Respiratory Flashcards
Ascites-restrictive or obstructive-Is it worse sitting
Restrictive
Yes, it is, because then the fluid pushes the diaphragm up even further
What does restrictive lung disease mean?
It means a decrease in all lung volumes, but the ratio of FEV1/FVC remains unchanged
What is FEV1 and what is FVC?
FEV1 is the maximum amount of air that can be exhaled in one second, and FVC is the most air that you can breathe out after taking in your max breath.
A decrease in the FEV1/FVC ratio is diagnostic of
An obstructive lung disease like COPD
What is FRC?
Functional residual capacity (FRC) refers to the volume of air left in the lungs at the end of a normal exhalation.
What’s generally less-closing capacity, or FRC?
Closing capacity is usually less than FRC, but if FRC decreases below closing capacity, it can lead to collapse of airways even in the upright position, which causes intrapulmonary shunt (perfusion without ventilation) and decreased oxygenation.
mnemonic for causes of decreased FRC:
PANGOS
Pregnancy, ascites, neonates, general anesthesia, obesity, supine position
Salicylate (aka aspirin) toxicity causes which type of disturbance. What sense is lost in almost 85% of these patients?
Ralk Macid-he broke up with her so that’s why she took those salicylates:
Resp alkalosis and metabolic acidosis.
Tinnitus or hearing loss seen in 85% of these patients
explain salicylate OD-it will cause ____ disturbances, but explain. What system does it mess up? What builds up b/c of it? What does it do to the brain? What’s their pH like?
Ralk Macid-resp alkalosis and met. acidosis.
Aspirin causes uncoupling of the oxidative phosphorylation system,This leads to a build up of organic acids such as lactate and ketoacids, causing an anion gap metabolic acidosis.
Salicylate also acts directly on the respiratory center to increase the respiratory drive leading to a respiratory alkalosis. For this reason, patients suffering from an overdose generally have a normal to low pH.
Tx of salicylate toxicity in 6 steps:
1) Supportive care (beginning with the ABC’s of airway and circulatory support)
2) Activated charcoal and/or gastric lavage if recent ingestion
3) Dextrose to avoid CSF hypoglycemia
4) IV fluids to replace losses from tachypnea and vomiting
5) Bicarbonate administration
- Raises systemic pH, decreases tissue distribution of salicylate
- Raises urine pH, increases the rate of renal clearance
6) Hemodialysis if severe symptoms
signs and symptoms of salicylate toxicity and severe intoxicatiom:
Signs and symptoms of salicylate toxicity include headache, tinnitus, vertigo, nausea, vomiting, diarrhea, hyperventilation, and tachycardia.
Severe intoxication can lead to lethargy, noncardiogenic pulmonary edema, mental status changes, seizures, coma, gastrointestinal bleeding, liver failure, renal failure, and death.
Jeopardy style: These symptoms often begin in the intrinsic muscles of the hands and, over the course of the disease, the atrophy and weakness spreads to involve all skeletal muscles.
What is ALS?
Can ALS people have autonomic issues? Spastic or flaccid paralysis? Increase risk of aspiration-if so, how does that affect your anesthetic plan?
Spasticity and hyperreflexia of the lower extremities can also be seen. Patients often also have autonomic nervous system dysfunction, which will manifest as orthostatic hypotension and resting tachycardia. Yes-increased risk of aspiration, which is why LMAs are not the best idea
PFTs in ALS
decreased FVC,
FRC and RV normal to increased
Pain mgmt plan in ALS:
Muscle relaxants in ALS .
opioid sparing technique as they are sensitive to them, and can have more respiratory depresion. No sux, can be sensitve to the non-depolarizing ones
Jeopardy style: Classically, serial chest radiographs show initially a white-out except for a small apical fluid level, which is an appropriate postsurgical change, followed by an “improved” appearing chest radiograph that has a more caudad air-fluid level.
What is a bronchopleural fistula?
How does BPF present in patients that have undergone a pneumonectomy?
In patients who have undergone a pneumonectomy, the BPF presents as acute dyspnea, subcutaneous emphysema, tracheal deviation, and a lower or more inferior air-fluid level. Initially, serous fluid fills the lung after pneumonectomy. After the development of a BPF, this fluid is displaced by the entrained air from the BPF, thus lowering the air-fluid level.
