Anesthesie voor Abdominale Heelkunde

Transcription

1 Anesthesie voor Abdominale Heelkunde Specifieke deeldomeinen M. Verhaegen

2 Anesthesie voor Abdominale Heelkunde 1. Algemene aandachtspunten Beknopt overzicht Rapid sequence induction 2. Laparoscopie met een CO 2 -pneumoperitoneum Insufflation gas Pathofysiologische effecten Verwikkelingen Contra-indicaties Anesthesie: aandachtspunten

3 Anesthesie voor Abdominale Heelkunde 1. ALGEMENE AANDACHTSPUNTEN

4 Preoperative Attention Points Preoperative evaluation Les Pre-operatieve screening en medicamenteuze voorbereiding (Prof. E. Vandermeulen) Assessment of intravascular volume status Les Vochtbeleid: krystalloïden colloïden Diagnosis of electrolyte or acid-base disturbances Les Zuur-base stoornissen Hepatobiliary pathology: (severe) hepatic dysfunction is possible Assess risk of pulmonary aspiration of gastric contents

5 Risk Factors for Pulmonary Aspiration of Gastric Contents Emergent surgery Npo < 6 hrs or < 2 hrs for clear liquids Acute trauma immediately after eating (delayed gastric emptying) Risk of increased intragastric-esophageal pressure gradient Gastric outlet obstruction Slow / delayed gastric emptying (e.g. diabetes mellitus, medication) Bowel obstruction Paralytic ileus Pregnancy > 12 weeks Morbid obesity Excessive ascites Impaired protective reflexes Parkinson s disease Neuromuscular disease Severe gastro-esophageal reflux disease Assess the need for a rapid sequence intubation (RSI)

6 Seven P s of RSI in Adults 1. Preparation 2. Preoxygenation 3. Pretreatment 4. Paralysis and induction 5. Protection and positioning 6. Placement with proof 7. Postintubation management

7 Seven P s : 1. Preparation (1) Assessment of the patient / airway Anticipated difficult intubation: contraindication for RSI (lecture Luchtwegmanagement, Prof. A. Neyrinck) Awake fiberoptic intubation Exclude other contra-indications to RSI E.g. allergy to rapid onset muscle relaxants Patient installation Fast-running intravenous line Monitoring ECG, pulse oximetry, blood pressure monitoring in place Capnometry/-graphy available and ready for immediate use Optimal positioning for intubation (lecture Luchtwegmanagement, Prof. A. Neyrinck)

8 Seven P s : 1. Preparation (2) Equipment Endotracheal tube(s) of appropriate size Cuff free of leaks (tested) Stylet (+/- placed in the tube) Laryngoscope Tested Different blades should be readily available Suction device, checked Oral airway Drugs Selection of induction and neuromuscular blocking agents Determination of the doses Drawn up in labeled syringes

9 Seven P s : 2. Preoxygenation (1) Goal: Increase the apnea period with an O 2 saturation > 90% Avoid mask ventilation before intubation Increasing oxyhemoglobin saturation Denitrogenation: replacing nitrogen with oxygen in the lungs (in the FRC) Increasing oxygen stores in lungs, blood and tissues Longer periods of apnea are tolerated without desaturation Time to desaturation, even after preoxygenation, depends on patient characteristics and clinical situation

10 Time to hemoglobin desaturation with initial F A O 2 = 0.87 Benumof et al, Anesthesiology 1997; 87:

11 Time to severe desaturation after onset of apnoea for different ambient oxygen concentrations. R. Sirian, and Jonathan Wills Contin Educ Anaesth Crit Care Pain 2009;9:

12 Seven P s : 2. Preoxygenation (2) Goal: Increase the apnea period with an O 2 saturation > 90% Avoid mask ventilation before intubation Techniques Technique of choice: 100 % oxygen by face mask during 5 minutes Eight vital capacity breaths (maximal breaths) during 100 % oxygen administration

