8. Surgery Flashcards
indications for surgical prophylaxis antibiotics
- Implants (joint or internal fixation)
- Prolonged surgery (>2 h)
- Trauma surgery
- Revisional surgery
- Immunocompromised patient
- Extensive dissection required
- Intra-operative contamination
- Endocarditis (SBE)
MC used antibiotics for surgical prophylaxis
- Ancef
- Clindamycin if PCN allergy
- Vancomycin if concerned about MRSA
pre-op orders needed for in-house patient
- NPO after midnight, except AM meds with sips of water
- Hold all AM hypoglycemics and cover with SSI (if patient with DM)
- Accu-Check on call to OR (if patient with DM)
- Begin ½NSS @ 60 mL/h at 0600 (D5W½NSS if patient with DM)
- Labs – CBC with diff, PT/PTT/INR, BMP
- Chest X-ray, EKG (if necessary)
- Consult medicine for medical clearance (if not already done)
- Anesthesia to see patient (if necessary)
indications for pre-op chest x-ray?
- >40 years of age
- smoker
- any history of cardiac or pulmonary disease
indications for pre-op EKG?
- >40 years of age
- any history of cardiac disease
MC timeframe for post-op myocardial infarction
Day 3
how long should elective surgery be DELAYED following an MI or CABG
6 months
how to calculate daily fluid input requirements?
- First 10 kg x 100 = 1000 mL/day
- Second 10 kg x 50 = 500 mL/day
- Remaining kg x 20 = ___ mL/day
- (e.g. 70 kg patient requires 1000 + 500 + 1000 = 2500 mL/day)
how to calculate IV fluid input rate
- “421 Rule” calculates IV mL/h
- First 10 kg x 4 = 40 mL/h
- Second10 kg x 20 = 20 mL/h
- Remaining kg x 1 = ___ mL/h
- (e.g. 70 kg patient requires 40 + 20 + 50 = 110 mL/h)
what other factors should be considered prior to surgery
- Is the patient on any insulin, anticoagulants, steroids, or anything else that might put them at risk
- *Note: any non-routine orders should be cleared with patient’s primary service
perioperative management for patients with diabetes
- NPO after midnight
- Start D5W½NSS in AM
- Accu-Check
- If insulin-controlled, hold regular insulin, give ½ NPH dose, and cover with sliding scale insulin (SSI)
- If oral-controlled, hold oral meds and cover with SSI
- If diet-controlled, cover with SSI
what should be obtained prior to surgery on a patient with:
rheumatoid arthritis
Cervical spine x-ray
Why? – Cervical joint destruction in rheumatoid arthritis may lead to vertebral instability. The incidence of cervical instability is 5–7% –> Sxs range from initial neck pain radiating to the occiput to painless sensory loss in the extremities and a slowly progressive quadraperesis. Sudden death may also occur.
effects of long-term, high-dose course of steroids
Long-term therapy suppresses adrenal function
- Risk of poor or delayed wound healing. Decreased inflammatory process.
- Risk of infection. Low WBC may mask infection.
periop management for patients on long-term, high-dose steroids
- Peri-op IV steroid supplementation
- Hydrocortisone 100 mg IV given the night before surgery, immediately prior to surgery, and then
- q8h until postoperative stress relieved
periop management for patients at risk for gout
- Begin colchicine 0.6 mg PO daily 3-5 days pre-op
- and continue 1 week post-op
periop management for patients with hypertension
- If the patient has been on long-term diuretics (e.g. HCTZ, Lasix), check for hypokalemia
- Avoid fluids high in sodium; may use ½NSS at low rate
when to discontinue med prior to surgery:
Aspirin
7 days preop
due to irreversible binding to platelets
when to discontinue med prior to surgery:
NSAIDs
3 days preop
due to reversible binding to platelets
when to discontinue med prior to surgery:
Heparin
8 hours preop
(monitor partial thromboplastin time (PTT)
when to discontinue med prior to surgery:
Coumadin
3-4 days preop
(monitor PT/INR)
*prothrombin time, international normalized ratio
INR for elective surgeries should be:
< 1.4
what should be done if INR is > 1.4?
- If necessary, transfuse Fresh Frozen Plasma (FFP)
- One unit of FFP will decrease INR by approximately 0.2
- Vitamin K can be given but is slow-acting
when should a patient with an INR > 1.4 be allowed to proceed with surgery?
- If the risk of not doing surgery outweighs the risk of excessive bleeding (i.e. if it is an emergency surgery and you have anesthesia’s approval)
- If the patient has PVD and the surgery is a simple debridement or amputation.
- Note: if the patient has PVD, make sure you have Vascular Surgery’s approval for surgery.
- In this case, it is acceptable for the patient to bleed a little extra.
if patient w/ a high INR undergoes surgery, what labs should be carefully monitored?
