Part 33 Flashcards
Sterility
Degree of acceptable contamination or bioburden of an object at a given point in time, when achieved, a break in technique results in contamination, with the item or surface being declared unsterile, no lesser level on the sterility continuum is acceptable, except when all items in contact with tissues below skin or mucus membranes should be sterile, some surfaces cannot be sterilized such as skin but surgical clean is acceptable, and contamination should be limited except when no other alternatives
3 basic principles of aseptic technique
- Sterile field is created for each surgical procedure
- Sterile team members are properly prepared and attired prior to entering the sterile field
- movement in and around the sterile field must not compromise the sterile field
Principle applications of sterile technique (9)
- sterile personnel keep well within the field, do not wander or leave field
- movement is kept to a minimum not to disrupt air currents
- nonsterile persons do not reach over the sterile surfaces
- sterile team members must face each other and the field at all times, can pass each other back to back using rolling method, do NOT turn back to sterile field
- Nonsterile items are not used within sterile field, if one item is contaminated, any item coming in contact with that item is also contaminated
- gowns are sterile in the front from axillary line to the waist, and the sleeves to three inches below the elbow
- when in doubt assume breach in sterility
- sterile tables are kept at sterile height
- gown cuffs at the wrist is unsterile and must be covered by gloves at all times
Scrubbing technique (8)
- 5-10 min
- remove gross contamination from nails
- begin at fingers using betadine
- cover all surfaces working gradually toward elbows
- rinse from distal to proximal***
- hold arms with hands pointing up
- enter OR without touching anything
- dry with sterile towel, hold away from body
Wet scrub vs dry scrub
A wet scrub is always done as the first scrub of the day, vs a dry scrub can be done for consecutive and involves using a hand sanitizer scrubbing up to the elbows and then no towel to dry
OR timeline (7)
- Patient arrives in holding area/pre-op
- identification verified
- documentation checked
- anethesia IV starts as well as pre op meds
- patient physically moved to OR bed
- positioned for anesthesia administration
- positioned for surgical intervention
Sterile to unsterile pathway
- sterile
- surgically clean
- clean
- contaminated
- unsterile
Kelly hemostat function
Arterovenous clamp used to control local bleeding, crushes tissue
Halstead Mosquito hemostat function
Arterovenous clamp used to control local bleeding that has delicate jaws for delicate tissue
Babcock clamp function
Grasping the bowel
Allis clamp function
Skin or bowel cut edges
Glassman clamp function
Clamp large areas of intestine to prevent spilling out
Adson forceps function
Used for delicate skin tissue closure
Backus towel forceps function
Used to secure to the margins of the sterile field, other towels, etc, hold sponges or other prepping materials
Straight forceps function
Used when handling contaminated sponges, pads, etc
Debakey forceps function
Used to occlude vessels to control bleeding during aortic repairs
Rat tooth forceps function
Used for grasping and lifting skin particularly edges to help place sutures to close wounds
Russian forceps funciton
Used on bowel or delicate structures but not directly on bowel surfaces, used where blunt tipped pickups needed in abdomen
Military retractor function
General use for multiple things
Richardson retractor and kelly retractor function
Handheld retractor for general body wall
Volkmann retractor (rake) function
Used for skin edge retraction and skin flap creation
Wetlainer retractor function
Useful in surgeon working alone to keep wound edges open
Deavor retractor function
Used in sometimes GYN surgery
Bookwalter Universal Ring retractor function
Self retaining retractor used as fixed abdominal wall retraction
Balfort retractor function
Self retaining retractor used to fix abdominal wall
Ochsner ribbon retractor function
Malleable retractor that can also help prevent iatrogenic bowel injury by placing under while suturing
Tips of curved scissors need to be pointed….
