Mechanical Ventilation: Basics

BasicsMechanical Ventilation

Control

• Volume Control – volume limited, volume targeted and Pressure

Variable

• Pressure Control– pressure limited, pressure targeted and

Volume Variable

• Dual Control– volume targeted (guaranteed) pressure

limited

Mode• Mandatory

– CMV• Continuous Mandatory Ventilation

• Assist– Intermittent Mandatory Ventilation

• SIMVSynchronized Intermittent Mandatory Ventilation

– Pressure Support• CPAP / PEEP

Continuous Positive Airway Pressure Positive End Expiratory Pressure

• Spontaneous

Flow Pattern

Indications for mechanical ventilation

Extra-pulmonary NS:- OD sedatives, Coma, failure of resp centers

Neuromuscular: - injury, MG, GB, diaphragmatic dysfunction, ALS, electroly imbalances

Musculoskeletal:- injury, flail chest

Pulmonary airway obstruction, non-compliant lung tissue

Goals

- maintain alveolar ventilation

- deliver oxygen

- administer gases under pressure

- main positive end expiratory pressure (PEEP) - reduce the work of breathing

Potential Complications from Mechanical Ventilation

A Effects on the cardiovascular system - decreased cardiac output due to decreased venous return, increased right ventricular afterload and decreased left ventricular compliance B. Barotrauma (esp. with PEEP) - consequence of high

pressure in airways - overdistention of the alveoli causing rupture; gas escapes into interstitial spaces leading to subcutaneous emphysema, pneumothorax C. Oxygen toxicity D. Acid-Base Disturbances E. Water Imbalances (fluid volume excess) F. GI Bleeding

Potential Complications from Mechanical Ventilation

G. CNS Disturbances

H. Potential Infection

I. I. Fighting the Ventilator - breathing out of synchrony with ventilator

Reasons - hypoxia, airway obstruction, ventilator malfunction, anxiety, etc.

Intervention - ALWAYS ASSESS FIRST, then troubleshoot, consider sedation

J. Sleep deprivation & Psychological consequences K. Mechanical Failure

Nursing Care of the Ventilated Patient

A. Use of Paralyzing Agents

B. Possible Nursing Diagnostic stems for the Patient receiving mechanical ventilation

Impaired communication

Alteration in nutrition

Ineffective airway clearance

Impaired Gas Exchange (actual/ Potential) Ineffective breathing pattern (actual/ potential) Anxiety

• Q&A

• End

• Prepared by SNM, Med• 20 Aug 07