anesthesia for laparoscopic interventions peter biro department of anesthesiology university...
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Anesthesia for Laparoscopic Interventions
Peter BiroDepartment of AnesthesiologyUniversity Hospital Zurichpeter.biro@usz.ch
The „Good“
Advantages
Better cosmetic results Less pain, less analgesics required Shorter in-hospital stay Less complications (outcome?) Better pulmonary function (in particular in obese patients) Fast recovery, better comfort
Cholecystectomies in my Hospital
1990 1991 1992 1993 1994 1995 1996 1997 2001 20020
30
60
90
120
150
180
210
240
Open Laparoscopic
Cholecystectomies in my Hospital
1990 1991 1992 1993 1994 1995 1996 1997 2001 20020
30
60
90
120
150
180
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240
Open Laparoscopic
Open portion
50%
Cholecystectomies in my Hospital
1990 1991 1992 1993 1994 1995 1996 1997 2001 20020
30
60
90
120
150
180
210
240
Open Laparoscopic
Open portion
33%
Cholecystectomies in my Hospital
1990 1991 1992 1993 1994 1995 1996 1997 2001 20020
30
60
90
120
150
180
210
240
Open Laparoscopic
Open portion
13%
Surgeon Urologist Gynecologist
DiagnosticIntestinal
HerniotomyLiver
SpleenFundioplication
CholecystectomyEsophagus
Axillar lymphonodesGastric bandingAdrenalectomy
Parathyreoidectomy
DiagnosticNephrectomyKidney cysts
ProstatectomyVaricocele
LymphadenectomyTesticular descensus
DiagnosticTubar ligationAdnexectomyOvarectomy
LymphadenectomyEndometriosisMyomectomy
Axillar lymphonodes
What about the Anesthetist?
General Anesthesia&
Perioperative maintenanceof vital functions
...and comfort
The „Bad“
Mechanical Effects of Pneumoperitoneum
Elevated intra- and retroperitoneal pressure Diaphragma displacement to cranial Elevated intrathoracic pressure Increase of airway pressure Decrease of total respiratory compliance Gas embolism (risk of)
Effects on Pulmonary Function
Change of FEV1 (post- vs. preoperative) ―55% ―30% Duration till return to baseline FEV1 9.5 days 5 days FRC on 1st postoperative day ―20% ―34% PEF25-75% on 2nd postoperative day ―50% ―25% Confirmed post operative atelectasis (X-ray) ―90% ―40%
Open vs. LaparoscopicCholecystectomy
Other Effects of Pneumoperitoneum
Resorption of CO2 (hypercarbia, acidosis) Increase of PCO2 (arterial and end-tidal) Acidosis Increase of lactic acid Hormonal changes (catecholamines, vasopressin) Aggravation or improvement of side effects due to posture
...but oxygenation remains basically unchanged
Hemodynamic Effects of Pneumoperitoneum
Increase of atrial filling pressures (right: CVP, left: wedge pressure) Increase of heart rate Increase of both, systemic and pulmonary vascular resistance Increase of both, arterial and pulmonary blood pressure Cardiac output and intrathoracic blood volume show unconsistent changes in both
directions
Hormonal Effects of Pneumoperitoneum
Increase of... Vasopressine Dopamine Adrenaline Noradrenaline Renine Cortisone
► sympatho-adrenergical stimulation, „stress“ metabolism
Example for Overlaping Effects
40
60
80
100
120
MAP HR SVR
40
60
80
100
120
40
60
80
100
120 Baseline PneumoperitoneummmHgBeats/min
Dyne/s/cm-5/20
CO2 Homeostasis and Pneumoperitoneum
CO2 uptake in 2 phases: Initially fast resorption for app. 30 minutes Followed by equlibration on higher level (>30% of baseline)
If spontaneous ventilation possible ►increase of alveolar ventilation
V/Q mismatch leads to arterio-alveolar CO2 difference.
