Laparoscopy and anaesthesia

1. ANAESTHETIC IMPLICATION
OF LAPROSCOPIC SURGERY
Dr.J.Jayalakshmi
First year postgraduate
Department of anaesthesiology
CMCH.

2. LAPAROSCOPY – OVERVIEW
Minimal invasive surgical procedure which allows endoscopic access to the
peritoneal cavity after insufflation of a gas (co2)
To create space between the anterior abdominal wall and the viscera.
The space is necessary for safe manipulation of instruments and organs.
Term coined by hans christian jacobaeus in 1910.
Co2 was used by richard zollikofer in 1924

3. Gases used in laparoscopic surgeries
Air was the first gas to be used poorly soluble in blood causing embolic
phenomenon.
O2 discarded because of being combustible
N2O also supported combustion , when mixed with the methane in the
bowels.
Inert gases like helium, argon & xenon are expensive and cause gas
embolism

4. WHY CARBON DIOXIDE ??
ADVANTAGES
• Non combustible
• More soluble in blood which increases
the safety margin and decreases the
consequences of gas embolism.
• Rapidly eliminated by lungs
• Inert & not irritant to tissues
DISADVANTAGES
• Hypercarbia
• Acidosis
• Sympathetic stimulation
• Need for hyperventilation

5. Ideal gas for pneumoperitoneum
 Limited systemic absorption
 Limited systemic effects if absorbed
 Rapid excretion
 High solubility in blood
 Should not support combustion
 Colourless, inert, nonexplosive
 Readily available
 Non explosive, nontoxic

6. Advantages
Minimizes surgical incision and stress response
Decreases postoperative pain and opioid requirements preserves diaphragmatic function
 improves postoperative pulmonary function
 earlier return of bowel function
Fewer wound related complications
 Earlier ambulation
 Shorter hospital stays
 Early return to normal activities and work

7. Disadvantages
More expensive
More operating time
Difficult in complicated cases
 potential for major complications in inexperianced hand

8. General contraindications
Raised icp
 Hypovolemia
Right to left shunts
Patent foramen ovale

9. Laparoscopy – anaesthetic concerns
Co2 pneumo peritoneum
Patient positioning
Surgical complications
Difficulty in estimating blood loss
Patient specific

10. Intra-abdominal pressure(IAP)
IAP is the steady pressure within the closed abdominal cavity.
Normal values of intra abdominal pressure are 0-5 mmhg.
Values more than 12-14 mm hg compromises venous return

11. Pneumoperitoneum
Initial access necessary for co2 insuflation could be achieved either
through a blind insertion of a veress needle that consists of a blunt tipped,
spring loaded inner stylet and sharp outer needle through a small
subumbilical incision or a trocar inserted under direct vision.
A variable low electronic insuflator that automatically terminates gas
flow at a preset intraabdominal pressure is used to achieve
pneumoperitoneum.

12. Preset pressures of 15 mm hg or less are safest to maintain
pneumoperitoneum and allow performance of laparoscopic techniques.
The gas is introduced at 21°c with almost zero percent humidity and
14°c lower than body temperature
Initial flow : 4-6 l/min.
Maintenance : 200-400 ml/min

13. What happens
Volume of the abdomen increases, abdominal wall compliance
decreases intra-abdominal pressure climbs. When the IAP exceeds
physiological thresholds, blood flow in individual organ systems
become compromised, potentially increasing patient’s morbidity and
mortality

14. Physiological changes during laparoscopy

15. IAP
INTRATHORACIC STIMULATION OF
PRESSURE PERITONEAL
RECEPTORS
IVC PERIPHERAL VENOUS
COMPRESSION POOLING RESISTANCE
ACTIVATION OF SNS/RAAS
VENOUS RETURN
CARDIAC OUTPUT
RELEASE OF CATECHOLAMINES
VASOPRESSIN
SVR BP
INCREASED VASCULAR
RESISTANCE OF ABDOMINAL ORGANS

16. Increased SVR
 Due to neuro humeral responses
 Plasma vasopressin levels parallels increase in SVR
 Hypercapnea causes decrease in SVR and increase in PVR
 Neuroendocrine responses >> hypercapnea induced decrease in SVR
 Normal heart tolerates increase in after load but deleterious for cardiac
patients
 Increase in PVR deleterious for pulmonary hypertension patients

17. Decreased Cardiac Output
Exaggerated if
Hypovolemic
 Head up position
 Haemodynamic changes occur at beginning of peritoneal Insufflation
 CO later becomes normal due to surgical stress

18. Cardiac filling pressures
 Paradoxical increase due to increased intra thoracic pressure due
to pneumoperitoneum
 CVP , right atrial pressure, pulmonary artery occlusion pressure
is not reliable
 Ejection fraction - no significant reduction until 15 mmhg
 Heart rate – remains same or will be increased slightly