13 Seven P s : 3. Pretreatment Goal: prevention of potentially adverse consequences of the physiologic responses to RSI Drugs used for pretreatment vary with clinical circumstances Opioid Fentanyl, sufentanil To blunt increases in heart rate and blood pressure during laryngoscopy and intubation Lidocaine 1.5 mg/kg iv 2-3 min before intubation Suppression of cough reflex and attenuation of increased airway resistance following intubation? Attenuation of ICP rise upon intubation in patients at risk of adverse effects of an increase in ICP

14 Seven P s : 4. Paralysis and Induction (1) Goal: almost simultaneous, rapid induction and paralysis Selection of agents (depends on the clinical situation) Precalculated doses adequate to provide prompt loss of consciousness and muscle relaxation (no time for titration) Intubation sec after the administration of the neuromuscular blocking agent 1. Induction: Rapidly acting intravenous induction agent Propofol (1.5 3 mg/kg) Advantage: Bronchodilation Disadvantage: Hypotension (reduction of cerebral perfusion pressure) Etomidate (0.3 mg/kg) Advantage: Hemodynamic stability Disadvantage: Suppression of adrenal cortisol production

15 Seven P s : 4. Paralysis and Induction (2) 2. Paralysis: Rapidly acting neuromuscular blocking agent immediately following the induction agent Depolarizing NMBA: Succinylcholine (1-1.5 mg/kg) Rapid onset (45-60 sec), short half-life (6-10 min) Rise in serum K + Contraindications Significant (acute) hyperkalemia (ECG changes) Risk of malignant hyperthermia» Personal or family history» Specific diseases Rhabdomyolysis Acetylcholine receptor upregulation» Denervating diseases» Myopathies» Prolonged total body immobilization» Extensive burn injuries 72 hrs old» Crush injuries 72 hrs old

16 Seven P s : 4. Paralysis and Induction (3) 2. Paralysis: Rapidly acting neuromuscular blocking agent immediately following the induction agent Non-depolarizing NMBA: Rocuronium ( mg/kg) Rapid onset (45-60 sec) Longer duration of action than succinylcholine Duration of action of approximately 60 min after 1 mg/kg (may be much longer in older patients) Reversal is possible» Neostigmine Only after sufficient spontaneous reversal (at least 2 and preferably 3 responses with TOF monitoring) No use in acute situations» Suggamadex» 16 mg/kg immediately after administration of high dose rocuronium (cannot intubate, cannot ventilate situation)» Ac

17 Seven P s : 5. Protection and Positioning Protection of the airway against aspiration of gastric contents prior to intubation Avoid mask ventilation Maximal preoxygenation O 2 -saturation < 90 % mask ventilation with cricoid pressure Cricoid pressure (Sellick s maneuver) Prevention of passive regurgitation by occlusion of the esophagus

18 Sellick s Maneuver (Cricoid Pressure) (1) Applied by an assistant during induction Effectiveness has been questioned Lateral displacement of esophagus, instead of occlusion (MRI) But: occlusion of hypopharynx is relevant Decreased lower esophageal sphincter tone? (clinical study) Potentially increased risk of regurgitation Risks May worsen visualization Laryngeal obstruction with difficulty to pass the endotracheal tube Trauma Laryngeal trauma Esophageal rupture Displacement of unstable cervical spine

19 Sellick s Maneuver (Cricoid Pressure) (2) Downward pressure on cricoid cartilage Using thumb and index finger to exert pressure on cricoid cartilage Avoid exerting pressure on thyroid cartilage Pressure of 30 N (10N before loss of consciousness) Release only after endotracheal tube placement has been confirmed

20 Seven P s : 6. Placement with Proof Laryngoscopy after sufficient muscle relaxation has been achieved (45-60 sec after NMBA administration) Placement of endotracheal tube (+/- stylet) Confirmation of endotracheal tube placement End-tidal CO 2 -measurement Auscultation over both sides of the chest and the stomach (Visualization of the endotracheal tube between the vocal cords) (Misting of the tube with ventilation) Check the depth of the tube Auscultation is equal over both lungs

