Laproscopic

Question 1

What are the common laparoscopic surgeries?

Answer 1

• GI
  
  • gastric
  • colonic
  • splenic
  • hepatic
  • gallbladder
• gynecologic
  
  • hysterectomy
• Urologic
  
  • nephrectomy

Question 2

How does laparoscopic surgery compare with general surgery?

Answer 2

• lower pain scores and opioid requirements
• earlier ambulation and return to normal activities
• lower incidence of post-operative ileius
• usually faster recovery, shorter hospital stay (SDS)
• reduced post-op pulmonary/diaphragmatic dysfunction
  
  • not for everyone, can still have severe post op pulmonary dysfunction leading to hypoxia
• less stress response and wound complications
• usually lower cost

Question 3

What are the relative contraindications of laparoscopic surgery?

Answer 3

• Increased ICP
• hypovolemia
• V/P shunt or peritoneojugular shunt
  
  • ok if they have unidirectional valve resistant to IAP (intra-abdominal pressure)
• Severe CV disease
• severe respiratory disease

Question 4

How is the laparoscopic technique done?

Answer 4

• small incisions made and intraperitoneal space is insufflated with CO2
• Trochars may be inserted blindly or by using a mini laparotomy (this is safer)
• After placement is verified , abdomen is insufflated until intraabdominal pressure reaches goal (usually 15 mmHg or less)

Question 5

How can the pneumoperitoneum be insufflated?

Answer 5

• CO2
  
  • stimulates cardiovascular system
• Inert gasses (helium and argon)
  
  • prevent the increase in absorbed CO2
  • accentuates decrease in cardiac output
• Gasless laparoscopy
  
  • more difficult for surgeon
  • relies on wall lift obtained by a fan retractor
  • may be safer for cancer patients in reducing metasis
  • less hemodynamically challenging for really fragile patients
  • increases surgical time and cost

Question 6

Why is CO2 the gas of choice?

Answer 6

• more soluble in blood than air, helium, oxygen, or nitrous oxide
• capacity for carriage in the blood
• rapid elimination
  
  • better outcomes compared with He embolus)
• nonflammable/noncombustible can be used with diathermy

Question 7

What changes can CO2 in the peritoneum cause?

Answer 7

• PaCO2 progressively rises to reach a plateau 15-30 minutes after insufflation
  
  • If it continues to rise, search for a pathologic cause (embolism, emphysema, MH)
• respiratory and cardiovascular changes

Question 8

What should you consider regarding the anesthesia for a laparoscopic procedure?

Answer 8

• It can potentially be a high-risk procedure
• pneumoperitoneum + positions required = pathophysiological changes
• often long duration
• risk of unsuspected visceral injury
• difficulty in evaluating the amount of blood loss
• at risk for aspiration of gastric contents

Question 9

Why does the PaCO2 increase during laparoscopic surgery?

(9)

Answer 9

• absorption of CO2 from the peritoneal cavity (primary reason)
• abdominal distension
  
  • VQ mismatch
  • decreased FRC
  • decreased pulmonary compliance
• Patient position
  
  • VQ mismatch
• Depression of ventilation by anesthetic agents if spontaneous breathing
• CO2 emphysema- SQ or body cavities
• Capnothorax (pneumothroax with CO2)
• CO2 embolism
• Selective bronchial intubation

Question 10

What affects the absorption of CO2?

(4)

Answer 10

• Diffusibility of gas
• absorption area
• vascularity of insufflation site
• greater in pelvic surgery than in intraperitoneal surgery

Question 11

How much does insufflation decrease pulmonary compliance?

How much should you increase alveolar ventilation?

Answer 11

• pulmonary compliance decreases 30-50%
• increase alveolar ventilation 10-25%

Question 12

What are the hemodynamic changes seen in laproscopic surgeries?

(9)

Answer 12

• Decreased CO 10-30% (depends on insufflation and position)
• decreased venous return
• decreased LVEDV
• Increased intrathoracic pressure
• increased right atrial and PA occlusion pressures
• minimal increase HR
• Increased aBP, PVR, SVR
  
  • catecholamines
  • renin-angio
  • vasopressin
  • arterial compression by high IAP
• may increase myocardial wall tension and O2 demand
• increased risk for arrhythmias
  
  • d/t peritoneal stretching, intolerance of hemodynamic changes, and increased CO2

Question 13

Explain the flow chart of what occurs with increased intra-abdominal pressure

Answer 13

Question 14

What are things a CRNA can do to attenuate the changes caused by increased abdominal pressure?

Answer 14

• fluid load before insufflation
• us alpha-2 agonists like clonidine, dexmedetomidine, and beta blockers
• Remifentanyl can help reduce hemodynamic response
• In pts at risk for CHF:
  
  • remember that normalization of HD parameter does not occur for at least one hour post-op so CHF can develop in PACU

Question 15

Describe hemodynamic alterations in:

Splanchnic

kidney

head

Answer 15

• Splanchnic
  
  • usually unchanged- mechanical compression + neuroendocrine vasoconstriction balance by hypercarbic dilation
• Kidney- decreased GFR, renal plasma flow, UOP
• Head-
  
  • increased cerebral blood flow and ICP in steep t-burg
  • increased IOP in steep t-burg

Question 16

What should you consider during induction for a laparoscopic surgery?

