Week 1 Abdominal General Surgery Flashcards
Name the surgical areas that embody General Surgery
Esophagus Stomach Intestine/Colon Liver Gallbladder Pancreas Thyroid Skin Hernias Breasts
Common GI Associated Problems (8)
Fluid and Electrolytes Anemia Cancer Obesity GERD Pain N/V Ascites
Three techniques for General Surgery
General Anesthesia
Regional Anesthesia
MAC/IV Sedation
Advantages of General Anesthesia
allows paralysis
more safely allows positioning extremes
more reliable
lower failure rate
Disadvantages of General Anesthesia
increased stress response
known full stomach (aspiration risk)
more postoperative nausea and sedation
Advantages of Regional Anesthesia
requires lower insufflation pressures, patient breathes spontaneously, decreased stress response, faster recovery period
Disadvantages of Regional Anesthesia
Occasional failure, sympathectomy
Describe MAC/Intravenous sedation
combined with local anesthesia
Patient breaths spontaneously
patient comfort levels
Considerations for Anesthetic Management of General Surgery (10)
choice of anesthetic routine monitors foley catheter cuffed ET pneumoperitoneum evacuation of gastric contents positioning smooth emergence/ extubation anti-emetics pain management
What is laparoscopic surgery used for?
diagnostic and surgical intervention
Minimally invasive
What do they insufflate the abdomen with?
CO2
Describe the view of laparoscopic and how
views abdominal contents through small incisions via small instruments through trocars
Camera will project image on monitor screen
Types of Laparoscopic Surgery (7)
gastric colonic splenic hepatic gallbladder gynecologic urologic
What are the advantages to laparoscopic surgery compared to open surgery? (7)
lower pain scores and opioid requirement
earlier ambulation and return to normal activities
lower incidence of post-operative ileus
usually faster recovery, shorter hospital stays
reduced post-operative pulmonary/diaphragmatic dysfunction: quicker return to preop pulm function
less stress response & less wound complications
lower cost (usually)
What are the disadvantages of laparoscopic technique? (8)
impaired visualization expensive equipment requires specific surgical skill limited range of motion altered depth perception no tactile sensation increased PONV referred pain
What are the relative contraindications of laparoscopic surgery? (6)
increased ICP severe CV disease severe respiratory disease dense adhesions Bi-directional V/P shunt or peritoneojugular shunt hypovolemia
What are the two entry methods of entering laparoscopically?
closed technique and/or open technique
Describe the closed technique
involves the spring-loaded needle known as the veress needle to pierce the abdominal wall at its thinnest point
then insufflation occurs
the trocar is blindly inserted or under direct vision to allow surgeon to pass instruments into abdominal cavity
Describe the open technique
development of a 1-2.5mm midline vertical incision that begins at the lower border of the umbilicus and extends through the subcutaneous tissue and underlying fascia
Once surgeon in abdominal cavity, trocar can be placed by direct site and sutured in place. Gas then is insufflated into the side port of the hasson trocar
Three types of gas that can be utilized for pneumoperitoneum
carbon dioxide
inert gases
gasless laparoscopy
Why is CO2 mostly chosen for pneumoperitoneum?
more soluble in blood then air, helium, oxygen or nitrous oxide
easily absorbed by the tissues (high blood solubility) with rapid elimination
eliminated through respiration
non-combustible
colorless, odorless, inexpensive
What the cardiovascular effects of CO2 insufflation?
HTN and Tachycardia from sympathetic stimulation
Hypotension from impaired venous return
Arrhythmia, bradycardia from vagal stimulation
What are the respiratory effect of CO2 insufflation?
decreased FRC, compliance, increased ventilatory pressures, barotrauma, atelesctasis
What are the renal effects of CO2 insufflation?
reduced renal perfusion
activation of RAAS, increased anti-diuretic hormone
What are the abdominal/gastric effects of CO2 insufflation?
increased intra-abdominal pressures, increased risk of gastric regurgitation, splanchic ischemia, carbon dioxide embolus, extra-peritoneal spread of carbon dioxide
What is physiologically increased in pneumoperitoneum? (11)
PaCO2 ETCO2 PAP (peak airway pressure) MAP (mean arterial pressure) SVR (systemic vascular resistance) HR CVP IAP ICP Vd Risk of regurgitation and aspiration
What is physiologically decreased with pneumoperitoneum? (7)
Cardiopulmonary function Cardiac output Venous Return Functional residual capacity vital capacity renal function
How do you clinically manage pulmonary physiologic changes with pneumoperiteneum?
