Intro Flashcards
Principle of x ray
- represent a form of ionizing radiation
produced by an X-ray tube. - The X-ray beam is passed through the body
where a portion of the X-rays are either
absorbed or scattered by the internal
structures, and the remaining X-ray is
transmitted to a detector (e.g., film)
The 5 X-ray densities
• air is represented as black on radiograph.
• Very dense material such as, cortical bones
metal, stones or contrast material are
represented as white.
• Body tissues are varying degrees of grey,
depending on density
Uses of X-ray
• Orthopedic evaluations
• Chest or abdomen screening
• Dental examination
• Mammography
• Verification of correct placement of surgical
markers prior to invasive procedures.
• Spot film or static recording during
fluoroscopy.
Advantages of X-ray
• Good bone resolution
• Widely available
• Quick imaging
Disadvantages of X-ray
• Uses ionising radiation can cause cells mutation
and cancer
• Not suitable for soft tissues
Fluoroscopy
Live radiographic examination detecting the anatomy and
motion of internal structures(Contrast agents often used).
Uses of Fluoroscopy
• Barium Study(meal, swallow, enema, fistolography )
• Hystero-salpingo-graphy
• Angiography and interventional radiology
• Orthopedic surgery, e.g. reduction and fixation of fractures,
joint replacements.
DXA scan
It is a test that measures the density of bones.
The denser the tissue, the less X-rays pass
through.
use of DEXA
calculate the strength of bones ,
measure bone loss, helps diagnose osteoporosis
and assess whether a person’s bones are at risk
of fracture.
ULTRASOUND?
Medical Ultrasound uses ultra-high-frequency
sound waves (1 MHz to 30 MH) to produce
cross-sectional images of the body.
Uses of ultrasound
- Examining deep structures:
Abdominal ultrasound»»>Using convex
transducer
Obstetrical and gynaecological»»Convex and or
transvaginal probe
Echocardiography»»sector probe
Transcranial US»>sector probe
- Examining superficial structures:»>using linear
probe
Small parts ( Neck,breast, scrotal)
Vascular Doppler
Musculoskelatal ultrasound
Advantages of US over other imaging
modalities
• Lack of ionizing radiation, a particular
advantage in pregnancy and pediatrics
• Relatively low cost
• Wide availability
• Portability of equipment.
Disadvantages and limitations of US
• US is highly operator dependent: US
relies on the operator to produce and
interpret images at the time of
examination.
• US cannot penetrate gas or bone.
• Bowel gas may obscure structures deep in
the abdomen, such as the pancreas .
Doppler principle
Doppler ultrasound measures the movement of
the RBCs through the ultrasound beam.
Uses:
Doppler principle
- Detection of tissue movement
- Measurement of blood flow velocity and
direction
Doppler Advantages
• Non Invasive
• Non Ionizing
• Portable
• No nephrotoxic agents
• See arterial Lumen & wall
• Assess haemodynamics
• Detect occluded Aneurysm
Doppler Limitations:
• Ca Hender
• Skin Henders : ulcers, bandages, scars
• Need patient co-operation
• Operator dependent
Computed tomography
Computed Tomography (CT) is a high-resolution technique using X-ray to
generate axial cuts of any area of the body (slices).
Images can be viewed in any anatomical plain (axial, coronal or sagittal)
also, reconstructed into three dimensional images (3D)
MOST COMMON INDICATIONS FOR
COMPUTED TOMOGRAPHY
1-Emergencies:
Head trauma as CT is the best modality in detection of acute
bleeding, skull fractures.
Stroke: differentiate ischemic from hemorrhagic stroke
Poly trauma: solid organ injury and acute hemorrhage
2- Bone fracture: the best imaging modalities
3-Complex intra-abdominal conditions: solid organ focal lesions
(hepatic, renal, spleen), intestinal obstruction, inflammatory conditions,
biliary obstruction, acute vascular conditions and different abdominal
masses
4- Chest: pneumonia (the standard imaging modality in COVID 19), lung
masses, mediastinal LNs, trauma, pneumothorax, hemothorax.
CONTRAINDICATIONS OF CT
1- Absolute contraindications: Early pregnancy, as the risk of
radiation usually outweighs diagnostic benefit.
2- Relative contraindications:
Children, since they are more radio-sensitive except when
indicated.
Renal impairment, since intravenous contrast can further injury the
kidneys, in severe cases necessitating dialysis.
Allergy to intravenous contrast media.
Pheochromocytoma patients, since intra-venous contrast may
induce hypertensive crisis
IMAGNETIC RESONANCE IMAGING
Magnetic resonance imaging is a medical imaging technique used in
radiology to form pictures of the anatomy and the physiological processes
of the body.
ADVANTAGES OF MRI
• MR image acquisition does not use X-ray or ionizing radiation. It
requires little patient preparation and is non-invasive, so patient
acceptability is high.
• MRI produces images in multiple planes with equivalent resolution
without moving the patient.
• MRI contrast agents are very well tolerated and are much less likely
than x-ray and CT contrast agents to cause allergic reactions or alter
kidney function
CONTRAINDICATION OF MRI:
1- People with implants, particularly those containing iron, —
pacemakers, vagus nerve stimulators, implantable cardioverterdefibrillators,
loop recorders, insulin pumps, cochlear implants, deep
brain stimulators, and capsules from capsule endoscopy should not
enter an MRI machine.
2- Pregnancy: Not in the 1st trimester
3- Contrast agents—patients with severe renal failure who require
dialysis may risk a rare but serious illness called nephrogenic
systemic fibrosis that may be linked to the use of certain gadoliniumcontaining
agents, such as gadodiami
DISADVATAGES OF MRI:
• Claustrophobia—people with even mild claustrophobia may
find it difficult to tolerate long scan times inside the machine.
• Noise—loud noise commonly referred to as clicking and beeping,
as well as sound intensity up to 120 decibels in certain MR
scanners, may require special ear protection.
• Keeping still for long time cannot be tolerated by many patients
• Expensive than x-ray imaging or CT scanning and not widely
available
1.ABRASION:
It is destruction of the surface epithelium of the skin without
loss of dermis integrity (Fig 1).
• It is caused by friction against rough surface e.g., roll-over
trauma
Treatment of ABRASION:
• Cleaning of the area with liberal amounts of normal saline
and antiseptic solution to remove all debris.
