Transcript of " anaesthsia for laparoscopic surgery final ppt"
Dr Santanu Kumar Dash
to understand the principles of anaesthesia for laparoscopic surgery to increase awareness of the risks of CO2 peritonium benefits of laparoscopic surgery from patient’s point of view special considerations in geriatrics, COPD, heart disease, pregnancy, paediatrics and obese patients
Laparoscopy introduced in 20 th Century 1975 : first laparoscopic salpingectomy 1970 -- 80 : used for gyne procedures 1981: Semm, from Germany,1st lap appendectomy 1989: laparoscopic cholecystectomy
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
More expensive More operating time Difficult in complicated cases Potential for major complications in inexperianced hand
Diaphragmatic hernia Acute or recent MI Severe obstructive lung disease Increased ICP V – P shunt Hypovolemia CCF Valvular heart diseases
CO2 pneumo peritoneumDue to patient positioningCardiovascular effectsRespiratory effectsGastro intestinal effectsUnsuspected visceral injuriesDifficulty in estimating blood lossDarkness in the OR
Insufflator Gas usedN2O /CO2 /Argon /He/ AirPreferred gas : CO2Working pressure : 12 to 14 mm HgSlow inflation of 1 liter / minute(Air & O2 –risk of embolism high.N2O –bowel distension,risk of explosion,PONV.He & Argon not available here- embolism)
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
Cardiovascular effects depends on ▪ Patient’s preexisting cardiopulmonary status ▪ the anesthetic technique ▪ intra-abdominal pressure (IAP) ▪ carbon dioxide (CO2) absorption ▪ patient position ▪ duration of the surgical procedure
- There is biphasic response on CO- If IAP <10mmHg, milking effect on veins 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
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
common during insufflation and during desufflation Volatile anaesthetic agents Hypercarbia, hypoxia and gas embolism ppt tachyarrythmias and VPDs Sudden stretching of peritoneum causes vagal stimulation Light planes of anaesthesia
Management : Adequate preload will improve cardiac output Intermittent pneumatic compression to legs will improve venous return Use of alpha 2 agonist such as clonidine or dexmedetomidine & or beta blocker reduces haemodynamic 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 2. increased IAP displaces the diaphragm upward 3. functional residual capacity and total lung compliance decreases 4. Early closure of smaller airways, basal atelectasis 5. increased peak airway pressures 6. increase in minute ventilation required to maintain normocarbia 7. Increase in intra pulmonary shunting
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
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 vasopressinall lead to decreased mesenteric circulation
Porto Hepatic circulation:Rise in IAP result in decreased total hepatic blood flow due to splanchnic compressionHormonal release (catecholamine, Vasopressin & Angiotensin lead on to overall reduction in splanchnic blood flow except for Adrenal glands
Increased IAP decreased RBF increased sympathetic activity elevated plasma Renin activity fall in filtration pressure fall in urine output
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
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.
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
Activation of Hypo thalamo pituitary Adreno cortical Axis Rise in ACTH, Cortisol and Glucogon Altered glucose metabolismLaparoscpic surgery is as stressful asconventional surgery
Head Down tilt - for pelvic and sub meso-colic surgery HeadUp tilt - for supra mesocolic surgery Lithotomy position - for gynecological procedures
Hyper extension of arm --- brachial plexus injury Lithotomy position --- common peroneal injury
Due to trochar injury Positioning and compression effect CVS and RS complications Thermal injuries Gas embolism
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
Pneumothorax, Pneumomediastinum and Pneumopericardium Sudden hypoxia, rise in peak airway pressure, hypercarbia, haemodynamic alterations and abnormal movement of the hemidiaphragm on laparoscopic view should raise a suspicion of pneumothorax
Recommended Guidelines 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
Most feared & fatal complication Seen frequently when laparoscopy is associated with hysteroscopy Intra vascular injection of gas following direct trocar placement into vessel Gas insufflation into abdominal organ 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
Depends on volume of air and rate of iv entry Rapid insufflation of gas into blood (2ml/kg) -> larger bubbles -Gas lock in RA & venacava -> Fall in cardiac output ->High pressure in RA -> Open foramen ovale ->Embolus in cerebral & coronary beds -> Paradoxical embolism
Detection of gas in right side of Heart –foamy blood aspirated in the central venous catheter 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)
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
Postoperative Pain abdominal and shoulder tip pain after laparoscopic surgery Complete removal of the insufflating gas is essential Infiltration of the portal sites with a local anaesthetic reduces pain right-sided subdiaphragmatic instillation with a local anaesthetic reduces shoulder tip pain
Post Operative Nausea & Vomiting (PONV) Peritoneal insufflation, bowel manipulation and pelvic surgery are some of the causative factors A meticulous anaesthetic technique along with antiemetics is helpful in reducing the incidence of PONV
J Emerg Trauma Shock. 2011 Apr;4(2):168-72.Comparison of ondansetron and combination of ondansetron(4mg)and dexamethasone(4mg) as a prophylaxis for postoperative nauseaand vomiting in adults undergoing elective laparoscopic surgery.Bhattarai B, Shrestha S, Singh J.SourceDepartment of Anesthesiology, Dhulikhel Hospital, KathmanduUniversity Hospital, Dhulikhel; Kavre, Nepal.Conclusion: Combination of ondanserton and dexamethasone is moreeffective in preventing post operative nausea vomiting in patientsundergoing laparoscopic surgerythan ondansetron alone.