Position changes (decrease degree of trendelenberg)
Modify ventilator settings (pressure control)
Use PEEP with caution
Consider increasing volatile
Consider bronchodilators
How do you clinically manage cardiac physiologic changes with pneumoperiteneum?
slow, gradual abdominal insufflations
vent abdomen if IAP > 20mmHg
Evaluate intravascular volume (consider IVF bolus)
Consider treatment for pre-existing cardiac dysfunction
How do you clinically manage renal/hepatic physiologic changes with pneumoperiteneum?
Closely monitor hourly UOP
Administer IVF boluses
Consider diuretics
Maintain IAP <15mmHg
How do you clinically manage cerebral blood flow changes with pneumoperiteneum?
decrease degree of trendelenberg (adjust head up)
vent abdomen if IAP > 20mmHg
Anesthesia Implications for Laparoscopic Surgery (Respiratory)
GA with cuffed ET tube for controlled ventilation
increased minute ventilation and positive inspiratory pressure often required
adjust respiratory rate, tidal volume and PEEP
Describe regional anesthesia and laparoscopic surgery
has been used
risky!
need to have a high block T4-T5 (SNS denervation) more difficult to compensate for CV, ventilatory changes, shoulder & distention pain completely alleviated
How do you avoid CV compromise in laparoscopic surgery?
avoid intra-abdominal pressure > 15mmHg
When do you need invasive monitoring with a laparoscopic case?
ASA 3-5 and/or abnormal gradient PaCO: ETCO2
Allows for blood gas and BP measurements
What are the anesthesia implications for using an LMA during a laparoscopic procedure
spontaneous ventilation
lower incidence of sore throat
lower pain scores, less analgesic medications, less PONV
unable to administer muscle relaxation
Important Positioning TA’s for Laparoscopic Surgery
prevent nerve injury
tilt not to exceed 15-20 degrees
make changes slowly
recheck ETT position after every position change
consider less aggressive fluid replacement in head down position
What are the common nerves damaged in laparoscopic surgery?
common peroneal nerve (lithotomy) brachial plexus (shoulder braces, etc)
Anesthetic Considerations for the Maintenance phase of laparoscopic surgery
balanced techniques appropriately using volatile agent, opioids, or TIVA (no N2O)
consider TIVA if PONV
Continue muscle relaxation
Monitor hemodynamic and pulmonary status
Watch for endobronchial intubation during position changes
What are considerations when converting from laparoscopic to an open procedure
supine position
new fluid plan (3rd space losses will increase)
new pain management plan (opioid requirements will change)
new ventilator settings- may need to increase rate and tidal volume
Where can vascular intraoperative injuries can occur during an lapaproscopic procedure?
d/t trocar insertion/veress needle
aorta, ICV, iliac vessels, cystic/ hepatic arteries, retroperitoneal hematoma
What cardiac intra-operative complications can occur during a lapaproscopic procedure
dysrhythmias, hybercarbia, increased vagal tone with peritoneal traction, BP changes
What are some intraoperative complications from laparoscopic surgery?
SQ emphysema
capnothorax, capnomediastinum, capnopericardium
CO2 embolism
How does capnothorax, capomediastinum, capnopericardium occur?
diaphragm defect, pleural tear, bullae rupture
High degree of suspicion can be lifesaving
How does an CO2 embolism occur?
direct needle placement in vessel, gas insufflation into abdominal organ
Pathophysiology of a Gas Embolism
depends on size of bubbles and rate of entrainment vapor lock in vena cava and right atrium obstruction to venous return acute RV HTN = paradoxical embolism circulatory collapse
Diagnostic Tools for a Gas Embolism
pulse oximetry esophogeal stethoscope- millwheel sound sudden ETCO2 decrease aspiration of gas from CVP hypotension bronchospasm increased PIPs
Treatment of Gas Embolism
stop insufflation and desufflate place into steep trendelenberg/ left lateral decubitus discontinue N2O administer 100% FiO2 hyperventilate Place CVP CPR Consider CPB
Subcutaneous Emphysema
Accidental insufflation of extraperitoneum
be aware of increases in PaCO2 after plateau has been reached
not a contraindication for extubation
can track to thorax and mediastinum (capnothorax or capnomediastinum)
What are common laparoscopic GI procedures?