• Application of topical antibiotic and Vaseline gauze for 7 to 10 days when
re-epithelialization becomes complete.
Complications of ABRASION:
• Infection leads to deep tissue destruction and may leave raw area.
• Pigmentation or tattooing of the area by embedded debris.
INCISED WOUNDS (CUT WOUNDS):
These wounds are caused by sharp objects such as knives and broken
glass. Surgical wounds belong to this type.
Clinically INCISED WOUNDS (CUT WOUNDS):
Incised wounds are cleanly cut, have regular
edges, bleed profusely and may be
accompanied by cut of deeper structures such as
muscles, tendons, nerves, and blood
vessels
Treatment:
• Management should entail resuscitation of the patient if the wound is a big
one and bleeds too much.
• Management of the wound itself includes:
o Cleaning the wound by washing it liberally with normal saline and
antiseptic solution
o Repair of cut important structures such as tendons, nerves if ends are
close and re-anastomosis of important nourishing blood vessels.
o Wound is closed primarily by simple suture without drainage if clean
not contaminated or with drainage if contaminated or potentially
infected.
LACERATED WOUNDS:
These are severely damaged wounds caused by traffic road accidents or rollover
trauma.
Clinically of LACERATED WOUNDS:
• Tissues are compressed and devitalized by severity
of trauma.
• Skin has irregular edges with scanty bleeding and
dirty ischemic margins (Fig 3).
• Devitalization may occur in deeper structures
such as muscles, nerves, tendons, and blood vessels. Dirties and debris
are usually found in these wounds.
• There may be significant skin loss or degloved skin (degloving wounds)
Treatment of LACERATED WOUNDS:
o Management should start by trauma life support in patients with big
wounds or polytraumatized.
o Under general anesthesia, the wound is cleaned with liberal amounts
of normal saline and antiseptic solution.
o All devitalized tissues and muscles should be excised until the tissues
look good vascularized and bleed freshly.
o Deep important structures are repaired according to their conditions,
tendons and big vessels are repaired, nerves if they can approximate
easily are repaired, otherwise marked for later repair.
o Skin is closed with drainage, if possible, if there is significant loss of
skin and approximation of skin edges is difficult, local skin flaps or
skin grafts are used.
o In some circumstances the wound is left open for later reconstruction.
PENETRATING WOUNDS (STAB WOUNDS):
• These are wounds caused by sharp
pointed objects penetrating deeply into
the body.
• Such wounds may penetrate the visceral
cavities (peritoneum, pleura or
pericardium) and cause serious injuries to
vital organs such as the liver, spleen,
bowel, lungs or heart.
Clinically of PENETRATING WOUNDS (STAB WOUNDS):
o Patients may become shocked shortly
after injury due to internal
hemorrhage. The wound itself may
look trivial and does not bleed
Treatment ofPENETRATING WOUNDS (STAB WOUNDS):
o Management of the patient on traumatic life support bases.
o With any suspicion that the wound is extending into the visceral
cavities, the patient should be explored by laparotomy or thoracotomy
according to the site of wound.
o Arrest of bleeding and repair of damaged vital organs according to the
nature of injury, liver repair, splenectomy, bowel repair…etc.
PERFORATING WOUNDS:
• These are wounds which penetrate the body and have an inlet and an exit.
The commonest example is gunshot injuries (Fig 5).
• Such wound usually has great damage to internal organ,
partly by the penetrating object and the damage of the
surrounding tissue caused by evacuation effect and
propagated extensive heat.
Clinically of PERFORATING WOUNDS:
o The patient may become shocked, hemodynamically unstable and
require emergency resuscitation and very early surgical
exploration to stop bleeding and removal of injurious
objects or foreign body if possible.
CONTUSION (BRUISES)
• It is reddish swelling caused by
extravasations of blood into the tissue
spaces. It is usually caused by hitting by
blunt object as blow or heavy stick. Due to
disintegration of extravasated blood, the area is at first red then within few, it
becomes yellow days and later becomes
greenish and lastly fades out
Treatment of CONTUSION (BRUISES)
o In the first 24 hours cold compresses are applied to the area to induce
vasoconstriction and stop further blood extravasation
o After 24 hours, warm compresses are applied to induce vasodilation
and enhance absorption of extravasated blood.
HEMATOMA:
• It is a collection of blood in
the tissue spaces caused by
extravasation from injured
sizable vessel.
• Blood is at first fluid and
then becomes clotted
within 3-4 days and after
one week it turns fluid
again
Treatment of HEMATOMA:
o Large rapidly increasing hematoma is treated by exploring the area or
re-opening the wound, washing out the hematoma and ligating the
bleeding vessel.
o Moderate-sized hematoma may resolve by repeated aspiration under
aseptic conditions.
o Small hematoma may be left to resolve spontaneously.
Complications of HEMATOMA:
- Infection leading to abscess formation.
- Calcification forming calcified hematoma.
- Pressure on neighboring structures
- Opening into the nearby vein leading to traumatic arteriovenous fistula
WOUND CLEANING
• Thoroughly clean the wound with normal saline or antiseptic solution.
• Use a large syringe for irrigation. Attach a 16- or 19-gauge needle or soft
IV catheter to generate pressure.
• Control residual bleeding with compression, ligation, and cautery
• Dead or devitalized muscle is dark in color, soft, easily damaged; does not
contract when pinched. Dead tissue does not bleed when cut.
• Prep skin with antiseptic.
TETANUS PROPHYLAXIS
• Patient vaccinated: give booster dose if needed.
• Patient not vaccinated: give antitetanic serum and start dose of tetanus
toxoid vaccine (separate syringes, separate sites)
• Tetanus immunoglobulin (human) 250 units IM.
ANTIBIOTIC PROPHYLAXIS
• Contaminated wounds
• Penetrating wounds
• Abdominal trauma
• Compound fractures
• Lacerations greater than 5 cm
• Wounds with devitalized tissue
• High risk anatomical sites—hand, foot
WOUND CLOSURE
• Less than 6 hours from injury, cleaned properly: primary closure.
• Greater than 24 hours, contaminated or animal bite: do not close.
• Wounds not closed primarily should be packed lightly with damp gauze.
