Anesthesia in Laparoscpic SurgeryDarma Wirawan Soeredi, M.D.Department of AnesthesiaManila Adventist Medical centerObjectivesTo discuss, briefly, the basic principles of laparoscopic surgeries.

To discuss the physiological consequences of laparoscopic surgeries.

To discuss the complications (management) of laparoscopic surgeries.

To discuss the anesthetic management of laparoscopic surgery.IntroductionLaparoscopy (or peritoneoscopy) is a minimally invasive procedure allowing endoscopic access to the peritoneal cavity after insufflation of a gas (CO2) to create space between the anterior abdominal wall and the visceraThe space is necessary for the safe manipulation of instruments and organsLaparoscopic surgery can also be extraperitoneal. It can also be gasless with abdominal wall retractionCommon Laparoscopic SurgeryCholecystectomyVagotomyAppendectomyColectomyInguinal hernia repairAdrenalectomyNephrectomyProstatectomyPancreatectomyBariatric surgeryNissen fundoplicationPara-esophageal hernia repairSplenectomyLiver resectionCystectomy with ileal conduitCommon Laparoscopic Surgery (Cont.)Ectopic pregnancyOvarian cystectomyReversal of ovarian torsionSalpingo-oophorectomyHysterectomyMyomectomySacrocolpopexyLymphadenectomyLymphadenectomy, stagingAblation of endometriosis

Advantagesthe cosmetic results (small, nonmuscle-splitting incisions)decreased blood lossless postoperative pain and ileus, shorter hospitalization and convalescence, and ultimately lower costPostoperative respiratory muscle function returns to normal more quickly than in open surgeryWound complications such as infection and dehiscence are less frequent, and host defense mechanisms may be greater in laparoscopic than in open surgery.Faster recovery respiratory muscle - especially in laparoscopic cholecystectomy and other upper abdominal procedures6Disadvantagesthe long learning curve for the surgeon (most complications occur during the first 10 laparoscopies)the narrowed two-dimensional visual field on videothe need for general anesthesia, and the often longer durationHigher costChange in haemodinamic and respiratory due to intra abdominal insufflation and hypercarbia

alter ofpatient's physiology The increase in intraabdominal pressure and volume (pneumoperitoneum). Extremes of patient positioning Carbon dioxide and hypercarbiaContraindicationspatients with coagulopathydiaphragmatic herniasevere cardiovascular or pulmonary disease (including bullae)increased intracranial pressure or space-occupying massesimpending renal shutdowna history of extensive surgery or adhesionssickle cell diseasePeritonitisa large intraabdominal mass, tumor of the abdominal wallhypovolemic shockPatients with shunts (e.g., ventriculoperitoneal)sickle crisis may be precipitated by acidosis

are at risk for gas emboli, shunt obstruction, andintracranial hypertension, all of which may occur during laparoscopy and may require intracranial pressure monitoring and ventricular drainage if laparoscopic surgery is necessary.

9Gas of Choice for LaparoscopyCarbon dioxide (CO2)Nitrous oxideOxygenHelium, air and nitrogen ArgonWhy???nonflammable, does not support combustion, readily diffuses across membranes, is rapidly removed in the lungs, and is highly soluble because of rapid buffering in blood. The risk of CO2 embolization is small. As much as 200 mL of CO2 injected directly into a peripheral vein may not be lethal, whereas only 20 mL of air may prove to be so. In addition, CO2 levels in blood and expired air can easily be measured, and its elimination can be augmented by increasing ventilation. As long as oxygen requirements are met, a high concentration of blood CO2 can be tolerated. Also, medical grade CO2 is readily available and inexpensive.

nitrous oxide (does not cause pain intraabdominally but does not suppress combustion), N2O found in the peritoneal cavity can be significant, and theoretically it can form an ignition hazard. (However, Hunter states that it is necessary for methane or hydrogen to occupy at least 5.5% of the gas volume for nitrous oxide to support combustion, a condition that does not naturally occur.)

