anaesthesia for lap cholecystectomy

1. Anesthesia for Laparoscopic
cholecystectomy
Dr Nirav
Dr Nilesh
Dr Abhijit

2.  41-year-old female, married, residing at wadala (E),
Mumbai, admitted with a complaint of significant right
upper quadrant abdominal pain for 3 days, constant and
radiating to the tip of the right scapula. The pain was
associated with nausea and few bouts of vomiting.
There was no history of jaundice and no history of fever
at the time of admission.
 On examination upon presentation, the patient was
conscious, alert, and oriented. She was in pain and
mildly dehydrated. She had normal vitals and she was
not jaundiced.
 Laboratory results are as follows: white cell count,
13700 cells/mL, normal (total bilirubin, direct bilirubin,
serum amylase, urea and electrolytes, and coagulation
profile).

3.  Pregnancy test was negative.
 Chest and abdominal X-rays were within normal
limits.Ultrasound was done which showed impacted
stone and the neck of the gallbladder, distended
gallbladder with wall edema and double wall sign.
 After confirming the case as being symptomatic
gallstones with acute cholecystitis, laparoscopic
cholecystectomy was planned.
 After obtaining written informed consent for anesthesia
and surgery, in OT,the patient was placed in supine
position.
 . General anesthesia was induced with midazolam 1mg
i.v., and fentanyl 100 mcgs i.v., and propofol 80mg i.v.,

4.  Rocuronium was administered to facilitate tracheal
intubation. After tracheal intubation with 7mm cuffed
ET Tube, anesthesia was maintained with sevoflurane
and fentanyl.
 Conventional four-port laparoscopic cholecystectomy
was carried out. The pneumoperitoneum was
maintained at 12 mmHg.
 The surgery was uneventful and the patient remained
haemodynamically stable throughout the procedure.
After a smooth emergence from anaesthesia and
reversal of neuromuscular block, her trachea was
extubated without any adverse events. The patient was
then transferred to the post-anaesthesia recovery unit

5. Overview
 Introduction & History.
 Definition, IAP.
 Risks & Benefits.
 Alteration in physiology (System wise).
 Associated complications & treatment.
 Effect of position.
 Conduct of anaesthesia.
 Conclusion.

6. Introduction
 1985: first laparoscopic cholecystectomy performed in
Germany
 Richard Zollikofer of Switzerland promoted the use of
Carbon dioxide for insufflating peritoneum
 Defination - Laparoscopy is a “minimally invasive”
procedure allowing endoscopic access to the peritoneal
cavity after insufflation of a gas to create space
between the anterior abdominal wall and the viscera.

7. Advantages of Laparoscopy
 Day care surgery
 Shorter hospital stay
 Improved cosmesis
 Less post-op ileus
 Faster recovery
 Rapid return to normal activities
 Minimal pain
 Small scar
 Better preservation of resp fn

8. Disdvantages……
 More expensive
 Difficult in complicated cases
Eg. Obesity, pregnancy, previous abdominal surgery
 Potential for major complications like damage to
viscera and vascular injury
 Pneumoperitonium leading to VQ mismatch
 LL pain, rhabdomyolysis and potentially myoglobin
associated acute renal failure

9. Contraindications for
Laparoscopy
 Diaphragmatic hernia
 Severe obstructive lung disease
 Increased ICP
 V – P shunt
 Hypovolemia
 MI
 CCF
 Valvular heart diseases

10. Laparoscopy – Anesthesia
concerns
CO2 pneumo peritoneum
Due to patient positioning
Cardiovascular effects
Respiratory effects
Gastro intestinal effects
Unsuspected visceral injuries
Difficulty in estimating blood loss
Darkness in the OR

11. Intra-abdominal
pressure(IAP)
 IAP is the steady pressure within the closed
abdominal cavity.
 normal values of IAP are 0-5 mmHg.
 values more than 12-14 mmHg compromises venous
return.
 Initial flow : 4-6 L/min.
 Maintenance : 200-400 ml/min.

12. Insufflator Gas used
N2O /CO2 /Argon /He/ Air
Preferred gas : CO2
Working pressure : 12 to 14 mm Hg
Slow inflation of 1 liter / minute
(Air & O2 –risk of embolism high)
N2O –bowel distension,risk of explosion, PONV.
He & Argon not available here- embolism)

13. CO2 as Insufflator Gas
 More soluble in blood than air
 Carriage is high due to bicarbonate buffering
and combination with Hb
 Rapidly eliminated by lungs
 Inert & not irritant to tissues

14. Gasless laparoscopy….
 Peritoneal cavity is expanded using abdominal wall
lift obtained with a fan retractor.
 Gasless laparoscopy compromises surgical exposure
and increases technical difficulty.
 Appealing for patients with severe cardiac or
pulmonary disease.