• If clean after 48 hours, delayed primary closure.
• If wound infected, pack lightly, heal by secondary intention.
Low COP symptoms:
• Easy fatigue
• Anginal pain
• Dizziness & ggiddiness
• Syncopal attack
Preoperative Considerations that influence the choice of anesthetic
technique:
1-Co-existing disease
2-Site of the surgery
3-Age of the patient
4-Preference of the patient
5-Body position of the patient during the surgery
6-Elective or emergency surgery
7-Likelihood of increased amounts or gastric contents (as in pregnancy)
Indication of general anesthesia:
❖ Extreme anxiety and fear
❖ Patient with mental or physical disability or disoriented
❖ Age (Infants and children)
❖ Prolonged procedure
Contraindication of general anesthesia
❖ Lack of adequate training by the doctor
❖ Lack of adequate equipment
❖ Lack of adequate facilities
❖ Compromised patient
Monitors for general anesthesia:
1-ECG
2-Blood pressure
3-Tempreture
4-Respiratory rate
5-Capnogram for end tidal CO2
6-Pulse oximeter for O2 saturation and pulse
7-Train of four for neuromuscular monitoring
Complication of general anesthesia and Postoperative care
➢ Anaphylaxis
Epinephrine (Adrenaline) is the only recommended medication for
treating anaphylaxis, antihistamines and steroids may also alleviate
symptoms.
➢ Hypothermia
Passive rewarming with heated blankets and warm fluids.
➢ Nerve injury
-Physical therapy
-Medication as Gabapentin, Pregabalin and Ibuprofen
➢ Nausea and vomiting
-Ensure good oxygenation and normal blood pressure
-IV fluids if dehydrated
-Medication as zofran
➢ Cardiovascular collapse
-Anticholinergic drugs for bradycardia
-Increase the venous return using gravity
-IV fluid
-Sympathomimetic drugs
➢ Respiratory depression
-Oxygen therapy
-Relieve pain
-Mechanical ventilation
➢ Sore throat
-Most cases resolve spontaneously
➢ Pain control
- Nonsteroidal anti-inflammatory drugs (NSAIDs)
- Opioids - Acetaminophen - Alpha-2 agonist
- Antidepressants - Anticonvulsant - Corticosteroids - Lidocaine
Indications of Spinal anesthesia
(1) Bone of the lower limb operations. (2) Obstetric, gynecological
operations.
(3) Urologic and rectal operations (pills and fissures).
(4) Operation of lower abdomen (appendix).
Contraindications of Spinal anesthesia
Absolute contraindications:
(1) Patient refusal. (2) Allergy to local anesthetics.
(3) Skin infection at the injection site. (4) Severe hypovolemia (shock).
(5) Coagulopathy and the use of therapeutic anticoagulant.
(6) Increased intracranial pressure (may predispose to brainstem
herniation) .
Relative contraindications:
(1) Neurological disorders. (2) Prior spine surgery and back pain.
(3) Uncooperative patient. (4) Psychosis, dementia or emotional
instability.
(5) Certain cardiac lesions e.g., Aortic stenosis
Preparation of the patient: as general anesthesia beside:
*History: Exclude history of back problems.
*Physical examination: Especially examination of the back for
dermatologic conditions, kyphoscoliosis or surgical scar. Palpation of
lumbar interspaces
*Investigation: Especially bleeding time, clotting time, Prothrombin Time
(PT) and Partial Thromboplastin Time (PTT).
*Premedication: Preoperative visit may allay fear, and pharmacologic
premedication can allow smooth block.
Complications of spinal and epidural anesthesia
(1) Hypotension: (especially with spinal anesthesia): Reflect
venodilatation with decreased venous return and cardiac output
Prophylaxis: Adequate hydration (10-15 ml/kg of crystalloid) before
induction of spinal and epidural anesthesia.
Treatment: - Rapid I.V fluid.
-Head down tilt 5-10 degrees after fixation of local anesthetic level.
-Vassopressor: as Ephedrine (α and ß agonist) 5-10 mg i.v. in incremental
doses.
(2) High spinal anesthesia:
Occur with spinal anesthesia manifested by severe hypotension,
bradycardia and respiratory insufficiency or apnea.
Treatment:
1-Support of the airway: -100% oxygen by simple face mask.
- Intubation and mechanical ventilation may be needed.
2-Support of circulation:
- Head down positioning
- I.V fluid
- Ephedrine (5-10 mg i.v) to treat hypotension.
- Atropine i.v to treat bradycardia.
- Inotropes as adrenaline (5-10 µg) in hypotension.
Complications of spinal and epidural anesthesia(other’s)
(3) Nerve injury:
During placement of a needle, it can come in direct contact with the nerve
roots. The nerve injuries lead to persistent paresthesia that resolve without
treatment within weeks or months.
(4) Vascular injury:
Injury to blood vessels result in hematoma due to continued bleeding from
the epidural venous plexus. This complication is reported in patients with
coagulopathy or has been taking anticoagulants, but it may occur in
patients with no apparent risk factors.
(5) Meningitis: The incidence of meningitis has fallen dramatically with
the use of disposable needles and trays.
6) Urinary retention:
Blockade of S2-S4 is associated with loss of bladder tone and inhibition of
the voiding reflex. It may require intermittent catheterization.
(7) Backache:
Needle penetration can cause hyperemia, local tissue irritation, and reflex
spasm of muscles. Backache may be also reflecting ligament strain due to
profound skeletal muscle relaxation and surgical positioning.
(8) Headache (postdural puncture headache):
It is believed to be due to decreased CSF pressure resulting from leakage
of CSF through the needle hole in the dura. This exerts downward traction
on the structures of the central nervous system and on the blood vessels
that are attached to both the dura and the brainstem.
Risk factors: -Young females - Using large gauge needle
Character of post dural puncture headache:
-It is frontal or occipital.
-Associated with nausea and vomiting.
-The headache is postural in nature, worse in the upright position.
-Beginning within 6-12 hours after lumbar puncture.
-Associated with diplopia and tinnitus.
Treatment of postdural puncture headache:
-Aggressive hydration. -Soft diet and stool softeners.
-Analgesics and bed rest. -Caffeine (300-500mg) oral once or twice
daily.
