Anesthesia for Laparoscopic Surgery

1. Anesthesia for Laparoscopic Surgery Garrett Peterson DNP, RN, CRNA Association of Veterans Affairs Nurse Anesthetists Annual Education Meeting May 2012

2. Objectives • Discuss the technique used to create a pneumoperitoneum • Describe the complications of laparoscopic surgery • Recognize the physiologic effects of pneumoperitoneum • Select the appropriate anesthetic management techniques used for laparoscopic surgery • Identify the postoperative considerations for laparoscopic surgery

3. Introduction • Laparoscopy • Greek words • Laparo- meaning flank • Skopein – meaning to examine • Definition: process of examining the contents of the abdominal cavity using a specially designed endoscope • Use of laparoscopy has been expanded by different surgical specialities over the decades

4. Common surgical applications of laparoscopy • General Surgery • Diagnosis • Evaluation of abdominal trauma • Lysis of adhesions • Cholecystectomy • Appendectomy • Inguinal hernia repair • Bowel resection • Esophageal reflux surgery • Splenectomy • Adrenalectomy • Gynecologic Surgery • Diagnosis • Lysis of adhesions • Fallopian-tube surgery • Fulgration of endometrrosis • Ovarian cyst surgery • Laparoscopic-assisted hysterectomy • Urologic Surgery • Nephrectomy

5. Advantages of laparoscopic surgery • Incisions are small • Earlier postoperative mobility • Shorter hospital stays

6. Creation of a Pneumoperitoneum • Pneumoperitoneum • Air within the peritoneal cavity • Essential to perform the surgery • Clears the view of the operative site allowing room to move instruments • Causes physical stress to the body and has residual effects that can increase morbidity • Highest risk to patient is during creation of the pneumoperitoneum

7. Creation of a Pneumoperitoneum • Creation of pneumoperitoneum • Two techniques • “open or closed” • Closed technique (older of the two) • Spring loaded needle (Veress needle) used to pierce the abdominal wall at the thinnest point the infraumbilical region • Position confirmed by injection of 10 ml of saline • If unable to aspirate saline, placement is correct • Carbon dioxide (CO2) is placed through the needle to create a space between abdominal wall and organs

8. Creation of a Pneumoperitoneum • The “open” or Hasson technique • Small incision (1.5-3 cm) inferior to the umbilicus • Peritoneum is directly incised • Trocar (Hasson cannula) is placed • Abdomen is insufflated and the catheter is sutured in place

9. Creation of a Pneumoperitoneum • Research • Visceral injuries less frequent with open technique (not statistically significant) • Major vascular injuries were less when Hasson technique was used compared to the Veress needle

10. Complications of Laparoscopic Surgery • Potential for injury • Structures close to puncture site • IVC, aorta, iliac arteries and veins, bladder, bowel, and uterus • Obesity, thin habitus, adhesions, masses (tumors) • Additional injuries • Trauma to major vascular structures • 0.02-0.9% of cases • Gas embolism • Injury to abdominal or pelvic organs • Migration of gas to extraperitoneal spaces

11. Complications of Laparoscopic Surgery • Gas embolism • Rare risk of cardiac arrest • Reported incidence 1 in 77,604 cases • Likely to occur during insufflation • Wrong placement of needle into vessel or organ • Gas bubbles enter circulation • Pulmonary hypertension • Right ventricular failure • Pulmonary edema • Large bubble can cause a “gas lock” phenomenon which can obstruct right ventricular outflow

12. Complications of Laparoscopic Surgery • Gas embolism • Signs/symptoms • Hypotension • Dysrhythmia • “mill wheel” murmur (churning sound) • Cyanosis • Pulmonary edema

13. Complications of Laparoscopic Surgery • Gas embolism • Management • Stop gas insufflation • Shut off nitrous if being used • 100% O2 administration • Release pneumoperitoneum • Place patient in left lateral decubitus position • Aspirate gas through a central venous catheter

14. Complications of Laparoscopic Surgery • Visceral Injuries • Occurring when closed technique is used • 0.1 – 0.4% • Trocar insertion • Gastrointestinal tract perforation • Hepatic and spleen tears • Reduction of risk of trauma • Decompression with NG for stomach • Emptying of bladder with foley catheter

15. Complications of Laparoscopic Surgery • Visceral lesions • Not recognized right away • Most in postoperative period when symptoms arise • Sepsis • Fistulas • Peritonitis • Abscesses