cholecystectomy
herniorrhapy
appendectomy
What is a cholecystectomy?
removal of a diseased gallbladder
can be due to cholecystitis, cholelithiasis, cancer
What is herniorrhapy?
defect in muscles of the abdominal wall (inguinal, umbilical, incisional, abdominal, femoral, diaphragmatic)
What is the most common surgical procedure of the abdomen?
appendectomy
What causes the need for an appendectomy?
obstruction with inflammation by lymphoid tissue or fecal matter
Risk factors of converting a cholecystectomy from lap to open (7)
acute cholecystitis with thickened gallbladder wall previous upper abdominal surgery male gender advanced age obesity bleeding bile duct injury
How is a cholecystectomy performed?
laparoscopic or open
Potential complications of a cholecystectomy
bleeding from cystic artery and cystic liver laceration
pnemothorax
Pre and Post-Operative Cholecystectomy considerations
Preoperative antibiotics controversial
DVT prophylaxis
How is a patient positioned for a cholecystectomy?
surgeon on patients left (supine) or between patient’s legs (lithotomy)
reverse trendelenberg, left tilt/right side up
What are symptoms of a spasm of the sphincter of Oddi?
recurrent attacks of upper right quadrant or epigastric abdominal pain
Non-colicky and steady pain
can be aggravated by foods, especially fatty foods
What can treat a sphincter of oddi spasm?
glucagon
Herniorrhapy Anesthetic considerations
outpatient, elective surgery
open or laparoscopic
potential for incarceration if not reduced
avoid strain
general, local, or regional (TB) anesthesia
What is an incarcerated hernia?
part of the intestine or abdominal tissue that becomes trapped in the sac of a hernia
They can cause intestinal obstruction or strangulation and infarction, resulting in a high incidence of infection, hernia recurrence and operative mortality esp in older patients
URGENT SURGERY
What is an strangulated hernia?
emergency surgery (requires general anesthesia) can lead to necrotic bowel requiring bowel resection higher morbidity and mortality
Can a patient cough after a herniorrhapy?
discuss with surgeon
What is the EBL of herniorrhapy?
about 50ml
What happens if an appendectomy perforates?
septic shock
peritonitis
What are some anesthetic implications of an appendectomy?
fluid and electrolyte deficits aspiration precautions antibiotics avoid reglan with obstruction skeletal muscle relaxant
Where is pain detected after a laparoscopic procedure?
procedures are associated with intra-abdominal, incisional, and shoulder pain (d/t irritation of diaphragm, and/or visceral pain from biliary spasms)
What are a good post operative pharmacological pain managements?
opioids NSAIDs acetaminophen dexamethasone local anesthetic infiltration (incisional and intraperitoneal)
What are the three parts of a robotic laparoscopic technique?
control console
patient side card (robotic arms)
equipment tower (screens)
Advantages of Robotic Laparoscopy
3 dimensional view depth perception intutitive movements increased precision 10-15x magnification increased free movement
Disadvantages of Robotic Laparoscopy
Massive system limited working space limited patient access limited instrument availability maintenance cost
Preparation for robotic surgery includes:
2 peripheral IVs consider arterial line limit IVF initially trendelenburg/lateral/flexion Limited patient access Padding
Types of GI Lab Diagnostic Tests include
esophagogastroduodenoscopy
endoscopic retrograde cholangiopancreatography
colonoscopy
What is a endoscopic retrograde cholangiopancreatography
procedure that combines upper gastrointestinal (GI) endoscopy and x-rays to treat problems of the bile and pancreatic ducts
used to diagnose and treat pancreatic and biliary disorders
contrast dye used
What is the purpose of an EGD/Colonoscopy?
diagnostic/therapeutic
minimally invasive
How can a EGD/Colonoscopy be performed?
conscious sedation, topical/ general anesthesia
Considerations for an EGD include
sharing the airway/ limited access
mouth piece inserted by endoscopist to prevent biting on scope
supplemental oxygen
may consider GETA if obese
What are the potential complications of EGD/colonoscopy?
perforation
bleeding
desaturation/laryngospasm
What is the purpose of a colonoscopy?
views lining of rectum and colon
cancer screening
treatment of polyps
What are potential complications of a colonoscopy?
perforation
bleeding
desaturation/laryngospasm
Anesthetic considerations for Colonoscopy?
