Ch.9 Monitoring in Mechanical Ventilation

Heart rate, blood pressure, respiratory rate, and temperature

Vital signs

60 - 100/min

Normal adult heart rate

Hypoxemia, hypovolemia, pain, anxiety, and stress, fever, drug reactions, and myocardial infarction

Tachycardia may be caused by

Deficiency of oxygen in blood; low PaO2

Hypoxemia

Deficiency of oxygen in tissues

Hypoxia

Heart rate higher than 100/min

Tachycardia

Heart rate lower than 60/min

Bradycardia

During suctioning

Bradycardia often occurs with

Pre oxygenate patient first

How to avoid bradycardia when performing suctioning

Arterial desaturation and arrhythmias

Preoxygenation is often necessary to minimize the occurrence of

Stop suction and provide 100% oxygen to the patient

While suctioning, if bradycardia and arrhythmia occurs you should

Hypertension

Fluid overload, vasoconstriction, stress, anxiety, and pain may lead to

Higher than normal blood pressure

Hypertension means

Congestive heart failure (CHF), cardiovascular disease, or polycythemia

What kinda of patient that can developed hypertension and can lead to complications during mechanical ventilation

• Sudden hypoxia and/or vag stimulation during endotracheal suctioning

• Inadequate coronary blood flow

• Heart block

• Abnormal SA node function

• Hypothermia

• Drug reaction (e.g., morphine sulfate)

Conditions that may cause bradycardia

Hypotension

Hypovolemia, positive pressure ventilation, and pump failure are conditions that may cause

Lower than normal blood pressure

Hypotension means

Absolute hypovolemia (blood loss)

Relative hypoxemia (shock)

Pump failure (CHF)

Hypotension may be due to

Excessive intrathoracic pressure

Peak inspiration pressureand

Lung volume

When hypotension occurs during mechanical ventilation is often associated with

True

True of False: Hypotension is one of the complications of positive ventilation or positive end-expiratory pressure

12-20

Respiratory normal rate

• Fluid overload

• Stress

• Anxiety

• Pain

• Congestive heart failure CHF

• Cardiovascular disease

• Polycythemia (increase viscosity)

Conditions that may caused by hypertension

• Decrease Venous return due to positive pressure Ventilation

• Absolute hypovolemia (blood loss and dehydration)

• Relative hypovolemia (sepsis, and shock)

• Pump failure (CHF)

Conditions that may cause Hypotension

Hypoventilation or hypoxia

An increased respiratory frequency may be an early warning sign of

Below normal level of alveolar ventilation characterized by an elevated PaCO2

Hypoventilation

Respiratory failure (need to use mechanical ventilation)

Tachypnea may precede the development of

Respiratory dysfunction

During mechanical ventilation tachypnea Is indicative of

Not likely

When patient is tachypnea and have low tidal volume, Successful weaning from mechanical ventilation is

Routine monitoring of a patient spontaneous respiratory frequency

What is the useful method to asses the pulmonary status of a ventilator patient?

Via a rectal, esophageal, or pulmonary artery catheter probe

In ICU, patient temperature may be measured routinely at regular intervals or monitored continuously

Lower oxygen saturation at any PaO2

Hyperthermia causes a

Basal metabolic rate

Hypothermia can lowers a person’s

• infection

• Tissue necrosis

• Leukemia

• Other conditions that increase metabolic rate and oxygen utilization

Hyperthermia can occurs as a result of

shift to the right (causing a lower oxygen saturation level at any PaO2)

Hyperthermia will cause the curve to shift to the

• central nervous system (CNS) problems

• Metabolic disorders

• Drugs or toxins

Hypothermia can occurs as a result of

140/90 mmHg

Hypertension stage 1

160/100 mmHg

Hypertension stage 2

Hypoventilation or hypoxia

Tachypnea is an early sign of

90/60 mmHg

Hypotension

• Respiratory dysfunction (Excessive secretions, Tension Pneumothorax)

• Inappropriate ventilator setting (insufficient tidal volume, flow, or pressure support)

Causes of tachypnea during mechanical ventilation

Head trauma patients as a means of decreasing the patients basal metabolic rate

Hypothermia is sometimes induced in

When hypotension occur during mechanical ventilation, it is often associated with

Excessive Intrathoracic pressure

Peak inspiratory pressure

Lung volume

Chest inspection use uses _____ Menthols to access evaluate the lungs and be related structures

Indirect

Asymmetrical movement Can occur in condition such as

• Right mainstem bronchial intubation

• Atelectasis

• Tension pneumothorax

The chest radiograph is the most common menthod to evaluate the condition of

• The thoracic structure

• Lungs

• Pleural space

• Insert catheter

• Lines

• Tubes

Conditions for Diminished or absent breath sound

• Airway obstruction

• Atelectasis

• Mainstem intubation

• Pleural effusion

• Pneumothorax

Conditions for wheezes breath sound

Airway narrowing

Condition for inspiratory, crackles breath, sound

• Lung consolidation

• Pulmonary edema

Conditions for coarse crackles breath sound

Excessive secretions

True or False auscultation should be performed every time we assesses patient with ventilator system

True

The stethoscope also can be used for detection of

• cuff leak

• Right main stem intubation

A cuff leak may be detected by placing the stethoscope over the

Trachea and on top of the cuff location

True or False A lateral chest radiograph is used in conjunction with the PA radiograph to verify the location of any abnormal findings in the lungs