21 Seven P s : 7. Postintubation Management Secure the properly placed endotracheal tube Start mechanical ventilation

22 Anesthesia Technique Selection criteria for anesthesia technique Surgical procedure Contra-indications for a specific technique Patient preference / objection Neuraxial anesthesia General anesthesia +/- epidural anesthesia

23 Perioperative Attention Points during General Anesthesia for Abdominal Surgery Monitoring Induction of general anesthesia Temperature Prevention of hypothermia: take measures to prevent hypothermia as soon as the patient enters the operating room (before induction of anesthesia!) Fluid management Muscle relaxation and neuromuscular monitoring Indicated intraoperatively Quantitative neuromuscular monitoring is absolutely necessary before emergence from anesthesia and extubation TOF ratio at adductor pollicis muscle

24 Abdominal Surgery: Postoperative Attention Points Postoperative analgesia Thrombosis prophylaxis Prevention of stress ulcers Postoperative nausea and vomiting Postoperative continuation of preoperative medication

25 Anesthesie voor Abdominale Heelkunde 2. LAPAROSCOPIE MET CO 2 -PNEUMOPERITONEUM

26 Anesthesia for Laparoscopic Surgery with CO 2 -Pneumoperitoneum: Topics Insufflation gas Pathophysiology Complications Contraindications Anesthesia

27 Laparoscopic Procedures for Gastrointesinal Surgery Diagnostic surgery Cholecystectomy Nissen fundiplication Bowel surgery Gastrectomy Bariatric surgery Pyloromyotomy Pancreatic surgery (Whipple) Partial hepatectomy Splenectomy Lymphadenectomy Inguinal hernia Appendectomy

28 Laparoscopic Surgery: Potential Benefits Less tissue trauma Reduced surgical stress response Pulmonary function less impaired postoperatively Less postoperative ileus Reduced postoperative pain Faster postoperative recovery and ambulation Shorter hospital stay Better cosmetic results High patient satisfaction Cost savings Mainly postoperative advantages Every benefit has not been demonstrated for each procedure

29 Laparoscopic Surgery: Technical Aspects Creation of working space Pneumoperitoneum Gasless lifting system Combination Gravity as a retractor Upper abdominal: reverse Trendelenburg positioning Lower abdominal: Trendelenburg positioning (extreme) Robot-assisted

30 Pneumoperitoneum: Ideal Insufflation Gas Nonflammable Metabolically and chemically inert Highly soluble in blood Nontoxic Odorless Colorless Readily available Inexpensive Wolf, Seminars in Surgical Oncology 12 (1996) Insufflation gas of choice: carbon dioxide (CO 2 )

31 Pneumoperitoneum: Insufflation Gas Carbon dioxide Highly soluble in blood Non-flammable Hypercapnia Irritation of diaphragma and peritoneum ( shoulder pain) Used for the vast majority of laparoscopic cases Nitrous oxide Highly soluble in blood (less soluble than CO 2 ) No irritation of diaphragm or peritoneum Surgery under local anesthesia Supports combustion No major surgery possible Used occasionally

32 CO 2 PP: Pathophysiologic Changes Absorption of insufflated CO 2 Extraperitoneal > intraperitoneal insufflation Increased intra-abdominal pressure (IAP) Intraperitoneal > extraperitoneal insufflation Cardiovascular effects Pulmonary effects

33 CO 2 - PP: Absorption of Insufflated CO 2 (1) Parameters affecting absorption of CO 2 Approach: extraperitoneal vs intraperitoneal insufflation Site of surgery: pelvic vs upper abdominal surgery Intra-abdominal pressure Duration of pneumoperitoneum Subcutaneous emphysema

34 PaCO 2 (mmhg) Extraperitoneally Intraperitoneally } * Time after insufflation (min) * P = 0.02 Liem et al., Anesth Analg 81 (1995)

