PHYSIOLOGIC PHYSIOLOGIC MONITORINGMONITORING

I.I. Hemodynamic MonitoringHemodynamic Monitoring

- provides information as to the C-P - provides information as to the C-P status of the patientstatus of the patient

- traditional clinical assessment are - traditional clinical assessment are usually unreliableusually unreliable

- major changes in the cardiovascular - major changes in the cardiovascular status may not be clinically obviousstatus may not be clinically obvious

- invasive techniques must be utilized- invasive techniques must be utilized

A. Arterial CatheterizationA. Arterial Catheterization

1. Indications1. Indications

a. Need for continuous blood a. Need for continuous blood pressure pressure monitoring.monitoring.

b. Need for frequent arterial b. Need for frequent arterial blood blood sampling. sampling.

Conditions that need continuous Conditions that need continuous and accurate BP monitoring:and accurate BP monitoring:

i. shock statesi. shock statesii. hypertensive crisisii. hypertensive crisisiii. surgery in high risk patientsiii. surgery in high risk patientsiv. use of potent vasoactive or iv. use of potent vasoactive or

inotropic drugsinotropic drugsv. controlled hypotensive v. controlled hypotensive anesthesiaanesthesiavi. situations that may lead to rapid vi. situations that may lead to rapid

changes in cardiac function changes in cardiac function

2. Contraindications2. Contraindications- no ABSOLUTE contraindication - no ABSOLUTE contraindication to arterial catheterizationto arterial catheterization- RELATIVE contraindications are:- RELATIVE contraindications are:

a. bleeding problems a. bleeding problems (hemophelia)(hemophelia)b. anticoagulant therapyb. anticoagulant therapyc. presence of a vascular prosthesisc. presence of a vascular prosthesisd. local infectiond. local infection

3. Sites of Catheterization3. Sites of Catheterizationa. radial artrerya. radial artrery- dual blood supply- dual blood supply- most commonly used site- most commonly used site- simple canulation- simple canulation- low complication rate- low complication rate- modified “Allen’s” test – assess - modified “Allen’s” test – assess ulnar arteryulnar artery- Doppler technique, - Doppler technique,

plethysmography, plethysmography, pulse pulse oximetryoximetry

b. axillary arteryb. axillary artery- for long term monitoring- for long term monitoring- large size- large size- close proximity to the aorta- close proximity to the aorta- deep location- deep location- technical difficulty in insertion- technical difficulty in insertion- located near neurovascular - located near neurovascular

structuresstructures

c. femoral arteryc. femoral artery- large size and superficial - large size and superficial locationlocation- prone to atherosclerosis- prone to atherosclerosis- difficult to keep clean- difficult to keep clean

d. dorsalis pedisd. dorsalis pedis

e. superficial temporal arterye. superficial temporal artery- surgical exposure is required- surgical exposure is required- neurologic complications observed- neurologic complications observed

f. brachial arteryf. brachial artery

- for short term use only- for short term use only

- median nerve contracture - median nerve contracture (Volkman’s contracture)(Volkman’s contracture)

*Complications of arterial catheterization*Complications of arterial catheterization1. failure to cannulate1. failure to cannulate2. hematoma2. hematoma3. disconnection from monitoring system3. disconnection from monitoring system4. infection4. infection

- catheters in place for more than 4 days- catheters in place for more than 4 days- surgical insertion- surgical insertion- local inflammation- local inflammation

5. retrograde cerebral embolization5. retrograde cerebral embolization6. A-V fistula / pseudoaneurysm6. A-V fistula / pseudoaneurysm7. severe pain, distal necrosis7. severe pain, distal necrosis

B. Central Venous CatheterizationB. Central Venous Catheterization1. Indications1. Indications

a. access for fluid therapya. access for fluid therapyb. access for drug infusionb. access for drug infusionc. parenteral nutritionc. parenteral nutritiond. CVP monitoringd. CVP monitoringe. other indicationse. other indications