helium, air and nitrogen (each has no hemodynamic or acid-base sequelae, but can cause gas emboli)Argon (adverse effect on hepatic blood flow, emboli )

10Gas of Choice for Laparoscopy (Cont.)Not inertHas local and systemic effectsCauses direct peritoneal irritation and pain during laparoscopy under local anesthesia Can remain in gaseous form intraperitoneally after laparoscopyHypercarbia and respiratory acidosis occur when the buffering capacity of blood is temporarily exceededDisadvantages of CO2CO2 transiently forms carbonic acid when in contact with the moist peritoneum.

causing referred shoulder pain.

CO2 exerts widespread local and (often contradictory) systemic effects that may manifest overall as hypertension, tachycardia, cerebral vasodilation, hypercarbia, and respiratory acidosis.

11Gas of Choice for Laparoscopy (Cont.)At the cellular level, hypercarbia is a direct depressor of myocardial contractility and rate of contraction, and it is also a direct stimulant of myocardial irritability and arrhythmicity. These effects may be enhanced by the reduced pH caused by hypercarbiaLocal effect on isolated or denervated blood vessels is a diminished responsiveness to catecholamines and vasodilation especially on the venous sideHypercarbia causes profound systemic changes secondary to stimulation of the central nervous system and sympathoadrenal systemEffects of CO2 on cardiovascular systemSystemic EffectsLocal EffectsNooooMUWAHAHAHAHAHAThe exception to the dilatory effect of hypercarbia and acidosis on blood vessels exists in the pulmonary vessels, which undergo vasoconstriction. It appears, however, that the effects on the pulmonary vessels are actually due to acidosis rather than hypercarbia because if the pH is kept constant while the PCO2 rises, then pulmonary vascular resistance (PVR) does not change

The net effect usually includes an increase in cardiac output, heart rate, force of myocardial contraction, blood pressure (BP), central venous pressure (CVP), vasoconstriction in the pulmonary (capacitance) vessels, anddecreased peripheral resistance12Physiologic Changesincrease in systemic vascular resistance, mean arterial pressure, and cardiac filling pressures more severe in patients with preexisting cardiac disease significant changes occur at pressures greater than 12 - 15 mmHg increased plasma renin activity (PRA) due to increased intra-abdominal pressure (IAP) and the local compression of renal vessels Hypertension, tachycardia leading to increased myocardial oxygen demand

Cardiovascular Changes associated with IAP13Physiologic Changes (Cont.)Head up PositionBlood pooling -> Venous stasisThrombo-embolism venous return cardiac output Blood Pressure

Head down Position: Increases CVP Increases cardiac outputIncreases cerebral circulation Increased ICP Increased intra-ocular pressure

Cardiovascular Changes associated with Patient Positioning14Physiologic Changes (Cont.)common during insufflation and during desufflationWith the use of HalothaneHypercarbia, hypoxia and gas embolismSudden stretching of peritoneum causes vagal stimulation Cardiac Arrhythmias during Laparoscopy 15Physiologic Changes (Cont.) Exaggerated in obese patients, ASA classII and III patients & in those with respiratory dysfunctionIntra-abdominal distension leads to a decrease in pulmonary dynamic compliance increased IAP displaces the diaphragm upward functional residual capacity and total lung compliance decreases early closure of smaller airways, basal atelectasis increased peak airway pressures increase in minute ventilation required to maintain normocarbiaIncrease in intra pulmonary shunting

Respiratory System Changes associated with IAP16Physiologic Changes (Cont.)Head-down position Endo-bronchial intubationPromotes atelectasis Decreases Functional Residual Capacity (FRC)Decreases Total Lung Capacity (TLC)Decreases pulmonary compliance

