Dissociation Curve

• Graph illustrates how hemoglobin's oxygen saturation changes with the blood's partial pressure of oxygen (PO2).
• Sigmoidal shape indicates that hemoglobin's oxygen-binding ability increases as more oxygen molecules attach.
• This allows efficient oxygen transport to tissues.

Right Shift on the Oxyhemoglobin Dissociation Curve

• Indicates decreased O2 saturation for a given PaO2, meaning Hgb has less affinity for O2.
• It picks up less O2 in the lungs and releases it more readily to tissues.
• Causes include fever, hypercapnea, and reduced pH (acidosis).

Left Shift on the Oxyhemoglobin Dissociation Curve

• Means increased O2 saturation for any PaO2, which impairs O2 delivery to tissues as Hgb holds onto O2 more tightly.
• Causes include cold conditions, alkalosis, low CO2, and low 2,3 DPG.

A-a Gradient Calculation

• Calculated using: PAO2 – PaO2
• PAO2 = [0.60 (713)] – 50/0.8 = 427.8 – 62.5 = 365.3 – PaO2 = 365.3 – 72 = 293.3 mmHg

Elevated A-a Gradient

• Indicates significant oxygenation impairment due to elevated V/Q mismatch or shunting.

Oxyhemoglobin Dissociation Curve Shift for COPD and Pneumonia

• Shifts to the right because of decreased pH and elevated partial CO2.
• Results in reduced attraction between hemoglobin to oxygen, which causes more oxygen to be released to the tissue.

Low-Flow Oxygen Delivery Systems

• Devices deliver oxygen at flows lower than the patient's ventilatory requirements.
• Used when precise FiO2 delivery is not critical and relies on the patient's anatomy and minute ventilation.
• Offer oxygen flows from 0 to 15 liters per minute.
• These include nasal cannulas, simple masks, reservoir masks, partial rebreathers, and nonrebreather/Tavish masks.
• Easy to use and comfortable, but cannulas and masks must fit well.

Reservoir Systems

• These are bags or face masks that allow an increased FiO2 rate compared to low-flow systems

High-Flow Oxygen Delivery

• Non-invasive respiratory support for critically ill patients, delivering accurate oxygen concentrations at flows exceeding patient's needs.
• It means administering gas flow above 6-l5 liters per minute or at least 40 liters per minute with conditioned gas.
• Used for acute hypoxemic respiratory failure and preventing intubation.
• Devices include ventilators, oxygen tents, tracheostomy collars, and aerosol masks.
• Venturi masks are the only devices capable of delivering controlled high-flow oxygen concentration to non-intubated patients.

Non-Invasive Ventilation

• Offers ventilator help without an invasive airway.

Oxygen Therapy Complications

• Oxygen Toxicity
• Absorptive Atelectasis
• CO2 retention
• Drying of Mucous Membranes
• Pressure Injuries

Nursing Care Related to Oxygen Therapy

• Monitor oxygen saturation and ABGs, and signs/symptoms of hypoxia.
• Administer the lowest effective FiO2 to achieve target oxygenation plus assess/evaluate/adjust the device.
• Prevent pressure injuries via tubing and mask or tubing.
• Humidify oxygen when using a high-flow system.
• Educate on the purpose, use of oxygen therapy and device usage, and the prohibition of smoking near the source.

Indications for Endotracheal Tube

• Airway patency, protection from aspiration, positive pressure ventilation, pulmonary hygiene, and the need for high O2 concentration.

Rapid Sequence Intubation (RSI) Steps

Preparation (Step 1)

• Gather and organize necessary equipment: suction, MRB, mask, 100% oxygen, laryngoscope, blades, ETTs, and stylet.
• Inspect equipment, prepare the patient with IV access, and monitor with pulse oximeter.

Preoxygenation (Step 2)

• Preoxygenate with 100% oxygen for 3-5 minutes via tight-fitting face mask.
• Assisted ventilations are initiated with an MRB if the patient cannot maintain adequate spontaneous ventilations.
• Avoid positive pressure ventilation to minimize gastric distention and aspiration risk.
• Cricoid pressure should be initiated if an MRB is used.

Pretreatment (Step 3)

• Administer adjunct medications (lidocaine, fentanyl, and atropine) to decrease the physiological response to intubation.
• A low paralytic dose may prevent fasciculations.
• Pretreatment should occur 3 minutes before the next step.

Paralysis with Induction (Step 4)

• Administer a sedative and a paralytic agent in rapid sequence, including etomidate, midazolam, ketamine, or propofol.
• Administer succinylcholine or rocuronium for skeletal muscle relaxation.