Mgmt of bronchopleural fistula (BPF)
Things to consider if going back to the OR
Management may be conservative with chest tube placement and different ventilation strategies or with surgical intervention, depending on the severity and presence of comorbid conditions.
Surgical management presents an anesthetic challenge for managing the airway while providing adequate ventilation, which may be compromised by a large air leak through the BPF. A double lumen tube (DLT) should be placed in a spontaneously breathing patient for not only ease of ventilation but also for isolation of contaminated material, such as in this patient. Communication with the surgeon is extremely important because a chest tube may need to be placed preoperatively in order to decrease the risk of tension pneumothorax. If there is a chest tube in place, it should be on water seal at the time of induction because a chest tube to suction will divert each breath administered through the chest tube and compromise positive-pressure ventilation (PPV).
Presentation of empyema vs bronchopleural fistula:
While an empyema (the girl from empyema-she new) would present with acute fever and sputum production, it would not present with a lower air-fluid level. It would present as a new air-fluid level, which may be difficult to discern in a post-pneumonectomy patient. The clinical presentation of this patient is more consistent with bronchopleural fistula.
Absolute indications for DLT:
Hint-there’s 7 (at least on this list)
BPF is one of the absolute indications for a DLT and lung isolation. Other absolute indications include:
Isolation for infectious material such as during a bronchopulmonary lavage
Isolation for hemorrhage
Isolation for pulmonary alveolar proteinosis
Tracheobronchial tree disruption
Bullae
Broncho-cutaneous fistula
What are the tenants of management to help decrease the risk of leakage across the bronchopleural fistula (BPF). Lung isolation? Spontaneous ventilation?
PEEP
short inspiratory time
low tidal volumes and low respiratory rate
Lung isolation techniques can help decrease the pressures and volumes needed. Spontaneous ventilation is preferred over positive pressure ventilation.
What can your body accomplish if you stop smoking for one week?
decreased cyanide levels
decreased carbon monoxide levels
decreased nicotine levels (nicotine causes vasoconstriction)
Pulmonary fibrosis requires ___ for definitive diagnosis.
Pulmonary fibrosis requires a biopsy for definitive diagnosis.
CT can be helpful but tissue is needed.
What is alveolar proteinosis?
Pulmonary alveolar proteinosis is a rare disorder that does not present acutely. It is caused by decreased clearance of protein and accumulation of surfactant phospholipids.
If sat starts going down during BPL, what can you do and what should you NOT do?
Bronchopulmonary lavage requires perfect lung isolation to prevent contamination of or leaking of lavage fluid into the ventilated lung. Hypoxia with one-lung ventilation during BPL should be managed by ensuring appropriate DLT position and delivery of FiO2 of 1.0 followed by the application of PEEP to the ventilated lung. Suctioning and use of bronchodilators may help. The application of CPAP to the nonventilated lung is contraindicated, and intermittent two-lung ventilation is either very challenging or not an option.
Which type of lung disease does GBS cause?
What is GBS?
Restrictive The incidence of Guillain-Barré syndrome (GBS) is around 1.5/100,000 people. Symptoms of GBS include weakness, loss of reflexes, and autonomic dysregulation. Pain and paresthesias are also associated with GBS. GBS is often described as an ascending muscle weakness. Weakness typically occurs within 2 weeks of a seemingly unrelated viral or bacterial illness, especially influenza, EBV, CMV, and Campylobacter jejuni. This illness incites an autoimmune response toward the myelin of peripheral nerves
DLCO in GBS:
The DLCO remains preserved during GBS as the process is due to muscle weakness with an inspiratory problem, not an intrinsic lung problem.
Obstructive lung disease FEV1/FVC ratio:
Obstruction is seen as a result of the FEV1/FVC ratio being <70% of predicted.
Restrictive lung disease PFT values:
A restrictive defect is a proportional decrease in all lung volumes; thus VC, FVC and FEV1 are all reduced but FEV1/FVC remains normal.
Trendelenburg position and cardiac output:
Trendelenburg decreases FRC by primarily decreasing whcih volume?
he increase in venous return causes an increase in mean arterial pressure, pulmonary artery pressure, and left-ventricular end-diastolic pressure. In patients with normal systolic function, the increase in venous return will lead to an increase in stroke volume, and hence an increase in cardiac index/output.
