Laproscopic & Robotics Flashcards
What is an artificial pneumoperitoneum?
The installation of air or gas into the perennial cavity under controlled pressure
although rare, more than 50% of all complications during laparoscopic surgery occurr during?
During initial surgical entry into the abdominal cavity and establishment of the pneumoperitoneum - Trocar Insertion
what is the leading cause of morbidity and mortality during laparoscopic procedures?
Severe vascular injury at the time of abdominal entry
evidence indicates that patients who are extremely _______ or______, or_________ at increased risk for laparoscopic entry related injuries at the umbilical entry point
Extremely thin, obese, or known to have abdominal adhesions
what are some advantages of laparoscopic surgery over open procedures
-less tissue trauma(small incisions)
-better postoperative pain control (less opioids)
-superior postoperative pulmonary function compared to GA
-earlier postoperative mobility
-shorter hospital stay
Describe the “closed technique”
Use of a spring loaded needle (Veress needle) to pierce the abdominal wall. Trocar is blindly inserted AFTER insufflation.
Describe the “open technique”
“Hasson” technique, minimize the risk of major vascular injury when creating pneumoperitoneum. A small incision up to 3 cm is made immediately inferior to the umbilicus through skin and fascia..
Insertion of trocar, then insufflation.
(studies are mixed if open is actually superior)
How does the Hasson Trocar minimize risk of injury?
Two fascial suture stabilize the abdominal wall and the true car is inserted under direct vision
Why do we use carbon dioxide for insufflation?
Readily available, inexpensive, does not support combustion, rapidly absorbed from the vascular space, easily excreted by respiratory system
What are some disadvantages to the use of carbon dioxide in laparoscopic surgery?
Hypercapnia-respiratory acidosis
Peritoneal and diaphragmatic irritation manifesting as postop shoulder pain
What two hemodynamic variables increase, regardless of whether the pneumoperitoneum is created under low pressure (12mmHg) or high pressure(20mmHg)?
MAP and SVR
What is the maximum pressure that can be used to maintain the inflation of the pneumoperitoneum for hours of a case?
15 mmHg
How many trocar sites are usually used?
4-6
can be (1-6)
At around 20-40mmHg, heart rate usually stops trending upwards. what causes the heart rate to trend down with pneumoperitoneum? How do you treat if necessary?
In some patients, the perennial stretch that coincides with the induction of pneumoperitoneum may stimulate a vaguely mediated bradycardia response can be relieved by releasing pressure maintained below 16 treat with anticholinergics if needed.
True or false: positioning appears to have a greater effect on central pressures than the pneumoperitoneum itself
True
Steep Trendelenburg or reverse Trendelenburg influence, Venous return and cardiac output
How does the pneumoperitoneum affect the cardiac conduction system even in healthy patients?
Prolonged QT dispersion in patients and undergoing laparoscopic procedure with high-pressure insufflation.
QTd reflects ventricular instability prolongation of this parameter is associated with an increased risk of arrhythmias.
What are some factors that influence patients response to the creation of pneumoperitoneum?
-length of surgery
-patient position
-patient age
-degree of intra-abdominal pressure during creation of pneumoperitoneum
-preoperative volume status
-presence of pre-existing pulmonary and or CV disease
under normal insufflation pressures. (~15mmHg) what CV affects are seen and why?
Increase HR, MAP, SVR
(could see bradycardia d/t vagus nerve)
-Due to the release of Neuro endocrine hormones(vasopressin, Renin, norepinephrine, cortisol, aldosterone)
-Pressure on abdominal aorta and organs
What is the proposed mechanism for increased abdominal pressure raising systemic, vascular resistance, causing hypertension?
And completely understood, but thought to involve compression of the aorta or intra-abdominal resistance arterioles
Distention of the abdominal wall in Viera, especially patients with high vehicle tone in young women predisposes them to vagaly mediated reflexes such as:
Bradycardia and bronchospasm
Increased intra-abdominal pressure displace is the diaphragm in a cephalad direction. What does this do to functional residual capacity and V/Q matching
Reduced FRC and predisposes to V/Q mismatching
Increased intra-abdominal pressure could have what effect on your ET tube?
