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Advanced Principles- Fall 2018 > Laproscopic > Flashcards

Flashcards in Laproscopic Deck (27)
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1

What are the common laparoscopic surgeries?

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

2

How does laparoscopic surgery compare with general surgery?

  • 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

3

What are the relative contraindications of laparoscopic surgery?

  • 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

4

How is the laparoscopic technique done?

  • 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)

5

How can the pneumoperitoneum be insufflated?

  • 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

6

Why is CO2 the gas of choice?

  • 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

7

What changes can CO2 in the peritoneum cause?

  • 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

8

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

  • 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

9

Why does the PaCO2 increase during laparoscopic surgery?

(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

10

What affects the absorption of CO2?

(4)

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

11

How much does insufflation decrease pulmonary compliance?

How much should you increase alveolar  ventilation?

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

12

What are the hemodynamic changes seen in laproscopic surgeries?

(9)

  • 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

13

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

14

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

  • 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

15

Describe hemodynamic alterations in:

Splanchnic

kidney

head

  • 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

16

What should you consider during induction for a laparoscopic surgery?

  • 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

17

Can you use an LMA for laparoscopic surgeries?

  • 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

18

What should you consider regarding positioning for laparoscopic surgery?

  • 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

19

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

  • 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

20

What do you do if the laparoscopic procedure is converted on 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 reduce rate and increase Vt

21

What kind of intraoperative surgical complications should you monitor for?

  • 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

22

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

  • procedure > 200 minutes
  • more than 6 ports used

23

What is the pathophysiology of Gas Embolism?

  • 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

24

How is Gas embolism diagnosed?

Ideally?

Real world?

 

  • 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

25

How is Gas embolism treated?

  • 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

26

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

  • 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

27

What affects PONV of laparoscopic surgeries?

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