PBL ILO’s Flashcards
Name some pre operative investigations
Pre operative investigations could include…
· COVID-19 test
· FBC
· ABG
· HbA1C
· U&E
· Clotting tests
· Group and save
· Pregnancy test
· ECG
· Echo
· Lung function tests
· Swabs to check for infection
· MRSA screening
What medications may need to be stopped prior to surgery?
- Whether to stop taking your usual medicines before going into hospital
- Anticoagulation needs to be stopped.
- Warfarin can be rapidly reversed with vitamin K in acute scenarios
- Treatment dose LMWH may be used to bridge the gap between stopping warfarin and surgery in higher risk patients (e.g mechanical heart valves or recent VTW)
- DOACs are stopped 24-72 hours before surgery
- Oestrogen-containing contraception need to be stopped 4 weeks before surgery
- Long-term corticosteroids requires additional management to help deal with the extra amount of steroid production produced during surgery
· Additional IV hydrocortisone at induction and for the immediate postoperative period
· Doubling of their normal dose once they are eating and drinking for 24-72 hours
Factors that make a patients risk for surgery higher
Factors that make a patients risk for surgery higher:
1. Obesity
- Excess weight can make it more challenging to safely administer anaesthesia, introducing potential problems with locating veins, determining dosage, and ensuring you get enough oxygen.
2. Age
- Some anaesthesia side effects are more likely to occur in elderly patients and aging-related health problems such as high blood pressure, clogged arteries and lung disease can increase risk
3. Smoking
- Smoking can increase the risk of anaesthesia-related complications during or after surgery. But quitting smoking before the procedure can help.
4. Sleep apnoea
- Millions of people in the united states are affected by sleep apnoea - millions more don't realise they have it - and anaesthesia can make the condition worse.
5. Diabetes
- The stress of surgery increases blood sugar levels. However, fasting may lead to hypoglycaemia.
- The risk of hypoglycaemia is greater than hyperglycaemia
Certain oral anti-diabetic medications may need to be adjusted or omitted around surgery
· Sulfonylureas (gliclazide) can cause hypoglycaemia and are omitted until the patient is eating and drinking
· Metformin is associated with lactic acidosis
· SGLT2 inhibitors - diabetic ketoacidosis
What factors make anaesthesia riskier?
What factors make anaesthesia riskier?
• Allergies to anaesthesia or a history of adverse reactions to anaesthesia
• Diabetes
• Heart disease (angina, valve disease, heart failure, or a previous heart attack)
• High BP
• Kidney problems
• Lung conditions (asthma and COPD)
• Stroke
• Seizures
Name the parts of the gall bladder and the biliary tree.
Fundus
Body
Neck
Cystic duct
Hepatic duct
Common bile duct
Name the parts of the pancreas
Head – the widest part of the pancreas. It lies within the C-shaped curve created by the duodenum and is connected to it by connective tissue.
Uncinate process – a projection arising from the lower part of the head and extending medially to lie beneath the body of the pancreas. It lies posterior to the superior mesenteric vessels. Neck – located between the head and the body of the pancreas. It overlies the superior mesenteric vessels which form a groove in its posterior aspect. Body – centrally located, crossing the midline of the human body to lie behind the stomach and to the left of the superior mesenteric vessels. Tail – the left end of the pancreas that lies within close proximity to the hilum of the spleen. It is contained within the splenorenal ligament with the splenic vessels. This is the only part of the pancreas that is intraperitoneal.
Composition of bile
Bile is made up of, Bile salts cholesterol unconjugated bilirubin electrolytes and water.
How are gall stones formed?
Gallstones form when bile becomes oversaturated with cholesterol (cholesterol supersaturation) or bilirubin or both. If the liver produces too much cholesterol, i.e. more than the bile is able to dissolve, that excess will precipitate ion the form of crystals,. Which then becomes gallbladder sludge, which will ultimately become gallstones.
