Exam 1 Flashcards
What are some examples of respiratory muscle dysfunction?
respiratory muscle fatigue, chest wall abnormalities, neuromuscular disease
What are some oxygen abnormalities that are indications for mechanical ventilation?
refractory hypoxemia, need for positive end- expiratory pressure (EEP), and excessive work for breathing
What are the different types of ventilator breaths?
volume-cycled breath, time-cycled breath, and flow-cycled breath
What is a volume cycled breath?
“Volume breath” with a preset tidal volume. Volume controlled systems of ventilation are based on a measured volume variable which is set by the clinician. When the ventilator detects the set volume having been applied the ventilator cycles to exhalation.
What is a time cycled breath?
“Pressure control breath”, there is constant pressure for preset time
What is a flow-cycled breath?
“Pressure support breath”, it is constant pressure during inspiration
What is NPPV?
noninvasive positive pressure ventilation
What are the goals of mechanical ventilation?
adequate ventilation and oxygenation, decreased work of breathing, and patient comfort and synchrony
What does CPAP stand for and what does it do?
Continuous positive airway pressure, no machine breaths are delivered here, it allows spontaneous breathing at elevated baseline pressure and the patient controls the rate and tidal volume
What is pressure support ventilation?
Pressure assist during spontaneous inspiration with flow-cycled breath. Pressure assist continues until inspiratory effort decreases, Delivered tidal volume dependent on inspiratory effort and resistance/compliance of lung/thorax.
What are the advantages of pressure support ventilation?
patient comfort, decreased work of breathing, may enhance patient-ventilator synchrony, and used with SIMV to support spontaneous breaths
What are the disadvantages of pressure support ventilation?
Variable tidal volume if pulmonary resistance/compliance changes rapidly, if sole mode of ventilation-apnea alarm mode may be only backup, and gas leak from circuit may interfere with cycling
What is synchronized intermittent mandatory ventilation?
Volume or time cycled breaths at a preset rate, additional spontaneous breaths at tidal volume and rate determined by patient and it’s used with pressure support
What are the advantages of synchronized intermittent mandatory ventilation?
It is more comfortable for some patients and there are less hemodynamic effects.
What is the disadvantage of synchronized intermittent mandatory ventilation?
Increased work of breathing
What is controlled mechanical ventilation?
Preset rate with volume and or time cycled breaths and there is no patient interaction with the ventilator
What is the advantage of controlled mechanical ventilation?
rests muscles of ventilation
What are the disadvantages of of controlled mechanical ventilation?
Requires sedation/neuromuscular blockade, potential adverse hemodynamic effects
What is inspiratory plateau pressure?
Airway pressure measured at end of inspiration with no gas flow present, estimates alveolar pressure at end-inspiration, and it’s an indirect indicator of alveolar distension
What could happen during high inspiratory plateau pressure?
Barotrauma, volutrauma, and decreased cardiac output
What are the methods to decrease inspiratory plateau pressure?
Decrease PEEP and and decrease tidal volume
Inspiratory time determinants with volume breaths are what?
Tidal volume, gas flow rate, respiratory rate, and inspiratory pause
Expiratory time is determined passively, true or false
true
What is the spontaneous breathing ratio for inspiratory and expiratory?
inspiratory time:expiratory time
What is the inspiratory:expiratory ratio during mechanical ventilation?
Expiratory time is too short for expiration and you need to reduce auto-PEEP by shortening inspiratory time
What is auto peep?
Auto-PEEP is gas trapped in alveoli at end expiration, due to inadequate time for expiration, because of bronchoconstriction or mucus plugging. It increased the work of breathing. It has potential harmful physiologic effects.
How do you reduce auto peep by shortening inspiratory time during mechanical ventilation?
decrease respiratory rate, decrease tidal volume and increase gas flow rate
When would you see permissive hypercapnia?
Severe asthma and ARDs
Permissive hypercapnia is contraindicated in what?
increased intracranial pressure
Can auto peep be measured on some ventilators?