- aspirate air embolism- aspirate air embolism- placement of cardiac - placement of cardiac

pacemaker / vena cava filterspacemaker / vena cava filters- hemodialysis access- hemodialysis access

*Central Venous Pressure Monitoring*Central Venous Pressure Monitoring1. useful in hypotensive patients1. useful in hypotensive patients2. tracings for arrythmias2. tracings for arrythmias3. gives information about the relationship 3. gives information about the relationship between intravascular volume and right between intravascular volume and right ventricular functionventricular function4. use of a water manometer for pressure 4. use of a water manometer for pressure measurementsmeasurements5. Normal CVP measurement – 5-10 mmH2O5. Normal CVP measurement – 5-10 mmH2O

2. Sites of catheterization2. Sites of catheterizationa. subclavian veina. subclavian vein- easiest to cannulate- easiest to cannulate- pneumothorax most common complication- pneumothorax most common complication- difficult to control bleeding- difficult to control bleeding

b. internal jugular veinb. internal jugular vein- lower risk of pneumothorax- lower risk of pneumothorax- arterial puncture most common complication- arterial puncture most common complication

c. external jugular veinc. external jugular vein

d. basilic veind. basilic vein

*Complications*Complications

1. catheter malposition1. catheter malposition

2. dysrythmmias2. dysrythmmias

3. embolization3. embolization

4. vascular injury4. vascular injury

5. cardiac, pleural, mediastinal, neurologic 5. cardiac, pleural, mediastinal, neurologic injuryinjury

II. Respiratory MonitoringII. Respiratory Monitoring- monitoring ventilation and gas exchange- monitoring ventilation and gas exchange* Indications* Indications

1. Decision making for the need of 1. Decision making for the need of mechanical ventilation.mechanical ventilation.2. Assessment of response to 2. Assessment of response to

therapy.therapy.3. Optimize ventilatory management.3. Optimize ventilatory management.4. Decision to wean from ventilator.4. Decision to wean from ventilator.

A. Ventilation monitoringA. Ventilation monitoring1. Tidal volume – volume of air moved in or 1. Tidal volume – volume of air moved in or out of the out of the

lung an lung an a single breatha single breath

2. Vital capacity – maximal volume at expiration after a 2. Vital capacity – maximal volume at expiration after a maximal maximal inspirationinspiration

3. Minute volume – total volume of air leaving the lung each 3. Minute volume – total volume of air leaving the lung each minuteminute

4. Phsiologic dead space – the portion of tidal volume that 4. Phsiologic dead space – the portion of tidal volume that does not does not participate in in gas exchangeparticipate in in gas exchange

a. anatomic dead spacea. anatomic dead spaceb. phsiologic dead spaceb. phsiologic dead space

B. Gas MonitoringB. Gas Monitoring- reported as directly measured partial pressures - reported as directly measured partial pressures (PO2 and PCO2)(PO2 and PCO2)- use of pulse oximeters for continuous - use of pulse oximeters for continuous measurementsmeasurements

1. Blood gas analysis – information 1. Blood gas analysis – information about:about:

a. efficacy of gas exchangea. efficacy of gas exchangeb. adequacy of alveolar ventilationb. adequacy of alveolar ventilationc. acid – base statusc. acid – base status

2. Capnography 2. Capnography - graphic display of CO2 concentration in wave form - graphic display of CO2 concentration in wave form - available systems- available systems

a. infrared analysisa. infrared analysisb. mass spectrometryb. mass spectrometryc. Raman scatteringc. Raman scatteringd. disposable colorimetric devicesd. disposable colorimetric devicese. semi-quantitive measurement on the e. semi-quantitive measurement on the

end-end- tidal CO2 concentrationtidal CO2 concentration

3. Pulse oximetry3. Pulse oximetry

- reliable, real time - reliable, real time estimation of the estimation of the arterialarterial