Uses for infiltrative anesthetics are as follows:
1-Subcutaneous infiltration (IV placement, superficial biopsy, suturing).
2-Submucosal infiltration (dental procedures, laceration repairs).
3-Wound infiltration (postoperative pain control at incision site).
4-Intraarticular injections (postsurgical pain control, arthritic joint pain
control).
5-Infiltrative nerve blocks (ankle block, scalp block, digit block).
Most common drugs used in local anesthetic infiltration:
Drug Onset Maximum dose Duration
Lidocaine Rapid 4.5 mg/kg 120 min
Bupivacaine Slow 2.5 mg/kg 4 hours
Complications associated with local anesthesia:
1- Pain on injection: Can be due to aggressive insertion of the needle,
damaging soft tissues, blood vessels, nerves.
To prevent: use topical
anesthetic application and using a smaller-gauge needle.
2- Needle fracture: In most cases, needle fracture happened due to
unexpected motion of the patient or assistants.
3- Lack of effect: may be due to anatomical variants, pathological and
psychological factors, and poor technique.
4-Prolongation of anesthesia and various sensory disorders:
paresthesia, or neuralgia. Avoiding high concentration of anesthetic agent
is recommended.
5-Hematoma: due to venous or arterial laceration.
To prevent hematoma
formation : aspiration before injection , using a short needle and a
minimum number of needle penetrations into tissues. When swelling forms
immediately after injection, localized pressure should be applied.
6-Edema: Swelling of tissues can be due to trauma during injection,
infection, allergy, hemorrhage, and injection of irritating solutions. It`s
managed as a hematoma.
7-Infection: is rare since the usage of disposable needles.
To prevent
infection: The area to be penetrated should be cleaned with a topical
antiseptic prior to insertion of the needle. The local anesthetic should not
be injected through the infected area. Antibiotics should be prescribed.
Natural suture materials
A. Catgut: natural absorbable suture material (made from the submucosa
of bovine intestine) is absorbable suture material, but
the resorption time is highly variable. It stimulates a
considerable inflammatory reaction and tends to
potentiate infections.
B. Silk: a natural nonabsorbable suture material and
is an animal protein but is relatively inert in human
tissue and is a non-absorbable suture material.
• It has a favorable handling characteristic.
• It is unsuitable for suturing arteries to plastic grafts or for insertion of
prosthetic cardiac valves.
• Silk sutures are multifilament, providing mechanical immune barriers
for bacteria.
Synthetic non-absorbable sutures
generally inert polymers that retain
strength. However, their handling characteristics are not as good as those of silk,
and they must usually be knotted at least four times, resulting in increased
amounts of retained foreign material.
• Multifilament plastic sutures may also become infected and migrate to
the surface like silk sutures.
• Monofilament plastics will not harbor bacteria. Nylon monofilament is
extremely nonreactive, but it is difficult to tie. Monofilament
polypropylene is intermediate in these propertie.
Vascular anastomoses rely indefinitely on the strength of sutures; therefore, use
of absorbable sutures may lead to aneurysm formation.
Synthetic absorbable sutures
strong, have predictable rates of loss of
tensile strength, incite a minimal inflammatory reaction, and have special
usefulness in gastrointestinal, urologic, and gynecologic operations that
are contaminated.
• Polyglycolic acid and polyglactin retain tensile strength longer in
gastrointestinal anastomoses.
• Polydioxanone sulfate and polyglycolate are monofilament and lose
about half their strength in 50 days, thus solving the problem of premature
breakage in fascial closures.
• Poliglecaprone monofilament synthetic
sutures have faster reabsorption, retaining
50% tensile strength at 7 days and 0% at 21
days. This suture is suitable for low-load
soft tissue approximation but is not intended
for fascial closure.
Stainless steel
wire is inert and maintains
strength for a long time. It is difficult to tie
and may have to be removed late postoperatively because of pain. It does
not harbor bacteria, and it can be left in granulating wounds, when
necessary, and will be covered by granulation tissue without causing
abscesses.
SUTURES SUBSTITUTES
- Staples, whether for internal use or skin closure, are mainly steel-tantalum
alloys that incite a minimal tissue reaction. The technique of staple placement
is different from that of sutures, but the same basic rules pertain.
• There are no real differences in the healing that follows
sutured or stapled closures. Stapling devices tend to
minimize errors in technique (Fig 17). - Surgical glues or tissue adhesives are now established
as safe and effective for the repair of small skin incisions.
The most common forms are cyanoacrylate-based glues. - Tissue adhesives (Steri-strips) are often less painful
than sutures or staples, and the seal can serve as the
wound dressing as well (Fig 18).
• Size of suture “bite” and interval between bites should be equal in length,
proportional to thickness of tissue being approximated.
• Suture is a foreign body: use minimal size, amount of suture necessary to
close wound.
Basics of wound closure
- Good approximation of wound edges is important to
proper wound closure technique (Fig 19). - The placement of deep sutures subcutaneously to approximate the skin
edges.
• When placing deep sutures, absorbables (e.g.,
gut, Dexon, Vicryl, Monocryl) are typically used. The knot is
buried.
• All deep sutures serve to eliminate the dead space and relieve
tension from the wound surface (Fig 20). - Achieve hemostasis prior to wound closure to avoid
future complications such as hematoma. - Use atraumatic skin-handling technique with
instruments such as skin hooks and small forceps.
Typically, a cutting needle is the needle of choice. - For wound closure in the head and neck region,
small 5-0 or 6-0 sutures of nonabsorbable Prolene. - Take great care to avoid tension during closure.
- Ensure that wound edges are not only aligned but are also
everted (Fig 21). Eversion of all skin edges avoids unnecessary
depression of the resultant scar.
Suturing techniques
o Surgical suture material
o Needle holder (Fig 22)
o Tissue forceps (Fig 23)
o Stitch scissor (Fig 24)
o Drapes
o Antiseptics
o Anesthetics
o Artery forceps
SUTURE MATERIALS
Non-absorbable
– Use when possible
– Braided suture not ideal for contaminated wounds
Absorbable
– Degrades, loses tensile strength within 60 days
– Option when not possible for patient to return or for
children for whom suture removal may be difficult
Types of wound suturing
- Interrupted sutures
- Simple running suture
- Vertical mattress suture
- Horizontal mattress suture
- Subcuticular suture
- Purse string suture
Perioperative
is a term used to
describe the entire span of surgery,
including what occurs before, during,
and after the actual operation.
