Monitoring in Mechanical Ventilation Chapter 9 Questions and Answers (Verified Solutions), Exams of Nursing

Download Monitoring in Mechanical Ventilation Chapter 9 Questions and Answers (Verified Solutions) and more Exams Nursing in PDF only on Docsity! Monitoring in Mechanical Ventilation Chapter 9: Questions and Answers (Verified Solutions) 2023 Four reasons for monitoring: - correct answer ✅Monitoring a pt's clinical condition during MV is vital because clinical status often changes rapidly & unpredictably. *Baseline measurements can be used to establish the initial treatment plan & serve as a reference point for future measurements *Trending progress or regression of a pts condition *Changes in treatment plan *Alarm limits can be set to safeguard a pts safety Vital signs - correct answer ✅*Can provide very useful information on the overall condition of the pt. Any changes often indicate changes in pt cardiopulmonary status. HR, BP, RR, & Temp are what's measured. Heart rate - correct answer ✅Normal is 60-100 bpm *Tachycardia may be caused by hypoxemia, pain, anxiety & stress, fever, drug reactions, & myocardial infarction Monitoring in Mechanical Ventilation Chapter 9: Questions and Answers (Verified Solutions) 2023 *Bradycardia & arrhythmias often occur during prolonged suction of the airways (vagal stimulation)-if this occurs stop suction & provide pt with 100% O2 Blood pressure - correct answer ✅*Continuous BP monitoring in the critically ill pt is usually done via an indwelling arterial catheter (A-Line)-More accurate in measuring systemic pressure *Most common insertion site for the catheter is the radial artery -Other sites are Brachial, Femoral, Popliteal, & Dorsalis Pedis Hypertension - correct answer ✅*Higher than normal *May be caused by acute or chronic pt conditions: -Fluid overload -Vasoconstriction -Stress -Anxiety -Pain -Hx CHF -Cardiovascular disease Monitoring in Mechanical Ventilation Chapter 9: Questions and Answers (Verified Solutions) 2023 *One should observe symmetrical movement of the chest with each inspiration as well as the depth & rhythm of each tidal volume cycle *Asymmetrical movement can occur in -Right mainstem (bronchial) intubation -Atelectasis -Tension pneumothorax (Absolute contraindication for MV) *Should be performed each time the practitioner assesses the pt/ventilator system Fluid balance & anion gap - correct answer ✅*PPV ⬇ ️cardiac output & renal perfusion *Since fluid balance & electrolyte concentration are related the anion gap may also be affected as a result of PPV *Anion Gap-the difference between cations (+) & anions (-) in the plasma. *Normal range •15-20 when K+ is included Anion Gap= Na+ + K+ - Cl- - HCO3- Monitoring in Mechanical Ventilation Chapter 9: Questions and Answers (Verified Solutions) 2023 •10-14 when K* is excluded Anion Gap= Na+ - Cl- - HCO3- *Proper fluid & electrolyte maintenance should be an integral part of MV to prevent adverse outcomes Fluid Balance - correct answer ✅*PPV ⬇ ️cardiac output & renal perfusion *Urine output is ⬇ ️due to hypoperfusion of the kidneys *MV also ⬇ ️urine output as a result of ⬆ ️ADH & ⬇ ️atrial natriuretic factor (ANF) *The end result of these changes is ⬇ ️fluid output & fluid retention **Oliguria-(⬇ ️urine output) may be seen: -Bleeding -Diarrhea -Renal failure -Shock -Drug poisoning -Deep coma Monitoring in Mechanical Ventilation Chapter 9: Questions and Answers (Verified Solutions) 2023 -Hypertrophy of the prostate **Normal U/O is 50-60 mL/hr **U/O below 20 mL/hr (or 400 mL in a 24 hr period or 160 mL in 8 hrs) is indicative of fluid deficiency Anion Gap - correct answer ✅*Metabolic acidosis in the presence of a normal anion gap is usually caused by a loss of base (Cl- & HCO3-) *Metabolic acidosis in the presence of an ⬆ ️anion gap is usually due to ⬆ ️ fixed acids (excreted by the kidneys) *Severe K+ depletion can lead to metabolic acidosis & compensatory hypoventilation (breath less to retain CO2, which brings ventilatory status close to normal range) Arterial blood gases - correct answer ✅*Direct measurement of PaCO2 via arterial puncture or indwelling catheter is the most accurate method of assessing a pt's ventilatory status *When the acid-balance is caused by metabolic acidosis or alkalosis, it calls for a different ventilator management strategy. The underlying metabolic problem must be corrected before changing vent settings Monitoring in Mechanical Ventilation Chapter 9: Questions and Answers (Verified Solutions) 2023 Limitations of blood gases - correct answer ✅*An invasive procedure requiring the puncture of an artery it placement of a catheter *Inaccurate results can occur with the introduction of air bubbles, too much heparin or with faulty handling of the sample itself *Reflect an isolated moment in time rather than a trend *Used to correlate & document trends with a pulse oximetry *A