2022 UWORLD CRITICAL CARE CONCEPT
1) Positive end-expiratory pressure (PEEP)
I) Applies given pressure at the end of expiration during mechanical
... [Show More] ventilation.
II) Alveoli is open to allow gas exchange; reduce hypoxemia and oxygen toxicity, uses lower FiO2!
III) PEEP is usually at 5 cm H20 (3.7 mm Hg); Higher levels of PEEP at 10-20 cm H20 treats ARDS.
IV) However, barotrauma of the lung and overdistention can rupture alveoli
i) Barotrauma causes pneumothorax and emphysema and hypotension.
2) Positive pressure ventilation (PPV)
I) Delivers positive pressure to the lungs using a mechanical ventilator.
II) Delivered via tracheostomy, endotracheal tube, or facemask, nasal prongs, or mouthpiece.
III) Common setting used is volume cycled positive pressure, which delivers 21%-100% oxygen.
IV) Positive pressure compresses thoracic vessels and increases intrathoracic pressure during inspiration. V) Reduced venous return, ventricular preload, and cardiac output → hypotension.
VI) Higher risk for hypotension are clients with hypovolemic, septic, and neurogenic shock. 3) Extra notes on medication use with Shock
I) Furosemide (Lasix) is appropriate to decrease left ventricular preload in cardiogenic shock.
II) Norepinephrine (Levophed) is a vasopressor used to increase stroke volume, cardiac output and MAP in anaphylactic shock.
III) Because of decreased peripheral tissue perfusion on vasopressors, Pulse oximetry on the forehead rather than the finger is appropriate for septic shock.
IV) Client with hypovolemic shock should not be in high fowler’s 90° → causes decreased BP.
4) Malignant hyperthermia
I) Life-threatening condition precipitated drugs used for anesthesia (e.g. desflurane inhalation). II) Also precipitated by Succinylcholine, a paralytic used for intubation and anesthesia.
III) Skeletal muscles become unable to control calcium → contracture and muscle stiffness.
IV) Early signs: tachypnea, tachycardia, hypercapnia, rigid jaw or muscle rigidity.
V) Later signs: high fever, hyperkalemia, cardiac dysrhythmias, and myoglobinuria.
VI) The nurse monitors the temperature as it can rise 1° C every 5 minutes; exceed 105° F. VII) Priority: IV dantrolene, treating potassium levels, and cooling the client.
5) Basic life support pulseless Ventricular tachycardia with implantable cardioverter defibrillator
I) Implantable cardioverter defibrillator (ICD) fires electrical shocks to interrupt dysrhythmia. II) ICD is unable to sense or treat pulselessness.
III) Still need to perform chest compressions → 30-60 seconds for ICD to cycle before defibrillating.
6) Hemodynamic monitoring – indications of heart failure
I) Central venous pressure (normal 2-8 mm Hg) elevated indicates increased systemic circulation volume and increased right ventricular preload.
II) Pulmonary artery wedge pressure (PAWP [6-12 mm Hg]) elevated indicates increased left ventricular preload.
III) Both increased CVP and PAWP = coarse crackles and left-sided heart failure.
IV) Treatment: loop diuretic to decrease fluid volume and in both left- and right ventricle preload.
7) Neurologic injury
I) Common cause of mortality in cardiac arrest, particularly in V. Fib. or pulseless V. Tach.
II) Clients who are comatose or do not follow commands after resuscitation require hypothermia.
III) Priority: therapeutic hypothermia within 6 hours of cardiac arrest; keep Head of bed 30°.
IV) During hypothermia care, bradycardia is common, temp is cooled to 89.6-93.2°F, MAP >80.
8) Emergency response protocols
I) Correct hand placement is in the center of the chest, lower half of the sternum (breastbone). II) If client has advanced airway, continuous compressions and 10 breaths/min.
III) Compression rate of 100-120/min and the chest should recoil completely after each compression.