Phases of perioperative care
- Preoperative: begins with the decision to perform
surgery and continues until the client has reached the
operating area.
2 .Intraoperative: includes the entire
duration of the surgical procedure, until
transfer of the client to the recovery area. - Postoperative: begins with admission to the recovery area and
continues until the client receives a follow up evaluation at home, or is
discharged to a rehabilitation unit.
Goal of preoperative assessment
- Assess the fitness for anesthesia.
- Optimizing patient physical condition for anesthesia and surgery.
- Arrange further investigations, consultations and treatments for
patients not yet optimized - Allay fear and anxiety.
- Establishment of preoperative fasting.
- Premedication.
- Provide appropriate information to the patient and obtain consent.
I. History
• History of present illness and reason for surgery
• Past medical history
• Medical conditions (acute and chronic)
• Previous hospitalization and surgeries
• History of any past problem with anesthesia
• Allergies
• Substance use: alcohol, tobacco, street drugs
• Family history: Hereditary diseases and Anesthetic history.
• Review of system
• Drug history
Drug history
Antihypertensive
ACEI May be associated with severe hypotension during induction.
B blocker -ve inotropic effect additive with anesthetic agents.
Ca blocker Decrease AV conduction and excitability.
Digoxin Toxicity enhanced by hypokalemia (should be corrected) pre
Diuretics
Can cause hypokalemia may potentiate Ms Relaxant
Anticonvulsant
MAOIs React with opioid (pethidine) causing coma or convulsion
Tricyclic A.D Inhibit metabolism of catech. Increase likehood of arrhythmia
Antibiotics
Aminoglycoside Potentiate effect of NM Blockers
History of smoking
• Vascular disease of peripheral, coronary and cerebral
circulation
• lung carcinoma.
• Effect of nicotine ..tachycardia and HPT
• Increase in CO hemoglobin decrease O2 delivery to the
tissues.
• Six fold increase in postoperative respiratory morbidity
• Should be stopped 6 weeks or at least 12 hrs before surgery
➢General examination
• Nutritional state
• Fluid balance.
• Condition of skin and mucus m.(anaemia –perfusion-jaundice )
• Temperature
➢Cardiovascular examination
• Presence of dyspnea, fatigue, chest pain.
• Peripheral pulse (rate, rhythm, volume).
• Neck veins
• Carotid bruits
• Heart sounds
• Lower Limb edema
➢Respiratory examination
• Presence of cyanosis ( peripheral or central).
• Presence of cough
• Presence of tachypnoea
• Tracheal shift
• Auscultation of all the lung fields
➢Nervous system
• Documentation of the level of consciousness
• Documentation of any cranial or peripheral nerve lesions
➢Skeletal system
• Documentation of any skeletal muscles dysfunction or syndromes
➢Airway examination
• Teeth exam. ( dentures, loose teeth, protruding upper incisors)
• Prediction of difficult airway (for ventilation or endotracheal intubation)
➢CBC
• Major surgery requiring group and screen or cross and match
• Male>50 years.
• All adult female.
• Bloody surgery.
•History of anemia.
•Haemoglobinopathy.
• CVD
➢Urine analysis
• Routine for all patients
➢FBS
•History of diabetes,
•Patients on steroid therapy
➢Renal function test (urea, creatinine ,electrolytes)
•All pts > 65 years
• +ve urinalysis
•Patient with renal or liver diseases
• Diabetic patients
• Malnutrition
• Dehydrated patients
•Patients on diuretics
•Antihypertensive
•Steroid drugs
•Pituitary or adrenal disease
•Vascular disease
•Digoxin , diuretic, or other drug therapies affecting electrolytes
➢Liver function test
•History of liver disease
•Previous hepatitis
• Malnutrition
•Alcoholism
➢Coagulation profile (INR, aPTT )
•History of bleeding disorder
•Liver disease
•Drug abuse
•Anticoagulant therapy
➢ECG
•All patients > 50 years
•Smoker>45 years
•History of CVD and DM
•History of Pulmonary disease
•History of medication active on CVS or diuretics
➢Chest X-ray
•All patients > 60 years
•Any possibility of cardiovascular and/or pulmonary disease
•Thyroid enlargement (thoracic inlet x-ray)
➢ Pulmonary Function test & arterial blood gases
•All COPD and asthmatic pts
•Patients scheduled for elective thoracotomy.
➢Pregnancy (HCG)
•Women of reproductive age
Go for surgery if
•Pt is fit for anesthesia.
•Pt is in the optimal
physical condition.
•Pt is in the almost possible
Correction.
•Pt is in high emergency
Situation.
•There is a legal consent.
•Pt is not fit for anesthesia.
•Pt is not in the optimal
physical condition.
•Pt is not in the almost possible
Correction.
•Pt is not in high emergency
Situation.
•There is no legal consent.===
Determine the degree of fitness
and the anesthetic risk by ASA
grading
Postpone surgery if
•Pt is not fit for anesthesia.
•Pt is not in the optimal
physical condition.
•Pt is not in the almost possible
Correction.
•Pt is not in high emergency
Situation.
•There is no legal consent.
Determine the degree of fitness
and the anesthetic risk by ASA
grading===
Cardiac, pulmonary consultation
Or any other measures to optimize
Physical condition of the pt
Pre-Operative Optimization(Medications )
Pre -operative medications to consider
Pre -operative medications to stop
Pre -operative medications to adjust
Pre-Operative Optimization(Diseases )
• Hypertension
• Coronary Artery Disease
• Respiratory Diseases
• Aspiration
• Fasting Guidelines
• Hematological Disorders
• Endocrine Disorders
• Obesity and Obstructive Sleep Apnea
➢Pre -operative medications to consider:
• Risk of GE reflux: sodium citrate and/or ranitidine and/or metoclopramide 30
min-1 h prior to surgery
• Risk of infective endocarditis: antibiotics
• Risk of adrenal suppression: steroid coverage
• Anxiety: consider benzodiazepines
• COPD, asthma: bronchodilators
• Coronary artery disease risk factors: nitroglycerin and -blockers
➢Pre -operative medications to stop:
❖Oral antihyperglycemics: do not take on morning of surgery
❖ACEI and angiotensin receptor blockers: do not take on the day of
surgery (controversial – they increase the risk of hypotension postinduction
but have not been shown to increase mortality or adverse
outcomes; therefore, some people hold and some do not)
❖Warfarin : (consider bridging with heparin).
