Self Assessment Questions Module 3 Flashcards

Intubation and Mechanical Ventilation Criteria

• Intubation is indicated based on multiple physiological parameters.
• pH levels below 7.20 suggest the need for ventilation support.
• PaO2 levels under 50 mmHg on room air or below 70 mmHg on 40% FIO2 necessitate intervention.
• P (A-a)DO2 values less than 25-65 mmHg on room air or under 350 mmHg on 100% FIO2 indicate inadequate oxygenation.
• PaCO2 exceeding 55 mmHg or 87 mmHg in CO2 retainers signals redistribution of ventilation.
• A minute ventilation greater than 10 LPM reflects a strong demand for air.
• VD/VT ratios above 60% suggest significant dead space ventilation.
• Respiratory rates greater than 35 also warrant mechanical ventilation.
• Negative Inspiratory Force (NIF) below -20 indicates inadequate respiratory muscle strength.

Hazards of Positive Pressure Ventilation and PEEP

• Positive Pressure Ventilation (PPV) disrupts normal respiratory pressure gradients, potentially reducing cardiac output.
• Increased pleural pressures during inspiration may elevate arterial pressures, leading to diminished perfusion.
• Positive End-Expiratory Pressure (PEEP) can elevate intracranial pressure (ICP).

PEEP Criteria and Goals

• PEEP is implemented when FIO2 exceeds 60%.
• The primary goal of PEEP is to improve Functional Residual Capacity (FRC) and enhance oxygenation while minimizing the FIO2 needed to achieve adequate PaO2 levels.

Utilization of PEEP in Mechanical Ventilation

• PEEP is indicated when FIO2 is 50% or less, and PaO2 remains below 60.
• Common modes utilizing PEEP include SIMV, BILEVEL, and CPAP.

Comparison of PEEP, EPAP, and CPAP

• PEEP, EPAP, and CPAP all employ positive airway pressure during expiration to recruit collapsed alveoli and increase FRC.

Effects of Changes in Peak Flow

• Decreased peak flow increases inspiratory time (TI) but decreases expiratory time (TE) and the I:E ratio, while total time (TT) decreases.
• Conversely, increased peak flow results in decreased TI, increased TE, and I:E ratios, leading to an increase in TT.

Goals of Mechanical Ventilation

• Improve minute ventilation in cases of hypercapnia.
• Enhance alveolar ventilation, impacting both oxygenation and hypercapnia conditions.
• Optimize gas distribution for effective external respiration.
• Improve ventilation/perfusion (VQ) ratios.
• Reduce work of breathing (WOB).
• Normalize arterial blood gases (ABG).

Volume Control Ventilation (VCV) Dynamics

• Increasing tidal volume in VCV enhances both alveolar ventilation and minute ventilation.
• Decreasing tidal volume in VCV results in diminished alveolar and minute ventilation.

Pressure Control Ventilation (PCV) Effects

• Increasing pressure in PCV corresponds to larger tidal volumes and improved alveolar ventilation.

Management of Patient Synchrony

• In cases of patient dysynchrony during VCV, increasing flow rates may help resolve the issue.

Monitoring During PEEP Implementation

• Close monitoring of Plateau Pressure (PPlat) and Peak Inspiratory Pressure (PIP) is essential to prevent barotrauma.

Protective Lung Strategy for Increased ICP

• Inducing an alkalotic state in patients with head injuries can lead to cerebral vasoconstriction, optimizing ICP.

Pharmacological Management for ICP

• Mannitol (generic) or Osmitrol (brand) is recommended to alleviate increased intracranial pressure.

Achieving Protective Lung Strategy

• Adjustments in respiratory rate contribute to the implementation of protective lung strategies during mechanical ventilation.

Scalar Wave Forms and MAP

• Specific waveforms influence Mean Arterial Pressure (MAP), with square waveforms shown to elevate MAP.
• Auto-PEEP is ideally detected through specific waveforms, warranting careful monitoring and management strategies.