Seminar on laparoscopic surgery and its anaesthetic considerationPresentation Transcript
Laparoscopic surgery and its anaesthetic consideration
Dr Saurav Das
Laparoscopy ( Greek λάπάРά =flank or λάЛάРОδ =soft σκОЛήтν = to look) has revolutionized surgical procedures because of the important advantages it offers namely less tissue trauma,decreased post operative pain as well as shorter hospital stay with minimized post operative morbidity and mortality.
Gyanecological laparoscopic surgery has been started since 1970’s.In 1987, Phillipe Mouret described the first laparoscopic cholecystectomy in France.Literature about low IAP and modern anaesthetic technique has started publishing after 1990’s.
ROUTINELY DONE LAPAROSCOPIC SURGERIES
3)Hiatus hernia repair
4)Diaphragmatic hernia repair
7)Inguinal hernia repair
9)Adrenalectomy for phaechromocytoma
10)many gynaecological procedures
Benefits of laparoscopic surgery:
It can summarized as follows:
1)Minimal abdominal inscision
2)Less metabolite derangements
(studies have confirmed the reduced metabolite derangement by measuring interlukin 6 level and c reactive protein ).
3)Reduced adverse effect
4)Better postoperative pulmonary function test
5)Less postoperative ileus due to less tissue handling ,so oral feeding can be started early .
6)Less postoperative pain .
This all leads to early ambulation .
Shorter hospital stay .
Early return to work and normal activity .
SPECIAL CHARACTERISTIC OF LAPAROSCOPIC SURGERY
Laparoscopic surgery,although enjoying ever increasing popularity present view anaesthetic challenges because of
Carbondioxide insufflation to produce pneumoperitoneum
Position of the patient that is trendelenburg and reverse trendelenburg
CHANGES DUE TO PNEUMOPERITONEUM Pneumoperitoneum is created by insufflation of gases through verses needle at @ 1-2 lit /min .
Once pmeumoperitoneum is achieved ,over all pressure over the diaphragm is almost 50 kg.( in trendelenburg position at an IAP of 15mmhg )This results in following respiratory changes:
Decreased Tidal and so Minute volume
Increased risk of barotrauma during IPPV
During an uneventful CO2 pneumoperitneum ,PCO2 rises till it reaches a plateau at 15 to 30 min after insufflation .Rise of PCO2 is mainly due to peritoneal absorption. Some other factors which also contributes to raise PCO2 are :
Va/Q mismatch – increased physiologic dead space due to
*position of patient (steep head down)
Controlled mechanical ventilation
Reduced cardiac output
(All these mechanism are attenuated in sick person like obese ,ASA2 and ASA3 )
Insufficient plan of anesthesia
Transfusion of more glucose containing fluid
3. Depression of ventilation by anesthetics in case spontaneous breathing
4. Accidental event
Changes of PACO2, PETCO2 and PH attain a plateau after 15 to 30 mins after insufflation . Any change there after requires a search for a cause
CARDIOVASCULAR CHANGES These changes are characterized by : Decreased cardiac output Elevation of arterial pressure and pulmonary vascular resistance HR may decrease or increase
G I T CHANGES:
Patient under going laparoscopy are considered at high risk acid aspiration syndrome .I t might be due to increased intragrastic pressure consequent to Increased IAP .
The visceral vascular bed is the primary site of compression during raised IAP resulting in organ dysfunction .Other contributing factor sympathetically mediated vasoconstriction and mechanical compression of abdominal organ.
Increase IAP adversely affects the portal vascular resistance. An IAP > 20mmhg decreases portal blood flow by 60% resulting liver dysfunction may persist for a prolong period.
Urine output. Renal blood flow and GFR decrease to less than 50% of base line value .Urine out put increases significantly after desufflation
CERBRAL BLOOD FLOW :
Both ICP and IOP are raised due to vasodialating action of CO2 . In normal individual these changes are tolerable but in patient with SOL or glaucoma may show some deleterious effects .
During laparoscopy continuous flow of dry gases over peritoneal surface under pressure can lead to fall of core body temperature .ie joule Thompson effect . some aggravating factors are higher flow rate ,prolong duration of surgery, leakage through port ,peritoneal lavage etc .
There is 0.30 c fall in core temperature per 50l volume flow of carbondio
CAN LAPAROSCOPY BE PERFORMED IN ALL PATIENT ???????
Following groups of patient need careful consideration :
Patient with in ICP , SOL and CVA
Patient having ventriculoperitoneal and juguloperitoneal shunt .
Patient with cardiac disease
Patient with renal dysfunction.
Patient with h/o of deep vein thrombosis .
All the standard which are set for in patient anesthetic care should be followed. They are:
Adequate muscle relaxation
Control of diaphragmatic excursion
Intra and post operative analgesia
Control of PONV
Deep vein thrombosis
Protection against hypothermia
Monitoring during laparoscopic surgery
Recommendation for routine patient monitoring:
Optional monitoring include
Arterial blood gas analysis
Most importantly a vigilant anaesthetist
Technique of anaesthesia
General anesthesia with endotracheal intubations and controlled ventilation is the safest technique and therefore is recommended for long laparoscopic procedure
Atropine is administered at the time of induction to prevent bradycardia .
The choice of anaesthetic technique does not seem to play a major role in patient’s outcome.
Adequate abdominal and diaphragmatic muscle relaxation is essential
Rapid sequence induction with suxamethonium is recommended in anti reflux surgery
Due to raised IAP and increase in the mechanical ventilation pressure is required to achieve adequate ventilation.Normocarbia is maintained by increasing respiratory rate.