❖ASA and NSAIDs : In patients undergoing non-cardiac surgery, starting or
continuing low-dose ASA in the perioperative period does not appear to
protect against post-operative MI or death, but increases the risk of
major bleeding
❖Herbal supplements: stop one week prior to elective surgery .
➢Pre -operative medications to adjust:
Insulin (consider insulin/dextrose infusion or holding dose)
Prednisone
Bronchodilators
Hypertension
• BP <180/110 is not an independent risk factor for perioperative
cardiovascular complications
• Target systolic blood pressure <180 mmhg, diastolic blood pressure
<110 mmhg
• Assess for end-organ damage and treat accordingly
Coronary Artery Disease
➢At least 60 day should elapse after a MI before a noncardiac surgery in the
absence of a coronary intervention
• This period carries an increased risk of re-infarction/death
➢Mortality with perioperative MI is 20-50%
➢Perioperative -blockers
• May decrease cardiac events and mortality (but increases risk of
perioperative strokes)
• Continue -blocker if patient is routinely taking it prior to surgery
• Consider initiation of -blocker in:
• Patients with CAD or indication for -blocker
• Intermediate or high risk surgery, especially vascular surgery
Risk factor assessment of Noncardiac Surgical Procedures
Higher»_space;• Emergent major operations, especially elderly
• Aortic and other noncarotid major vascular surgery (endovascular and nonendovascular)
• Prolonged surgery associated with large fluid shift and/or blood loss
Intermediate» • Major thoracic surgery
• Major abdominal surgery
• Carotid endarterectomy surgery
• Head/neck surgery
• Orthopedic surgery
• Prostate surgery
Lower» • Eye, skin, and superficial surgery
• Endoscopic procedures
Respiratory Diseases (1)
Smoking
• Adverse effects: altered mucus secretion and clearance, decreased small
airway calibre, altered oxygen carrying capacity, increased airway reactivity,
and altered immune response
• Abstain at least 8 wk pre-operatively if possible
• If unable, abstaining even 24 h pre-operatively has been shown to increase
oxygen availability to tissues
Respiratory Diseases (2)
Asthma
Asthma
• Increased risk of bronchospasm from intubation
• Administration of short course (up to 1 wk) pre-operative corticosteroids
and inhaled 2-agonists decreases the risk of bronchospasm and does not
increase the risk of infection or delay wound healing
• Avoid non-selective -blockers due to risk of bronchospasm (cardioselective -
blockers (metoprolol, Atenolol) do not increase risk in the short-term)
• Delay elective surgery for poorly controlled asthma (increased cough or
sputum production, active Wheezing)
• Ideally, delay elective surgery by a minimum of 6 wk if patient develops URTI
Respiratory Diseases (3)
COPD
• Anesthesia, surgery (especially abdominal surgery, in particular upper
abdominal surgery) and pain Predispose the patient to atelectasis,
bronchospasm, pneumonia, prolonged need for mechanical Ventilation, and
respiratory failure
• Pre-operative ABG is needed for all COPD stage II and III patients to assess
baseline respiratory Acidosis and plan post-operative management of
hypercapnea
• Cancel/delay elective surgery for acute exacerbation
Predisposing Risk Factors for Pulmonary Complications
- Upper respiratory tract infection: cough, dyspnea
- Age >60 years
- COPD
- American Society of Anesthesiologists Class 2
- Functionally dependent
- Congestive heart failure
- Serum albumin <3.5 g/dL
- FEV1<2 L
- MVV <50% of predicted
- PEF <100 L or 50% predicted value
- PCO245 mmHg
- PO250 mmHg
Aspiration
➢Increased risk of aspiration with:
•Decreased level of conscious (drugs/alcohol, head injury, CNS pathology, trauma/shock)
•Delayed gastric emptying (non-fasted within 8 h, diabetes, narcotics)
•Decreased sphincter competence (GERD, hiatus hernia, nasogastric tube, pregnancy,
obesity)
•Increased abdominal pressure (pregnancy, obesity, bowel obstruction, acute abdomen)
•Unprotected airway (laryngeal mask vs. endotracheal tube )
Aspiration
➢Management
• Manage risk factors if possible
• Utilize protected airway (i.e. Endotracheal tube)
• Reduce gastric volume and acidity
• Delay inhibiting airway reflexes with muscular relaxants
• Employ rapid sequence induction
Fasting Guidelines
Fasting Guidelines Prior to Surgery :
Before elective procedures, the minimum duration of fasting should be:
• 8 h after a meal that includes meat, fried or fatty foods
• 6 h after a light meal (such as toast or crackers) or after ingestion of
infant formula or non-human milk
• 4 h after ingestion of breast milk
• 2 h after clear fluids (water, black coffee, tea, carbonated beverages,
juice without pulp)
Hematological Disorders
deficiency, ITP, liver disease)
➢Evaluate hemoglobin, hematocrit and coagulation proles when indicated .
➢Anemia:
Pre -operative treatments to increase hemoglobin (PO or IV iron
supplementation, erythropoietin or pre-admission blood collection in
certain populations)
➢Coagulopathies
• Discontinue or modify anticoagulation therapies (warfarin, clopidogrel,
ASA, apixaban, dabigatran) in advance of elective surgeries
• Administration of reversal agents if necessary: vitamin K, FFP, prothrombin
complex concentrate, recombinant activated factor VII
Endocrine Disorders (1)
Diabetes mellitus (DM)
• Clarify type 1 vs. Type 2
• Clarify treatment – oral anti-hyperglycemics and/or insulin
• Assess glucose control with history and Hba1c; well controlled diabetics have more
stable glucose levels intraoperatively
• End organ damage: be aware of damage to cardiovascular, renal, and central,
peripheral and autonomic nervous systems
• Preoperative guidelines for DM:
1. Verify target blood glucose concentration with frequent glucose monitoring: <180
mg/dl in critical patients, <140 mg/dl in stable patients)
2. Use insulin therapy to maintain glycemic goals
3. Hold biguanides, -glucosidase inhibitors, thiazolidinediones, sulfonylureas and GLP1
agonists on the morning of surgery
4. Consider cancelling nonemergency procedures if patient presents with metabolic
abnormalities (DKA, HHS, etc.) Or glucose reading above 400 mg/dl
Endocrine Disorders (2)
Hyperthyroidism and hypothyroidism
Hyperthyroidism : can experience sudden release of thyroid hormone
(thyroid storm) if not treated or well-controlled pre-operatively.