35 CO 2 - PP: Absorption of Insufflated CO 2 (2) Extraperitoneal vs intraperitoneal insufflation Intraperitoneal pneumoperitoneum Gas filled space lined by a membrane Limited expansion ( absorption is self-limiting) PaCO 2 increase reaches plateau after min Subcutaneous emphysema < 2 % Extraperitoneal pneumoperitoneum Gas migrates into tissues (not confined by a membrane) Gas progressively dissects tissues (absorption = unlimited) PaCO 2 increase continues for much longer than 30 min High incidence of subcutaneous emphysema

36 CO 2 -PP: Absorption of Insufflated CO 2 (3) Upper vs lower abdominal surgery Upper abdominal surgery: intraperitoneal insufflation PaCO 2 increase during min PaCO 2 increase of % from baseline Lower abdominal surgery Intraperitoneal insufflation PaCO 2 increase during min PaCO 2 increase of % from baseline Extraperitoneal insufflation PaCO 2 increase continues (> 30 min) PaCO 2 increase is generally > 30 % from baseline

37 CO 2 - PP: Absorption of Insufflated CO 2 (4) Approach: extraperitoneal vs intraperitoneal insufflation Site of surgery: pelvic vs upper abdominal surgery Intra-abdominal pressure Role at low IAP during intraperitoneal insufflation More important during extraperitoneal insufflation? Duration of pneumoperitoneum Important during extraperitoneal insufflation Subcutaneous emphysema Complication May result in severe hypercarbia Incidence: extraperitoneal >>> intraperitoneal insufflation

38 CO 2 PP: Cardiovascular Effects Cardiac arrhythmias Systemic hemodynamic effects Regional hemodynamic effects Renal effects Splanchnic perfusion Venous stasis

39 CO 2 PP: Cardiac Arrhythmias (1) Reflex increase of vagal tonus Bradycardia, asystole Eliciting factors Stretching of the peritoneum Insufflation Electrocoagulation of the fallopian tubes Accentuated in case of Superficial level of anesthesia Patients on β blocking drugs Treatment Immediately interrupt insufflation Atropine Deepening of anesthesia after recovery of heart rate

40 CO 2 PP: Cardiac Arrhythmias (2) Pathophysiologic hemodynamic changes Arrhythmias due to acute changes caused by insufflation Early during insufflation Patients with cardiac disease may be at higher risk Gas embolism may cause cardiac arrhythmias Increased PaCO 2? Arrhythmias also occur without a high PaCO 2 Arrhythmias do not correlate with magnitude of PaCO 2

41 CO 2 PP: Systemic Hemodynamic Effects Mean arterial blood pressure Heart rate Central venous pressure Pulm. cap. wedge pressure Cardiac output Systemic vascular resistance Initiation of pneumoperitoneum (IAP > 10 mmhg)

42 CO 2 PP: Systemic Hemodynamic Effects (1) Pathophysiologic mechanism: Multifactorial Autotransfusion effect Compression of splanchnic blood vessels Reduced venous return Compression of vena cava inferior Pooling of blood in the legs Increased intrathoracic pressure Increased systemic vascular resistance Mechanical mechanism Release of neurohumoral factors Vasopressin

43 CO 2 PP: Systemic Hemodynamic Effects (2) Parameters affecting balance between mechanisms Intra-abdominal pressure Intravascular volume status Patient positioning PaCO 2 Associated cardiac disease Anesthesia

44 Cardiopulmonary healthy normovolemic person Pneumoperitoneum: IAP 10 mmhg Compression of splanchnic vessels Neurohumoral effects Venous return (autotransfusion) SVR Preload Afterload CO CO Cardiac output

45 Cardiopulmonary healthy normovolemic person Pneumoperitoneum: IAP > 15 mmhg ITP Compression of v. cava Pooling of blood in legs Neurohumoral effects Venous return SVR Afterload Preload Cardiac output

46 CO 2 PP: Systemic Hemodynamic Effects (3) Intravascular volume status Hypovolemia increases the negative hemodynamic effects of an increased IAP No splanchnic recruitment Aggravates SVR increase Patient positioning: influences SVR Trendelenburg positioning Attenuates SVR increase Reverse Trendelenburg positioning Pooling of blood in the lower limbs Aggravates increase of SVR Avoid before insufflation