Answer 16

• GA w/cuffed ETT and controlled ventilation
  
  • increased MV (20-30%) and PIP often required
  • adjust RR, Vt (6-8 ml/kg), PEEP (5-10) and PIP
  • Goals: ETCO2 = 35 mmHG, PIP low 30’s
  • aspiration risk
• RA has been used- risky
  
  • need high block (T4-5) which causes SNS denervation, making it more difficult to compensate
  • shoulder and distension pain incompletely alleviated
• Intra-abdominal pressure limit of <15 mmHg is best to avoid CV compromise
• ASA III-IV and/or abnormal gradient PaCO2:ETCO2 require invasive monitors
  
  • blood gas and BP

Question 17

Can you use an LMA for laparoscopic surgeries?

Answer 17

• ETT
  
  • secures airway (aspiration protection)
  • allows for control of ventilation
• ProSeal LMA (controversial)
  
  • spontaneous ventilation
  • lower incidence of sore throat
  • lower pain scores, less analgesic medications required, less PONV
  • 1/3 of deaths during lap surery occurred during GA without ETT
  • unable to:
    
    • secure the airway
    • control ventilation
    • administer muscle relaxation

Question 18

What should you consider regarding positioning for laparoscopic surgery?

Answer 18

• prevent nerve injury
  
  • lithotomy: common peroneal
  • shoulder braces: brachial plexus
• Tilt should not exceed 15-20 degrees
• make changes slowly
• recheck the ETT position after every change
• consider less aggressive fluid replacement in head down position d/t edema

Question 19

What should you consider regarding GA maintenance for a laparoscopic surgery?

Answer 19

• Standard maintenance
  
  • balanced techniqe appropriate or TIVA
  • Consider TIVA if pt has history of PONV
• Continue muscle relaxation
  
  • new evidence suggests this might not be necessary
• Continue careful monitoring of pulmonary and hemodynamic status
• Watch for endobronchial intubation during position changes

Question 20

What do you do if the laparoscopic procedure is converted on an open procedure?

Answer 20

• Supine position
• new fluid plan- 3rd space losses will increase
• new pain management plan- opioid requirements will change
• New ventilator settings- may need to reduce rate and increase Vt

Question 21

What kind of intraoperative surgical complications should you monitor for?

Answer 21

• Vascular injury- trocar insertion/veress needle
  
  • aorta, ICV, iliac vessels, cystic hepatic arteries, retroperitoneal hematoma
• GI- trocar insertion/veress needle
  
  • bowel, liver, spleen, mesenteric
• Cardiac
  
  • dysrhythmias- hypercarbia, vagal, BP changes
• SQ emphysema- extra-peritoneal insufflation
  
  • accidental or inguinal hernia repair
• Capnothorax, capnomediastinum, capnopericardium
  
  • diaphragm defect, pleural tear, bullae rupture
• CO2 embolism
  
  • direct needle placement in vessel
  • gas insufflation into abdominal organ

Question 22

What makes a procedure higher risk for SQ emphysema or capnothorax?

Answer 22

• procedure > 200 minutes
• more than 6 ports used

Question 23

What is the pathophysiology of Gas Embolism?

Answer 23

• Depends on size of bubbles and rate of entrainment
• Can cause vapor lock in vena cava and RA
• Obstruction to venous return
• Acute RV hypertension = paradoxical embolism (to cerebral and coronary vasculature)
• Circulatory collapse

Question 24

How is Gas embolism diagnosed?

Ideally?

Real world?

Answer 24

• In the ideal world:
  
  • Trans-esophageal echo (TEE)
  • Swan-Ganz catheter
  • precordial dopplers
• In the real world:
  
  • Pulse oximetry (hypoxemia)
  • Esophageal stethescope- millwheel sound
  • ETCO2 decrease
  • Aspiration of gas from CVP
  • hypotension

Question 25

How is Gas embolism treated?

Answer 25

• Stop insufflation and desufflate
• Position
  
  • steep trendelenberg
  • left lateral decub- to displace from RV outflow tract
• d/c N2O and give 100% FiO2
• hyperventilate
• place CVP
• CPR
• consider CPB

Question 26

What should you consider for GA emergence and post-operatively for laparoscopic cases?

Answer 26

• Procedures are associated with intra-abdominal, incisional, and shoulder pain
  
  • irritation of diaphragm and/or visceral pain from biliary spasm
• treat with:
  
  • opioids
  • NSAIDS
  • acetaminophen
  • LA (Tap block)
• PONV

Question 27

What affects PONV of laparoscopic surgeries?

Answer 27

• experienced by 40-75% of patients after laparoscopic procedures
• meds that can help:
  
  • propofol
  • versed
  • decadron
  • zofran
• minimize opioids
• gastric decompression