By primarily decreasing ERV
Diagnosis of central sleep apnea can be made by:
How does this differ from OSA? What does this mean as far as one of the classic signs of OSA?
Central sleep apnea occurs when brain respiratory centers do not function properly during sleep and periodically fail to trigger inhalation. A CSA event is defined as an apneic period (≥10 seconds) without an identifiable respiratory effort and a diagnosis requires ≥10 episodes per hour of sleep. Hypoxia may or may not occur during apneic periods. Periods of apnea are usually followed by periods of compensatory hyperpnea. Unlike in OSA, there is no effort to breathe during periods of apnea in CSA.
Diagnosis of OSA and one of the most common signs:
Obstructive sleep apnea is defined as ≥5 episodes per hour of sleep of complete cessation of airflow during breathing lasting ≥10 seconds despite maintenance of neuromuscular ventilatory effort, accompanied by an SaO2 decrease of at ≥4%. Since ventilatory effort is made in the presence of an upper airway obstruction, snoring is the most common sign of (though not specific for) OSA
What is AHI, and how does it go about defining, mild/moderate/severe disease?
The total number of episodes of apnea or hypopnea (reduction of airflow of greater than 50%) divided by the total sleep time creates a apnea/hypopnea index (AHI). An AHI of 5-15 events per hour indicates mild disease, an AHI of 15-30 indicates moderate disease, and severe disease is indicated by an AHI of >30.
Tx of OSA vs CSA:
OSA: CPaP
CSA: BiPAP
Either way, both can receive positive airway pressure
How can OSA result in heart failure?
Long-standing and/or severe OSA can result in heart failure: OSA -> Hypoxia/Hypercapnia -> Pulmonary hypertension -> Right ventricle hypertrophy -> Right ventricle failure
What are your anesthetic plans for a patient with symptomatic anterior mediastinal mass?
The anesthetic plan may include any or all of the following options: an awake intubation sitting upright, spontaneous ventilation throughout the procedure (avoidance of muscle paralysis), capability of quickly changing patient positioning (in order to relieve cardiopulmonary compression), rigid bronchoscopy readily available (to “stent” open bronchial tree), cardiopulmonary bypass (CPB) readily available, and possibly femoral artery cannulation in preparation of CPB prior to induction.
During preoperative evaluation of a patient with an anterior mediastinal mass, if there is any indication of heart or PA compression, what should you do?
Make sure you maintain the preload
MOST common anesthetic complication associated with an anterior mediastinal mass?
Compression of the tracheobronchial tree
So, if a patient needs a pneumonectomy, what is the deal with testing.
Preoperative pulmonary function testing for pneumonectomy is broken down into two phases. The first phase is composed of arterial blood gas (ABG) analysis and spirometry. If the patient passes the criteria for phase one testing, then the pneumonectomy is performed. If the patient fails any portion of phase one criteria, the second phase of testing begins. The extent of phase two testing is institution dependent and can involve split lung function testing, radionucleotide scans, and determination of postoperative forced expiratory volume in one second (FEV1) and diffusing capacity of the lung for carbon monoxide (DLCO). In addition, exercise testing, right heart catheterization, and oxygen consumption determinations may be performed.
hase two criteria which predict poor perioperative outcome following pneumonectomy include:
suuuuper important slide
1) Inability to ascend at least 2 flights of stairs
2) Postoperative FEV1 < 30% of normal predicted value for the patient (some studies suggest FEV1 < 50%)
3) Combined predicted postoperative FEV1 < 35% and DLCO < 35% of normal predicted value for the patient
4) Right heart catheterization data: mean PAP > 35 mm Hg; PCO2 > 45 mm Hg; PO2 < 60 mm Hg; and the following with exercise: PVR > 190 dynes/sec/cm^5 , decrease in SaO2 > 2-4%, and max VO2 < 15 mL/kg/min
Signs and symptoms of pulmonary embolism:
When you see bradycardia with PE-what does that mean?
The most common patient complaints are dyspnea, pleuritic pain, and cough. There may be a history of calf or thigh pain and/or swelling. Common presenting signs include tachypnea, crackles, tachycardia, and a fourth heart sound. Jugular venous distention is associated with massive PE and right heart failure. When bradycardia is seen, this is often an ominous sign of right ventricular strain and impending shock.