16. Complications of Laparoscopic Surgery • Pneumothorax (serious but rare) • A review of 968 cases revealed the incidence of pneumothorax or pneumomediastinum in 1.9% of patients • Higher risk for those undergoing surgery for esophageal reflux disease • Occurs by two mechanisms • Gas entering weak points in esophagus or aorta • Barotrauma secondary to increased airway pressures and decreased pulmonary compliance • Ruptured bleb

17. Complications of Laparoscopic Surgery • Subcutaneous emphysema (minor complication) • Trocar or Veress needle misplacement in subcutaneous tissue • Manifested by crepitus

18. Complications of Laparoscopic Surgery • Gas used • Most common is CO2 • Readily available and inexpensive • Does not support combustion • Rapidly absorbed from the vascular space • Easily excreted • Can cause hypercarbia • Peritoneal and diaphragmatic irritation • Leading to shoulder pain

19. Physiologic Effects of Pneumoperitoneum • Degree of intraabdominalpressure (impede diaphragmatic expansion) • Presence of preexisting cardiac disease (increased catecholamine release) • Intravascular volume depletion (decrease cardiac output) • Duration of the surgery (hypercarbia)

20. Physiologic Effects of Pneumoperitoneum • Three mechanisms of how pneumoperitoneum affects the body • Direct mechanical effect • Presence of neurohumoral responses • Effects of absorbed CO2 • Pneumoperitoneum-induced physiological changes • Ventilatory techniques • Intraoperative positioning • Surgical conditions (presence of retractors and packing in)

21. Physiologic Effects of Pneumoperitoneum • Hemodynamic Changes Associated with Pneumoperitoneum

22. Physiologic Effects of Pneumoperitoneum • SVR increased • Documented in laparoscopy patients • At intraabdominal pressures of 14 mmHg • Increases in SVR as high as 65% • Mechanism • Increased compression of abdominal arteries and humoral factor release (vasopressin, renin) have caused increased afterload

23. Physiologic Effects of Pneumoperitoneum • CVP filling pressures • Mixed opinions • Patients with increased intrabdominal pressures in range of 14 to 20 mmHg had increased CVP • Patients with increased intraabdominal pressures > 20 mmHg had a decrease in CVP • Mechanisms • Vasodilation actions of anesthetics • Intraoperative positioning

24. Physiologic Effects of Pneumoperitoneum • Stroke Volume • Reduction • Decreases seen when intraabdominal pressure was in range of 14 to 15 mmHg • Interventions to attenuate the decrease in SV • Trendelenburg position • Adequate hydration • Compression of the lower extremities

25. Physiologic Effects of Pneumoperitoneum • Cardiac Output/Cardiac Index • Typically decreased • Up to 50% reduction in CO has been seen • Noticed with intraabdominal pressures of 8 to 12 mmHg, with significant reduction at 16 mmHg • 5 to 10 minutes after initial decrease, it will partially reverse and increase back to baseline • Increase in heart rate occurs in laparoscopy patients • Interventions • Wrapping of legs • Optimize intravascular volume

26. Physiologic Effects of Pneumoperitoneum • Arterial Blood Pressure • Increased • At intraabdominal pressures as low as 14 mmHg • Up to 35% increase in MAP • Mechanism • Increased afterload caused from pneumoperitoneum

27. Physiologic Effects of Pneumoperitoneum • Humoral factors • Increased afterload in patients with CO2 pneumoperitoneum • Increased dopamine, vasopressin, epinephrine, norepinephrine, renin, and cortisol • Vasopressin is the most significant mediator • Catecholamine level increase secondary to stress response

28. Physiologic Effects of Pneumoperitoneum • Cardiovascular effect of pneumoperitoneum • Distention of the vagus nerve during insufflation • Bradycardia is sometimes observed • Increased intraabdominal pressure can reduce lower extremity blood flow velocity

29. Physiologic Effects of Pneumoperitoneum • Patients who are ASA Class III or IV are significantly more prone to the effects of pneumoperitoneum especially if they suffer from altered hemodynamics

30. Physiologic Effects of Pneumoperitoneum • CO2 pneumoperitoneum • Increases in partial pressure of arterial CO2 (PaCO2) and end-tidal CO2 with or without acidosis • Caused by absorption of gas on peritoneal surface • No increase in O2 consumption during insufflation • Maximum absorption rate of CO2 is noted with intraabdominal pressure of 10 mmHg • PaCO2 levels reach a plateau approximately after 40 minutes of induction of the peritoneum

31. Physiologic Effects of Pneumoperitoneum • Mild hypercapnia (45 to 50 mmHg) not clinically significant • Hypercapnia (50 to 70 mmHg) can cause increased physiologic effects • Increased CBF • Peripheral vasodilation • Pulmonary vasoconstriction • Increase risk of cardiac dysrhythmias