colon prep, clear liquid diet
left lateral decubitus
usually heavy sedation or general
Describe the ERCP procedure
left lateral or prone; positioned changed during procedure
length 30 minutes- several hours
Complications of ERCP
perforation
bleeding
laryngospasm
desaturation
Indications for esophageal surgery
GERD
Cancer
Histal Hernia
Motility disorders
Patient symptoms for Esophageal surgery
dysphagia
heartburn
hoarse voice
chest pain
What a nissen fundoplication?
can be performed laparoscopically or open (transthoracic)
3-4 hours
fundus is wrapped around lower esophagus and sutured to reinforce lower esophageal sphincter
Describe the anesthesia plan for a nissen fundoplication
GETA (cuffed tube)
position, rapid sequence cricoid pressure for induction
H2 blockers, reglan, antibiotics, antiemetics
Position includes: lithotomy and reverse trendelenburg
Needs a smooth extubation
What is an esophagectomy?
when majority of the thoracic esophagus and nearby lymph nodes are removed
stomach is moved up and attahed to the remaining portion of the esophagus
Why would a patient need a esophagectomy?
tobacco/ETOH
concomitant chemo/radiation
Anesthetic considerations for Esophagectomy
surgical approach
invasive monitors
double lumen tube
post-op pain management
What does the surgical approach of an esophagectomy depend on?
patient condition, portion to be removed and surgeon skill/ preference
What is a gastrostomy?
creates an opening through the skin and the stomach wall to provide nutritioinal support or GI decrompression
Indications for gastrostomy?
dysphagia, high risk or active aspiration
How is a gastrostomy performed?
laparoscopic, percutaneous (PEG) or open
What is the surgical time for a gastrostomy?
less then 1 hour
What anesthesia can be used for a gastrostomy?
general anesthesia (rapid sequence induction) or local anesthesia and sedation
What is a gastrectomy?
partial or total removal of stomach
Indications for a gastrectomy?
peptic ulcers, gastric perforation, cancer, benign tumors/ polyps
What do you have to watch for post-gastrectomy?
gastric dumping syndrome, vitamin B12 deficiency, iron deficiency anemia and poor calcium absorption
Anesthetic considerations for abdominal surgery
stable or acutely ill/malnourished correct hypovolemia & anemia chemo/radiation cross matched blood available full stomach/NGT invasive monitoring warming extubate?
What organs include intestinal surgery?
small bowel resection, colectomy, colonscopy
Indications for intestinal surgery include:
diverticulitis
cancer
crohn’s disease
ulcerative colitis
Considerations for Intestinal surgery include:
bowel preparation
postoperative colostomy, ileostomy
Indications for a small bowel resection
obstruction
cancer
diverticulum, crohn’s disease
Surgical time for a small bowel resection
2-4 hours
EBL for small bowel resection
< 500ml
Pre-operative considerations for small bowel resection
bowel prep (hypokalemia, hypovolemia) Pre-op EKG, CBC, electrolytes, type and screen
Small Bowel Anesthetic considerations
aspiration precautions RSI with cricoid pressure NGT & Foley NO REGLAN consider epidural for post op pain large third space fluid loss (10-15ml/hr) hypothermia
Post-operative Complications for Small bowel resection include
pulmonary effusion, anastomotic leak, short bowel syndrome, sepsis, small bowel necrosis
Colectomy is
removing all or part of the colon
Colectomy can be performed
open or laparoscopic
Pre-op for Colectomy
bowel preparation
clear liquids 1-2 days prior
volume and electrolyte depleted
IV and oral antibiotics
Post-operative pain for colectomies can have
thoracic epidural
What are the four lobes of the liver?
left right quadrate and caudate
What is the role of the liver?
metabolic and hematologic roles
Name characteristics of the liver
eight segments
only organ capable of regenerating functional parenchyma within 24 hours of resection
highly vascular about 1.5:/min
Where does majority of deoxygenated blood from the liver empty into?
portal vein 80%
What supplies the liver with oxygenated blood?
20%
hepatic artery
For a liver resection, what do history do you want to ask pre-operatively?
bruising GI bleeding palmary erythema spider angiomata, petechiae ecchymosis anorexia or weight changes N/V or pain with fatty meals abdominal distention/ ascites hepatomegaly or splenomgealy scleral icterus gynecomsatia asterixis pruritus or fatigue
What do you include in the pre-op workup for a liver resection?