Yes
What does auto peep increase?
increases peak, plateau, and mean airway pressures
Peak inspiratory pressure initiated at 1_____ H2O in Pediatric ventilation (<5 kg)
18-20 cm
time cycled, pressure limited ventilation is good for pediatric ventilation (<5 kg), true or false
true
Adjust to adequate chest movement or exhaled tidal volume ~_____mL/kg is good for pediatric ventilation (<5 kg)
Adjust to adequate chest movement or exhaled tidal volume ~8 mL/kg
Low level of PEEP (______cm H2O) to prevent alveolar collapse is good for pediatric ventilation (<5 kg)
Low level of PEEP (2–4 cm H2O) to prevent alveolar collapse is good for pediatric ventilation (<5 kg)
Flow rate adjusted to yield desired inspiratory time Infants ______ secs Toddlers ______ secs Older _______ secs
Flow rate adjusted to yield desired inspiratory time Infants 0.5–0.6 secs Toddlers 0.6-0.8 secs Older 0.8–1.0 secs
When initiating mechanical ventilation, what should the initial tidal volume be?
8-10 mL/kg
To avoid high IPP, what should you lower the tidal volume to?
5-8 mL/kg
What is PEEP?
Abbreviation for positive end-expiratory pressure. A method of ventilation in which airway pressure is maintained above atmospheric pressure at the end of exhalation by means of a mechanical impedance, usually a valve, within the circuit. The purpose of PEEP is to increase the volume of gas remaining in the lungs at the end of expiration in order to decrease the shunting of blood through the lungs and improve gas exchange. PEEP is done in ARDS (acute respiratory failure syndrome) to allow reduction in the level of oxygen being given
Initiation of mechanical ventilation starts with ____ cm H20
Typically start with 5 cm H2O; Levels > 15 cm H2O rarely needed
What are the variables usually set by the respiratory care practitioner?
Alarms – high and low pressure, low volume, apnea Humidifier temperature Inspiratory flow rate with volume ventilation
What tests do you do and rates you evaluate after initiating mechanical ventilation for someone?
Chest radiograph Inspiratory plateau pressure Exhaled tidal volume and rate Patient-ventilator synchrony Auto-PEEP SpO2 and arterial blood gas measurement Hemodynamic status
What are the primary variables for oxygenation PaO2?
FlO2 and mean airway pressure
What are the primary variables for ventilation PaCO2?
Tidal volume, Respiratory rate and dead space
What are the possible harmful consequences of mechanical ventilation?
Potential oxygen injury to lung Barotrauma/volutrauma Damage in more compliant lung zones due to high airway pressure/volume Hemodynamic compromise due to high intrathoracic pressure
What are the challenges in laparoscopic surgery?
Depth perception Limited space with in trocar for manipulation Suturing Electrosurgical safety
What are the benefits of laparoscopic surgery?
Reduces morbidity, handling of bowel, adhesion formation and exposure to drying and bacteria
What is a trocar?
a sharp-pointed surgical instrument fitted with a cannula and used especially to insert the cannula into a body cavity as a drainage outlet
What is a morecellator?
a surgical instrument used for division (“morcellation”) and removal of large masses of tissues during laparoscopic surgery.[1] It can consist of a hollow cylinder that penetrates the abdominal wall, ending with sharp edges[1] or cutting jaws,[2] through which a grasper can be inserted to pull the mass into the cylinder to cut out an extractable piece.
What is a harmonic scalpel?
a cutting instrument used during surgical procedures to simultaneously cut and coagulate tissue.
What is hydrodissection?
injection of a small amount of fluid into the capsule of the lens for dissection and maneuverability during extracapsular or phacoemulsification surgery
What area of the body are you doing surgery on when the patient is in the trendelenberg position laparoscopically?
pelvic
When the patient is supine, what area of the body are you doing surgery on laparoscopically?
small and large bowel
What position is the patient in when doing surgery laparoscopically on the stomach, liver and spleen?
head up tilt
What position is the patient in when doing surgery laparoscopically on the paracolic gutters?
lateral tilt
How do you prep the patient for surgery? In what areas?
The entire, anterior abdominal wall should be prepped from mid thigh to the nipple line and as lateral as possible. All patients must be properly grounded.
What kinds of tubing do you use on the patient while prepping for surgery?
Nasogastric intubation Bladder catheterization
When do we induce a pneumoperitoneum and how do we do it?
A pneumoperitoneum is deliberately created by the surgical team in order to perform laparoscopic surgery. This is achieved by insufflating the abdomen with carbon dioxide. CO2 is absorbed from the peritoneum and excreted from the lungs.
