Surgical Semiology

asepsis

asepsis

measures that prevent germ contact with patient, status free of germs

antisepsis

curative measure to destroy germs in wound or enviro

status of asepsis is produced by

sterilization

antiseptic principle

applying carbolic acid and wound dressing to prevent infection, by Pasteur

methods of asepsis in OR

washing hands disinfecting operating field sterilization of materials

humid heat sterilization is called

autoclave

sterilization by dry heat is called

poupinel (double wall chamber, for metal instruments)

sterilization by irradation

by gama rays, highly efficient but expensive, for packaged materials

ethylene oxide sterilization is for which equipment

special equipment, soft materials

diff bw formaldehyde and glutaraldehyde solution sterilization

both for bio materials glutha is more stable

__________ methods use changing of colour of test

chemical

_________ methods use bacteriological cultures from samples

biological

desinfectant vs antiseptic

fluid which removes microbes from inanimate objects

antiseptic - on tissue

prep before operation

patient washes with antiseptic, hair removed by clipping

prep in operating room

cleaning with antiseptics, skin prep w/ iodine, draping of operative field

antisepsis of hands of surgeons

dressing, surgical scrubbing

method of performing antisepsis

desinfection

antiseptics

bactericidal chemical products

chlorhexidine

organic compounds - antiseptics

role of OR circulators

verifies equipment, charts etc

scrub technicians vs surgical assistants

scrub technicians - deal w/ tools

surgical assistants help them

bowel prep

fasting liquids 2 hrs, solids 6 hrs

patient prep involves

bowel prep, atb use, cessation/administration meds (anticoags)

Postoperative Pathway - recovery area for complex surgeries is called

ICU

screening done before surgery

1. Full blood count - Hb, coagulation screen, leukocytes

2. Biochem - urea, creatinine, electrolytes

3. Urinalysis

4. Microbio

5. Cardiac - ECG

6. Lung fxn

7. cross matching blood

objectives for patient preop

1. establish diagnosis

2. diagnose other comorbidities

3. screening common disorders

sensitivity

ability of clinical test to identify patient with abnormality

specificity

ability of test to identify healthy patient who doesn’t have abnormality

+/- predictive value

probability that individual who tested pos/neg does/not have abnormality

patient flow: patient handed to ____ staff to confirm identity → theatre trolley → _____ → ______operating table

theatre

anesthetic room

methods of infection control

• sterilization equipment

• skin prep + draping

  • prep of operating team

effects of ventilation control and sterilization

infection control

__________ must be divided, stable, highly adjustable w/ rubber padding

operating table

most used position for patient on operating room

supine

Trendelenburg position

patient on operating table supine but head down (reverse in up)

prone position of patient on operating room is for

spinal surgeries

jackknife position is used for

access to anus/rectum

complications of patient position in surgery

ischemia, pressure ulcers, n injury, compartment syndrome

why is trendelenburg position used

organs go towards head - better view for lower gi surgeries

increased v return, intracranial + ocular p, pul compliance, myocardial work

what must be used for a patient in reverse trendelenburg

compression stockings

lateral position - requirements

cushions, secure fastening

precautions when positioning patients on operating table

unintentional contact w/ metal, padding around pressure points, legs down positions preferred (to avoid compartment syndrome)

common nerves at risk during surgery

brachial plexus, ulnar nerve, radial nerve, common peroneal nerve

routine cases - vascular access

one peripheral IV line

vascular access in more complex cases

2+ large-bore IVs, central v catheters (for patients w/ comorbidities)

fxns arterial lines

monitoring BP & ABG

if regional anesthesia, what airway management is used?

nasal/facial canule

if general anesthesia, what airway management is used?

endotracheal tube

when is bag-mask ventilation used?