32. Physiologic Effects of Pneumoperitoneum • Pulmonary Function Changes Associated with Pneumoperitoneum

33. Physiologic Effects of Pneumoperitoneum • Controlled ventilation • Increase of 20 to 30 % in minute ventilation will help to decrease the hypercapnia that occurs during pneumoperitoneum • Careful with respiratory compromised patients • May have CO2 retention leading to decreases in arterial pH • With very high ETCO2, a direct measurement of PaCO2 may be warranted because ETCO2 may underestimate PaCO2

34. Physiologic Effects of Pneumoperitoneum • Endobronchialintubation • Cephalad displacement of the diaphragm from the increased intraabdominal pressure • One study 50 patients withIAP 15 mmHg • Patients in reverse Trendelenburg position • 6% had right mainstem intubation

35. Physiologic Effects of Pneumoperitoneum • Kidneys • Oliguria • Compression of kidneys • Compression of inferior vena cava • Increase in levels of antidiuretic hormone • Significant reduction in renal blood flow • Intraabdominal pressure around 24 mmHg • Humoral factors • Vasopressin, renin, aldosterone

36. Physiologic Effects of Pneumoperitoneum • Hepatic/Spleen • One study, Intraabdominal pressure around 16 mmHg and elevated head of bed caused a 68% decrease in hepatic blood flow • Another study, IAP of 12 mmHg increased hepatic perfusion • Splanchnic blood flow not disrupted with IAP of 11 to 13 mmHg

37. Anesthetic Management • General, regional and local have been used • Local • Minor GYN procedures • Diagnostic laparoscopy or sterilization • Only one hole is created and scope is very small • Shorter hospital stay and reduction in anesthetic costs • 5.5% converted to general • Surgical exposure was limited

38. Anesthetic Management • General, regional and local have been used • Regional • Limited to minor GYN surgical procedures • Shoulder and chest discomfort result from pneumoperitoneum is not well managed with the regional technique

39. Anesthetic Management • General, regional and local have been used • General • Most practical • Manages patient discomfort • Controlled ventilation • Use of muscle relaxation

40. Anesthetic Management • Use of LMA • Controversial • Increased intraabdominal and intrathoracic pressures • Increase risk of gastroesophageal reflux and pulmonary aspiration • Study with 1469 GYN laps concluded that use of an LMA “appears safe” • Study using fiberoptic examination of the laryngopharynx of 91 pts with an LMA failed to show any regurgitation

41. Anesthetic Management • Guidelines for Use of the Laryngeal Mask Airway During Laparoscopy • Ensure clinician is an experienced LMA user • Select patients carefully (e.g., fasted, not obese) • Use correct size of LMA • Make surgeon aware of the use of the LMA • Use total IV anesthetic technique or volatile agent • Adhere to “15” rule: <15 degrees tilt; < 15 cm H2O intraabdominal pressure; <15 min duration • Avoid inadequate anesthesia during surgery • Avoid disturbance of the patient during emergence • Maltby JR et al. LMA-Classic and LMA-ProSeal are effective alternatives to endotracheal intubation for gynecological laparoscopy. Can J Anaesth. 2003; 50:71-77.

42. Postoperative Considerations • N&V • Common after laparoscopy surgery • Some research shows 50-62% incidence • Pain • Usually visceral quality on day of surgery • Abdominal distension • Traction on the nerves and trauma to blood vessels • Shoulder pain on first day post-op • CO2 induced intraperitoneal acidosis irritates the phrenic nerve, leading to the shoulder pain

43. Postoperative Considerations • Post-op pain • Managed with multimodal approach • NSAIDS, local anesthetics, and opioids • Research shows the use of NSAIDS in combination with opioids result in a synergism leading to decreased opioid consumption • Research on port-site infiltration showed value but short lived

44. Future of Laparoscopic Surgery • Overcomes some of the limitations imposed by standard laparoscope technology • Robotic surgery • Robotic-assisted surgery • daVinci surgical system • Surgeon can be 100’s of miles away • 3-d imaging • Robot assisted radical prostatectomy requires steep Trendelenburg tile (30 to 45 degrees) which increases laryngeal edema and brachial plexus injury

45. References • Nagelhout, John J. & Plaus, Karen L. Nurse Anesthesia, W.B. Saunders Company, 4th ed., 2010;32:771-779. • Sandhu, T., Yamada, S, et al. (2008). Surgical Endoscopy