CT or MRI of tumor location
12-lead EKG/echocardiogram
CXR
CBC, PT/PTT, bleeding time, chemistry profile, LFTs
Monitoring for Liver Resection
large bore IVs A-line for BP and laboratory data May or may not have CVP or PA (if pulm HTN) TEG Foley OGT/NGT TEE?
How do you optimize our liver resection patient pre-operatively?
correction of ETOH dependency, coagulopathy, pH, electrolyte abnormalities, malnutrition, anemia, esophageal varices and hepatic encephalopathy
consider platelet infusion if < 100,000 cells/microliter
assume full stomach (h2 receptor blocker, metoclopromide, sodium citrate)
PT or INR considerations for liver resection
parental vitamin K, recombinant factor VIII (FFP in emergency)
Anesthetic Management in Liver Resection
Local/MAC adequate sedation is essential to minimize SNS stimulation and resultant decrease in hepatic blood flow and O2 delivery- titrate carefully
GETA: RSI or awake intubation
Iso and Sevo agents of choice
Altered pharmacokinetics
Controversial epidural placement for post-op pain
Benzodiazepines in Liver Resection Cases
increased cerebral uptake
decreased clearance
prolonged E1/2 life
Dexmedetomidine in Liver Resection Cases
decreased clearance and prolonged 1/2 life
Propofol in Liver Resection Cases
single dose similar response as normal patients, recovery times may be longer after infusions
what is the drug of choice in patients with encephalopathy?
propofol
What drugs are unchanged in most studies during a liver resection?
TPL, etomidate, ketamine, methohexital
Morphine and Liver Disease
prolonged E1/2 life
increased bioavailibity of oral form
decreased plasma protein binding and exaggerated sedative and respiratory depressant effects
Meperidine and Liver Disease
50% reduction in clearance and a doubling of the half-life
may experience neuro-toxicity from accumulation of normeperdine
Fentanyl and Liver Diseaes
plasma clearance is decreased
continous infusions or repeated dosing in cirrhotic patients may produce more exaggerated and pronounced of effect
Sufentanil and Liver Disease
pharmacokinetics are not significantly altered
some differences seen in E1/2
so infusions are multiple doses could cause prolonged effect
Alfentanil and Liver Disease
E1/2 Life almost doubled and higher free fractions of the drug are observed, which can lead to a prolonged duration of action and enhanced effects
Remifentanil and Liver Disease
Elimination unaltered
NMB and Liver Disease
increase volume of distribution may require a higher initial dose
Cirrhosis/Advanced liver disease reduces elimination of whatNMB?
vec, roc, pan and mivacurium
increased DOA, especially with repeated doses or infusions
What NMB are not dependent on hepatic elimination?
Atracurium and cisatracurium
What NMB may have a prolonged effect?
Succinylcholine
d/t decreased plasma cholinesterase levels
How is sugammadex excreted?
unchanged in urine
Catecholamines in Liver Disease
decreased because of circulating vasodilators including bile acids and glucagon
Impaired ability to translocate blood from pulmonary and splanchic blood reservoirs to systemic circulation
consider increased doses or addition of non-adrenergic vasoconstrictor (vasopressin) to support BP
What patients are particularly intolerant of blood loss?
biliary obstruction
Intra-operative fluid management of Liver Resection
volume loading can lead to distention of vessels with difficulty controlling blood loss
limiting fluid pre-resection will lead to a CVP less then 5cmH20
portal triad clamping
post resection restore euvolemia
Intraoperative Potential Complications of Liver Resection
hemorrhage coagulopathy hypocalcemia hypoglycemia VAE pulmonary disturbances
Post-operative Potential Complications of Liver Resection
bleeding
bile leak
portal vein/ hepatic artery thrombosis
liver failure
Characteristics of the Spleen
upper left abdomen, just inside the rib cage (9-11th ribs)
part of the lympatic system
filters foreign substances from the blood and removes blood cells
regulates blood flow to the liver and sometimes stores blood cells (sequestration)
highly vascular organ
Indications for splenectomy
only treatment for hereditary spheroctosis an cancers of spleen trauma abscesses idiopathic thrombocytopenia purpura hodgkin's staging
Complication of Splenectomy
splenic artery rupture (pregnancy)
pre-operative anesthetic implications for Splenectomy
underlying disease process and implications chemotherapy ITP CBC platelets PT PTT type and cross
intraoperative anesthetic implications for Splenectomy
asepsis
large bore venous access
warming measures
epidural for post op pain
Complications of a splenectomy
Atelectasis pneumothorax infection hemorrhage VAE