15. What happens on creating a
pneumoperitoneum?
 As the volume of the abdomen increases, abdominal wall
compliance decreases and intra-abdominal pressure (IAP) climbs.
 When the IAP exceeds physiological thresholds, blood flow in
individual organ systems become compromised, potentially
increasing patient’s morbidity and mortality.

16. What are the hemodynamic effects of
pnuemoperitoneum in CVS?

17. Physiological effects
Cardiovascular
 There is biphasic response on CO
 IAP <10mmHg, milking effect on veins increasing CO
 If IAP >15mmHg, 10%-30% reduction in CO
 increase 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
 (ASA class III Patients or IV) who are volume
depleted experience the most severe
hemodynamic changes.


18. Physiological Effects
 Increased noradrenalin levels leads to increased
SVR
 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
 Hypercarbia and acidosis

19. Reasons for arrythmias during
laparoscopy….
1. Reflex increases of vagal tone may result from sudden
stretching of the peritoneum.
2. Hypercarbia & hypoxia.
3. Gas embolism.
4. Lighter planes of anaesthesia.
5. Volatile anaesthetics
 Treatment consists of interruption of insufflation, atropine
administration, inj. Lignocaine, Amiodarone and deepening of
anesthesia after recovery of the heart rate.

20. Management of CVS
changes-
 Intermittent pneumatic compression to legs will improve
venous return
 Preoperative preload augmentation offsets the hemodynamic
effect of pneumoperitoneum.
 Intravenous nitroglycerin, nicardipine, or dobutamine has
been used to manage the hemodynamic changes induced by
increased IAP.
 Use of alpha 2 agonist such as clonidine or dexmedetomidine
& or beta blocker reduces haemodynamic changes

21. Pulmonary changes
Exaggerated in obese patients, ASA classII and III patients
& in those with respiratory dysfunction
Intra-abdominal distension leads to a decrease in
pulmonary dynamic compliance
1. increased IAP displaces the diaphragm upward
2. functional residual capacity and total lung
compliance decreases by 30 to 40%
3. Early closure of smaller airways, basal atelectasis
4. increased peak airway pressures
5. increase in minute ventilation required to maintain
normocarbia
6. Increase in intra pulmonary shunting
7. Approximately 15 min after abdominal deflation,
respiratory compliance and resistance return to pre-
insufflation level.

22. Effect of pnuemoperitoneum on
PaCO2?
 CO2 is absorbed from the peritoneal cavity and
carried by blood through the systemic and portal
veins and excreted via the lungs.
 Pneumoperitoneum increases pulmonary excretion of
CO2 (VCO2) and PaCO2.
 High increase in VCO2 and PaCO2 does not happen
because of impaired peritoneal perfusion due to
haemodynamic changes and enormous buffering
capacity of the blood.

23. PaCO2
 under general anesthesia, PaCO2 progressively
increases and reaches a plateau 15 to 30 min after
beginning of CO2 insufflation.
 the main mechanism of the increased PaCO2 during
CO2 pneumoperitoneum is absorption of CO2 rather
than the mechanical ventilatory repercussions of
increased IAP.
 Correction of increased PaCO2 can be achieved by a
10% to 25% increase in alveolar ventilation.

24. What is the role of Capnography
during laparoscopy
 It serves as a non-invasive monitor of PaCO2 during
CO2 insufflation.
 helps in detection of accidental intravascular
insufflation of CO2.
 EtCO2 increases in Endo-Bron.Intubation, Sub.
Cut.emphysema & capnothorax and decreases in
Pneumothorax & CO2 embolism.

25. Capnography during
laparoscopy…
 Mean gradients (Δa-EtCO2) do not change significantly
during peritoneal insufflation of CO2.
 lack of correlation between PaCO2 and EtCO2 is seen
particularly in those with impaired CO2 excretion
capacity, and cardiopulmonary disturbances.
 Hypercapnia can develop, even in the absence of
abnormal EtCO2.
 Postoperative intra-abdominal CO2 retention can
result in increased respiratory rate and EtCO2 of
patients breathing spontaneously.