Treatment : -blockers and pre-operative prophylaxis
Adrenocortical insufficiency (Addison’s, exogenous steroid use)
Consider intraoperative steroid supp
Obesity and Obstructive Sleep Apnea(OSA)
• Severity of OSA may be determined from sleep studies and level of
pressure prescribed for home CPAP device
• Both obesity and OSA independently increase risk of difficult
ventilation, intubation and post-operative respiratory complications
Total testing process (TTP)
It is a set of steps of laboratory testing, beginning from the test
requested by the clinician to the interpretation of the results.
The TTP is
typically divided into the following three phases
I)Pre-analytical
• Selection of tests
• Test request
• Patient identification & preparation
• Specimen identification
• Sample collection and labeling procedures
• Sample transportation
• Sample receipt and preparation for analysis
II) Analytical
• Selection of analytical method and device.
• Quality control
• Performance of analysis.
III) Post analytical
- Result transcription & reporting
- Interpretation of results.
Test selection:
selection of the appropriate investigation for each patient
is a must so as to provide the patient with the best possible medical service, with minimal side-effects on the patient and at an appropriate cost
to the health
Request a laboratory service
The communication link between the clinician and clinical laboratory is
the laboratory request form (LRF)
ISO15189, LRF should include:
1) At least 2 unique patient identifiers (full name, date of birth, national
ID number, hospital file number…)
2) Sex
3) Date and time of collection (where supplied)
4) Date and time of receipt in Laboratory
5) Type of Specimen (e.g., blood, urine, body fluid)
6) Person collecting the sample.
7) Clinical status of patient (e.g., fasting), where required.
8) Specimen characteristics which may provide information relevant to
interpretation of results (e.g., hemolysis)
9) Informed consent where required by legislation.
10) The name of the requesting clinician.
11) Adequate clinical information, which is essential for proper
result interpretation (e.g., clinical diagnosis, cause of admission,.)
Examples for lab tests that can be ordered as STAT:
-Cardiac enzymes (CKMB, troponins)
-Electrolytes: Na, K, Cl.
-Complete Blood picture (CBC)
Patient identification:
Confirmed positive identification of a patient is a must before sampling.
Failure of proper patient identification may results in mix up of lab
results with grave medical consequences.
Sampling:
1) Blood specimens:
• Venous: the easiest sample to obtain. The commonest site is the
veins of antecubital fossa. Phlebotomy is a technique to acquire a
venous blood sample.
• Arterial: arterial blood is used to measure arterial blood gases, like
oxygen, CO2, and pH.
• Capillary: capillary blood is mostly used in the pediatric patient’s
group and for bedside tests where there is no need for a large amount
of blood. The common sites are the fingertips and heel.
2) Urine, stool, sputum, nasal discharge.
3) Ascitic, synovial, pleural, and cerebrospinal fluids.
4) Seminal and prostatic fluids.
5) Bronchoalveolar lavage, tissues for culture.
6) Swabs for nasopharynx, oral cavity, vagina, and wounds.
7) Any unknown collection of fluid and abscess.
8) Bone marrow
General rules before sampling:
1) The appropriate container is ready: tube, urine collection container,
heparinized syringe for blood gases, etc.
2) Proper labelling of the sample container with full patient data (full
name, hospital number, ward, ….), type of sample (blood, body
fluid,…), and the required tests. In clinical laboratories, where
information system is applied, barcoded label with the previous date in
addition to unique sample number is used for labelling the samples.
3) The clinician/nurses must ensure proper patient preparation
prerequisites before sampling (e.g., fasting patient, 2 hours after drug
therapy in case of therapeutic drug monitoring, etc.). Clinical
pathologists provide the clinician with these data.
4) The appropriate transport container is available: ice on a chilled
container, and courier to transport the sample promptly, etc.
Types of blood containers used for sampling
• Light blue capped tubes: contain Na citrate as an anticoagulant.
Used for coagulation testing (PT, PTT and coagulation factor assay).
• Red capped tubes: empty tubes without adding any anticoagulant
material which are used in serology and some routine samples.
• Yellow capped tubes: contain a clot activator which cause blood
to clot quickly and serum gel separator that separates blood cells
from serum, allowing the clear serum to be removed easily for
testing after centrifugation. Used for the same purposes as the red
capped tubes but not for PCR testing.
• Green capped tubes: contain Na or lithium heparin. Used for
cytogenetic analysis sampling.
• Purple capped tubes: contain EDTA as an anticoagulant. Used for
CBC, reticulocyte counting, and for HbA1c estimation.
• Grey capped tubes: contain K oxalate as an anticoagulant and Na
fluoride, which acts as sample preservative, that preserve glucose in
whole blood by inhibition of glycolysis by the red cells, which would
subsequently cause false-low glucose level. Used for glucose testing
(figure 3)
Phlebotomy (Venipuncture) Procedure:
- Ensure proper patient preparation (e.g., fasting before sampling;
8 hours for fasting blood glucose and 12 hours for serum lipid
profile). - Put on gloves.
- Position the patient properly.
- Apply a tourniquet just above the venipuncture site and ask the
patient to make a fist without vigorous hand pumping. Select a
suitable vein for puncture. - Clean the skin with 70% alcohol and allowed to dry spontaneously.
- Withdraw blood from an antecubital vein or other visible veins in
the forearm. - Enter the skin with the needle at approximately a 20-30-degree
angle or less to the arm, with the bevel of the needle up. Insert the
needle smoothly and fairly rapid to minimize patient discomfort. - Venipuncture is done by means of either an evacuated tube or a
syringe.
▪ If evacuated tube is used for blood collection, the vacuum
controls the amount of blood which enters the tube.