Head-Up position: favorable for respiration

Respiratory System Changes associated with Patient Positioning 17Laparoscopic Surgery ComplicationsDue to trochar injuryPositioning and compression effectCardiovascular complicationsRespiratory complicationsThermal injuriesGas embolism18Laparoscopic Surgery Complications (Cont.)The laparoscopic procedure itself. AgeSmoking/chronic obstructive pulmonary disease (COPD).ObesityOverhydrationFactors that increase risk of respiratory complicationsThe laparoscopic procedure itself. The basic laparoscopic Trendelenburg position and the increased intraperitoneal volumes and pressures in a paralyzed, mechanically ventilated patient cause respiratory dysfunction. Insufflation pressures should not exceed 12 to 15mm Hg. Lower pressures are especially advantageous in American Society of Anesthesiologists (ASA) class III and IV patients with diminished cardiopulmonary reserve. In addition, an increased CO2 load might call for respiratory minute volumes that are so large that further cardiopulmonary compromise occurs.

Age. Pulmonary function declines with age, especially in a patient older than age 70.

Smoking/chronic obstructive pulmonary disease (COPD). Smokers have increased tracheobronchial secretions with decreased ciliary transport function. They may already have significant pulmonary dysfunction, which may be manifested by diminished exercise tolerance. The forced vital capacity (FVC) may be diminished in restrictive pulmonary disease, whereas the forced expired volume in 1 second (FEV1) is likely to be decreased in obstructive pulmonary disease.

Obesity. Obesity compounds the problems of increased intraabdominal pressure in the Trendelenburg position. Excessive weight and pressure on the diaphragm and lung bases can lead to marked ventilation and perfusion abnormalities, difficulty in inserting trocars, upward displacement of the carina (leading to possible endobronchial intubation), barotrauma, and so forth.

Overhydration. Patients often experience oliguria during laparoscopy. This may be interpreted as insufficient hydration, and a relative overtransfusion may ensue. Unless frank pulmonary edema occurs, this cause of mild or moderate respiratory distress in the postanesthesia care unit (PACU) may not be recognized without a chest x-ray film.

19Laparoscopic Surgery Complications (Cont.)Patent pleuro-peritoneal channelsPleural injuries Ruptured emphysematous bullaeSudden hypoxia, rise in peak airway pressure, hypercarbia, haemodynamic alterationsAbnormal movement of the hemidiaphragm on laparoscopic view should raise a suspicion of pneumothorax

Pneumothorax and Pneumomediastinum20Laparoscopic Surgery Complications (Cont.)Recommended Guidelines Stop N2O Adjust ventilator settings to correct hypoxemia If due to pleuro peritoneal channel route apply PEEP Reduce intra-abdominal pressure Communicate with surgeon Avoid thoracocentesis unless necessaryAvoid PEEP if there is rupture of emphysematous bulla; thoracocentesis is mandatoryManagement of Pneumothorax21Laparoscopic Surgery Complications (Cont.)During laparoscopy, insufflation of a large amount of CO2 directly into a blood vessel can occur initially after blind Veress needle insertionShould be suspected if the abdominal cavity does not distend equally in all four quadrants despite insufflation of several liters of CO2.Hypotension, hypoxia, cyanosis, or cardiac arrest can occurThe most sensitive means to detect gas emboli are the precordial andTransesophageal Doppler and transesophageal echocardiographyAspiration of foamy blood from a central venous catheter is diagnostic and treatmentGas EmbolismDurants maneuver=left lateral decubitus and trendelenberg22Anesthetic GoalsAccommodate surgical requirements and allow for physiological changes during surgery. Monitoring devices available for the early detection of complications. Recovery from anesthesia should be rapid with minimal residual effects. The possibility of the procedures being converted to open laparotomy to be considered

Anesthesia ManagementPre-operative assessment The cardiac and pulmonary status of all patients should be carefully assessed Pre-medication Anxiolytics antiemetic H2 receptor blockers Prokinetic drugs Preemptive analgesia with NSAIDs Atropine to prevent vagally mediated bradyarrhythmias