….superiorally
Most common suction type in R
Yankaeur
Poole suction
Multiple fenestrations used for large cavity full of fluid such as perforated viscus without sticking directly to bowel wall
“The golden hour”
The first hour after injury largely determining the critically injured patient’s chances for survival, concept that emphasizes the urgency of care required by major trauma patients to prevent early deaths predominantly from hemorrhage
Guiding principle of initial trauma management
Airway Breathing and ventilation Circulation and hemorrhage control Disability Exposure
Airway assessment in trauma bay
Goal is to establish patient airway and protect c spine, fastest way is to assess by asking name (if can tell then airway patent), consider establishing an airway with decreased mental status, excessive secretions, loss of cough, smoke/inhalation injury, facial trauma, consider surgical airway if endotracheal intubation is unsuccessful
Breathing assessment in trauma bay
Goal is to ensure adequate oxygenation and ventilation, will auscultate for equal bilateral breath sounds while observing the respiratory rate (hook up to monitor), chest movement, and o2 sat, palpate for crepitus and tenderness
Circulation assessment in trauma bay
Goal is to ensure end organ perfusion, palpate pulses, observe manual blood pressure, mental status assessment is one way, taking dorsal pedis pulse and radial pulses (want +2 bilaterally) is another, look at skin color and cap refill and temp is another
Disability assessment in the trauma bay
Perform glascow coma score
Exposure assessment in trauma bay
Completely undress patient for assessment then cover to protect against hypothermia
Labs typically gotten in a trauma bay setting (9)
- CBC with diff
- BNP
- PT/INR
- lactic acid
- ETOH
- urine tox screen
- troponin
- creatinine
- ABG
Imaging studies typically gotten in a trauma bay setting (4)
- CXR #1
- pelvic x ray in hemodynamic instability
- FAST exam
- if hemodynamically stable then CT of head and cervical spine without contrast and chest, abdomen and pelvis with CT with contrast if have time
3 common types of shock in trauma setting from most common to least
- hemorrhagic/hypovolemic (most common)
- caridogenic
- neurogenic (MUST rule out hemorrhagic first)
Classes of hemorrhage (4)
I - Small amount of blood loss (10-19%), BP, HR, RR, and U/O remain the same
II - Decreased pulse pressure (20-29%), HR >100, RR increase, U/O decrease
III - (30-39%)decreased BP, HR >120, RR >30, U/O oligouric
IV - up to 40-50% blood loss, BP very low, >140HR, RR>40, aneuric
5 major areas of blood loss in trauma
- chest
- abdomen
- pelvis
- femur
- floor (open wound)
Rapid response to initial fluid resuscitation (with lactated ringer)
See vital signs return to normal, estimated blood loss is minimal, monitor and reassess patient
Transient response to initial fluid resuscitation (with lactated ringer)
Sees Transient improvement of vital signs, estimated blood loss moderate, will need more fluid and likely will need blood
Minimal or no response to initial fluid resuscitation (with lactated ringer)
Sees no change in vital signs, estimated blood loss is severe, need fluid and blood and massive transfusion protocol of 1:1:1 RBC to FFP to platelets
Central venous access definition, benefits and cons, procedure
- Insertion of thin long catheter that terminates in superior or inferior vena cava, sterile procedure performed at bedside typically under ultrasound guidance, either accessed via internal jugular (preferred), femoral, or subclavian vein (most common in trauma setting)
- allows for CVP monitoring and rapid infusion of blood or crystalloid products as well as to get frequent blood draws, but risks include bleeding, infection, arterial stick, pneumothorax, etc
- Done by identifying vein with ultrasound, infiltrating the skin with local anesthetic, confirm intravenous location of needle, insert guidwire into vein thru access, remove needle while controlling guidwire, make small incision of skin at puncture site adjacent to guidwire, advance dilator to guide then remove dilator, threat catheter, remove guidwire, taking care to control catheter, flush with saline, suture catheter in place and address site with sterile technique, Get chest XR after to ensure in right place and haven’t caused a pneumothorax
Tube thoracostomy (standard chest tube or pig tail catheter) definition, benefits and cons, procedure
- Tube or catheter is placed thru chest wall 4th or fifth intercostal space on mid anterior axillary line into pleural cavity and used to drain air or fluid
- indicated in trauma pneumothorax, tension pneumothorax, or hemothorax, risk of bleeding, infection, injury to lung or heart
- prep skin, inject local anesthesia, use curved clamp to blunty dissect and create tunnel over superior portion of rib, will confirm location by observing condensation within the tube with breathing and or drainage from tube, advance until the last drainage hole is fully within the thoracic cavity, and then confirm with CXR
Chest tube drainage systems (2 types)
Wet system - tube from chest tube drains into collection chamber that can be measured, adjacent chamber is water seal chamber (keeps air from getting sucked back into chest tube) and suction chamber (prevents air from escaping by being hooked up to wall suction) (together the last 2 )tells if the patient is leaking air from their lungs into the system, if answer is yes need to continue using tube but if not then can consider changing system)