▪ If a syringe is used for blood collection, the piston of the
syringe should be withdrawn slowly and no attempt made to
withdraw blood faster than the vein is filling. Haemolysis can
be avoided or minimized by withdrawing the blood slowly. - Release it as soon as the blood begins to flow into the syringe /
vacutainer tube. - After obtaining the blood, remove the needle and then press a
sterile swab over the puncture site for a minute or two. Then cover
the puncture site with a small adhesive dressing. - Anticoagulated specimens must be mixed gently by inverting the
containers several times. - Needle disposal: place needle, together with the used swab and any
other dressings, in a puncture-resistant container, for disposal.
Don’t try to recover the needle.
Post-phlebotomy Procedure:
• Check the patient’s identity and sample barcoded label again and
make sure that it corresponds to the details on the LRF.
• The specimen tubes must be set upright in a holder or rack and
placed -
in a carrier together with the request forms for transport to the
laboratory.
Causes of errors related to sample collection procedure: Pre-collection:
• Failure to adhere to proper patient preparation according to the
requested test (e.g., fasting blood glucose is requested but dietary
supplement was administrated within 8 hours).
• Failure to adhere to proper timing in sampling (e.g., cortisol AM/PM,
therapeutic drug monitoring, and fertility hormones)
• Vigorous activity before sample collection affect results of some tests
(e.g., CK, protein in urine)
Causes of errors related to sample collection procedure: During collection:
• Prolonged tourniquet pressure results in haemo-concentration.
• Excessive negative pressure when drawing blood into syringe results
in hemolysis.
• Using incorrect type of tube for blood collection ( e.g., EDTA tube for
liver enzymes test
Causes of errors related to sample collection procedure: Handling of specimen:
• Insufficient or excess anticoagulant
• Inadequate mixing of blood with anticoagulant.
• Error in patient and/or specimen identification results in mix up of
results
• Inadequate specimen storage conditions affect the result of some tests
(e.g., light cause breakdown of bilirubin)
• Delay in transport to laboratory affects the result of some tests (e.g.,
culture of fastidious organisms)
Sample transport:
Specimens should always be placed upright in the plastic biohazard
transport container. LRFs are transported separate from samples (don’t
place them in the same container with samples so as not to be contaminated
by any possible sample spills).
Performance of analysis: some examples of tests performed in each:
1) Microbiology: Urine culture, culture for tuberculosis.
2) Immunology: Anti-Nuclear anti body testing, Epstein Barr virus
serology.
3) Chemistry: kidney & liver function tests, and hormones testing.
4) Hematology: Complete blood counts, and prothrombin time.
Laboratory test panels:
Test panels are groups of tests that are routinely ordered to determine the
status of a major body organs. The tests are usually performed on a blood
sample
Examples of common chemistry panels include:
1- Liver Panel (also called Hepatic Function tests) – used to screen,
detect, evaluate, and monitor acute and chronic liver inflammation
(hepatitis), liver disease and/or damage. It includes Total ,direct bilirubin,
total protein, albumin, and liver enzymes [AST, ALT, and Alkaline
phosphatase enzyme ( ALP)].
2- Renal Panel (also called Kidney Function tests) – contains tests such
as creatinine, urea, uric acid , estimated glomerular filtration rate (eGFR)
to evaluate kidney function.
3- Thyroid Function Panel – used to evaluate thyroid gland function,
diagnose thyroid disorders, and follow up of treatment. It includes TSH,
FreeT4, Free T3, T4, T3.
Results transcription and reporting:
• Patient identifiers (full name, age, sex, hospital number).
• Requester name
• Date and time of analysis.
• Test name, result, measuring unite, and reference interval.
• Result interpretation (where required and appropriate).
• Name of Clinical pathologist who released the report and date of
release.
Test result interpretation:
1) Is it normal?
2) Is it significantly different from any previous results?
3) Is it consistent with the clinical findings?
Is it normal?
Comparison of a patient’s laboratory test result versus a reference or
“normal” range is an important aspect of medical decision making.
Examples for some laboratory critical results:
- White blood cell count (WBCs) <2 x109
/L & >30 x109
/L. - Platelets <20 x109
/L & >1000 x109
/L. - Hemoglobin <5 g/dl & >20 g/dl
- Bilirubin (newborn) >15 mg/dl.
- Sodium < 120 mmol/L & ˃150 mmol/L.
I) Pre-analytical phase:
Pre-analytical phase issues are related to patient’s interaction, specimen
collection, sample receiving and its transport. It includes the following
ethical issues:
A) Respect for persons:
- Consent must be understood by the patient.
- The patient’s right to refuse to get tests done should be appreciated.
- Confidentiality
B) Beneficence:
- All tests performed/referred must benefit to patient.
- Collection of samples should be done as per universally
recommended precautions so as to protect the patient and the
healthcare worker.
- The additional samples should not be drawn from the patient without
informing and getting the permission from Institutional ethics
committee.
- The specimens should be well-labeled with minimum two unique
identifiers.
- Transportation of samples should be done to protect the integrity of
the sample.
C) Justice:
No preference should be given to some patients in order to facilitate
or accelerate the collection procedure at the cost of others.
II) Analytical phase:
A) Respect for persons:
- After collection, patients have the right to refuse to have their
specimens examined.
- Confidential information
B) Beneficence:
The aim is to provide the best possible result to the patients. This is
accomplished via good laboratory practices which should involve the
establishment of quality assurance program including quality control
analysis, proficiency testing and accreditation of laboratory.
C) Justice:
- All patient samples are treated equally.
- Develop operating procedures for STAT samples.
- All specimens are analyzed accurately and in a timely manner.
III) Post analytical phase:
A) Respect for persons:
- Specimens will not be used beyond the testing prescribed by a
clinician.
- Maintain the confidentiality of results.
B) Beneficence:
- Reporting of results by qualified persons
- Reports should be understandable and interpretable.
- Notifying for errors and correction
C) Justice:
- Consistent reporting for all patients.
- Avoid withholding of results because of financial causes
Respect for persons:
We must respect patient and their self-respect. It is
an obligation to respect the decisions made by people concerning their own
samples.
Beneficence:
The goal is to maximize benefits and minimize harms,
Everyone must be fair and correct in all their actions to prevent harm.