Basic tests should include complete blood count (CBC), urinalysis, clotting functions,electrocardiogram (ECG), and blood typing and screening. In addition, baseline electrolytes, chemistries, and renal function tests (blood urea nitrogen [BUN],creatinine) should be obtained because of the possibility of oliguria during a longlaparoscopy. Patient with pulmonary problem: Baseline pulmonary function tests, arterial blood gas measurement, andoxygen saturation values while breathing room air would be helpful Markedly abnormal values might suggest the need for bronchodilators, antibiotics, postural drainage, and delay in surgery until pulmonary function is optimal for thisparticular patient.Baseline chest films are necessary not only to rule out active disease but also for postoperative comparison of acute changes such as subcutaneous or mediastinal emphysema, pneumothorax, or interstitial or pulmonary edema. Thepresence of bullae on preoperative chest x-ray films may represent a contraindication to laparoscopic surgery because of the accompanying large tidal volumes and highintrathoracic pressures. 24Anesthesia Management (Cont.)1. Routine Patient Monitoring IncludeContinuous ECG Intermittent NIBP Pulse oximetry (SpO2) Capnography (EtCO2) Temperature Intraabdominal pressure 2. Optional Monitoring IncludePulmonary airway pressure Oesophageal stethoscope Precordial doppler Transoesophageal echocardiography

25Anesthesia Management (Cont.)General AnesthesiaSpinal / Epidural AnesthesiaLocal AnesthesiaAnesthesia Techniques Duration may be long. Patient may be anxious. The Trendelenburg position may cause respiratory compromise and dyspnea in the awake or in the spontaneously breathing patient with abdominal contents under pressure. The obese patient may be especially uncomfortable in this position. A nasogastric or orogastric tube, difficult to insert in a conscious patient, is necessary to decompress the stomach and minimize the risk of aspiration or perforation by trocars. Carbon dioxide, as with N2O, diffuses into the stomach. However, perhaps the most important reason relates to muscle relaxation

local anesthesia, with N2O, which is nonirritating to the peritoneum, has been used as the insufflating gas for brief diagnostic laparoscopy underlocal anesthesia without cautery26Anesthesia Management (Cont.)Goals:IAP: 12 15 mmHg (dont allow to rise >20 mmHg)Airway pressure muscle relaxant (Succinylcholine / rocuronium / atracurium / cisatracurium / vecuronium) + Inj Dexamethasone 4 mg iv for PONV prophylaxisIntubation: appropriate size cuffed ET tube (LMA not recommended). NG or OG tube insertion and aspiration of stomach content (air)Maintenance: either anesthetic gas or TIVA can be used + O2 + Muscle relaxant.Fluid 4cc/kg/hour - depending on the situationsVentilation: O2 + IPPV or CPPV (spontaneous ventilation not recommended) adjusted to eliminate CO2End: Give antiemetic injectionReversal agent GA-ET with Controlled VentilationAnesthesia Management (Cont.)Watch out for facial edemaDelay extubation if the patient has edema, venous congestion, and duskiness of the head and neck. Sometimes the tongue becomes edematous. If unsure, check the eyes for conjunctival and lid edema, and keep the patient in head-up position until the conjunctivae no longer seem raised or wateryWatch for subcutaneous emphysemaInspect oropharynxAvoid extubation on light plane anesthesiaExtubationAnesthesia Management (Cont.)Post-Operative PainAt post op siteReferred pain on shoulder

Post Operative Nausea and VomitingPostoperative managementAnesthesia Management (Cont.)Preoperative or intraoperative administration of a non-opioid analgesic (e.g. NSAID, Paracetamol)Local anesthetic infiltration at trocar insertion sites (e.g. bupivacaine 0.25%, lidocaine 0.5%)Rescue medication with small doses of an opioid (e.g. morphine)Treat postoperative shivering.Postoperative management (Pain)Anesthesia Management (Cont.)Incidence as high as 42%.Inj Dexamethasone 4 mg iv at the time of induction.Inj Ondansetron 4 mg iv at the end of surgery.Third anti-emetic for rescue therapy.Adequate pain control also help the PONV

Postoperative management (PONV)Thank You

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