9) Hypovolemia
I) Hypovolemic shock occurs when blood volume decreases through hemorrhage or third-spacing.
II) Treatment: Stopping the source of blood loss, increasing volume via IV fluids, improving blood pressure with vasoactive medications (dopamine, norepinephrine).
III) Norepinephrine is the drug of choice and improves heart contraction and output, but end quickly. IV) Abruptly stopping vasoactive medication causes hemodynamic instability; always taper slowly. 10) Adult AED pad placement
I) Pediatric AED pads or pediatric dose attenuator should be used on children age birth to 8 years. II) Standard adult pads can be used as long as they do not overlap or touch.
III) If adult AED pads are used on pediatric, one pad placed on chest and other pad on the back.
11) Ventricular tachycardia
I) V.Tach. with a pulse should be assessed for hypotension, altered mental status, shock, chest pain, and acute heart failure.
II) Unstable client in ventricular tachycardia with pulse is treated with synchronized cardioversion. III) Stable client in ventricular tachycardia with a pulse is treated with amiodarone, procainamide.
I) Near-drowning occurs when client is under water and unable to breathe.
II) A sign of severe brain damage would be Decerebrate posturing
III) Major body organs begin to shut down from lack of oxygen and permanent damage results.
IV) Priority: assess arms and legs straight out, toes pointed downward, and head/neck arched back.
12) Submersion injury
13) Arterial blood gas
14) Diabetic ketoacidosis ABG
I) Diabetes Ketoacidosis (DKA) is a life-threatening complication of type 1 diabetes charactrerized by hyperglycemia (>250 mg/dL) resulting in ketosis, a metabolic acidosis.
II) Glucose cannot be taken out of the bloodstream due to lack of insulin production.
III) Body begins to break down fat stores into ketones → causing metabolic acidosis.
IV) As a compensatory mechanism, deep, rapid respiration with fruity/acetone smell (kussmaul) in an attempt to reduce carbon dioxide levels by inducing a respiratory alkalosis to partially compensate for the ketoacidosis.
15) The arterial blood gas (ABG) result most consistent with the diagnosis of DKA is METABOLIC ACIDOSIS or partially compensated metabolic acidosis.
I) pH levels will be below <7.35
II) PaCO2 levels will be below <35
III) HCO3 levels will be below <22
16) Radial, brachial, or femoral Arterial line safety precautions
I) Allen’s test is performed before cannulating the radial artery and determines the adequacy of ulnar artery blood flow.
II) However, impairment in circulation, sensation, movement must be reported immediately.
III) Priority: assess for, capillary refill, sensation, hemorrhage, thrombus, & neurovascular infection.
17) Abdominal Trauma Impaled Object
I) An impaled object should not be manipulated or removed at the scene as further trauma and bleeding of soft tissue and surrounding organs may occur.
II) First responders should not remove the impaled object.
III) Priority: stabilization of the object
i) Exception to the rule: EMS providers may remove impaled object if it obstructs the airway and prevents effective cardiopulmonary resuscitation.
18) Skull fractures
• Cerebrospinal fluid (CSF) rhinorrhea confirms skull fracture occurred and transversed the dura.
I) Dextrose testing can determine CSF; halo/ring tests for coagulated blood surrounded by CSF.
II) CSF leakage places the client at risk for infection.
III) Absolutely no nasogastric or oral gastric tube insertion when basilar skull fracture is suspected.
IV) Only HCP using fluoroscopic guidance in clients with skull fractures.
19) Submersion injury
I) Initial management of a near-drowning victim focuses on airway management.
II) Possible aspiration → Acute Respiratory distress syndrome; pulmonary edema, or bronchospasm (leading to airway obstruction).
III) Remove wet clothing, providing dry clothing, give warm IV fluids, and apply warm blankets.
20) Respiratory alkalosis
I) Increased loss of acidic carbon dioxide from hyperventilation (rapid respirations).