Protection and Positioning (Step 5)

• Position the patient in the "sniff" position with neck flexed and head extended slightly.
• Suction the oral cavity and pharynx while removing dental devices.
• Apply cricoid pressure to protect the airway from aspiration.

Placement of the Endotracheal Tube (Step 6)

• Insert the ETT into the trachea and confirm placement.
• Limit each intubation attempt to 30 seconds.
• Assess for bilateral breath sounds and chest movement.
• Use disposable end-tidal CO2 detector to initially verify placement, inflate the cuff, and secure the tube.
• Obtain a chest radiograph to confirm placement.
• The tip of the ETT should be 3-4 cm above the carina.

Post Intubation Management (Step 7)

• Note the level of insertion in centimeters at the teeth.
• Secure the ETT to the patient's face to prevent movement and dislodgement.

Possible Complications of Endotracheal Tubes

• Trauma: Prevented by correct cuff inflation pressure, securing the tube, and monitoring pressure.
• Vomiting with aspiration: Can be prevented by elevating the HOB to 30-45 degrees, affirming tube placement via chest x-ray, and prescribing medications like Protonix or H2 inhibitors.
• Hypoxemia and hypercapnia: Prevented by monitoring ABGs, SpO2, and end-tidal CO2 and also performing routine suction and correct humidification, and using hand restraints.
• Inflammation: Prevented by using humidified oxygen and avoiding tube movement.
• Sinusitis: Prevented by assessing/monitoring for sinus infection and using oral rather than nasal intubation.
• Fistula: Prevented by maintaining proper cuff pressure (20-25 cm H2O) and preventing prolonged intubation.
• Tube obstruction or displacement: Prevented by routine suctioning, maintaining hydration, assessing tube positioning, securing the tube, and being cautious during repositioning and transport.
• Tracheal stenosis: Prevented by avoiding prolonged intubation, assessing cuff pressure, and maintaining humidification.

Indications for Tracheostomy Placement

• Prolonged Mechanical Ventilation
• Airway Obstruction
• Neuromuscular Disorder
• Severe Neck/Head Trauma
• Ineffective Airway Clearance
• Facial or Airway Burns
• Repeated/Chronic Intubations

Complications with Tracheostomy

Complications

• Displacement
• Bleeding
• Nerve injury
• Pneumothorax
• Fistulas

Prevention

• Use correct tube size
• Treat local infection
• Gentle suction
• Inflate cuff with minimal amount of air as necessary
• Assess/Monitor cuff pressure

Nursing Management of a Patient with an Artifical Airway

• Humidification, cuff management, suctioning, communication, oral hygiene, extubation, and decannulation.

Indications for Mechanical Ventilation

• Respiratory Failure
• Airway Protection and Patency
• Increased Work for Breathing and Respiratory Distress

Ventilator Settings

FiO2 (Fraction of Inspired Oxygen)

• Represents percentage of oxygen; ranges from 21% (room air) to 100% (pure oxygen).
• Adjusted to maintain sufficient oxygenation while minimizing oxygen toxicity.

Tidal Volume

• Amount of air the ventilator delivers with each breath, based on ideal body weight (IBW).
• Important for adequate ventilation without causing overdistension or barotrauma.

Rate

• Speed at which tidal volume is delivered, influencing patient comfort and ventilation effectiveness.

Frequency Rate

• Breaths set by the ventilator per minute to ensure adequate ventilation and CO2 levels.

PEEP (Positive End Expiratory Pressure)

• Pressure maintains lungs at the end of expiration, which keeps alveoli open and improves oxygenation.

Pressure Support

• Spontaneous mode where the ventilator supports each patient-initiated breath with a preset pressure.

I:E Ratio (Inspiratory to Expiratory Ratio)

• Duration of inhalation compared to exhalation(normal is 1:2).
• In ARDS, a longer inspiratory time is beneficial and in COPD, a longer exhalation is needed for complete exhalation.

Sensitivity

• Responsiveness of the ventilator to patient's spontaneous breathing efforts.

High Pressure Limit

• Maximum pressure configurable during ventilation

Ventilator Patient Readings

• Patient Tidal Volume: Air administered per breath (mL)
• Minute Volume: Total air breathed per minute by the patient.
• Peak Inspiratory Pressure: Highest pressure achieved during inspiration.

Ventilator Modes

Assist Control (AC)

• Administers preset tidal volume or pressure with every breath.

Assist Control Pressure Control (ACPC)

• Administers a configured preset measure of pressure instead of volume.

Assist Control Volume Control (ACVC)

• Administers a set tidal volume with every breath, to maintain ventilation consistently.