True

Dark-shaded x-ray shows

Air-filled structure (trachea and lung parenchyma) over exposure

White shade on x-ray shows

Tissue and bones (unexposure)

Normal chest radiograph appearance

• Midline trachea and mediasternum

• Dark lung parenchyma with mild scattered white shadows

• Sharply pointed right and left costophrenic angels

• Smooth and continuing bony structures

• Cardiac shadow <50%

Shift trachea or mediasternum to affected side shows

• Atelectasis

• Pulmonary fibrosis

Shift trachea or mediasternum to unaffected side shows

Tension pneumothorax

Shift of mediastinum to opposite

tension pneumothorax, pleural effusion, main-stem intubation

No shift of mediastinum

Consolidation

Infiltrates X-ray shows

White shadows suggest accumulation of secretions and Atelectasis

Blunted costophrenic angle suggests

Accumulation of fluid in pleural space

(Pleural effusion, hemothorax, empyema)

Jagged appearance suggests

Fracture or broken bones

Congestive heart may cause the cardiac shadow to

Exceed 50%

True or false mechanical ventilation may affect a patient’s renal function and fluid balance

True

During positive pressure ventilation

• reduced urine output and fluid retention occur due to Decrease in cardiac output and renal perfusion, Increase in antidiuretic hormone (ADH), Decrease in atrial natriuretic factor (ANF)

Oliguria may be seen after

Bleeding, Diarrhea, Renal failure, Shock, Drug poisoning, Deep coma, And hypertrophy of the prostate

Oliguria indicates

Flute deficiency and may occur as a Result of decrease renal perfusion, Decrease fluid intake, And decrease cardiac output

Normal urine output

50 to 60 ml per hour

Oliguria (low urine output)

<20 mL/hr

- <400 mL/24 hr

- <160 mL/8 hr

anion gap

Using some of these Parameters, the anion gap May be calculated and used to assess a patient overall electrolyte balance

Anion gap = Na - Cl - HCO3

Normal range is 10 to 14 mEq/L

Anion gap = Na + K - Cl - HCO3

Normal is 15 to 20 mEq/L

Sodium (Na)

135-145

Potassium (K)

3.5-5.0

Chloride (Cl)

95-105

HCO3

22-26

Calcium (Ca)

8.5-10.5

Magnesium (Mg)

1.5-2.5

Hypoventilation and respiratory acidosis are present when the PaCO2 is

increased with a concurrent decrease in pH.

Increase PaCO2

-Acute increase: acute ventilatory failure

- Progressive increase: impending ventilatory failure

- Trending of PaCO2 is crucial

Decrease PaCO2

- Improvement of pulmonary mechanics or patient condition

- In response to hypoxia, pain, anxiety

- Ventilator frequency must not be reduced as it will cause further hyperventilation, muscle fatigue, and ventilatory failure

Hypoxemia may be due to Hypoventilation

Increased PaCO2, Primary treatment is to improve ventilation

Hypoxemia may be due to V/Q mismatch

Near normal PaCO2, Responds very well to low to moderate levels of FIO2, Primary treatment is oxygen therapy

Hypoxemia may be due to Intrapulmonary Shunting

Near normal PaCO2, Responds poorly to moderate to high levels of FIO2(refractory hypoxemia), Primary treatment is PEEP (with mechanical ventilation) or CPAP (with spontaneous breathing)

hypoxemia may be due to diffusion detect

Near normal PaCO2

- Variable response to FIO2 depending on severity of diffusion defect (e.g., mild vs. severe pulmonary edema)

- Primary treatment is oxygen therapy for mild diffusion defect

- Find and treat cause of severe diffusion defect

 

PaCO2 Response is often variable depends on

severity of condition and pulmonary reserve of patient

Which type of hypoxemia causes refractory hypoxemia

Intrapulmonary shunting hypoxemia (treatment is PEEP or CPAP) But shay said most people will get intubated

Blood gas technical error

-Unrecognized “mixed” venous or venous sample

- Air bubble

- Excessive heparin due to small sample volume

Blood gas inconsistent result

-Single sample does not reflect patient condition over time

- Blood gas results must correlate with clinical signs (e.g., patient’s appearance, vital signs, pulse oximetry)

Normal SPO2

95% to 100%

Normal SPO2 for ventilated patient

Above 92%

Normal SPO2 for COPD

88% to 92%

Factors that affects SpO2 measures lower than actual SaO2

Sunlight, nail polish, fluorescent light, intravenous dyes.

Factor that affects SpO2 measures higher than actual SaO2

Dyshemoglobin, sulfahemoglobin, carboxyhemoglobin

Normal Perfusion index

Measures pulse strength (low 0.02% to high 20%)

how a low value indicates vasoconstriction.

- Low PI: vasoconstriction

- Low PI corresponds with illness in neonates

- Used in assessment of pain

- Early indicator of successful epidural block in laboring women

True os false The correlation between PaCO2 and PetCO2 is excellent. PaCO2 is about 2 mmHg higher than the PetCO2 in normal individuals.

True

For critical patient a gradient of ___ is considered acceptable.

5 mmHg

The P(a-et)CO2 gradient is primarily affected by

alveolar deadspace ventilation, old age, presence of pulmonary disease, and changes in mechanical volume and modality.