47 Figure 68-5 Changes in the cardiac index and systemic vascular resistance during laparoscopy in two groups of patients. For group 1 (controls, n = 10, yellow bars), pneumoperitoneum was induced with patients in a 10-degree head-up position. Group 2 (volume loaded, n = 10, blue bars) patients received 500 ml of lactated Ringer's solution before anesthesia induction and were insufflated in the supine position. Data are presented as the mean ± SEM. Jean J. Joris in Miller Anesthesia, 7th edition, p. 2190

48 CO 2 PP: Systemic Hemodynamic Effects (4) PaCO 2 Moderate hypercarbia Slight myocardial stimulation Decreased systemic vascular resistance Severe hypercarbia Decreased myocardial contractility Decreased arrhythmia threshold Associated cardiac disease More severe hemodynamic changes? Anesthesia Vasodilatation reduces SVR increase Negative inotropic effects of anesthetics

49 CO 2 PP: Renal Effects Decreased diuresis, glomerular filtration rate, renal blood flow < 50 % of baseline values Normalization after deflation Mechanisms Direct renal parenchymal compression Venous congestion (reduced flow in v. cava inferior) Clinical consequences? Recuperation after release of pneumoperitoneum Postoperative renal dysfunction in specific patients? Pre-existing renal dysfunction?

50 CO 2 PP: Effects on Splanchnic Perfusion (1) Mechanisms with opposing effects variable effect on splanchnic perfusion Mechanical compression: splanchnic blood flow decrease Abdominal organ microcirculation Abdominal blood vessels Direct effect of CO 2 from the PP: splanchnic vasodilation

51 CO 2 PP: Effects on Splanchnic Perfusion (2) Hepatoportal circulation Decreased blood flow Postoperative liver dysfunction? Pre-existing liver disease? Gastrointestinal blood flow Effects on blood flow depend on IAP IAP < 12 mmhg: moderate splanchnic hyperemia IAP > 15 mmhg: pressure-induced blood flow decrease Risk of splanchnic ischemia and bacterial translocation?

52 CO 2 PP: Venous Stasis (1) Venous stasis in the lower limbs Increased femoral venous pressure Decreased femoral peak velocity Mechanisms Increased IAP and compression of v. cava inferior Reverse Trendelenburg positioning Pooling of blood in lower limbs

53 CO 2 PP: Venous Stasis (2) Increased risk of venous thrombosis? Factors increasing risk vs open procedures Venous stasis in the legs Longer lasting procedures Factors reducing risk vs open procedures Earlier ambulation Less surgery-induced hypercoagulability Less tissue trauma With thrombosis prevention: no increased risk Low molecular weight heparins Compressive stockings

54 CO 2 -PP: Pulmonary Effects CO 2 PP: may have significant pulmonary effects Increased intra-abdominal pressure CO 2 absorption

55 CO 2 -PP: Intra-Operative Pulmonary Effects (1) Increased intra-abdominal pressure Cranial displacement of diaphragm Increased airway pressure V/Q mismatches Functional residual capacity: decrease Thoracopulmonary compliance: decrease % decrease in healthy persons (Micro)Atelectasis Impaired oxygenation and hypoxemia Generally no problem in healthy persons Obese patients, patients with pre-existing pulmonary disease

56 CO 2 -PP: Intra-Operative Pulmonary Effects (2) PaCO 2 increase Mechanical factors V/Q mismatching Abdominal distension Patient positioning (Trendelenburg) These mechanical factors contribute more to the PaCO 2 increase in patients with cardiorespiratory disease than in healthy patients Absorption of CO 2 from the pneumoperitoneum % PaCO 2 increase (with constant minute volume) Plateau after min If no plateau: search for cause (subcutaneous emphysema?)

