Week 2 Monitoring in Critical Care Flashcards
(23 cards)
What is monitoring?
- Regular recording of physiologic function
- Evaluate health status and guide treatment decisions
- Evaluate the effects of treatment
Why do physios need to know about monitoring?
- helps us treat patients who are being monitored
- guides decisions using the monitoring information
- ensure that patients are safe when moving and handling equipment
How do monitoring systems work?
- A SENSOR picks up change
- An AMPLIFIER increases signal
3, And then the signal is DISPLAYED
What are transducers?
- turns pressure changes into waveforms
1. Waveforms
2. Piezoelectric crystal - converts it into voltage
3. Zeroed - Transducers need to be zeroed for accurate reading
4. Numerical output is displayed
What does Central Venous Pressure assess (CVP)?
- fluid balance and venous return
What does Arterial Blood Pressure provide? And what are some information about Arterial blood pressure?
- continuous blood pressure readings
- MAP (Mean arterial pressure) = DBP + (SBP-DPB)/3. Normal MAP is 90-100mmHg
- The transducer needs to be at the level of the right atrium for best results.
Note: Movement may compromise the reading or the trace - Arterial lines can also take blood for ABG and FBC testing
Where is the Central Venous Pressure (CVP) located? And what does it measure?
- subclavian or internal jugular
- Measures central venous pressure
What is the normal value of CVP?
0-5mmHg or 3-15cmH2O
What are the effects of CVP in respiration?
- CVP fluctuates with respiration and positive pressure
- Important to take note of changes in TREND rather than absolute values
- Can guide fluid therapy - if CVP is low it may indicate patient may be dehydrated
Give me information about Pulmonary Artery Catheter (PAC)…
- also known as the Swan-Ganz Catheter
- measures pulmonary artery pressure (it extends through the right atrium, right ventricle and sits on the pulmonary arteries0, it can also measure blood movement, pressure, and temperature
- Balloon tipped, flow directed catheter with multiple lumens
- Distal port monitors pulmonary artery (PA), while proximal port monitors CVP
What are the normal values for Pulmonary Artery Pressure (PAP)?
- SBP: 15-25mmHg
- DBP: 5-15 mmHg
- Mean: 10-20mmHg
What are the complications of having a Pulmonary Artery Catheter (PAC)?
- Dysrhythmias
- pulmonary infection or haemorrhage
- Balloon rupture which causes air embolism
- Thromboembolic effects
- Infection (due to it being in the patient) - needs to be surgically put in place
- Kinking/line twisting
- Misplacement
What factors affect Pulmonary artery pressure and how is cardiac output measured through a PAC?
- PAP is closely related to pulmonary capillary wedge pressure (PCWP). Respiratory status and heart function influences it more,
- Increase blood flow can cause higher pressure readings
- CO is measured via thermodilution (Normal CO value is 4-7l/min)
- Cardiac index relates to body size - normal cardiac index is 3L/min/m2
Give me information about PCWP (Pulmonary Capillary Wedge pressure)
- PCWP normal range - 8-12 mmHg and reflects left atrial pressure
- High PCWP indicates congestion: 18-20mmHg. Above 20-30mmHg indicates pulmonary edema
- Low PCP indicates hypovolemia
- Identifies issues: Can identify left ventricle failure and fluid overload
When is Intra-aortic Balloon Pump (IABP) used and where is it inserted?
- IABP is used in very unstable patients and it is inserted in the FEMORAL ARTERY.
- the tip just sits below the subclavian
- Catheter linked to ECG and works due to counterpulsation
What are the indications for IABP?
- heart failure
- Failure to wean from CPB (cardiopulmonary bypass)
- Prophylactic use
What are the complications of having a IABP?
- limb ischemia can occur due to femoral access (Decrease in BF going to the limb)
- Vascular trauma - artery dissection
- Balloon rupture and infection are risks
- malposition and kinking
What is a Ventricular Assist Device (VAD)? (Cardiac support)
- replaces the function of the RV or the LV
- VAD supports patients with heart failure who are waiting for a transplant
- Blood is drawn from the heart, pumped through the device and returned (can be continuous of pulsatile)
What is an ECMO (Extracorporeal membrane oxygenation)?
- provides temporary by-ventricular bypass (external oxygenation).
- a VV-ECMO is used for respiratory bypass
- a VA-ECMO provides cardiac and respiratory support
- There is an increase in usage of ECMO ever since the H1N1 outbreak
- access points are typically vial femoral or internal jugular vein.
How is the respiratory system monitored?
- Oxygen saturation - measures percentage of hemoglobin saturated with oxygen (Non-invasive)
- ABGs - measures PaO2, PaCO2, pH, and bicarbonate levels
- END-Tidal CO2 (PETCO2) - reflects PaCO2 by measuring CO2 levels in expired gas. Aids in assessing ventilation.
- Ventilator settings - monitors tidal volume and PEEP
How do we monitor patient cognition in the ICU?
- RASS (Richmond Agitation-Sedation Scale)
- RASS measures level of sedation or agitation. Scores range from -5 (unrousable to +4 (combative). - CAM-ICU (Confusion Assessment Method)
- screens for delirium. Quick to administer and assesses acute mental status changes - ICDSC (Intensive Care Delirium Screening Checklist
- assesses delirium based on eight criteria. Scores are tallied to evaluate the presence of severity of delirium and it proves a structured scoring system
With regards to CNS monitoring…
ICP is crucial after brain injury. Helps detect secondary damage.
- an Elevated ICP would indicate worsening conditions and monitoring ICP aids in timely intervention
- Epidural, subarachnoid, and intraventricular catheters exist and helps measure ICP effectively
With regards to Renal Replacement therapy (RRT) in ICU…
- RRT addresses oliguria and rising levels of urea and creatinine
- it is crucial for managing acute and chronic renal failure in critical care
Note: Conventional Hemodialysis is poorly tolerated by critical patients. Takes 4-6 hours to complete