► invasive blood gas measurements mandatory in high risk patients (>ASA III)
Patients at Cardial Risk
Due to... acute elevated afterload and sometimes decreased preload (head up posture)
► one must aplly: invasive arterial blood pressure measurement In case of cardial insufficiency / pulmonary hypertension: TEE, Swann-Ganz
catheter IAP not above 10 mmHg or even better
...arrangement for or transition to
open surgical procedurein neutral horizontal position
Patients at Cardial Risk
Measures to improve situation (before transition to open surgical approach)... Reduction of afterload with vasodilators Carefull fluid replacement (under continuous TEE controll) Application of positive inotropic and vasodilating agents such as
dobutamine or phosphodiesterase inhibitors
Immediate measures in case of dramatic cardial deterioration: reversal of pneumoperitoneum (stop CO2 inflow, deflate abdomen) reversal of head down position to neutral or slightly elevated
Organ Perfusion and Pneumoperitoneum
Decrease of... gastrointestinal blood flow (in particular with IAP > 15 mmHg) renal blood flow
Increase of... cerebral blood flow (cave: patients with elevated intracranial pressure)
Pneumoperitoneum and Pregnancy
Increase of intrauterine pressure Decrease of uterine blood flow Decrease of fetal blood pressure
Consequences have to be evaluated on an individuall scale. Eventually consideration of
open surgical procedurein neutral horizontal position
Pneumoperitoneum and Pregnancy
Cholecystectomy is the most often perfomed non-obstetric surgical intervention in pregnancy
Meanwhile 50% are performed in laparoscopic mode However,...
surgery before 20th week of gestation bears elevated risk for preterm birth No evidence for difference in malformation frequency in open vs.
laparoscopic surgery
Actually there is no general contraindication for
laparoscopic surgeryin pregnancy
Pediatric Surgery
Since the nineties laparoscopy usual for neonates and toddlers
Hemodynamic effects are more pronounced
►Therefore... ► limit IAP to < 8 mmHg ► table positioning angle not exceeding ±15° ► avoid vagal reflexe (bradycardia) ► not recommended for emergency operations
Morbid Obesity
Higher rate of complications (+18%) Longer in-hospital stay (4-5 days more)
However, laparoscopic procedures have strong advantages... less problems with wound healing less tendency for burst abdomen early mobilization
CO2 Homeostasis and Pneumoperitoneum
Amount of CO2 uptake is dependent on intraabdominal pressure (IAP) and duration of pneumoperitoneum
With IAP < 10 mmHg hyperkapnia is unlikely After discontinuation of pneumoperitoneum fast reversal of
hypercarbia even without forced hyperventilation
Complications
Aspiration of gastric content Intraoperative occurrence up to 6% in 50% of cases reflux of gastric acid
Consequences ► gastric tubing ► tracheal intubation (no laryngeal mask or similar supraglottic devices)
Complications
Secondary unilateral bronchial ETT displacement Etiology
diaphragma elevation airway shifts upwards while ETT is fixed at teeth level
Consequences ► ETT advancement not deeper than 20 cm ► carefull checking and ►re-checking of bilateral ventilation (in case of
doubt fiberbronchoscopy)
Complications
Hypothermia not less than in open surgery ► use patient warming devices as usual
Smoke resorption carbon monoxide (CO) poisoning possible ►check blood gases regularly
Surgical emphysema due to improper CO2 insuflation ►check for airway obstruction
Vascular injury and bleeding may occurr during insertion of scope ►avoidance by muscular relaxation
Complications
Pneumothorax ► stop CO2 inflow, ► deflate abdomen, ► insert thoracic drainage
Pneumomediastinum typical for surgery of diaphragma or esophagus differencial diagnosis to pneumothorax or gas embolism necessary risk of pericardial tamponade
► diagnosis to be made with echoecardiography
Complications
Gas (CO2) embolism Etiology
intravasal gas insufflation (CO2 voulme 5x larger than for air) Symptoms
fast decrease of PetCO2
decrease of oxygen saturation (SpO2) without change of airway pressure Hypotension Cardiac arrhytmia Precordial „mill wheel sound“
► Measures stop CO2 inflow, ► deflate abdomen, ► left tilt position, ► aspiration of gas via central
venous line
Side Effects
Postoperative pain positive correlation to level and duration of IAP and intraabdominal pH projection into the shoulder due to irritation of diaphragm sometimes free interval up to 24 hours duration up to 3-4 days
►Therapy
multi modal analgesia (combination of different drugs and application modalities according to standardized protocolls)
Side Effects
Postoperative Nausea and Vomiting (PONV) more in laparoscopic than in open surgery (in particular
gynecology) young females < 30 years non smokers early pregnancy first phase of menstruation amount of CO2 uptake
Therapy
corticoids, 5-HT3 antagonists, dehydrobenzperidol
Schulte Steinberg H., Euchner Wamser I., Zalunardo M.P. Anästhesie für laparoskopische Eingriffe. Anaesthesist 1999, 48: 755-768
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