57 CO 2 -PP: Intra-Operative Pulmonary Effects (3) Monitoring of PaCO 2 changes during CO 2 - PP Capnography is reliable in healthy patients ASA II and III patients: PaCO 2 and arterial-end tidal PCO 2 gradient increase more COPD patients, children with cyanotic congenital heart disease Hypercapnia may develop in the absence of an abnormal PETCO 2 Wittgen et al. Arch Surg 1991

58 CO 2 -PP: Postoperative Respiratory Effects (1) Increased minute ventilation to eliminate absorbed CO 2 Increased respiratory rate Increased PETCO 2 Up to 2 hours postoperatively Increased work of breathing may be a problem in patients with serious cardiopulmonary disease

59 CO 2 -PP: Postoperative Respiratory Effects (2) Postoperative pulmonary function is better perserved after laparoscopy than after laparotomy Postoperative pulmonary dysfunction is less severe 75 % of preoperative values (50 % after laparotomy) Pulmonary function recovers faster Generally within h (3-5 d after laparotomy) Pulmonary dysfunction is less severe after gynecologic than after upper abdominal laparoscopy Pulmonary dysfunction after laparoscopy is more severe and recovers slower in older patients, obese patients, smokers and COPD patients But also in these patients pulmonary function is better preserved after laparoscopy than after laparotomy

60 CO 2 -PP: Postoperative Respiratory Effects (3) Diaphragm dysfunction is significant following upper abdominal laparoscopic surgery Inhibition of phrenic discharge by visceral afferents from the gallbladder area or somatic afferents from the abdominal wall

61 Laparoscopy with CO 2 -PP: Complications (1) Veress needle / trocar trauma Subcutaneous emphysema Pneumothorax Pneumomediastinum Pneumopericardium Gas embolism Endobronchial intubation Peripheral nerve damage Incidence: no precise data Consequences may be severe

62 Laparoscopy with CO 2 -PP: Complications (2) Anesthesiologist may be the first to notice signs of a complication, even if the event is surgery related Diagnosis may be difficult and delayed E.g. Significant retroperitoneal hematoma may develop insidiously Differential diagnosis of complications with pulmonary effects Endobronchial intubation Subcutaneous emphysema Capnothorax Pneumothorax Massive CO 2 embolism

63 Veress Needle / Trocar Trauma Injury to large blood vessels Aorta, inferior v. cava, iliac vessels Injury to abdominal wall vasculature Retroperitoneal hematoma Concealed bleeding difficult diagnosis Abdominal organ perforation Small / large bowel, liver, spleen Avoid gastric distension (mask ventilation) Diafragm, pleura, pericard perforation

64 CO 2 PP: Subcutaneous Emphysema (1) Severe hypercapnia Persisting in spite of increasing minute ventilation Mechanism Accidental extraperitoneal CO 2 insufflation Side-effect of intentional extraperitoneal CO 2 - PP Diagnosis Sudden large increase in PETCO 2 after P ET CO 2 had reached a plateau P ET CO 2 increase larger than 30 % from baseline P ET CO 2 increase later than 30 min after beginning of insufflation Crepitus: abdominal wall, chest wall Sometimes there is ocular and/or pharyngeal emphysema

65 CO 2 PP: Subcutaneous Emphysema (2) Intraoperative management Increase minute ventilation Sometimes it is impossible to sufficiently increase MV Reduce insufflation pressure Muscle relaxation May facilitate mechanical ventilation (?) If PCO 2 remains too high Determine if hypercapnia is acceptable Limit duration of surgery Desufflate intermittently Abolish laparoscopic procedure Determined by PCO 2 and cardiopulmonary status

66 CO 2 PP: Subcutaneous Emphysema (3) Postoperative attention points Subcutaneous CO 2 readily resolves after desufflation Keep patient mechanically ventilated until hypercapnia is sufficiently corrected This avoids excessive work of breathing Be aware of risk of pharyngeal emphysema Generally, patients can be extubated, but if in doubt check presence of air leak with deflated cuff Anesthesia and Analgesia 1995; 80:

67 CO 2 -PP: Pneumothorax, Pneumomediastinum, Pneumopericardium Increased P ET CO 2 Pneumothorax: differential diagnosis Capnothorax CO 2 pneumothorax Combination From: Wolf and Stoller, J. Urol. 152 (1994)

68 CO 2 PP: Pneumothorax vs Capnothorax Pneumothorax (lung injury) Capnothorax (CO 2 pneumothorax) P ET CO 2 decrease IPPV risk of tension pneumothorax Chest drain is generally indicated P ET CO 2 increase IPPV (+ PEEP) reduction of capnothorax Chest drain is not always necessary

69 CO 2 - PP: Gas Embolism (1) Venous CO 2 embolism Early after Veress needle insertion (during induction of PP) Direct intravenous insufflation Insufflation in abdominal organs Gas lock in v. cava and right atrium fall in cardiac output, even circulatory arrest Passage of CO 2 into abdominal wall and peritoneal vessels Open vessels on liver surface during gallbladder dissection Paradoxal embolism through patent foramen ovale or ASD Acute right ventricular hypertension Cerebral CO 2 embolism

70 CO 2 - PP: Gas Embolism (2) Lethal volume of CO 2 embolism is five times greater than of air Signs and symptoms Decrease in P ET CO 2 Sometimes preceded by a brief increase in P ET CO 2 due to pulmonary excretion of absorbed CO 2 Mill-wheel murmur Hypoxemia Hypotension Cardiovascular collapse

71 CO 2 - PP: Gas Embolism No physiologic changes Precordial doppler Transesophageal echocardiography Modest physiologic changes Decreased PETCO 2 Increased pulmonary artery pressure Clinical symptoms Cardiovascular collapse Decreased blood pressure Increased central venous pressure Decreased cardiac output ECG changes Arrhythmias Aspiration of foamy blood from central venous line Esophageal stethoscope

72 CO 2 - PP: Gas Embolism No physiologic changes Precordial doppler Transesophageal echocardiography Modest physiologic changes Decreased PETCO 2 Increased pulmonary artery pressure Clinical symptoms Cardiovascular collapse Decreased blood pressure Increased central venous pressure Decreased cardiac output ECG changes Arrhythmias Aspiration of foamy blood from central venous line Esophageal stethoscope

73 CO 2 - PP: Gas Embolism (3) Immediately stop insufflation and release pneumoperitoneum Ventilation with 100 % oxygen Hyperventilation Durant s position to clear right ventricular outflow Left lateral decubitus Steep Trendelenburg Aspiration of gas (central venous catheter) Cardiopulmonary resuscitation

74 CO 2 PP: Endobronchial Intubation Cephalad displacement of the diaphragm (and carina) Increase in airway pressure O 2 saturation decrease Lobato et al., Anesth Analg 1998; 86:

75 Peripheral Nerve Damage Careful positioning Head-down position Avoid shoulder braces (risk of brachial plexus lesion) Vacuum mattress Lithotomy position Common peroneal nerve lesion Long-lasting procedures: compartment syndrome

76 CO 2 PP: Contra-indications (1) Patients with or at risk for an increased ICP Cerebral trauma Intracranial space occupying lesions (tumor, aneurysm) Hydrocephalus Pressure (mmhg) Pressure (mmhg) ICP 10 0 Baseline PP (15 mmhg) Epid balloon EB + PP EB + Retractor MAP P a CO 2 Este-McDonald et al., Arch Surg 130 (1995)

77 CO 2 PP: Contra-indications (2) Significant hypovolemia, shock More pronounced hemodynamic effects of increased IAP Low cardiac output Renal and splanchnic hypoperfusion Selected cardiopulmonary problems Very low cardiac output Severe heart failure Cardiac right-left shunt Severe aortic valve insufficiency Severe pulmonary hypertension Some complex congenital cardiopathies

78 CO 2 PP: Relative Contra-indications (1) Heart failure Patent foramen ovale Severe pulmonary disease Intra-operative ventilation problems Less postoperative pulmonary dysfunction Significantly impaired renal function? Avoid prolonged laparoscopic surgery with high IAP? Hemodynamic optimalization Avoid nephrotoxic drugs Patients at risk for splanchnic ischemia? Avoid prolonged laparoscopic surgery with high IAP?