II) Loss of acidic carbon dioxide from hyperventilation causes an increase in ↑pH.
III) pH will be above <7.35
IV) PaCO2 will be below <35
V) PaO2 will also be below <80
21) Allen’s Test for ABG
I) Radial artery site at the wrist is preferred for collecting an arterial blood gas sample because it is near the surface, is easy to palpate and stabilize, and has collateral supply form the ulnar artery.
II) If the Allen’s test is positive, the arterial blood gas is drawn; if negative, an alternate site is used. 22) Arterial line blood pressure readings
I) To measure pressures accurately using continual arterial and/or pulmonary artery pressure, the zeroing stopcock of the transducer system must be placed at the phlebostatic axis.
II)
The anatomical location is at the 4th intercostal space (ICS), midway point of the AP diameter (1/2 AP) of the chest wall.
23) Mechanical ventilation dropping oxygen saturation
I) When an artificial airway is present, the nurse should assess for hypoventilation. II) Pneumothorax can cause hypoventilation and a drop in oxygen saturation.
III) Priority: auscultate the lungs bilaterally to confirm proper tube placement.
24) Mechanical ventilation preventing aspiration with enteral nutrition
I) Clients are at increased risk when receiving bolus rather than continual enteral feedings. II) Continuous feeding: enteral nutrition is administered using a feeding pump over 24 hrs.
III) Bolus feeding, enteral nutrition is administered via a syringe or gravity drip over 4-10 minutes.
IV) Proper feeding tube care:
i) Assess gastric residual volumes according to institution policy every 4 hours.
ii) Ramsay Scale is a sedation scale used at regular intervals. iii) Check enteral feeding tube placement at the nares every 4 hours; X-ray confirmation.
iv) Administer continual rather than bolus tube feeding.
25) Intubation and extubation
I) Recently extubated clients are high risk for aspiration, airway obstruction, & respiratory distress. II) Priority: humidified warm oxygen, high fowler’s position 90°, mouth care with oral sponges III) Clients frequently cough, deep breathe, and use incentive spirometer to prevent atelectasis.
IV) Clients remain NPO until swallowing function has been evaluated.
26) Mechanical ventilation endotracheal tube
I) A low tidal volume alarm indicates air ventilator is delivering lower than set volume.
II) Commonly due to disconnection, loose connection, or leak in the circuit.
III) If condition is deteriorating (decreasing oxygen saturation) and alarm persists, then the priority of nursing action is disconnect the ventilator and manually ventilate the clients lung with a resuscitation bag at 1015 L.min oxygen.
27) Increased Intracranial pressure
I) ICP should not exceed 25 mm Hg and should return to baseline within a few minutes.
II) Pain, straining, agitation, shivering, fever, and hypoxia increase brain blood supply and raise ICP.
III) Nursing interventions to control ICP:
i) Elevate the head of the bed 30° with the head/neck in neutral position.
ii) Administer stool softeners to reduce the risk of straining. iii) Managing pain, managing fever (cool sponges, ice chip). iv) Maintaining a calm environment with minimal noise. v) Ensuring adequate oxygenation.
vi) Hyperventilating and preoxygenating the client before suctioning → reduces CO2 and ↓ICP.
vii) Suction for a maximum of 10 seconds; prolong suctioning increases ICP.
28) Basic life support in pregnancy
I) Common causes are embolism, eclampsia, magnesium overdose, and uterine rupture. II) In pregnancy, the heart is displaced in the third trimester.
III) Place hands on sternum slightly higher than usual for compressions during CPR.
IV) The uterus should be manually displaced to the client’s left to reduce this pressure. V) The nurse can roll a blanket or wedge under the right hip to displace the uterus.
VI) If return of spontaneous circulation (ROSC) does not occur after 4 minutes of CPR, EMERGENCY CSECTION! → Delivery should occur within 5 minutes of initiating CPR. [Show Less]