Why do we need a pneumoperitoneum during laparoscopic surgery?
its a visual field
What is the optimum exposure for a pneumoperitoneum?
About 12.0-16.0 mmHg- must be maintained
The most common access into the intra abdominal cavity is with what type of needle?
The most common access into the intra-abdominal cavity is with a Veress needle is the sub-umbilical area. The anterior abdominal wall is elevated to distance it from the intra-abdominal contents. 1 mm incision is made with a # 11 Scalpel below the umbilicus.
What do you palpate before beginning laparoscopic surgery?
aorta
What does a primary trocar do?
Primary trocar Introduced subq 2-3 cm the angled 45 degrees towards sacrum Remove trocar & introduce telescope
What does a secondary trocar do?
Secondary trocar Placed under direct visualization
What are ports and where are they placed during laparoscopic surgery?
In medicine, a port (or portacath) is a small medical appliance that is installed beneath the skin. A catheter connects the port to a vein. Under the skin, the port has a septum through which drugs can be injected and blood samples can be drawn many times, usually with less discomfort for the patient than a more typical “needle stick”. They are placed laterally.
Where are adhesions placed during laparoscopic surgery? What are adhesions?
9th intercostals space, anterior axillary line- adhesions are fibrous bands that form between tissues and organs, often as a result of injury during surgery. They may be thought of as internal scar tissue that connect tissues not normally connected.
What is a complication that occurs with a trocar site?
Controversial because hernias are related to multiple ports
Where are some common areas you see complications after laparoscopic surgery?
Shoulder pain, bowel, vascular, bladder, neuropathic and port site mets
What is the most common vascular injury during laparoscopic surgery? Insufflation occurs to what mm Hg?
Retroperitoneal hemorrhage most common Insufflation to 8.0 mmHg Check entire peritoneal cavity If + immediate midline lap Compress/clamp vessels, aspirate blood Replace blood- use the blood bank Call for vascular surgeon
William T. Bowie-refined electrical generator has what kind of current? What does it do?
VHF current→localized heating and tissue destruction. Can cut or coagulate
What is the most electrical generator? Why is the name misleading?
Monopolar-Most common-circle with the patient in the middle so current passes through the patient. Really not “mono” as there are active and return electrodes. Electrode may touch tissue or a clamp on the vessel. Monopolar coagulates, cutes pure and blends (argon (non-contact) and contact)
High frequency electrosurgical dissection- what are the different kinds?
Bipolar and Monopolar current
How does the monopoloar circuit flow in the electrical generator?
passes through an “active” electrode, crosses the patient’s body, and goes back to the electro-generator through a “passive” electrode
How does a bipolar circuit flow in the electrical generator?
Active and return electrodes are present in the same instrument. Allows heating of a very discrete amount of tissue.
What is bipolar cautery?
A surgical procedure involving bipolar cautery uses electrical current through a medical device, which generally cuts through human tissue and or seals bleeding vessels. Surgeons often combine this type of surgical instrument simultaneously with some type of fluid irrigation that to control the amount of tissue damage occurring during surgery. A number of medical fields typically use bipolar cautery including dentistry, general surgery and neurosurgery.
Electrosurgery performs what 3 things?
Cut (vaporization), fulgurates and dessicates
What is pure cutting?
Continuous Sine wave of current-instant vaporization Relatively low voltage Best with very small (needle) tip held just off the tissue to be cut Minimal coagulation and homeostasis, Minimal lateral tissue damage
What is blend cutting?
Less cell explosion Moderate desiccation
How does the process of coagulation work during surgery?
There is no constant waveform Debris heat up and denatures protein Desiccation or fulguration Causes deeper tissue injury than cut
What are the qualities of dessication during surgery?
Tip in direct contact with tissue Less heat, no cutting action Achieved with the “cutting” current at low power
What are the qualities of fulguration during surgery?
Tip not in direct contact with tissue Current arcs to the target Eschar formed High voltage but low frequency (The greater the heat generated with any of the methods, the greater the collateral damage.)
What is an argon beam coagulator?