79 CO 2 PP: Relative Contra-indications (2) Increased intraocular pressure? There is no increase in intraocular pressure in patients without preexisting eye disease Uncontrolled glaucoma? Trendelenburg positioning can increase intraocular venous pressure and worsen acute glaucoma Clinical significance?

80 Anesthesia for Laparoscopy with CO 2 PP (1) Preoperatively Identify contra-indications Thrombosis prophylaxis Compressive stockings if indicated Premedication Standard Antacids? No. No indication of increased risk of regurgitation Preservation of gastro-esophageal barrier pressure

81 Anesthesia for Laparoscopy with CO 2 PP (2) Monitoring Standard intraoperative monitoring Blood pressure, heart rate, ECG, capnometry, pulse oxymetry Only indirect evidence of PP-induced hemodynamic changes Arterial line Severe pre-existing cardiac and pulmonary disease Hemodynamic response to PP + positioning Arterial end tidal PCO 2 difference Surgical procedure Transesophageal echocardiography Severe cardiac co-morbidity, but indication for laparoscopy?

82 Anesthesia for Laparoscopy with CO 2 PP (3) Neuraxial anesthesia (epidural, CSE, spinal) Extensive block is necessary (T4 - L5) for surgical laparoscopy Short procedures E.g. tubal ligation Reduced insufflation pressure No extreme head-down positioning Hemodynamic effects of PP under epidural anesthesia: no data Insufflation gas Nitrous oxide? Less irritation of peritoneum and diaphragm No electrocautery possible CO 2 Increased minute ventilation (increased work of breathing) to maintain PaCO 2 For selected procedures only

83 Anesthesia for Laparoscopy with CO 2 PP (4) General anesthesia: technique of choice for laparoscopy Intubation and mechanical ventilation Technique of choice Adjust minute volume to maintain P ET CO 2 between mmhg Check position of endotracheal tube after induction of PP Risk of endobronchial intubation Check again with Trendelenburg positioning Laryngeal mask? Does not protect airway against aspiration of gastric contents Ventilation problems» thoracopulmonary compliance and airway pressure > 20 cmh 2 O» ProSeal laryngeal mask?

84 Anesthesia for Laparoscopy with CO 2 PP (5) General anesthesia: technique of choice for laparoscopy Antiemetic Laparoscopy: increased risk of PONV (40 75% of patients) Nitrous oxide? Controversial Bowel distension? Not convincingly demonstrated Worsens cardiovascular effects of CO 2 emboli Explosion hazard? Bowel perforation and combustion of bowel gases Unlikely in routine clinical practice Increased incidence of PONV? No conclusive evidence against the use of N 2 O

85 Anesthesia for Laparoscopy with CO 2 PP (6) Recovery and postoperative care Postoperative CO 2 elimination Absorption of residual CO 2 CO 2 release from body stores Increased work of breathing Caution in patients with severe cardiopulmonary disease Nausea and vomiting Prevention indicated

86 Anesthesia for Laparoscopy with CO 2 PP (7) Postoperative analgesia Incisional pain, intra-abdominal (visceral) pain, shoulder pain After laparoscopy pain is generally less intense and of shorter duration than after laparotomy, but Pain is variable in duration, severity and character Patients may experience severe pain after laparoscopic surgery

87 Anesthesia for Laparoscopy with CO 2 PP (8) Postoperative analgesia: multimodal approach Intraperitoneal local anesthetic Conflicting results More successful after pelvic laparoscopy? Generally not effective for visceral pain Infiltration of skin with local anesthetic Evacuation of insufflation gas Residual CO 2 causes shoulder pain Gas drain NSAIDs Reduced need for opioid analgesia Opioids may be necessary!