Uses positive pressure to bring air into the lungs Can be used for both invasive and non invasive ventilation

PPV has 3 types:

Airway pressures such as: ____,____,____= __,___,___/____ have direct impact on: a. b c indirectly on ______

Lungs with normal compliance - __________________ is transmitted to the thoracic cavity. Lungs with low compliance - pressure transmitted to the thoracic cavity is much less due to dampening effect of ______. - for this reason the decrease in cardiac due to excessive_____or _______ is less severe.

Mean Airway Pressure and Cardiac Output 1. PIP, I Time, RR, PEEP – shld be kept at minimum to keep mPaw at lowest possible level 2. Decrease in Cardiac Output and delivery O2 content x ↓ CO = ↓ O2 delivery 3. Blood Pressure Changes

in CARDIOVASCULAR CONSIDERATION Mean Airway Pressure and Cardiac Output 1. ___,__,___,___ – shld be kept at minimum to keep mPaw at lowest possible level 2. Decrease in Cardiac Output and delivery O2 content x ↓ CO =______ 3. Blood Pressure Changes

Diagram of PPV leading to decrease in O2 Delivery

Blood Pressure Changes _____________ ↓ in systolic in asthma patient, cardiac tamponade_____ ___________________ ↑ in systolic ______ – hypovolemia note: ____+___ may further lower cardiac output/ compromise cardiovascular functions in patients with cardiopulmonary disease.

Pulmonary Blood flow and Thoracic Pump mechanism PPV affects pulmonary blood flow entering and leaving the heart ________________: ↑ in lung volume results in ↓pulmonary venous return to the Left ventricle ________________: ↑ in lung volume results in ↑pulmonary venous return to the Left ventricle due to: 1. compression of pulmonary blood vessel is minimal 2. due to thoracic pump mechanism - blood flow is enhanced during expiratory phase of PPV.

EFFECTS OF PPV ON HEMODYNAMIC MEASUREMENTS

Eliminating waste, clearance of certain drugs, regulating fluid, electrolytes and acid-base balance Affected due to hypoperfusion Can lead to: 1. renal failure – urine output of < 400ml in 24 hours, ↑ BUN and Creatinine level

renal consideration Eliminating waste, clearance of certain drugs, regulating fluid, electrolytes and acid-base balance Affected due to hypoperfusion Can lead to: 1. _____ _____ – urine output of ____ in 24 hours, ↑ BUN and Creatinine level

Perfusion accounts for 15% of total CO Can lead to liver dysfunction - prothrombin (coagulation) time > 4 sec - bilirubin level level > 50mg/L - albumin < 20g/L Affects rate of drug clearance – increased concentration and prolonged drug effect

hepatic consideration Perfusion accounts for ___ of total CO Can lead to liver dysfunction - prothrombin (coagulation) time ____ - bilirubin level level ____ - albumin ____ Affects rate of drug clearance – increased concentration and prolonged drug effect

↑ Intraabdominal Pressure (IAP), due to: 1. bowel edema or obstruction 2. ascites 3. procedures such as: a. pneumatic anti shock garments b. surgical repair of abdominal hernia

abdominal consideration ↑ IAP (_______) + PPV + PEEP (_____) can cause: 1. potentiation of pressures exerted on heart and blood vessels, leading to: a. cardiovascular dysfunction - ↓ CO b. renal dysfunction ↓ renal perfusion ↓Glomerular filtration rate c. pulmonary dysfunction decrease FRC increase atelectasis impaired gas exchange increase V/Q mismatch

abdominal consideration c. Pulmonary dysfunction ___FRC ___atelectasis impaired gas exchange ___ V/Qmismatch

Complications: Erosive esophagitis stress related mucosal damage (SRMD) diarrhea decreased bowel sound high gastric residual constipation

gastrointestinal consideration Complications are due to: 1. __ perfusion to GI tract 2. _______ used during MV

malnutrition - are due to: frequent interuptions in enteral feeding > protein catabolism > loss of muscle performance > difficulty of weaning due to muscle weakness

nutritional consideration Diaphragmatic dysfunction - is due to: _____ > cause by muscle proteolysis - leads to ___ in muscle fiber content

______________ or ________ - a complete nutritional program provided to patients by any method other than intestinal route

nutrition and work od breathing hypertonic solution consisting of: 1 2 3 4 5

nutrition and work of breathing should keep _____(___)to a minimum > ↑ O2 consumption and CO2 production

nutrition and work of breathing _________ > provide maximum caloric intake with minimum CO2 production > less WOB > patients with significant or persistent CO2 production

Neurologic Changes in Hyperventilation Decreased cerebral blood flow

neurologic changes in hyperventilation Reduced intracranial pressure

neurologic changes in hyperventilation Left shift of oxyhemoglobin curve

neurologic changes in hyperventilation Increased O2 affinity for hemoglobin

neurologic changes in hyperventilation Reduced O2 releases to tissues

neurologic changes in hyperventilation Cerebral tissue hypoxia

neurologic changes in hyperventilation Neurologic dysfunction

neurologic changes in hyperventilation hypophosphatemia

Neurologic Changes in Hypercapnia and hypoxemia Increased cerebral blood flow

Neurologic Changes in Hypercapnia and hypoxemia increased intracranial pressure

Neurologic Changes in Hypercapnia and hypoxemia Impaired cerebral metabolism

neurogenic changes in hypercapnia and hypoxemia Decreased mental and motor functions