• From excess bilirubin, sometimes there are haemolytic conditions that cause too much bilirubin to be taken up and secreted into the bile by the liver, this causes gallstone formation in the same way.
• Another way gallstones can form is by gallbladder hypomotility or impaired contractility, which usually means there is bile stasis and a higher chance of gallstone formation.
Risk factors of gall stones
Risk Factors are the 5 Fs
• Fat
• Female
• Forty
• Fertile
• Family History
Symptoms of gall stones
Symptoms
Patients with gallstone disease typically present with symptoms of biliary colic (intermittent episodes of constant, sharp, right upper quadrant abdominal pain often associated with nausea and vomiting).
Complications of gall stones
Complications
• Acute cholecystitis - inflame of gallbladder caused by obstruction of the opening cystic duct by a stone.
• Ascending cholangitis - this is where the gallstone travels down the and occludes the common bile duct, this blocks the flow completely and is a medical emergency.
• Pancreatitis - Gallstones are a common cause of pancreatitis. Gallstones, produced in the gallbladder, can slip out of the gallbladder and block the bile duct, stopping pancreatic enzymes from traveling to the small intestine and forcing them back into the pancreas.
• Gallbladder Empyema and necrosis - more common in diabetic patients and those who are immunosuppressed, this is where bacteria capable of living ion bile infect the gallbladder and it becomes filled with pus, this is a medical emergency and can lead to necrosis of the gallbladder and subsequent sepsis.
• Gallbladder Cancer -
• Cholecystoenteric fistula
Risks of general anaesthesia
Risks of General Anaesthesia
Sore throat and post-operative nausea and vomiting are common adverse effects of general anaesthesia.
Significant risks of general anaesthesia include:
• Accidental awareness (waking during the anaesthetic)
• Aspiration
• Dental injury, mainly when the laryngoscope is used for intubation
• Anaphylaxis
• Cardiovascular events (e.g., myocardial infarction, stroke and arrhythmias)
• Malignant hyperthermia (rare)
• Death
Malignant Hyperthermia
Malignant hyperthermia is a rare but potentially fatal hypermetabolic response to anaesthesia. The risk is mainly with:
○ Volatile anaesthetics (isoflurane, sevoflurane and desflurane)
○ Suxamethonium
There are genetic mutations that increase the risk of malignant hyperthermia. These are inherited in an autosomal dominant pattern.
Malignant hyperthermia causes:
§ Increased body temperature (hyperthermia)
§ Increased carbon dioxide production
§ Tachycardia
§ Muscle rigidity
§ Acidosis
§ Hyperkalaemia
It is treated with dantrolene. Dantrolene interrupts the muscle rigidity and hypermetabolism by interfering with the movement of calcium ions in skeletal muscle.
What complications may occur after surgery?
Shock
Bleeding
Wound infection
DVT
PE
Lung problems
Urinary retention
Post operative complication - shock
Shock
Shock is a severe drop in blood pressure that causes a dangerous slowing of blood flow throughout the body. Shock may be caused by blood loss, infection, spine injury, or metabolic problems. Treatment may include any or all of the following:
• Stopping any blood loss
• Helping with breathing. This might be with a breathing machine.
• Reducing heat loss
• Giving IV fluids or blood
• Giving extra oxygen
• Prescribing medicines to help raise blood pressure.
Post operative complication - bleeding
Bleeding
Rapid blood loss from the site of surgery, for example, can lead to shock. Treatment of rapid blood loss may include:
• IV fluids
• Blood transfusion of red cells or other blood products, such as plasma
• More surgery or other procedures to control the bleeding
Post operative complication - wound infection
Wound infection
When bacteria enter the site of surgery, an infection can happen. Infections can delay healing. Wound infections can spread to nearby organs or tissue, or to distant areas through the bloodstream, which when severe can cause death.
Treatment of wound infections may include:
• Antibiotics
• Surgery or procedure to clean or drain the infected area
