General Surgery Flashcards
What does the term general surgery refer to?
Surgery involving the abdominal organs
What is the highest ranked comorbidity in patients?
HTN 87%
What is the second highest comorbidity in patients?
Obesity 47%
What are some common advantages to general anesthesia?
Allows paralysis
Safely allows position extremes
Moe reliable, lower failure rate
What are some common disadvantage to general anesthesia?
Increased stress response
Known full stomach = increased aspiration risk
Post operative nausea and sedation
How are insufflation pressure affected if regional anesthesia is performed?
Lowered insufflation pressures
What medications can induce sphincter of Oddi pain?
Opioids
What is the treatment for sphincter of Oddi spasms?
Narcan
LA
Glucagon
What is the purpose of a laparoscopy?
Diagnostic and surgical intervention
What is the only absolute contraindication to laparoscopic surgery?
Hemodynamic instability
What are the telltale signs that a pulmonary embolus as occurred?
Hypoxemia Sudden increase in PAWP Sudden HoTN Bronchospasm Sudden decrease in ETCO2 Increased CVP Increased PAP
What is the safe range of insufflation pressures in the abdomen?
12-15mmHg
At what insufflation pressure will you see CO and lung compliance decrease
16-20mmHg
At what insufflation pressures will you see a decrease in Renal blood flow?
20-30mmHg
At what insufflation pressures will you see adverse hemodynamic outcomes?
30-40mmHg
What is the gas of choice for insufflation?
Carbon dioxide
What characteristics of CO2 make it the insufflation gas of choice?
Easily absorbed by the tissues Decreased risk of air emboli Eliminated through respiration Non-combustable Colorless/Odorless Inexpensive
What alternative gas can be used for insufflation?
Nitrous Oxide
Why did Nitrous Oxide lose favor as the gas of choice for insufflation?
It is combustable
What physiologic functions are increased by the pneumoperitoneum?
PaCO2, ETCO2, PAP, MAP, SVR, HR, CVP, IAP, ICP, dead space
What physiologic functions are decreased by the pneumoperitoneum?
Cardiopulmonary function Mean CO Venous return FRC/VC Renal function
How does the pneumoperitoneum cause HTN and tachycardia?
Sympathetic stimulation
How does the pneumoperitoneum cause HoTN?
Impaired venous return
How does the pneumoperitoneum cause arrhythmias and bradycardia?
Vagal stimulation
How does the pneumoperitoneum cause increased ADH to be released?
Reduced renal perfusion causes activation of the RAAS system
What ventilatory setting may be most effective when a pneumoperitoneum is created?
Pressure control ventilation
What interventions can be done if there is pulmonary decompensation with the pneumoperitioneum?
Decrease the degree of trandelenburg
Use caution with PEEP
Consider increasing the volatile
Bronchodilators
What interventions can be done if there is cardiac decompensation with the pneumoperitioneum?
Vent the abdomen if IAP >20mmHg
Evaluate intravascular volume (fluid bolus)
Consider pre-existing cardiac disease
What is the goal of urine output during surgery?
0.5mL/kg/hr
What are the advantages to using a robot for laparoscopy?
3D view and depth perception
Increased precision
10-15x magnification
Increased free movement
What are the disadvantages to using a robot for laparoscopy?
Large system/limited working space
Limited patient access
Expensive/Maintenance cost
Instrument availability
What are the common indications for esophageal surgery?
GERD Cancer Hiatal or Paraesophageal hernia Achalasia Motility disorder
What is the Nissen fundoplication procedure?
Fundus is wrapped around LES and sutured to reinforce LES
The esophagus is narrowed to prevent/treat GERD or hiatal hernia
How is the nissen wrapped around the LES?
Posterior to anterior
What can occur if the French esophageal dilator is advanced too quickly?
Risk of esophageal rupture
What is the major indication for an esophagectomy?
Carcinoma
Where would the incision be made in a trans-hiatal esophagectomy?
Neck and abdomen incisions
Where would the incision be made in a trans-thoracic esophagectomy?
Thoracotomy
What is the incidence of symptomatic AF or SVT after an esophagectomy?
17%
What is a major complication associated with the THE approach?
RLN injury
What should the provider be looking for post-op to determine if damage has been done to the RLN?
Voice quality
Coughing/Choking
Frequent breaths when speaking
Ineffective cough
What is done during a gastrostomy?
An opening is made through the skin and the stomach wall to provide nutritional support or GI compression
What complications should be assessed for after a gastrectomy is performed?
Dumping syndrome
Vitamin B12 deficiency
Iron deficiency anemia
Poor calcium absorption
What are the differences in the two types of gastrectomy approaches?