Uses ionized argon gas to conduct monopolar RF current to tissue Pinpoint or spray modes Pluses-less eschar and smoke-good for wide area coagulation (liver) Minuses-can’t cut, can overheat. Can raise intraabdominal pressure when used in laparoscopy (7 liters/min)
How does a ultrasonic scalpel work?
Transducer produces vibrations around 55,000 cycles/sec. Cellular friction denatures proteins Less heat production than electrosurgery Cavitation along cell surfaces→ vaporization/cell rupture
What are the advantages of a ultrasonic scalpel?
Good in tight spaces (Laparoscopy) No risk of current “arcing” No neuromuscular stimulation Minimal lateral thermal damage No eschar/smoke Can be used in pts. with defibrillators
What is the diadvantage of an ultrasonic scalpel?
Expensive, can’t be used efficiently except for certain parts of cases, tend to break down
What are some electrosurgery problems?
Alternate Site Burns Surgical Fires Trocar burns in minimally invasive surgery Poor grounding + EKG pad = burn Fetal stimulation Pacemaker (Interfere, burn. damage device) Bowel explosion?
What can you use during electrosurgery to minimize risk of trocar burns?
using all metal cannulas
What is a Implantable Cardioverter Defibrillator?
a small battery-powered electrical impulse generator that is implanted in patients who are at risk of sudden cardiac death due to ventricular fibrillation and ventricular tachycardia. The device is programmed to detect cardiac arrhythmia and correct it by delivering a brief electrical impulse to the heart.
What problems can you run in to during electrosurgery with someone who has a implantable cardioverter defibrillator?
triggers device, damages it or asystole
What should you ask about when taking a history from someone who needs surgery?
Pain: scale 1-10, type of pain, radiation Change in bowel or urinary habits: diarrhea, constipation, vomiting Trauma: must know precise details of trauma related to injury Past Medical History Medications, especially herbals and OTCs Social History: nutritional status, EtOH, smoking, illicit drug use Family History
What does AMPLE stand for?
allergies, meds, past medical hx, last meal, and events to emergency
What are the essential steps for physical exam before surgery?
inspection, palpation, auscultation (IPA)
What are some factors predisposing patient to surgery- and anesthesia-related pulmonary complications?
-COPD (asthma, chronic bronchitis, occupational lung diseases) -Obesity -Tobacco history -Neuromuscular disease -Nutritional depletion -Coma -Age
When someone has a pulmonary disease, what should the pre-op evaluation include?
Pre-op evaluation should include -baseline ABG on room air -O2 sat with pulse oximetry - pre-op PFTs
Aim of pre-op treatment for someone with pulm disease is to optimize pt’s pulmonary perfusion and may include what?
-nebulizer treatments w/ Beta agonists -steroids -chest PT
What are some screening pulm function tests for someone with pulm disease before surgery?
Screening pulmonary function tests: FVC (forced vital capacity) and FEV1 (forced expiratory volume in 1 second) If < 50% predicted then likely significant airway disease and high risk of complications
What helps clear secretions in someone with pulm disease before surgery?
Bronchodilators with twice-daily chest PT and postural drainage, it help clear secretions
What are some neuropathies in diabetics that can cause problems in surgery?
Gastroparesis - chance of aspiration Sinus tachycardia secondary to autonomic cardiac neuropathy Neurogenic bladder Most are temporary problems and resolve in recuperative period
Pre-operatively, what kind of information do you get from diabetics?
Need careful history including -duration of diabetes -insulin requirements – last dose? -diet -level of blood sugar control -history of angina, MI, arrhythmias -history of diabetic ulcers on feet or legs
How do you monitor a diabetic while in surgery?
Accuchecks bid or qid, sliding scale for insulin doses Care of feet and extremities to prevent skin breakdown (i.e., hygiene, foot cradles, lambs wool, heel pads, etc.)
Hyperthyroidism patients can have what surgical complications?
Hyperthyroidism can cause increased risk of cardiac arrhythmias, especially a-fib
Hypothyroidism patients can have what surgical complications?
Hypothyroidism is associated w/ decreased hepatic metabolism, which can cause reduced drug metabolism -occasionally see hypotension
Cirrhosis: mortality from surgery in cirrhotic pts. 10-80% depending on hepatic impairment. Complications include what?