26. Physiological effects of
carbon- dioxide cont’d…..
 10-15 minutes after CO2 insufflation due to reflex
vasodilatation, an increase in ICP is seen.
 PaCO2 level has the regulatory effect on ventilation via
central & peripheral chemoreceptors.
 CO2, which easily crosses the blood-brain barrier, indirectly
controls inspiratory centre by formation of carbonic acid,
which dissociates to produce HCO3
- and H+ & increase in the
rate of respiration.
 The maximal stimulation is attained at a PaCO2 level of about
100 mmHg. Any further increase results in respiratory
depression.

27. Physiological effects of
carbon- dioxide cont’d…..
 The cardiovascular effects of hypercarbia are the
result of a balance between the direct
cardiodepressant effect of CO2 and increased activity
of the sympathetic nervous system.
 Activation of the sympathetic nervous system by CO2
in healthy individuals overcompensates for direct
cardiodepression.

28. Gastro intestinal system
 Risk factor for Regurgitation
Increased intra-abdominal pressure
Decreased lower esophageal sphincter tone (if barrier
pressure is increased>30cm of H2O)
Head down position
NG tube mandatory

29. Gastro intestinal system..
Mesentric circulation:
 Reduced bowel circulation resulting
in decreased gastric intra mucosal
pH
 Due to IAP, collapse of capillaries
and small veins,
 Reverse Trendelenburg position,
 Release of vasopressin
all lead to decreased mesenteric circulation

30. Gastro intestinal system...
 Porto Hepatic circulation:
Rise in IAP result in decreased total hepatic blood flow due
to splanchnic compression
Hormonal release (catecholamine, Vasopressin &
Angiotensin lead on to overall reduction in splanchnic
blood flow except for Adrenal glands)
 Reverse Trendelenburg position,
 Release of vasopressin
all lead to decreased mesenteric circulation

31. Renal function
 Increased IAP 
 decreased RBF 
 increased sympathetic activity 
 elevated plasma Renin activity 
 fall in filtration pressure 
 fall in urine output

32. Central Nervous System
 Increased IAP Increased lumbar spinal pressure
Decreased drainage from lumbar plexus  Increased
ICP
 Hypercapnia, high systemic vascular resistance and
head low position combine to elevate intracranial
pressure.
 The induction of pneumoperitoneum itself increases
middle cerebral artery blood flow

33. Coagulation System
 Increased IAP may lead to increased venous stasis
 causing deep vein thrombosis especially in prolonged
surgery
 deep vein thrombosis prophylaxis
should be done in such patients.

34. Temperature Variation
 Continuous flow of dry gases into peritoneal cavity
under pressure can lead to fall in body temperature.
 (sudden expansion of gas produces hypothermia due to
Joule Thompson effect)
 0.30 C fall in core temperature/50 Lit flow of CO2

35. Neuro humoral response
 Activation of Hypo thalamo pituitary Adreno cortical
Axis 
 Rise in ACTH, Cortisol and Glucogon 
 Altered glucose metabolism
Laparoscpic surgery is as stressful as
conventional surgery

36. Complications of lap
surgeries
 Due to trochar injury
 Positioning and compression effect
 CVS and RS complications
 Thermal injuries
 Gas embolism

37. Complications of gas
insufflation
 Subcutaneous emphysema
 occur if the tip of the Veress needle does not
penetrate the peritoneal cavity prior to
insufflation of gas.
 Occur in inguinal hernia repair, renal surgery
 During fundoplication for hiatus hernia repair
Extraperitoneal insufflation, which is associated
with higher levels of CO2 absorption than
intraperitoneal insufflation, is reflected by a
sudden rise in the EtCO2, excessive changes in
airway pressure and respiratory acidosis
 CO2 subcutaneous emphysema readily
resolves after insufflation has ceased

38. Respiratory Complications:
2) Pneumothorax, Pneumomediastinum,
Pneumopericardium
 peritoneal cavity ---potential channels--- pleural and
pericardial sacs.
 Defects in the diaphragm or weak points in the aortic
and esophageal hiatus allow gas passage into the
thorax.
 pleural tears occurs during laparoscopic surgical
procedures at the level of the gastroesophageal
junction.
 For diffusible gas such as CO2 without associated
pulmonary trauma, spontaneous resolution of the
pneumothorax occurs within 30 to 60 minutes.

39. Management of
Pneumothorax
 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 necessary
 Avoid PEEP if there is rupture of
emphysematous bulla and
thoracocentesis is mandatory

40. Respiratory Complications:
3)Endobronchial Intubation
 cephalad movement of the carina & diaphragm during
pneumoperitoneum, leads to endobronchial
intubation.
 Oxygen saturation decreases as measured by pulse
oximetry (SpO2) associated with an increase in
plateau airway pressure & increase in EtCO2 .