19. What can be done ???....
Increased VR and CO - increase circulating volume before
pneumoperitoneum
Peripheral pooling - fluid loading/ head down before pneumo/ IPC
devices
Incresed SVR – Vasodialtors (inhalational/ NTG/ nicardipine)
 Haemodynamic responses - clonidine, dexmeditomidine,
betablockers

20. Cardiac arrythmias
Occurs during insufflation brady/arrythmia/asystole
Causes
Reflex increase in vagal tone due
to sudden stretching of peritoneum
 Light plane of anaesthesia
 Embolism
 Hypercarbia
 Hypoxia
 Preexisting cardiac disease
 Reversible event
 Stop insufflation
 Atropine
 Deepen palne after hr becomes normal

21. Pneumoperitoneum in cardiac patients
 Patients (ASA class III or IV) who are volume depleted
experience the most severe hemodynamic changes.
 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.
 Advantage of nicardipine - arterial vasodilator . Venous return
preserved

22. Cardiovascular collapse during laparoscopy
 Profound vasovagal reaction
 Cardiac dysrhythmias
 Excessive intraabdominal pressure
 Tension capno (pneumo) thorax
 Cardiac tamponade
 Significant gas embolism
 Acute blood loss
 Myocardial ischemia/infarction
 Severe respiratory acidosis (hypercapnia)
 Anaesthetic drug related

23. Respiratory effects
 Diaphragm elevated
 Reduced thoraco pulmonary
compliance
 FRC reduced
 Basal atelectasis
 Increased min ventilation- airway pressure
 Pulmonary resistance increase
Elevated diaphragm
V/q mismatch
position

24. Hypercarbia
 Co2 is absorbed from the peritoneal cavity and carried by blood
through the systemic and portal veins and excreted via the lungs.
 Increases pulmonary excretion of co2 (vco2) and paco2.
 Absorption depends on the gases diffusivity, the absorption area, and
vascularity of insufflation site & Extra or intraperitoneal insufflation

25. Paco2 increase
Increase of paco2
Absorption of co2 from the peritoneal cavity,
Impairment of pulmonary ventilation and perfusion by
• Abdominal distention
• Patient position
• Volume-controlled mechanical ventilation
Carbon dioxide absorption is greater during extraperitoneal insufflation
than during intraperitoneal insufflation.

26.  The co2 absorption reaches a plateau within 10 to 15 minutes
after initiation of intraperitoneal insuflation and not influenced by
the duration of the surgery.
 Continuous to increase progressively throughout
extraperitoneal co2 insuflation.
 Any significant increase in paco2 after this period - co2
subcutaneous emphysema.
 Increase in paco2 depends on the IAP.

27.  If controlled ventilation is not adjusted in response to the
increased dead space, alveolar ventilation will decrease and
paco2 will rise.
 Correction of increased paco2 can be achieved by a 10% to
25% increase in alveolar ventilation.

28. Capnography during laparoscopy
Non-invasive monitor of paco2 during co2 insufflation.
Helps in detection of accidental intravascular insufflation of co2
ETCo2 increases in
 Endobronchial Intubation,
 Subcutaneous emphysema
 Capnothorax
Decreases in
 Pneumothorax
 Co2 embolism

29.  Mean gradients (δa-etco2) do not change significantly during
peritoneal insufflation of co2
 Less correlation between paco2 and etco2 in those with impaired
co2 excretion capacity, and cardiopulmonary disturbances.

30. Respiratory complications
 Co2 subcutaneous emphysema
 Pneumothorax
 Endobronchial intubation
 Gas embolism

31. Co2 subcutaneous emphysema
Accidental extraperitoneal insufflation
Extensive subcutaneous emphysema can develop involving the
abdomen, chest, neck, and groin.
If the emphysema extends to the chest wall and the neck, the co2 can
track to the thorax and mediastinum
Capnothorax or capnomediastinum

32.  Predictors of subcutaneous emphysema
 Operative time of >200 minutes
 Use of six or more surgical ports
 Any increase in petco2 occurring after petco2 has plateaued should
suggest this complication.
 If there is neck or face emphysema, a chest xray should be obtained to
rule out capnothorax or capnomediastinum.

33. Management
 In most cases, no specific intervention is required,
 Subcutaneous emphysema resolves soon after the abdomen is
deflated.
 Significant hypercarbia despite aggressive hyperventilation
 Temporarily stop
 Subcutaneous emphysema readily resolves once insufflation has
ceased.
 Resumed after correction of hypercapnia using a lower
insufflation pressure.
 Not a contraindication for tracheal extubation at the end of surgery.