short procedures

lines of langer

cleavage lines of skin in parallel with fibers, indications for incisions → nicer scar

median sternotomy

exposure for thoracic surgeries, from sternal notch to xiphoid process

thoracotomy

incision for open thoracic surgeries, into pleural space

thoracoabdominal incision

good exposure but increases postop complications

upper midline incisions

from xiphoid process to umbilicus

lower midline

from umbilicus to pubic symphysis, good exposure

paramedian incision

2cm either side of midline depending on organ to be operated on, avoiding linea alba

chevron incision

exposes upper abd, from midaxillary line under ribs

flank incision

for retroperitoneum access, from rib to anterior midline, risk flank bulge postop

transverse abd incision - why is it unnatural

must cut muscle

phannenstiel incision

1-2cm above pubic symphysis, for c section

right subcostal Kocher incision

from xiphoid process → costal inf margin, for liver/gallbladder access

thoracoscopy vs laparoscopy

thoracoscopy has free passage of air into the chest & for pleural space, laparoscopy has peritoneal cavity is distended with a gas

invasive monitoring

to maintain adequate hemodynamic status in an anesthetized patient

After the induction of general anesthesia, the patient’s ability to ___________ is lost

maintain the airway

how is stomach aspiration prevented under anesthesia

fasting, endotracheal tube

indications nasogastric tube

vomiting, gastric dilatation, prevent gastro-esophageal reflux/damage

indications urethral catheterisation

before any surgery or to assess urinary output (retention), incontinence

how to help male catheterisation

pull penis upwards first, then down

Allen test

ulnar collateral supply checked before getting access to radial artery, ask patient to make tight fist

seldinger technique

for central venous catheterisation, needle placed in vessel and guide wire inserted into veie first,

int jugular, femoral and median basilic veins are sites of choice for

central venous catheterisation

central venous pressure

measure of p in vena cava, assessment hemodynamic statush

high vs low CVP levels (normal 8-12mmHg)

• high is hypervolemia, RV failure, tamponade

• low is hypovelemia, decreased v return

swan-ganz catheter

pulmonary artery flotation catheter to measure wedge p, bp, cvp, co

low vs high levels paco2 associated w/ low pao2

low is hyperventilation, high is RF

low vs high values paco2

low is hyperventilation, metabolic acidosis/resp alkalosis

high is hypoventilation, RF

local host factors causing an infection

foreign body, necrosis, ischemia (reduces phagocytes + increases anaerobes), hematoma, DM (hyperglycemia, vasc + neuro pathies)

host defense system of skin

mechanical, acidic sebum

why is the proximal small bowel mostly sterile

stomach acid + peristaltic movement

how do skin + GI flora prevent infection

prevents adherence and chemical barrier

___________ are responsible for high morbidity + mortality and prolonged stay in hospital

postop infections

what surgeries have high infection risk

perforated bowel, pus at site (perforated appendicitis)

disinfectants

substances that kill most pathogens (not spores or slow viruses), cleans instruments + surfaces

antiseptics

disinfectants used on living tissue

sterilization

complete destruction of all organisms, for surgical instruments

personal protective equipment for staff

double gloving if HIV, HCV, gowns during operation

maintaining normothermia and hemostasis prevents what

postop infection

aim of prophylactic use of antibiotics

high conc of drug at the surgical site at the time of incision

doses of prophylactic atb

single IV (same as multiple doses), if surgery >4h → 2nd dose

which types of infections are in early postop period (<48h)

resp or urinary

when do wound infections clinically manifest postop

48h

how many days postop of GI anastomosis leakage pccur

5-6

when do implant-related infections manifest postop?

weeks or months

signs of postop infection

cough, dysuria, abd pain, tachycardia, shock, wound tenderness

blood count if postop infection

raised WBC, low + anemia if severe infection

general measures for postop infection management

resuscitation, analgesia, anti-emetics, antipyretics

specific measures for postop infection management

atb, drainage

management of infected wounds

open wound, debride necrosis, take swab + mark cellulitis, dress + antiseptic gauze, secondary closure

when are stoma wound bags and vacuum dressing used

complex/large infected wound

methods of drainage of infected wounds

needle aspiration (leaves no scar), guided drainage, surgical drainage