41. Respiratory Complications:
4) Gas Embolism
 most feared and dangerous complication of
laparoscopy.
 Early events, occurring with 0.5 mL/kg of air or less,
include changes in Doppler sounds and increased
mean pulmonary artery pressure.
 lethal dose of embolized CO2 is approximately five
times greater than that of air.

42. Diagnosis of Gas-embolism
 Detection of gas in right side of Heart –foamy
blood aspirated in the central venous catheter
 Difference between PaCO2 ETCO2 increases.
 Recognition of physiological changes secondary to
emboli:
 Tachycardia
 Cardiac arrhythmia
 Hypotension
 CVP rise
 Mill-wheel murmur
 Cyanosis
 Right heart strain pattern in ECG
 Pulmonary edema
 Doppler & TEE ---- very sensitive (0.5ml/kg)

43. Gas Embolism
Suspicion of Gas Embolism
 Blood on aspiration from Vere’s needle
 Pulsation of flow meter pressure gauge
 Disappearance of abdominal distention
despite sufficient volume of gas

44. Treatment of Gas Embolism
 Immediate cessation of insufflation
 Release of pneumo-peritoneum
 Patient in head down and left lateral
decubitus (Durant’s) position
 Cessation of N2O
 Give 100% oxygen
 CVP insertion and aspiration of gas
 CPR help to fragment CO2 emboli
into small bubbles

45. How Durant position
helps?
 Head-down position keeps a left-ventricular air bubble away from
the coronary artery ostia (which are near the aortic valve) so that
air bubbles do not enter and occlude the cornonary arteries.
 Left lateral decubitus positioning helps to trap air in the non-
dependent segment of the right ventricle, preventing it entering
the pulmonary artery & also prevents the air from passing through a
patent foramen ovale.

46. Treatment of gas embolism
cont’d…
 A central venous or pulmonary artery catheter may
be introduced for aspiration of the gas.
 External cardiac massage may be helpful in
fragmenting CO2 emboli into small bubbles.
 Cardiopulmonary bypass of blood has been used
successfully to treat massive CO2 embolism.
 Hyperbaric oxygen treatment should be strongly
considered if cerebral gas embolism is suspected.

47. What are the effects of pneumoperitoneum
on Renal physiology?
 An IAP of 20 mm Hg will reduce GFR by 25%.
 Mechanism for this is postulated to be an impaired renal perfusion
secondary to the combined effect of-
 reduced renal afferent flow due to impaired cardiac output and
 reduced efferent flow due to raised renal venous pressure.
 Diminished RBF is a potent trigger for renal angiotensin aldosterone
system.

48. Effect of pneumoperitoneum on
splanchnic physiology
 Initially with an IAP <10 mmHg venous return from splanchnic vessels
increase leading to a transient increase in Cardiac output.
 Persistent IAPs over 20 mm Hg will cause a reduction in mesenteric and
gastrointestinal mucosal blood flow by up to 40% with progressive tissue
acidosis.

49. the problems with positioning
during laparoscopy :
 Extreme positions place the patient at risk of movement
on the table.
 patient should be securely positioned with vulnerable
pressure points and eyes being protected throughout
the procedure.
 No significant changes in shunt fraction or dead space
ventilation occurs even in a 10 0 - 20 0 head up or
head down position.

50. Position- Cardio-Vascular
Effects
 Head up tilt----- Blood pooling
Venous stasis
Thrombo-embolism
↓ venous return
↓cardiac output
→ ↓ Blood Pressure

51. Problems due to positioning
cont’d….
 Nerve compression due to overextension of the arm must be
avoided.
 Shoulder braces should be used with great caution and must not
impinge the brachial plexus.

52. Anaesthetic Plan
 Pre-operative assessment
 The cardiac and pulmonary status of all patients should
be carefully assessed
 Pre-medication
 Anxiolytics
 antiemetic
 H2 receptor blockers
 Gastro-kinetic drugs
 Preemptive analgesia with NSAIDs
 Atropine to prevent vagally mediated bradyarrhythmias

53. Monitoring
1.Routine Patient Monitoring Include
 Continuous ECG
 Intermittent NIBP
 Pulse oximetry (SpO2)
 Capnography (EtCO2)
 Temperature
 Intraabdominal pressure
2. Optional Monitoring Include
 Pulmonary airway pressure
 Oesophageal stethoscope
 Precordial doppler
 Transoesophageal echocardiography
VIGILANT ANAESTHESIOLOGIST