34. Pneumothorax Pneumomediastinum&
Pneumopericardium
 Movement of gas during the creation of a pneumoperitoneum
Causes
 Peritoneal cavity ---potential channels--- pleural and pericardial sacs.
 Defects in the diaphragm or weak points in the aortic and esophageal
hiatus
 Pleural tears occurs during laparoscopic surgical procedures
 Rupture of a lung bulla or bleb could produce a tension pneumothorax
independent of the pneumoperitoneum

35. Presentation
 Undetected intraoperatively
 Unexplained increase in airway pressure
 Hypoxemia
 Hypercapnia
 Surgical emphysema
 Inequality in chest expansion
 Reduced air entry
 Bulging diaphragm
 Severe cardiovascular compromise with profound hypotension in tension
pneumothorax
 Confirmed by chest Xray.

36. Management
PEEP - reduce the pressure gradient between the abdomen and the thorax
during both inspiration and expiration
• Inflate the lung
 Deflation of the abdomen
 Supportive treatment
 Conservative if minimum physiologic compromise
 Hyperventilation

37. No PEEP in bullae rupture, thoracocentesis mandatory in such cases.
 Intercostal cannula in severe compromise.
 After stabilization can be resumed at lower IAP.
 Chest drain if re accumulation occurs.
 conversion to an open procedure.

38. Endobronchial intubation
Cephalad displacement of the diaphragm
during pneumoperitoneum
Cephalad movement of the Carina
Endobronchial intubation.
 Decrease in the oxygen
saturation
 Increase in plateau
airway pressure.
 Increase in etco2

39. Gas embolism
 Intravascular injection of gas - direct needle placement into a vessel
 Gas insufflation into an abdominal organ during the induction of
pneumoperitoneum
 Lethal dose of embolized co2 is approximately five times greater than
that of air
 Effects are determined by
 Size of bubbles
 Rate of insufflation

40. Rapid insufflation of gas under
High pressure
Gas lock in the vena cava and
right atrium
Obstruction to venous return
with a fall in cardiac output
Circulatory collapse

41.  Acute right ventricular hypertension may open
the foramen ovale, allowing paradoxical gas
embolization
 Cardiac
arrhythmia,
 Hypoxemia,
 Hypotension,
 Decrease in etco2.
 Cerebral co2
embolism
Ecg changes
A right strain pattern
and widening of the
qrs complex.

42. Diagnosis
 Detection of gas emboli in the right side of the heart
 Recognition of the physiologic changes from embolization
 Early events, occurring with 0.5 ml/kg of air or less, include changes in
doppler sounds and increased mean pulmonary artery pressure.
• ECG changes of right-sided heart strain
 When the size of the embolus increases (2 ml/kg of air)
• Tachycardia
• Cardiac arrhythmias, hypotension, increased CVP
• Alteration in heart tones (eg-Millwheel murmur), cyanosis

43. Management
 Stop insufflation
 Release of pneumoperitoneum
 Steep head down . left lateral (durrant)
 100% o2
 Hyperventilate
 Central venous – gas aspirated
 External cardiac massage – fragments embolus into small bubbles
 CPCR
 Cardiopulmonary bypass
 Hyperbaric oxygen therapy in cerebral embolus

44. 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 coronary 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.

45. Risk of aspiration of gastric contents
 At risk for acid aspiration syndrome
 The increased IAP results in changes of the lower esophageal sphincter that
allow maintenance of the pressure gradient across the gastroesophageal
junction and that reduce the risk of regurgitation.
 The head-down position should help to prevent any regurgitated fluid
from entering the airway.

46. Regional perfusion
 Increased cerebral perfusion and intracranial pressure
 Caution in patient with brain tumor or ventriculo peritoneal
shunt
 Decreased splanchnic blood low
 Decreased hepatic blood low
 Variable (decreased or no change) in bowel perfusion, mechanical
pneumoperitoneum compression balanced by hypercarbic vasodilatation )

47.  Reduced renal perfusion and urine output (reduced during
pneumoperitoneum/recovery following dilation)
 The urine output generally normalizes following pneumoperitoneum
deflation with no consequent renal dysfunction.
 Increased IAP and the head-up position result in lower limb venous stasis.
 Decreased femoral vein flow.
 Increased potential for deep vein thrombosis and pulmonary
embolism.

51. Problems related to patient position
 Patient positioning depends on the site of surgery
 Head-down tilt for pelvic and lower abdominal surgery
 Head-up position for upper abdominal surgery.
 Positions may be responsible for, or contribute to, the
development of pathophysiologic changes or injury during
laparoscopy
 The steepness of the tilt also affects the magnitude of these
Changes.

