Critical Care Flashcards
Goals for ventilating intubated asthma patients
Mechanical ventilation: Objective: maximize expiratory time Low respiratory rate High inspiratory flow rate Maintain plateau pressure <30 cm H2O Permissive hypercapnia to avoid breath stacking
What is the first maneuver that should be attempted when a patient with a tracheostomy presents with massive bleeding concerning for a tracheoinnominate artery fistula?
Hyperinflate the cuff of the trachea to attempt to tamponade the bleeding vessel. If this fails, orotracheal or nasotracheal intubation followed by direct digital pressure should be pursued
What acid-base status would be found in a trauma patient who lost a large amount of blood and was just intubated due to airway loss?
A mixed respiratory-metabolic acidosis from hypoventilation and hypoperfusion
Acid-base derangement found in COPD patients
Respiratory acidosis with metabolic compensation (C) could occur in chronic obstructive pulmonary disease where chronic hypoventilation and CO2 retention lead to an acidosis that the kidney responds to by retaining bicarbonate over a long period of time
Acid-base derangement found after vomiting
Metabolic alkalosis with respiratory compensation (B) could occur with gastrointestinal acid loss (vomiting), as well as in dehydration or diuretic use, which activates the renin-angiotensin-aldosterone pathway, leading to potassium and hydrogen ion loss in the urine
Besides procedural sedation, what are three other critical applications of capnography?
ETT placement, cardiac arrest, elevated ICP
Type of hypoventilation seen with benzodiazepines
Type 2 is hypopneic hypoventilation, commonly seen with sedative-hypnotic drugs like midazolam. In these cases, there is primarily a reduced tidal volume, with an increase in the fraction of airway dead space to tidal volume. As a result, there is often initially a decrease in EtCO2, as expired gas is proportionally more diluted by the dead space. As hypoventilation progresses to apnea, there will be complete loss of waveform and EtCO2
What is the optimal respiratory rate (low, normal, or high) in an intubated asthma or COPD patient?
A low respiratory rate allows for the patient to fully exhale in between breaths and avoids over-inflation and air stacking (also known as auto-PEEPing)
For what condition (aside from post-arrest care) is therapeutic hypothermia also indicated?
Uncontrolled seizure disorders
Three causes of elevated ketones
DKA
Alcohol
Starvation
Formula for arterial O2 content (CaO2)
CaO2 = (1.34 x Hgb x SaO2) + (0.003 x PaO2)
Normal CaO2 is approx 20 mL/dL
Formula for Delivery of O2
DO2 = CO x CaO2 (ml/min/m2)
Highest Risk conditions for Stress Ulcer formation
Mechanical ventilation > 48 hours
Coagulopathy is plt <50k, INR>1.5, PTT > 2x
Burns involving> 30% BSA
Secondary High Risk for Stress Ulcer Development
Circulatory Shock Severe Sepsis Multisystem Trauma TBI, SCI Renal Failure Steroid Therapy