Hgb and Hct
hemoglobin and hematocrit
RBC transfusion indications
- If Hgb <8 or Hct<24, consider transfusing 1-2 units PRBC
- One unit of PRBC will increase Hct by approximately 3 percentage points
if patient is thrombocytopenic, what can be done
- Order a six-pack of platelets, which is a concentration of six pooled platelet units, and consult hematology
how are relaxed skin tension lines (RSTL) oriented
perpendicular to the long axis of the leg and foot
*also called Langer lines, Cleavage lines, Wrinkle lines and Skin tension lines
Source: https://musculoskeletalkey.com/plastic-and-reconstructive-surgery/
should a skin incision typically be made parallel or perpendicular to the RSTL?
parallel incisions will remain approximated and heal better,
while perpendicular incisions may gap apart due to increased transverse forces
define: anti-tension line
S-shaped or zig-zagged incision when exposure needed is not parallel to RSTL
what should the ratio of length to width be to close a lesion with minimal tension
3:1 length:width
how much lengthening can be achieved with a 60o Z-plasty
75% lengthening
- can be achieved with a 60% Z-plasty*
- source: https://www.aafp.org/afp/2003/0601/p2329.html*
how should the Z-plasty incisions be oriented to correct a skin contracture
The central arm of the “Z” should be parallel to the contracture
Notes: The scar is excised, and a z-plasty is created with the lateral arms being the same length as the central wound. The lateral arms are drawn 60 degrees to the original central wound. The flaps are transposed, lengthening the direction of the original central line. The new central arm aligns with the flexor crease. The added length of skin across the crease prevents reformation of a contracted scar.
source: https://www.aafp.org/afp/2003/0601/p2329.html
how should the skin incision be oriented to correct
a 5th digit adductovarus rotation
Distal medial to proximal lateral
order of wound graft closure
- Direct closure
- Graft
- Local flap
- Distant flap
stages of skin graft healing
- Plasmatic
- Inosculation of blood vessels
- Re-organization
- Re-innervation
what are Blair and Humby knives?
Knives for harvesting skin grafts
MC device for harvesting skin grafts
dermatome
*used with a mesher
MC complication: skin grafts
*seroma, hematome
how to prevent seroma/hematoma during skin grafting
mesh or pie-crust graft and apply compressive dressing
advantages of meshing skin grafts
- donor site heals spontaneously
- expands tissue - smaller graft can cover larger site
- allows drainage of hematoma/seroma through the graft
- can drape extremely well around irregular surfaces
- increases surface area for re-epithelialization
disadvantages of meshing skin grafts
- graft is very fragile/delicate and easily torn
- contraction of graft during healing
-
inferior cosmetic appearance after healing
- may appear abnormally pigmented
- heals by secondary intention
- graft is very fragile/delicate and easily torn
can you mesh a full-thickness skin graft?
NO,
meshing is only for partial thickness skin grafts
advantages of full-thickness skin graft
- Minimal contraction of graft
- Better appearance
disadvantages of full-thickness skin graft
- More difficult to take
- Must close donor site
advantages of using a muscle flap
it brings immediate increased blood supply to donor site
AO principles of internal fixation (2002)
- Anatomic articular reduction, adequate shaft reduction
- Stable/biologic fixation
- Preservation of blood supply
- Early ROM
steps to inserting a fully threaded screw
- Overdrill near cortex
- Underdrill through far cortex
- Countersink
- Measure
- Tap
- Screw
how much of a screw should pass the far cortex
1.5 threads
(one and one-half)
purpose of tapping a screw
creates a path for the screw heads
- Technique: 2 forward, 1 back
- Cuts the thread pattern of the screw –> to RELEASE BONE DEBRIS
- Always the same size as the thread diameter.
purpose of countersinking a screw
Crozer:
- prevents stress risers and soft tissue irritation
- provides even compression from screw head (land)
Surg Skills:
- Increases the surface contact area
- makes the screw head less prominent
describe mini fragment sets
- Screw sizes of 1.5, 2.0, 2.7
- all fully threaded, cortical screws
screwdriver handle is made of:
pressed linen
differences between cortical and cancellous screws
- Cortical has smaller pitch
- Cortical has smaller rake angle
- Cortical has smaller difference between thread diameter and core diameter
define: malleolar screw
- function: for fixation of medial malleolus
- characteristics
- partially threaded
- same thread profile and pitch as cortical screw
-
trephine self-cutting tip
- allows insertion w/o tapping, and in osteoporotic bone sometimes even without predrilling the cancellous bone
- however, designed as lag screw for medial mall fx, but due to large diameter & large screw head –> smaller cancellous bone screws are used instead
what screw has a fluted tip
self-tapping
sizes in Synthes modular hand screw system
- 1.0
- 1.3
- 1.5
- 2.0
- 2.4
- 2.7
cannulated screw sizes in Synthes set?
- 3.0
- 4.0
cannulated screw sizes in Smith & Nephew set?
- 4.0
- 5.5
- 6.5
- 7.0
steps for inserting a 4.0 cannulated screw
- Insert 1.3 mm guide pin to far cortex
- Measure
- Drill near cortex with 4.0 cannulated bit (optional)
- Drill far cortex with 2.7 cannulated bit (unnecessary for soft bone)
- Tap (unnecessary with self tapping screws)
- Countersink
- Screw
define: Herbert screw
- Headless screw – can be inserted through articular cartilage
- *Also called “compression screws”
- Characteristics:
- Threaded portion proximally and distally and smooth in between.
- Proximal portion has tighter pitch for compression.
define: Reese screw
- Headless – create compression through arthrodesis.
- Characteristics:
- Proximal threads run clockwise
- Distal threads run counterclockwise. Smooth in between.
what are the K wire sizes and widths in millimeters?
why is there a question about K-wires in a screw set section in Crozer?
K-wires can be used for the underdrill if the situation arises (e.g. underdrill bit is missing or it
fell on the floor)
- The 0.062 can be used for the 1.5 underdrill (for the 2.0 screw)
- The 0.045 can be used for the 1.1 underdrill (for the 1.5 screw)
Mnemonic: Young Boys Wear Green