Displace the carina cephalad, which predisposes to inadvertent mainstem bronchial intubation
Just because laparoscopic procedures are mentally invasive that does not mean they are minimal _____
Risk
What sort of hemodynamic changes should you expect in the elderly patient undergoing a laparoscopic surgery
Exaggerated hemodynamic responses compared to healthy younger patients
Moderate decreases in CO
Increased afterload and CVP, but decrease MAP
what capacities or volumes are reduced due to the effects of pneumoperitoneum
-Decreased forced vital capacity (FVC)
-Dec. forced expiratory volume in one second(FEV1), and
-Dec. functional residual capacity (FRC)
Creating areas of atelectasis in making ventilation difficult
How does Positive Inspiratory Pressure (PIP) change with pneurmoperitoneum?
Increased
Increased PaCO2 and etCO2 from the carbon dioxide insufflation can cause?
acidosis
Characterized as respiratory acidosis.
How does pulmonary compliance change with insufflation?
Decreases
(less change in volume / change in pressure)
What are peak plateau pressures? When are they measured?
Relationship between volume and compliance. Is a reflection of lung compliance. Reflects the pressure. It takes to hold a given volume inside the lungs.
Measured during end inspiration
How would you expect me to return to change with a reverse Trendelenburg position?
Reduces meanness return which may lead to a fall in cardiac output and arterial pressure
Steep Trendelenburg position decreases Venus return from the head, which can result in?
Increase intracranial and intraocular pressures
Venus engorgement of face and neck
What position would you expect to put a patient in for a laparoscopic appendectomy?
Trendelenburg
In Trendelenburg position by about what percent does pulmonary compliance and peak Plateau pressures change?
Pulmonary compliance decreased by ~ 50%
Peak plateau pressures increased by ~50%
How do you expect to position a patient for a laparoscopic Cholecysectomy? How do you expect functional residual capacity in venous return to change?
Reverse Trendelenburg
Increase FRC
Decrease Venous Return
How do you expect etCO2 to change during laparoscopy?
Increase. CO2 used for insufflation of the abdomen, is highly soluble and will dissolve across tissues into the bloodstream.
Will etCO2 reflect PaCO2 during laparoscopy?
Unlikely. etCO2 will often still UNDERestimate the arterial CO2 by as much as 10mmHg
Renal effects of pneumoperitoneum?
-transient increase in creatinine clearance
-decreased urine output due to decreased renal blood flow, release of ADH, and PACO2 levels, create a sympathetic response leading to renal vasoconstriction
Hepatic and Splanchnic Effects of pneumoperitoneum
Decrease in splanchnic and liver perfusion
-intestinal ischemia
immunological effects of pneumoperitoneum
Controversial
-influences growth of human cancer cells
-pressure dependent
Controversial
What three major organs could be damaged during umbilical entry for laparoscopic procedures?
Bladder, bowel, uterus
Name the top three complication/injuries that can occur when performing laparoscopic procedure procedures
- 50% of vascular injury upon entry into abdomen with trocar
- Visceral injuries, particularly intestinal.
- Urinary tract injury.
the migration of gas to create the pneumoperitoneum can result in what complications?
-Pneumothorax
-Pneumomediastinum
-Pneumopericardium
-Subcutaneous emphysema
-Gas embolism
While mortality and the incident is rare, how often does gas embolism occur during laparoscopic procedures?
Studies using TEE show that actual incident of gas embolism maybe between 65 to 100%
-however, most are very small and don’t create a problem
What are some signs of gas embolism?