Following induction the patient is catheterized to empty urinary bladder and nasogastric tube is inserted to avoid stomach injury.
Insufflation flow rate should be low, initially 1-1.5 Ltr/min.
Use of nitrous oxide(N2O) is controversial for maintenance of anesthesia because of concern about its ability to produce bowel distension during surgery and PONV.
Halothane in the presence of hypercarbia can cause arrhythmia.
The position of ET tube to be checked repeatedly because of the likelihood of endobronchial intubatiion.
Regional anaesthesia(Epidural/ Spinal /CSE)
Early diagnosis of complication.
During a creation of pneumoperitoneum, patient breathing spontaneously under epidural anesthesia results in increased minute ventilation with unchanged ET CO2.
Provides excellent post-operative analgesia with low incidence of PONV.
Fewer hemodynamic changes due to absence of positive pressure ventilation
Increase anxiety, pain, discomfort of the patient during manipulation.
Supplemental sedation can depress respiration, sensitivity to CO2 and hypoxia.
Shoulder tip pain from diaphragmatic irritation and discomfort from abdominal distention are incompletely alleviated
1. Trochar may cause abdominal vessel injury, GIT perforation, hepatic and splenic tear and omental injury.
Hassen minilaparotomy technique has been advocated for pneumoperitoneum creation .
2. Extraperitoneal insufflation of CO2 is a common complication of laparoscopy.ET CO2, VCO2 and PACO2 all increases more than expected.
Once diagnosed, insufflation should be stopped and ventilation should be continued to wash out extra CO2.
3) Pneumothorax pneumomediastinum and pneumopericardium :-
Causes :- Trespass of gases through embryonic remnants , defects in diaphragm, weak points in aortic and esophageal hiatus.
Rupture of emphysematous bullae .
By pleural tear caused by surgical tear.
It can be diagnosed by
Progressive hypoxemia ,increasing paw and subcutaneous emphysema.
Observation of abnormal motion of diaphragm by laparoscopist
Chest x ray
With out any associated pulmonary trauma this condition resolve after 15 to 30 mins after exsufflation.
The recommended guidelines are as follows
Adjust ventilation to correct hypoxaemia
Maintain close communication with surgeon
Avoid thoracocentesis unless necessary
In case of pneumothorax from rupture of pre existing bullae ,PEEP must not be applied and tharococentesis is mandatory
Cephald displacement of the diaphragm during pneumoperitoneum result in cephald movement of carina leading to endobronchial intubation
Causes are –
Direct insufflation of gas into a vessel by misplaced trochar or veress needle.
Small bubble of gas carried through injured vein at operative site
Large gas absorption into portal circulation may be caused by very fast rate of gas flow and very high intra abdominal pressure.
Suspicion of gas embolism
To be aroused by
ECG changes of rt hart strain
If paradoxical cerebral embolism occurs ,signs are:
Immediate – Bilateral Mydriasis
At the of anesthesia –comma, delayed awakening, seizures, paresis or paralysis
Precordial or esophageal stethoscope : Metallic murmur heard 2to3 sec. after gas inflow. With increasing volume typical Mill Wheal murmur appears
Precordial Doppler can detect 2 ml of gas
Swan ganz catheter detects haemodynemic changes at earliest
Capnograph Its response is biphasic :-
Small volume of gas gives high ETCO2 due to high Vco2
Large volume makes ETCO2 falls rapidly for low CO
Early and energetic management of air embolism
Stop insufflation immediately
Release pneumo peritoneum
Place pt in Durant position
Stop N2O – it helps bubble resorbtion
Insert central venous catheter to aspirate gas or foam
External cardiac message to breaks the air bubble
If all fails,Cardio pulmonary by pass and internal cardiac compression.
Patient undergoing laparoscopy are prone to develop cardiac arrythmias due to high PCO2 and raised vagal tone .
POST OPERATIVE PROBLEMS
Incidence of post operative sickness is significant , may be due to peritoneal stretching & hypercapnia
Significant pain occur in first 24 hr period
Hypothermia during recovery
Hypoxia after recovery
Post operative shoulder pain may be agonizing. It may be due to intra pleural H2CO3 which goes on dissociating to CO2
CARE FOR PREVENTION POST OPERATIVE PROBLEMS
O2 administration for couple of hours to prevent alveolar hypoxia as CO2 excretion continues
Energetic care for prevention of sickness must be taken as PONV can jeopardize all the benefits of laparoscopy and anesthesiologist gets total blame .
Proper warming of patient.
Attention must be paid for pain relief.
INERT GASES : Use of inert gases like helium ,argon can reduce hypercarbia but other changes due to increased IAP remain same .Since solubility of these gases is low, there is always a chance of gas embolism.
GASLESS LAPAROSCOPY:Here the peritoneal cavity is expanded with a fan retractor.this technique avoids hemodynamic and respiratory repercussions.Post operative PONV and port site metastasis are reduced.This thing is very appealing in severe cardiac and pulmonary diseases.Disadvantages are poor surgical site and increased technical difficulty.Combined this technique with low IAP(<5mm of Hg) is an interesting prospect .
Despite multiple advantages, Laparoscopy is not a synonym for risk free operation. The death rate during laparoscopic surgery is 0.1 to 1 per 1000 cases. Anesthesiologist must be aware, able to detect and manage those life threatening complication. .Capnography is one of the most important tool to tackle these complication and every one should know how to interrelate ETCO2 with other important findings
CO2 remains the insufflation gas of choice because of –
Its readily availability
A high ostwald blood / gas partion co efficient makes it highly soluble in blood. So the gas embolism is rare.
rapidly buffered in the blood by bicarbonates and excreted via lungs