late indicator of respiratory failure & of limited use as an early warning sign Oxygen saturation monitoring - correct answer ✅*Pulse oximetry: a device that estimates arterial O2 saturation by emitting dual wavelengths of light through a pulsating vascular bed *The most frequently used method of oxygenation assessing a pt O2 status *Non-invasive & easy to use *May be used to spot check or continuously to monitor saturation *HR should be very close to actual but it does not necessarily indicate an accurate sat Monitoring in Mechanical Ventilation Chapter 9: Questions and Answers (Verified Solutions) 2023 Accuracy & limitation of Pulse Oximetry - correct answer ✅*SpO2 of >95% has shown a strong correlation with PaO2 of >70 torr with a sensitivity of 100% *Oxygenation of the vent-dependent pt can be assured when the SpO2 is kept above 92% as this level correlated with PaO2 above 60 torr *Dyshemoglobins: Hb that DO NOT carry oxygen (In the presence of this, PO reads higher than actual saturation) Factors the affect the accuracy of Pulse Oximetry - correct answer ✅*Sunlight *Nail polish *Intravascular dyes *Fluorescent light *Dyshemoglobins (MetHb, SulfHb, COHb) *Low perfusion states **A new technology for PO has been developed to counter-act common problems such as motion artifacts, low perfusion, & low signal to noise situations Monitoring in Mechanical Ventilation Chapter 9: Questions and Answers (Verified Solutions) 2023 End-Tidal CO2 Monitoring (EtCO2) - correct answer ✅*Monitor a pt's ventilatory status (how much CO2 is blown off) *Measured at the end of exhalation *Once good correlation is established ABG's can be reduced Capnography - correct answer ✅*A measurement of the partial pressure of carbon dioxide in a gas sample *When the sample is collected at the end of expiration, it is called end-tidal partial pressure of carbon dioxide (PetCO2) *The exhaled CO2 from the circuit is collected & measured by the infrared absorption technique **Mainstream sensor is placed directly onto the vent circuit usually attached to an adaptor on the ET tube **Side stream sensor aspirates a sample of gas via a small tube connected to the ET tube Mainstream - correct answer ✅Advantage: *Fast response time Monitoring in Mechanical Ventilation Chapter 9: Questions and Answers (Verified Solutions) 2023 Limitations of Capnography Monitoring - correct answer ✅*Reflect changes in a pt's ventilatory status, rather than improvement or deterioration of the pt *Decreased PetCO2 MAY NOT be indicative of improvement in gas exchange, lowering the ventilator frequency in this situation could lead to grave consequences: *Conditions leading to an increase in deadspace ventilation *Hypotension *High intrathoracic pressure secondary to MV Transcutaneous Blood Gas Monitoring - correct answer ✅*Involves placement of a miniature Clark (PO2) or a Severinghaus (PCO2) electrode on the skin via a double-sided adhesive disk *A heating coil in the electrode increases the permeability of the epidermis thus facilitating diffusion of gas from the underlying capillaries to the electrode *Used most often in neonates Transcutaneous Monitoring PtcO2 (Oxygen) - correct answer ✅*Measurement of PO2 through the skin by means of the Clark electrode Monitoring in Mechanical Ventilation Chapter 9: Questions and Answers (Verified Solutions) 2023 *Approximates the central organ PO2 Accuracy is the electrode is affected by: *Skin edema *Hypothermia *Capillary perfusion status *Frequent changes are needed every 4 hours to avoid erythemia & burns & long equilibration time after each site change Transcutaneous Monitoring PtcCO2 (Carbon Dioxide) - correct answer ✅*Measurement of PCO2 through the skin by means of Severinghaus electrode *Continuous ventilatory assessment *Values are usually higher than PaCO2 due to increased CO2 production as underlying tissues are heated Cerebral Perfusion Pressure (CPP) - correct answer ✅Requires to provide: *Blood flow *Oxygen Monitoring in Mechanical Ventilation Chapter 9: Questions and Answers (Verified Solutions) 2023 *Metabolite to brain (essential vitamins & nutrients) **Under normal conditions, the brain regulates its own blood flow regardless of the systemic BP & cerebral vascular resistance *This autoregulation may be lost following head trauma whereas CVR is often elevated *Brain becomes vulnerable to BP changes *The degree of decrease in cerebral perfusion, effects range from cerebral ischemia (blood pooling) to brain death Cerebral Perfusion Pressure (CPP)-Continued - correct answer ✅*Mortality increases about 20% for each 10 torr drop in CPP *Studies involving severe head injuries, 35% reduction in mortality was achieved when CPP was maintained above 70 torr *The difference between mean arterial pressure (MAP) & the intracranial pressure (ICP) *CPP=MAP-ICP *MAP=Systolic + Diastolic x 2/3 *CPP ranges from 70 & 80 torr