Dry - Tube from chest tube drains into collection chamber that can be measured, adjacent chambers simplified to not need water seal but can still be read easily
Arterial line definition, considerations and risks, procedure
- Used for continuous BP monitoring or frequent ABG’s at the radial or femoral sites
- considerations include performing allens test for hand, using nondominant hand, risks include arterial injury, infection, bleeding, thrombosis
- placed similarly to central line by injecting needle, withdrawing till get blood, putting guidewire on, and inserting it
Thoracotomy procedure
Procedure of last resort performed to gain rapid access to the heart and major thoracic vessels thru anterolateral chest incision to control exsanguinating hemorrhage or other life threatening chest injuries, incision made at margin of the sternum along intercostal space between 4th and 5th ribs and carried laterally to the left posterior axillary line following curvature of rib
When are rib fractures surgically managed? (4)
- impending or actual respiratory fracture
- flail chest
- significantly displaced ribs
- sternal plating often occurs after open heart surgery
When is exploratory laparotomy indicated in hepatic injury? (3)
- hemodynamically unstable patient
- positive FAST exam
- hemodynamically stable with CT grade 1 or 2 WITH extravasation (go to IR embolization) or if class 3-4
When is exploratory laparotomy indicated in splenic injury? (3)
- hemodynamically unstable patient
- Positive FAST exam
- CT active extravasation (go to IR embolization) or class 3-4
Retroperitoneal hemorrhage and how is it diagnosed?
Hard to detect (sometimes seen with “seatbelt” sign with bruising over abdomen), not seen on FAST exam or CXR, often found incidentally in surgery, CT with IV contrast best in hemodynamically stable patient to diagnose
3 Zones of the retroperitoneum
I - aorta, inferior vena cava, portion of duodenum, pancreas
II - adrenal glands, kidneys, renal vessels, ureters, ascending/descending colon
III - right and left internal and external iliac arteries and veins, distal ureters, distal sigmoid colon and rectum
For penetrating retroperitoneal hemorrhage in zone I, what is the likely choice of treatment? what about II and III?
I - Explore with major vascular surgery
II - Selectively explore area for expanding hematoma
III - Explore with major vascular surgery
For blunt retroperitoneal hemorrhage in zone I, what is likey choice of treatment? What about II and III?
I - Explore, likely with major vascular surgery
II - Do NOT explore contained nonexpanding hematoma
III - Do NOT explore
In hemodynamically stable retroperitoneal patients who do not have other indications for surgical exploration often do not require…
…operative exploration
Post trauma care after acute injuires are stabilized (6)
- DVT prophylaxis (lovenox most often)
- avoiding pulmonary insufficiency
- bowel regimen
- GI prophylaxis
- insulin sliding scale in ICU patients
- disposition planning for PT/OT
Laparoscopic surgery
Surgical technique in which operations are performed thru small incisions and placement of trocars (holes) where a viewing tube and instruments are inserted, it has a camera that transmits the image to monitors and allows a surgeon to perform an operation
Insufflation
Blowing air gas or powder into a cavity of body, can be done for abdomen or chest, often done to achieve necessary work space for laproscopic surgery, device responds dynamically to ensure CO2 level (used because it does not distort image and is absorbed more quickly than air) remains at 10-15mmHg
Most common complaint after laparoscopic surgery
Referred shoulder pain from irritation of phrenic nerve
Trochar
A device that acts as a portal for instruments to gain access to the peritoneal cavity without loss of pneumoperitoneum (air in the cavity)
Electrocautery
Process in which direct current is passed thru resistant metal wire electrode generating heat, can be monopolar or bipolar (like tweezers) applied to living tissue to achieve hemostasis or varying degrees of tissue destruction, current does not enter patient body, only heated wire comes in contact with tissue, monoppolar easy to use and good dissecting capabilities but can cause large volume of tissue injury and interfere with pacemakers, bipolar harder to use and has no dissecting capability, but have smaller volume of tissues injured and is safe with pacemaker
Direct couplling
Complication of electrocautery where a burn occurs due to faulty insulation or accidental contact with noninsulated tools
Benefits of laparoscopic surgery (6)
- pulmonary function maintained better
- less acute phase stress response than open
- less inflammation
- decreased intra-abdominal adhesions compared to open
- quicker GI tract recovery
- decrease and smaller and more aesthetic incisions
Negative effects of pneumoperitoneum
- pressure on the cardiovascular system inferior vena cava due to inflation (tachycardia)
- hypercarbia or acidosis
- decreased lung volumes and compliance potentially resulting in atelectasis
Reverse trendelenberg position
Patient head above feet, results in pooling of blood, decreased venous return, decreased preload, but increased pulmonary function
Trendelenberg position
Patients feet higher than head, sees increased preload due to increased venous return but can see decreased pulmonary functioning
Contraindications to laparoscopic surgery (6)
- previous open operation
- intraperitoneal mesh
- cirrhosis and portal hypertension
- COPD or pickwickian syndrome
- hemorrhagic shock
- acute brain injury (trendelenberg can increase ICP)
Can laparoscopic surgery be done in pregnancy?
