Physiology
Why is CO2 preferred for insufflation instead of inert gasses (ex. helium)?
Poor absorption of inert gasses can lead to air emboli
What is the name and anatomical location of the most common placement of a Veress needle?
Palmer's point. 2 cm beneath the costal margin in the left midclavicular line.
What is the most commonly injured (by positioning) upper extremity nerve?
The ulnar never
Other commonly injured nerves are the peroneal and lateral femoral cutaneous
Name an initial easy maneuver to reduce hemorrhage after an intraoperative vascular injury during laparoscopic/robotic surgery.
Rais insufflation to 20-25 mm Hg
What acid-base abnormality can occur due to induction of pneumoperitoneum?
Metabolic Acidosis:
The risk is higher in patients with COPD or restrictive lung disease. It can be alleviated by decreasing insufflation pressure or desufflating temporarily and allowing anesthesia to clear the CO2 via the lungs
What is the maximum insufflation to avoid decreased visceral perfusion?
15 mm Hg
How should Veress needle injuries of the gallbladder be managed?
Cholecystectomy
After cauterizing a vessel, you notice a small blanched area in the adjacent small bowel. What should you do?
Thermal injury can cause delayed bowel perforation. It is recommended to repair with Lembert stitches.
What happens to cardiac output in Trendelenburg position?
Increases due to increased ICP, decreased SVR. HR is decreased.
Which type of trocar is more likely to require fascial closure. Blunt or sharp?
Sharp. Blunt trocars leave peritoneal defects half the size of the trocar itself and therefore can be left without repair even up to 12 mm.
Cutting trocars also have a demonstrated increased risk of abdominal wall vessel injuries.
Blunt trocars are associated with a decreased incidence of hernia compared with bladed trocars (0.19% vs. 1.83%).
Prevention of hernia involves fascial closure for all bladed trocars >10mm in adults and >5 mm in pediatric surgery. 8 mm robotic trocars rarely require closure although this may be required if significant dilation occurred due to excessive repositioning of the robotic arm.
Name three risk factors for rhabdomyolysis
Obesity, large muscle mass, >5hrs surgery, blood pressure extremes, extreme positioning, diabetes, poor renal function
In addition to hemostatic agents, what is recommended for achieving hemostasis after a liver or spleen injury? (not electrocautery)
Argon beam coagulation - a non-contact cautery method that uses heated argon plasma
Three mechanisms by which GFR is decreased during laparoscopy:
Parenchymal compression
Venous insufficiency
Increased RAAS
Decreased cardiac output
Increased ADH
What should you do if you insert a Veress needle and aspirate blood?
1. if minor, you can withdraw and re-attempt placement
2. if major, pulsatile bleeding, close stopcock and leave it in place so you can trace it to the bleeding. You should consider converting to open
Immediately after insufflation there is sudden circulatory collapse, tachycardia and arrhythmia, hypotension, an acute decrease in end-tidal CO2, cyanosis of the head and upper extremities, elevated right heart pressures and central venous pressure, and "millwheel" murmur.
What is happening?
Air embolus, most likely due to direct vessel insufflation.
Treatment: The surgeon must have a high index of suspicion for gas embolism given such a rare complication, and prompt recognition and communication with anesthesia colleagues is critical. Treatment involves: immediate release of pneumoperitoneum and cessation of insufflation, administration of 100% oxygen, placement of the patient in the left lateral decubitus position with the head down (Durant's position), and aspiration of the CO2 bubble with a central venous catheter extending into the right heart.
Two days after a left adrenalectomy a patient has severe abdominal and back pain, rising white count, and is not tolerating a diet. What labs can help with the diagnosis?
Pancreatic tail injury
Serum amylase/lypase - can also have a retroperitoneal collection.
Avoid retracting the pancreas and if you need to use a broad smooth instrument. NPO, bowel rest, possible drainage if a large collection/pseudocyst occurs.
What is the effect of pneumoperitoneum on the following parameters?
Cardiac preload
Cardiac afterload
Systemic vascular resistance
Heart rate
Preload - decreased due to decreased venous return
Afterload - due to decreased systemic vascular resistance
Systemic vascular resistance - decreased due to hypercarbia and increased sympathetic system activation of the RAAS pathway and catecholamine release
Tachycardia - arrhythmias may be precipitated in which case insufflation should be released
Robotic surgery centers should have an "emergency undocking protocol" that triggers certain immediate actions. What are these?
Name 3 actions you would take after recognizing a small rectal injury without gross spillage.
1. Primary repair
2. Omental overlay
3. Place a drain
Large injuries with spillage can require a stool diversion in order to heal.
What are the motor and sensory deficits caused by peroneal nerve injury?