Hypotension
Hypoxemia
Dysrhythmias
“mill-wheel” murmur
Wheezing
Decreased SPO2
Pulmonary edema
Abrupt decrease in ETCO2
Treatment of gas embolism:
-100% 02
-Release pneumoperitoneum
-Stop nitrous oxide if using
-Flood filled with NS
-Left lateral decubitus position (Durant Maneuver)
-Aspirate CVP line
-Supportive measure measures
Subcutaneous emphysema has an increased incident when?
The insufflator has high gas, flow and high gas pressure settings
-abdominal pressure greater than 15 mmHg
-multiple attempts at abdominal entry
-Veress needle, or cannula not placed in peritoneal cavity
-skin or seal around cannula is not snug
-use of more than five cannulas
-procedures lasting longer than 3.5 hours
-etCO2>50mmHg
Signs of subcutaneous emphysema
-late hypercarbia
-decreased lung compliance
-increase CO2 absorption, increased ET CO2 above 50
-cardiac arrhythmias, tachycardia, hypertension
-crepitus around abdomen chest, neck or groin
Management of sub Q emphysema
-Evaluate for pneumothorax
-check, etCO2 CO2 and arterial CO2
-increase, ventilation rate entitled volume (Ve)
-increase oxygen to 100%
-check CO2 absorber in circuit
-decrease inter-abdominal pressure
-d/c N2O if in use
-assess airway to ensure there is no compression before extubating
Shoulder pain is due to insufflation, pushing up on the diaphragm, causing which nerve to be irritated? When does it usually resolve?
phrenic nerve
Normally resolve spontaneously in one to two days
What type of anesthesia is usually used for laparoscopic cases?
General anesthesia most common with ETT
What ventilator setting is usually preferred during laparoscopic cases?
Pressure controlled ventilation
Able to use recruitment maneuvers and add peep
Describe the recruitment maneuver an anesthesia provider could use via the ventilator during a laparoscopic case?
Apply pressures of 35-40cmH2O x40s to inflate alveoli. Apply PEEP after this maneuver
Can you use an LMA for Laparoscopy?
Controversial.
Depends on type of surgery, body habits, and aspiration factors.
Most advantageous LMA: ProSeal LMA
PONV is as high as ___% in laparoscopic surgery
72%
PONV post laparoscopic surgery is associated with?
-Surgical wound dehiscence
-Aspiration
-Unanticipated hospital admission
For higher risk PONV patients what might be your anesthetic management plan for a laparoscopic case?
TIVA combined with anti-emetics
What drugs can cause the Sphincter of Oddi to spasm?
Morphine
(meperidine as well)
What are some anesthetic considerations when working a robotic surgery case?
-prolonged surgical times
-spatial restrictions
-inability to alter patient position after “docking”
-physiological changes d/t extreme positioning
-risk of postop visual loss
-physiological changes related to pneumoperitoneum
-implementation of ERAS protocol
In steep Trendelenburg (40-45 degree head down tilt), what are some CV changes you expect?
Increased MAP, CVP, SVR, PAOP
In steep Trendelenburg (40-45 degree head down tilt), what are some respiratory changes you expect?
Increased: airway resistance, peak pressure, plateau, pressure, ETC O2, upper airway edema
Decreased: Lung compliance, vital capacity, FEV1
In steep Trendelenburg (40-45 degree head down tilt), what are some cerebrovascular changes you expect?
Increase: ICP, hydrostatic pressure gradient, cerebral vascular resistance
Decrease: Cerebral venous drainage
Effects of increased systemic CO2
Respiratory Acidosis
Arrhythmias
Cerebral Vascular Dilation: inc. ICP
How might the oxy – hemoglobin dissociation curve change during laparoscopic procedures?
Shift to the Right via the Haldane Effect.
Helps deliver oxygen to the tissues and results and slightly less ischemia than would be expected.
What are some anesthetic management considerations for a patient in steep Trendelenburg?
-keep patient paralyzed
-OG/NG to decompress stomach
-limit fluids (facial edema)
-pulse oximeter placement
-prolonged pressure on back of scalp