Yes, second trimester is best and good to use lowest possible pressure to avoid fetal acidosis and intra operative fetal monitoring is required
Natural oriface transluminal endoscopic surgery
Novel technique to use openings of the mouth or vagina to remove organs such as during cholycystectomy or appendectomy
Benefits/cons of robotic surgery (2 and 2)
+majorly improved dexterity as can angle tools around corners
+enhanced 3D visual field for surgeon
-no tactile feedback
-expensive and take long time
Etiology of obesity (3)
- unknown
- familial component
- thrifty gene hypothesis (more efficient absorption of calories ingested was evolutionary advantageous until modern society)
Leptin is an appetite ___ while ghrelin is a ____
suppressor, stimulant
Obesity treatment options (3)
- diet, exercise, behavior changes
- weight loss medications
- weight loss surgery (surgery is most effective long term than medical management)
Roux en Y gastric bipass has a __% chance of curing type 2 diabetes
0.8
Who qualifies for bariatric surgery? (3)
- patients with BMI of 40 or above, or more than 100 lbs overweight
- BMI of 35 and 1 or more obesity related comorbidities
- inability to achieve healthy weight loss sustained for period of time with prior weight loss efforts
Who doesn’t qualify for bariatric surgery? (4)
- untreated depression
- binge eating disorder
- endocrine caused obesity
- prohibitive anesthetic risks
Pre-op for bariatric surgery (2)
- protein shake protocol based on BMI 2 weeks before surgery
- 2 days prior only allowed clear liquids (goal to shrink liver by mobilizing hepatic fat)
3 main types of bariatric surgery and a description of them
- lap band (least common, restrict stomach with device, lowest complication rate but not as efficient weight loss)
- sleeve gastrectomy (most common, restrictive type, reduce stomach volume by 85%, huge decrease in ghrelin secretions as result seeing good long term outcomes in weight loss, but can see malabsorption complications and it is nonreversible)
- Route en y gastric bipass (gold standard bariatric procedure, very effective weight loss, cut stomach at gastric pouch (just distal to GE junction) and staple off stomach, then locate ligament of trietz, cut it in half and anastamose distal end to create gastrojejunostomy, and then anastamose the proximal jejunum to the a further distal portion of the jejunum creating a JJ anastamosis, has highest risk of morbidity and mortality)
Ligament of trietz
Divides the duodenum from the jejunum
1 presenting sign for bariatric emergency as complication due to surgery
-tachycardia (a leak until proven otherwise!!!)
Post op diet for bariatric surgeries (2)
- clear liquids, protein supplements
- avoid gum chewing for blockage, alcohol, straws or carbonated beverages for gas build up
Dumping syndrome
A complication seen in post gastric bipass surgery patients where when they eat high carbohydrate simple sugar meals it goes immediately thru the digestive tract causing diarrhea, diaphoresis, dizziness, etc as a malabsorption occurs
Malabsorption/nutritional considerations post gastric bipass patient (5)
- protein levels monitored as primarily absorbed in duodenum
- carb digestion begins after jejunojejunostomy, decreased absorption
- B12 deficiency as intrinsic factor is released from parietal cells in stomach, might need PO or IM
- iron defficiency absorption occurs in duodenum
- Ca2+ deficiency absorption occurs in the duodenum
A BMI over 40 puts a person at ASA level ___
III
Clot in the calf is ___ common but ___ risk, in the thigh is ____ common but ___ risk
more, less, less, higher
Does clean contaminated wounds need prophylactic antibiotics?