Hgb saturationHgb saturation

- wide clinical - wide clinical acceptanceacceptance

4. Gastric Tonometry4. Gastric Tonometry

- relatvely non-invasive monitor of - relatvely non-invasive monitor of adequacy of aerobic metabolism in adequacy of aerobic metabolism in organs organs whose superficial mucosal whose superficial mucosal lining is lining is extremely vulnerable to low extremely vulnerable to low flow flow changes changes and hypoxemiaand hypoxemia

III. Renal MonitoringIII. Renal Monitoring

- the kidney is an excellent monitor of - the kidney is an excellent monitor of adequacy of perfusionadequacy of perfusion

- prevention of renal failure- prevention of renal failure

- predict drug clearance and proper dose - predict drug clearance and proper dose adjustmentadjustment

A. Urine OutputA. Urine Output

- commonly monitored but may be - commonly monitored but may be misleadingmisleading

- normal urine output - normal urine output 0.5 ml/kg/hour 0.5 ml/kg/hour

- correlates with glomerular filtration rate - correlates with glomerular filtration rate (GFR)(GFR)

- high output may not accurately reflect GFR - high output may not accurately reflect GFR ex. Diabetes Insipidusex. Diabetes Insipidus

- may be affected by other factors- may be affected by other factors

B. Glomerular Function TestsB. Glomerular Function Tests1. Blood Urea Nitrogen (BUN)1. Blood Urea Nitrogen (BUN)

a. affected by GFR and urea a. affected by GFR and urea productionproduction

b. increased in TPN, GI bleeding, b. increased in TPN, GI bleeding, trauma, sepsis, steroid usetrauma, sepsis, steroid use

c. lowered in starvation, liver c. lowered in starvation, liver diseasediseased. not a reliable testd. not a reliable test

2. Plasma Creatinine2. Plasma Creatininea. more accurate than BUNa. more accurate than BUNb. directly proportional to b. directly proportional to

creatinine creatinine productionproductionc. inversely related to GFRc. inversely related to GFRd. not affected by protein or d. not affected by protein or

nitrogen production or rate nitrogen production or rate of fluid of fluid flow through tubulesflow through tubules

e. related to muscle masse. related to muscle mass

3. Creatinine Clearance3. Creatinine Clearance

a. used if values of plasma a. used if values of plasma creatinine are affected by creatinine are affected by

muscle muscle diseasedisease

b. serial determination of urine is b. serial determination of urine is done and is currently the done and is currently the

most most reliable method of reliable method of assessing GFRassessing GFR

C. Tubular Function TestsC. Tubular Function Tests

1. The most reliable test to 1. The most reliable test to distinguish distinguish pre-pre- renal azotemia from renal azotemia from tubular tubular necrosisnecrosis

2. Requires simultaneous collected 2. Requires simultaneous collected urine and blood samplesurine and blood samples

IV. Neurologic MonitoringIV. Neurologic Monitoring- early recognition of cerebral dysfunction- early recognition of cerebral dysfunction- facilitate prompt intervention and treatment- facilitate prompt intervention and treatment

A. Intracranial Pressure MonitoringA. Intracranial Pressure Monitoring1. Cerebral Perfusion Pressure - 1. Cerebral Perfusion Pressure -

>70mmHg>70mmHg2. Glasgow Coma Scale2. Glasgow Coma Scale

B. Electrophysiologic MonitoringB. Electrophysiologic Monitoring- reflects spontaneous and on-going electrical activity in - reflects spontaneous and on-going electrical activity in the brainthe brain

C. Transcranial UltrasoundC. Transcranial Ultrasound- monitors cerebral blood flow- monitors cerebral blood flow- detects vasospasm- detects vasospasm

D. Jugular Venous OximetryD. Jugular Venous Oximetry- measures relationship of blood flow to O2 consumption- measures relationship of blood flow to O2 consumption

V. Metabolic MonitoringV. Metabolic MonitoringA. Caloric DemandsA. Caloric DemandsB. Respiratory Quotient of FoodB. Respiratory Quotient of Food

VI. Temperature MonitoringVI. Temperature MonitoringA. Rectal A. Rectal B. Middle EarB. Middle EarC. EsophagealC. Esophageal