Pressure Regulated Volume Control (PRVP)

• Hybrid mode that administers a preset tidal volume that adjusts pressure.

Synchronized Intermittent Mandatory Ventilation (SIMV)

• Offers preconfigured breaths and also allows for spontaneous breaths.

Continuous Positive Airway Pressure (CPAP)

• Offers a consistent airway pressure which is used to wean, for sleep apnea or if patient has mild respiratory failure.

Complications of Ventilation

Ventilator-induced Lung Injury

• Air leaks (barotrauma, volutrauma, atelectrauma) and biotrauma.
• To limit lung injury: Plateau pressure should be kept at less than 32 cm H2O, PEEP should be used to avoid end-expiratory collapse, and tidal volume should be set at 6 to 10 mL/kg.

Cardiovascular Compromise

• Positive-pressure ventilation increases intrathoracic pressure, which decreases venous return.
• Impaired autoregulation can result in increased intracranial pressure

Gastrointestinal Disturbances

• Can be prevented by inserting a nasogastric tube and ensuring appropriate cuff inflation
• Gastric distention and vomiting can occur.

Patient-Ventilator Dysynchrony

• Can be minimized by adjusting ventilator and accommodating spontaneous breathing

Ventilator-Associated Pneumonia (VAP)

• Pneumonia 48-72 hours after intubation
• Prevention includes elevation of the head of the bed, daily “sedation vacations”, peptic ulcer disease and DVT prophylaxis, and daily oral care.

Cues that Indicate Patient Readiness for Weaning

• Decrease in LOC
• Systolic blood pressure increased or decreased by 20 mm Hg
• Diastolic blood pressure greater than 100 mm Hg
• Elevated heart rate
• Premature ventricular contractions greater than 6 per minute, couplets, or runs of ventricular tachycardia
• Changes in ST segment
• Abnormal respiratory rate
• Spontaneous tidal volume less than 250 mL
• High Arterial partial pressure of carbon dioxide
• Low Oxygen saturation
• Complaints of dyspnea, fatigue, or pain
• Paradoxical chest wall motion or chest abdominal asynchrony
• Diaphoresis
• Severe agitation or anxiety unrelieved by reassurance

Methods of Weaning

• T-tube (T-piece) trials, synchronized intermittent mandatory ventilation (SIMV), and pressure support ventilation (PSV).
• Standardized approach decreases weaning time and the length of stay in the critical care unit.

Nursing Management of the Patient on the Ventilator

• Monitor conditions indicating need for ventilation support.
• Monitor for impending respiratory failure.
• Consult with other health care personnel in selection of a ventilator mode.
• Obtain baseline total body assessment of patient initially and with each change of caregiver.
• Initiate setup and application of the ventilator.
• Ensure that ventilator alarms are on.
• Instruct patient and family about rationale and expected sensations associated with the mechanical ventilators.
• Routinely monitor ventilator settings, including temperature and humidification of inspired air.
• Check all ventilator connections are on, and monitor for decrease in exhaled volume and increase in inspiratory pressure.
• Administer muscle paralyzing agents, sedatives, and narcotic analgesics, as appropriate.
• Monitor for activities that increase oxygen consumption.
• Monitor for symptoms that indicate increased work of breathing and effectiveness of mechanical ventilation on patient's physiologic and psychologic status.
• Provide care to alleviate patient distress like patient positioning, tracheobronchial toileting, bronchodilator therapy, sedation and/or analgesia, frequent equipment checks. Also, provide patient with means for communication.
• Perform other standard procedures like emptying condensed water from water traps, aseptic suctioning, monitoring pressure readings, or monitor pulmonary secretions.
• Also perform routine tasks like stopping tube feedings during suctioning, monitor adverse effects, mucosal damage or provide oral care.

Ventilator Adjustments Based on ABGs (Patient A; pH 7.20, PaCO2 62, PaO2 40, O2 Sat 84%)

• Increase Tidal Volume(TV)
• Increase FiO2
• Increase Peep
• Increase Rate

Long-Term Mechanical Ventilator Dependence (LTMVD)

• Patient requires assisted ventilation longer than expected.
• NAMDRC definition: The need for ≥2] consecutive days of mechanical ventilation for ≥6 hours per day.

Interventions to Manage a Patient with Ventilator Dependence

• Monitor settings and parameters
• Assess breath sounds and chest movement
• Maintain proper positioning and sterile technique during suctioning.
• Perform oral care every 4 hours.
• Maintain head-of-bed elevation at 30-45 degrees
• Monitor arterial blood gases
• Perform airway clearance
• Adjust ventilator settings
• Provide additional care protocols like implementing the turning schedule, proper ETT securing, or establishing an effective communication method.