Yes, broad spectrum 1st gen cephalosporins first choice
What type of incision is used most often in c section?
Transverse (iliac crest to liac crest)
Maylard incision
Transverse incision that cuts the rectus muscles transversely to gain large exposure often for c section with large uterus
Cherney Incision
Transverse incision that cuts the tendinous portion of the rectus muscle where it connects to the symphisis, less commonly used due to risk of osteomyelitis
Pfannenstiel incision
Traverse incision that involves lateral retraction of the rectus muscles and midline** incision of the peritoneum, used for most c sections and abdominal hysterectomies
Kustner incision
Traverse incision that involves lateral retraction of the rectus muscles and transverse*** incision of the peritoneum, used for most c sections and abdominal hysterectomies
Diagnostic indications for D&C (4)
- abnormal bleeding
- oligomenorrhea or amenorrhea
- dysmenorrhea
- rule out endometrial disease and malignancy
Therapeutic indications for D&C (4)
- menometrorrhagia (bleeding between periods)
- suspected intrauterine pathology
- postpartum bleeding and retained secundines
- retrieval of lost IUD
Approaches to tubal sterilization (4)
-laparoscopy (bipolar electrocoagulation or some kind of banding or tying off the base)
-laparotomy (similar to a c section)
-colpotomy (removal thru the vagina)
-hysteroscopy
#1 contraception in women over 35
Total hysterectomy definition
Uterus and cervix removal
Partial hysterectomy definition
Uterus removed while retaining the cervix
Total hysterectomy with bilateral salpingoophorectomy definition
Removal of the uterus, cervix, fallopian tubes, and ovaries
Indications for hysterectomy (4)
- leiomyoma (most common if they cause pain or bleeding)
- endometriosis
- cancer
- adenomyosis (endometrial glands growing in muscle of the uterus itself, more rare and probably genetic but causes discomfort)
1 approach for hysterectomy and why?
Vaginal (has less ileus as mostly extraperitnoeal, abdominal incision avoided, lower cost)
Alternative for hysterectomy
Endometrial ablation (popular for menorrhagia or dysmenorrhea) inject liquid to uterus and heat it to near boiling to cook off the tissue
Hysteroscopy
Used to analyze causes of potential pain or bleeding and remove polyps or other materials, done under anesthesia to avoid discomfort of uterine distension
Surgical treatment for genital prolapse
Anterior colporrhapy (suturing it back in)
Milk is produced in the ___ of the breast and transferred thru the ___
lobules, ducts
Coopers ligaments
Suspensory breast ligaments that may create retraction of skin with underlaying tumor
Lactiferous sinus
Space directly below nipple, attempt needs to be made to preserve if patient wishes to breast feed after surgery
Tail of spence
Tissue of breast that tapers into the axilla
Mammary milk line
Embryological theoretical space extendig from shoulder to thigh where extra breast and nipples may be present
Main blood supply to the breast
Branches of the axillary artery coming off inferior
Borders of the axilla
Superior - axillary vein
Posterior - long thoracic nerve
Lateral - lats muscle
Medial - pec minor muscle
Injury to the long thoracic nerve leads to what condition?
Winged scapula
3 main routes of lymphatic drainage from the breast
- axillary lateral pathway (dominant pathway, into axillary nodes)
- Internal mammary pathway (medial that drains into the parasternal area)
- retromammary pathway (drains deeper portions of breast into the subclavicular plexus)
3 surgical levels of axillary lymphatics
Level 1 (low) lateral to pec minor Level 2 (middle) deep to pec minor Level 3 (high) medial to pec minor
Higher level of lymph node involvement in axillary lymphatics the….