Bilroth1: remaining portion of the stomach is attached to the duodenum
Bilroth2: seal off remaining portion of the stomach and attached to the jejunum
What types of surgeries can be performed for peptic ulcer disease?
Vagotomy of the parietal cells
Pylorplasty
How can a vagotomy cause pernicious anemia?
By denervating the parietal cells, intrinsic factor is not produced leading to a B12 deficiency and pernicious anemia
When operating on the stomach, what tool can cause an acute change in PAWP?
Liver retractor
What should be considered if a bowel prep is given to a patient pre-operatively?
Hypovolemia and Electrolyte abnormalities
What are some complications that can occur with a small bowel resection?
Pulmonary embolism
Anastomotic leak
Short Bowel syndrome
What is the most common acute surgical procedure of the abdomen?
Appendectomy
What complications can occur if the appendix perforates before removal?
Septic shock
Peritonitis
What two antibiotics are known to affect the duration of neuromuscular blockade?
Gentamicin
Clindamycin
What might the surgeon ask the patient to do prior to induction?
Cough to see where the hernia bulges
What is a hernia?
It is a defect in muscles of the abdomen wall
What two occurrences require emergency hernia surgery?
Incarcerated
Strangulated
What is a major post operative consideration for patients that have undergone hernia surgery?
Avoid straining, help them move to the bed, avoid bucking and plan for a smooth wake up
What can result from peritoneal retraction?
Bradycardia
What is the rate of conversion from a laparoscopic to an open cholecystectomy?
5-10%
What are risk factors associated with a conversion from a laparoscopic to open cholecystectomy?
Choledocholithiasis Bile duct injury Bleeding Obesity Male Gender Advanced age Previous abdominal surgery Thickened wall
What is the breakdown of open versus laparoscopic cholecystectomies?
25% Open
75% Laparoscopic
What are potential complications associated with a cholecystectomy?
Bleeding from cystic artery and cystic duct
Liver laceration
Pneumothorax
What are the major functions of the liver?
Metabolic: carbohydrate metabolism (gluconeogenesis, glycogenolysis and glycogenesis)
Hematologic: synthesis of heparin, synthesis of bile pigment from worn Hgb
How many lobes are in the liver?
Four lobes –> eight segments
Why is the liver considered a blood reservoir?
It receives 1.5L/min
80% Blood flow from portal vein
20% hepatic artery
How does the liver participate in lipid metabolism?
Cholesterol synthesis
Production of triglycerides
What does the liver store?
Glycogen, B12, iron and copper
What coagulation factors are produced by the liver?
I, II, V, VII, IX, XI, C, S and antithrombin
What is considered a major hepatectomy versus a minor one?
Minor: removes less or equal to 2 liver segments
Major: removes more than or equal to 3 liver segments
Why does a hepacectomy have a 3-5% mortality rate?
Major bleeding since the liver is a blood reservoir
Why might the provider consider a RSI on a patient undergoing a liver resection?
Ascites
What is the paralytic of choice for a patient undergoing a liver resection?
Cisatracurium - Hoffman elimination
What is an appropriate clamp time in a healthy liver and cirrhosis?
Healthy 60m
Cirrosis 20m
What is the pringle maneuver?
Compression of hepatoduodenal ligament, eliminated blood flow to the liver which can decrease CO and increase afterload
Why does significant bleeding occur in hepatic veins?
There are no valves in hepatic veins
What is the most common postoperative complication requiring surgical exploration after a liver resection?
Bleeding and bile leak
What are the functions of the spleen?
Filters foreign substances from the blood and removes blood cells
Regulates blood flow to the liver and sometimes stores blood cells
What percentage of platelets are sequestered in the spleen in a healthy patient?
30%
What is the purpose of give a patient vaccines prior to a splenectomy?
Helps to rev up the patients immune system prior to removing the spleen
What type of immunoglobulins should be administered to a patient that has had a splenectomy?
IgM
How does the gastric band work?
It limits the amount of food taken in by placing an adjustable silicone band around the upper stomach
What type of surgery accounts for 80% of the weight loss surgeries in the US?
Roux-en Y Gastric Bypass
What drugs for bariatrics should be dosed based on their ideal body weight?
Propofol
Vec
Roc
What anesthetic drugs can bariatric patients be dosed on their total body weight?
Remifentanil Midazolam Succinylcholine Cisatracurium Fentanyl Sufentanil
Why is succinylcholine dosed based on total body weight?
Obesity causes an increase in pseudocholinesterase activity