54. Anaesthetic techniques
 General anaesthesia
 The most common technique used for laparoscopic
surgeries is General anaesthesia
 Preloading with crystalloid solution is
recommended
 Preoxygenation
 During induction of Anaesthesia, avoid stomach
inflation
 tracheal intubation – mandatory
 PLMA should only be used by experienced LMA
users
 NG tube placement for Stomach decompression
 Catheterisation to empty the urinary bladder

55. G.A. for laproscopic surgery
 bag and mask ventilation before intubation should be minimized
to avoid gastric distension.
 insertion of a nasogastric tube may be required to deflate the
stomach-improve surgical view, avoid gastric injury on trochar
insertion.
 Maintaining with agents like, Isoflurane, Desflurane & Sevoflurane
blunt the haemodynamic response to pneumoperitoneum.
 Nitrous oxide causing nausea & vomiting is controversial. But it may
distend the bowel, in patients with intestinal obstruction.

56. Muscle relaxants
 Prevents high intra-abdominal and intra-thoracic
pressures due to pneumoperitoneum..
 Muscle paralysis reduces the IAP needed for the same
degree of abdominal distention.

57. About PEEP…
 Various studies support that a PEEP of 5 cm H2O should
be considered essential during laparoscopic surgeries to
decrease intraoperative atelectasis.
 Addition of titrated levels of PEEP can be used to
minimize alveolar de-recruitment.
 But must be used cautiously as increasing PEEP may
further compromise cardiac output.

58. COPD and LAP surgery
 Helium for pneumo peritonium
 Minimal tilt
 Procedure time should be minimized to less than 2hrs
 PFT,CXR,ABG, SpO2 in addition to history and physical
examination
 Cessation of smoking, adequate bronchodilators,
steroids and chest physiotherapy with incentive
spirometry help to reduce post op pul c/o

59. Laparoscopic surgery in
obese patients
 Detrimental effect in respiratory mechanics is due to
supine position and increased weight
 Carbon dioxide production and oxygen consumption are
increased.
 Reduced chest wall compliance & decreased lung
compliance.
 FRC will be reduced 25 per cent in the supine position,
with a further reduction of 20 per cent with
Anaesthesia.
 airway closure and hypoxemia,
 Increase in intrapulmonary shunting.
 Alterations to gastric function and drug distribution. In
obese patients, the umbilicus is located 3-6cm caudal to
the aortic bifurcation, making trocar placement more
difficult..

60. Laparoscopic surgery in
obese patients
 complications may be reduced by filling the
peritoneal cavity with carbon dioxide (CO2) to a
predetermined pressure level rather than to a
preset volume
 Tilt Test:
 Placing the patient in steep Trendelenburg for two
to five minutes following intubation and
positioning, observing the patient’s cardiac and
respiratory indices. Patients who remain
Normotensive and maintain peak airway pressures
at < 30-40mmHg during the Tilt Test
before and after insufflation , the surgery is
relatively straightforward, producing excellent
results.

61. Lap cholecystectomy in
pregnancy…
 Increased risk of acid aspiration
 Increased risk of abortion/ miscarriage / premature
labor
 Greater distribution volume due to increase in blood
volume
 More prone to hypoxemia due to decrease in FRC and
increase in O2 consumption

62. Contd…
 Difficult airway due to wt. gain, soft tissue in the neck,
breast enlargement, and laryngeal edema
 Relatively safe in 8-24 wks of pregnancy.
 Chances for damage to gravid uterus by Verees needle
 Fetal acidosis common

63. SAGES recommendations for safe
lap in pregnancy
 Operation in 2nd trimester before 24 wks
 Tocolytics therapy if risk of preterm labor
 Open laparoscopy for abdominal access (HASSON’S TECH) to
avoid damage to gravid uterus
 IAP less than 12mmHg
 Continuous Fetal heart monitoring with trans vaginal USG
 PaCO2 to be maintained at normal levels with the help of
EtCO2 monitor/ABG
 Mechanical ventilation to maintain physiologic maternal
alkalosis (pH7.44)
 Pneumatic compression devices to calf muscles to prevent
DVT
 *(SAGES- society of American Gastrointestinal and
Endoscopic surgeons)

64. Postoperative management
 All patients should receive supplemental oxygen.
 This helps to mitigate the effects of pneumoperitoneum
on respiratory function.
 Alveolar recruitment techniques, using short-term
continuous positive airway pressure or high flow oxygen
delivery systems may be used.
 Refered Shoulder pain-generaly resolves after 30 to 60
minutes. Diaphragmatic irritation d/to gas used to creat
pneumoperitonium.

65. Thank you
 Thank you
& wake up