….worse outcome for the cancer patient
Most common cause of mastodynia
Cyclic hormonal variations in menstruating women
Fibrocystic breast changes
General term for benign breast changes that may include lumps and pain but entail poorly defined symptoms and etiology
Fibroadenoma
Common in women 15-35, firm freely mobile solid benign solitary breast mass, 2nd most common tumor in breast after carcinoma
Intraductal papilloma
Benign tumor within the ductal system, relieved by passage of discharge, masses are rare but core needle biopsy determines whether to remove
Most common cause of unilateral bloody nipple discharge
Intraductal papilloma
Possible signs or symptoms of breast cancer (6)
- nontender firm with irregular border fixed to skin or muscle palpable lump
- most nipple discharge is benign
- skin dimpling (peau d’orange)
- nipple retraction
- excoriated nipple
- mammmographic abnormalities
Breast cancer risk factors (6)
- Age
- BRCA 1 and 2
- family history
- early menarche
- nulliparity
- no breastfeeding
Imaging modality for suspected breast cancer (3)
- mammogram (patients over 40)
- ultrasound (under than 30)
- MRI
BIRADS score of 4 of 5 requires a….
….breast biopsy for histologic analysis
2 most common types of breast cancer
- ductal carcinoma (starts in ducts that move milk from breast to nipple)
- lobular carinoma (starts in lobules that produce milk)
Pagets disease
Much less common type of breast cancer that sees scaly raw vesicular and ulcerated breast appearance
Needle localization
Needed when there is not a palpable mass on breast tissue of suspected malignancy, done by radiologist under mammogram assistance to penetrate lesion and hold in place sticking out of skin of breast until procedure
SAVI scout localization
Alternative for needle localization that is less painful, involves infared implantation of reflector prior to surgery that makes audible signal for surgeon to detect with device
Lumpectomy/partial mastectomy
Removal of breast malignancy with clear or negative margins, incision periareolar for cosmetics, after removed tumor is inked to understand orientation of tissue removed to ensure that margins are clear and what direction there may have been not full clearing in for surgeons future procedure
Mastectomy
Removal of all of breast tissue, either simple with dissection of all of breast tissue, modified radical form includes removal of level 1 and 2 axillary nodes in addition for biopsy proven lymph node involvement
Sentinal lymph node biopsy
Often done in conjunction with mastectomy, injection of radioactive dye into tumor site of breast that probe can sense tracer located at the nearby lymph nodes (sentinal ones), once located, incision is made and node or multiple nodes are removed and sent to pathology, helps determine staging based on how far cancer has spread
A patient will need axillary lymph node dissection AFTER sentinal lymph node biopsy if these 4 conditions are met
- 3 or more positive nodes on patient with small tumor
- any # of positive lymph nodes in patients with large tumor
- any # of positive lymph nodes found with extranodal extension of tumor cells
- any # of positive nodes in patients who will not receive breast irradiation because they undergo mastectomy, or refusal of radiation
Breast flaps surgery (DIEP, TRAM, TDAP)
Chunk of tissue (skin, fat, muscle) reimplanted including vasculature and perfusion over site of mastectomy, for example TDap (removal of part of latismus dorsi muscle) TRAM (transverse rectus abdominus muscle), or DIEP (deep inferior epigastric perforator artery)
General vs local anesthetics
General abolish response to pain by depressing CNS and producing loss of consciousness vs local produce a temporary loss of sensation or feeling in a confined area of the body without loss of consciousness, much less risk and much more rapid recovery
Local anesthetics mechanism of action and how does epinephrine impact it?
- block nerve fiber conduction by directly acting on nerve membranes, inhibit sodium ions from crossing membrane by blocking sodium channels
- Reversible with metabolism and with time
- Perception of pain is lost first, followed by cold, warmth, touch, and deep pressure (small fibers), large motor nerves tend to be last nerves to be inhibited (large motor nerves, we don’t want these to be inhibited)
- epi injected with it increases time of effectiveness as it causes vasoconstriction of tissue decreasing blood flow increasing time in which the dispersion occurs (very dilute ratio of epi to anesthetic)
Examples of ester local anesthetics (4)
- benzocaine
- cocaine
- procaine
- tetracaine
Examples of amide local anesthetics (4) - these work longer than the esters!