-coagulopathies -decreased drug clearance/metabolism -encephalopathy, seizures, DTs -increased risk of intraperitoneal sepsis -electrolyte abnormalities -infection, poor healing -changes in glucose production/metabolism
When discussing coagulation abnormalities in patients what do you ask them when getting their history? What labs and physical exam components are included?
-easy bruising -excessive bleeding after minor surgical procedures -family history of bleeding problems -history of liver disease -meds (especially ASA) Physical exam -look for bruises, petechiae, hepatosplenomegaly, severe malnutrition Pre-op evaluation -PT, PTT, bleeding time if any questions
In chronic renal failure, what peri-operative problems could occur?
Chronic renal failure is associated w/ multiple peri-operative problems -fluid and electrolyte control, especially Na+ and K+ -chronic metabolic acidosis -chronic anemia -poor nutritional state -coagulopahty
Pre-operatively, what should you obtain in the history for a patient with chronic renal failure?
Pre-op evaluation -baseline weight -baseline electrolytes, BUN, Cr -baseline coagulation profile -nephrology consult to optimize fluid/electrolyte balances and proper dosing of peri-operative meds
What pre-op labs should you obtain for someone with chronic renal failure?
-CBC w/ diff -Chem 7 (electrolytes, glucose, BUN, Cr) -UA -EKG (50+) -Chest x-ray (50+)
What are some pre-op orders for any patient? What do you tell them to do and what to you give them?
NPO after midnight Pre-op antibiotics IV if necessary Consent for operative procedure Labs Type & screen or crossmatch Skin prep (i.e., betadine shower) Pre-op enema Pre-op meds Sleeping med (usually ordered by anesthesia) Pre-op sedation
Pre-op and peri-op patient orders include what? (ADCADVA-IMLNCP)
Admit: to Dr.___ or to a service (i.e.,Blue Service) Dx: reason patient was admitted Condition: fair, guarded, serious, critical, etc. Allergies: drug allergies, also food/env. allergies Diet: NPO, full liquids, clear liquids, 1800 cal ADA, etc. Vitals: per routine or however often is necessary Activity: bed rest w/wo BR privileges, OOB to chair, etc.3 IV: type and rate +/- any additives Meds: patient’s normal meds plus analgesics, etc. Labs: bloodwork, CXR, EKG, CT scan, etc. Nursing: dressing changes, I/Os, daily weights, etc. Consults: medicine, social services, PT Parameters: call MD or HO for - SBP101.5 - Pulse 110 - Urine Output 30
What does ADC-VAN-DIS-AL stand for writing the orders and needs of a patient pre and perioperatively?
A - admit D - diagnosis C - condition V - vitals A - allergies N - nursing D - diet I - IVs, I/Os S - special orders (i.e., consults) A - activity L - labs
What information does a pre-op note have?
Date, One sentence detailing significant past medical history and procedure (Example: 79 yo W female, h/o HTN, IDDM x 1yr, for cholecystectomy) Meds/Allergies H&P: done/dictated Anesthesia:done Labs:WBC, Hct, Plt, Na, K, Cl, HCO3 Bun, Cr, Gluc, ABG, PT/PTT Imaging/Studies: EKG, CXR Type & hold/crossmatch/autologous blood available Operative consent: signed or ordered Signature, Title Time/Date
What are the proper monitors for mechanical ventilation?
ECG, SpO2, and vital signs
What is FIO2?
fraction or percentage of oxygen in the space being measured. Medical patients experiencing difficulty breathing are provided with oxygen-enriched air, which means a higher-than-atmospheric FiO2. Natural air includes 20.9% oxygen, which is equivalent to FiO2 of 0.21. Oxygen-enriched air has a higher FiO2 than 0.21, up to 1.00, which means 100% oxygen.[1] FiO2 is typically maintained below 0.5 even with mechanical ventilation, to avoid oxygen toxicity.[2]
What is initial FIO2 for mechanical ventilation?
1.0
You decrease initial FIO2 (1.0) to maintain a certain SpO2 range of what?
SpO2 > 92% to 94%
What is the initial tidal volume at the beginning of mechanical ventilation?
8-10 mL/kg
Why should you lower the tidal volume in mechanical ventilation?
to avoid IPP (inspiratory plateau pressure?), lower to 5-8 mL/kg