52. CVS effects
NORMOTENSIVE IN HEAD DOWN
CVP CO
SYSTEMIC VASODILATATION ,
BRADYCARDIA
EXAGGERATED CHANGES IN CARDIAC
PATIENTS
CARDIAC WORK& MVO2
PROLONGED HEAD DOWN CEREBRAL & UPPER AIRWAY
EDEMA
INCREASE IOP

53. HEAD UP
VENOUS RETURN
CO MAP
STEEPER THE TILT CARDIAC
OUTPUT VENOUS STASIS IN HEAD UP ,
LITHOTOMY

54. Respiratory changes
 Head down postition facilitates the development of atelectasis.
Decreases in the FRC / total lung volume
pulmonary compliance
 More marked in obese, elderly, and debilitated patients.
 In healthy patients no major changes are seen.
 The head-up position is usually considered to be more favorable to
respiration

55. Nerve injury
 Potential complication during the head-down position.
 Overextension of the arm must be avoided.
 Shoulder braces should be used with great caution and must not impinge on the brachial
plexus.
 Lower extremity neuropathies (e.G., Peroneal neuropathy, meralgia paresthetica,
femoral neuropathy) have been reported after laparoscopy.
 The common peroneal nerve is particularly vulnerable and must be protected when the
patient is placed in the lithotomy position.
 Prolonged lithotomy position can result in lower extremity compartment syndrome.

56. Well leg compartment syndrome
 Complication of prolonged steep trendelenberg position
 Causes
 Impaired perfusion to lower limbs venous
compression by stirrups
 Femoral venous drainage due to pneumoperitoneum
 Presentation
 Disproportionate lower limb pain after surgery
 Rhabdomyolysis
 Myoglobin associated renal failure

57.  Risk factors
 Surgery > 4 hrs muscular lower limbs obesity
 Peripheral vascular disease hypotension
 Steep trendelenberg
 Prevention
 Ipc /compression stockings
 Heel –ankle supports (over calf knee supports) moving patients limbs
during surgery
 Pulse oximeter in great toe to assess adequacy of lower limb perfusion

58. Post operative benefits
STRESS RESPONSE
 Low plasma concentrations of c-reactive protein and interleukin- 6 –
less tissue damage
 Reduced metabolic response ( hyperglycemia ,leukocytosis)
 Nitrogen balance and immune function better preserved.
 Avoids prolonged exposure and manipulation of the intestine
 Postoperative ileus and fasting, duration of intravenous infusion, and
hospital stay are significantly reduced

59. Post operative pain
 Reduction in postoperative pain and analgesic
 Preoperative NSAIDs and cox -2 inhibitors decreases pain
 Visceral type of pain
 Shoulder tip pain
 Multimodal analgesia
Pre op NSAIDs
Local infiltration
Intraperitoneal LA
Opiates
Complete evacuation
of co2 pneumoperitoneum

60. Pulmonary dysfunction
 Upper abdominal surgery causes postoperative changes in pulmonary
function
 Less severe and recovery is quicker after laparoscopy.
 Greater reductions in expiratory volumes and slower recovery of
pulmonary function may be seen in
 Older patients
 obese patients
 smokers
 Patients with COPD

61. PONV
 Lap – risk factor for PONV
 Peri operative opioids – risk factor
 Prevention
 Propofol anaesthesia
 5 ht3 antagonists

62. Anaesthesia for laparoscopy

63. Pre operative evaluation
 Done in the usual manner
 Particular attention to cardiovascular and respiratory status
 Cardiac evaluation in patients with cardiac disease
 Risk vs benefit in cardiac patients
 Nephrotoxic drugs avoided in renal impairment
 Always consider the fact that there is chance of converting to open
procedure

64.  Undesirable in patients with increased intracranial pressure and
hypovolemia
 In a patient with poor pulmonary reserve more extensive preoperative
evaluation including PFT is advisable.
 Pulmonary function tests (PFT) identify patients who are likely to
experience hypercarbia and acidosis
 Prophylaxis of deep vein thrombosis
 Routine investigations

65. Premedication
Adapted to the duration of the laparoscopy and to the necessity for quick recovery
 Anxiolytics - Midazolam , alprazolam
 Anti emetics - Ondansetron , promethazine, dexamethasone
 Antacids - Ranitidine ,pantoprazole
 Prokinetics – Metoclopramide
 Anticholinergics to prevent vagally mediated brady
 Alpha 2 agonists reduce intra op stress & improve Haemodynamics
 Analgesics pre op nsaids reduce post op pain opiods

66. Patient positioning
 Positioned with great care to prevent nerve injuries
 Padding should protect from nerve compression, and shoulder braces,
placed overlying the coracoid process.
 Patient tilt should be reduced as much as possible and should
Not exceed 15 to 20 degrees.
 Tilting must be slow and progressive to avoid sudden
hemodynamic and respiratory changes

67. Monitoring
• All standard monitors
• TEE - In significant cardiopulmonary disease, To monitor response to
pneumoperitoneum & position
• ABG - In pre existing pulmonary disease persistant refractory introp
hypercapnia
• Cerebral oximetry – high risk patient /prolonged surgery/ head up/down,
Provides information on brain oxygenation

68. Thank you