- lidocaine
- mepivacaine
- dyclonine
- ethyl chloride
Topical anesthetics OTC products and their uses (3)
- benzocaine (sun burn)
- dibucaine (hemorrhoids)
- lidocaine (small cuts)
Peripheral nerve block (field block)
Anesthetic injected close to nerve trunk to block transmission along peripheral nerrve interrupted, either minor impacting 1 distinct nerve or major affecting a plexus
Central neural blockade and subtypes (3)
- Anesthetic directed within membranes surrounding the spinal cord, used when analgesia needed in a large region, frequently used during surgical and obstetric procedures
- epidural, caudal block, spinal block (btwn arachnoid and pia)
Adverse effects of central neural blockade (4)
- hypotension
- autonomic blockade
- headache from CSF leak (relieved in supine position)
- meningitis type effect
Cocaine surgical uses (2)
- topically in procedures on eyes and nasal mucosa because of vasoconstrictor action
- local anesthetic with epi
The only local anesthetic that causes vasoconstriction is ___, the rest cause vasodilatory effects
cocaine
Toxic buildup of systemic local anesthetics signs and symptoms (3)
- hypotension
- tremors
- convulsions
Injectable local anesthetics with epinephrine drug interactions (4)
- tricyclic antidepressants
- MAOI
- succinycholine
- diazepam
Procaine (novocain) function
Ester type local anesthetic only effective via injection often combined with epi, metabolized very rapidly and rarely systemic toxicity, used less often
Lidocaine (xylocaine) funciton
Prototype amide type anesthetic, most widely used, more effective then procaine and often combined with epi, higher risk of systemic toxicity
Cocaine function
Ester type anesthetic that has vasoconstriction effects and that also has pronounced sympathetic effect on CNS, only used topically for anesthesia of ears nose and throat, lasts about an hour
2 types of general anesthetics
- Inhalation- Intravenous
Analgesia vs anesthesia
Loss of pain sensation vs loss of pain and other sensations sometimes including consciousness
Minimum alveolar concentration (MAC)
Measures general anesthetic potency, defined as minimum conc at which alveolar air will produce immobility in 50% of patients exposed to painful stimulus, low MAC indicates high anesthetic potency
Blood flow to brain is high, anesthetic levels drop rapidly when drug administration stops, therefore tissues with lower blood flow have slower decline in drug levels resulting in…
….patients waking up from anesthesia before all has left the body
General anesthesia adverse effects (4)
- respiratory and cardiac depression
- increased risk of heart arrhythmias
- malignant hyperthermia (rare)
- aspiration of gastric contents
Preanesthetic agents and examples (5)
- benzodiazepines (midazolam - versed)
- opioids (relieve pre and post op pain)
- clonidine (reduces anxiety and cause sedation)
- atropine (decrease risk of bradycardia and suppress bronchial secretions)
- neuromuscular blocking agents (succinycholine)
Postanesthetic agents and examples (3)
- analgesics (opioids, nsaids)
- antiemetics (odensetron)
- muscarinic agonists (bethanechol)
Isoflurane (forane) and enflurane (ethrane), and desflurane (adults only!) function and ADRs (2)
Prototype of volatile inhalation anesthetics, low MAC at 1.15%,
-respiratory depression, hypotension,
Nitrous oxide function
Very low anesthetic potency impossible to produce anesthesia alone as MAC is very high, but high analgesic potency so combined with other agents, inhaling 20% can provide analgesic effects similar to morphine
-no serious ADRs
Intravenous anesthetics function and examples (2)
- used alone or with other analgesic agents to supplement their effects
- short acting barbiturates (methohexital) - rapid onset in 10-20 seconds
- benzos (diazepam, midazolam)
Methohexital ADRs (2)
- reflex tachycardia
- CV and respiratory depression
Conscious sedation drug combo
midazolam (versed) and opioid analgesic (morphine, fentanyl)
Propofol (diprivan)
Most widely used IV anesthetic, 90% receive, sedative hpynotic for induction and maintenance of general anesthesia, has no analgesic actions, brings rapid onset of 60 seconds, continuous use prolongs effects
Propofol (diprivan) ADR’s (4)
- severe respiratory depression
- hypotension
- high risk of bacterial infection (contamination)
- propofol infusion syndrome (metabolic acidosis and rhabdo) very rarely, requires CPK monitoring (skeletal and cardiac muscle injury)
Ketamine (ketalar) function
Anesthetic that produces dissociative anesthesia, causes sedation, immobility, analgesia and amnesia, rapid induction and recovery but full recovery may take hours useful in young patients undergoing minor procedures
Ketamine (ketalar) ADR’s (2)
- unpleasant psychological reactions during recovery
- high abuse
Droperidol plus fentanyl function
Produces neruolept analgesia, characterized by indifference to surroundings and insensitivity to pain, lack of consciousness does not occur, useful for minor procedures