Am J Ther. 2011 Apr 23. [Epub ahead of print]A Randomized Double Blind Study to Evaluate Efficacy ofPalonosetron(0.075mg) With Dexamethasone(8mg) VersusPalonosetron Alone for Prevention of Postoperative andPostdischarge Nausea and Vomiting in SubjectsUndergoing Laparoscopic Surgeries with High Emetogenic Risk.Blitz JD, Haile M, Kline R, Franco L, Didehvar S, Pachter HL, Newman E, Bekker A.SourceDepartment of Anesthesiology, New York Uiversity Langone MedicalCenter, New York, NY.Conclusion: There was no change in comparative efficacy over 72hours, most likely due to the low incidence of PDNV in both groups.
Peritoneal cavity is expanded using abdominal wall lifter. This avoids haemodynamic & respiratory repercussions of increased IAP It increases technical difficulty
Anaesthetic Goals Accommodate surgical requirements and allow for physiological changes during surgery. Monitoring devices available for the early detection of complications. Recovery from anaesthesia should be rapid with minimal residual effects. The possibility of the procedures being converted to open laparotomy to be considered
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
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
Maintenance of Anaesthesia ▪ intermittent positive pressure ventilation (IPPV) . ▪ Normocarbia (34-38mmHg) to be maintained by adjusting the minute volume ▪ The use of nitrous oxide during laparoscopic surgery is controversial (bowel distension during surgery and the increase in postoperative nausea) . ▪ Halothane increases the incidence of arrhythmia ▪ Isoflurane / sevoflurane comparatively better Reversal of NM blockade
▪ Epidural anaesthesia for outpatient gynaecological laparoscopic procedures to reduce complications and shorten recovery time after anaesthesia .▪ not been reported for laparoscopic cholecystectomy or other upper abdominal surgical procedures except in patients with cystic fibrosis .▪ The high block produces myocardial depression and reduction in venous return, aggravating the haemodynamic effects of tension pneumoperitoneum
Local anesthesia with IV sedation Quick recovery less PONV Less haemodynamic changes Early diagnosis of complications
Risk for post operative pulmonary complications can be minimised by meticulous pre op.preparation. 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
Standard monitoring IAP less than 12mmHg GA with controlled ventilation Helium for pneumo peritonium Monitor peak airway pressure to avoid barotraumas Minimal tilt Multimodal approach for P.O.analgesia to avoid respiratory depression
Obesity is associated with Diabetes Mellitus, hypertension and hypercholesterolemia, angina and sudden death. Life expectancy in obese patients is shortened by as much as eight years.
Obesity is defined as a body mass index (BMI) >30kg/m2. Laparoscopy is not contraindicated in healthy obese patients who experience reduced pain, faster recovery and fewer postoperative problems compared to laparotomy
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. Functional residual capacity (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.
Potential airway and intubation problems Difficulties may be encountered during intravenous access, positioning, pneumoperitoneum induction, trocar access In obese patients, the umbilicus is located 3-6cm caudal to the aortic bifurcation, making trocar placement more difficult. .
Two tables may be necessary. Mechanical lifting devices, with extra padding should be available. Monitoring equipment such as a large blood pressure cuff, compression lower extremity stockings and pneumatic boots should be available. Intravenous access may need to be central rather than peripheral in some cases. Positioning should include padded stirrups with extra padding, compression devices Towels behind shoulder blades to elevate the head, facilitating intubation and airway access .
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.
Postoperative Care: Early mobilisation and avoidance of the supine position will facilitate early recovery. oxygen therapy Aggressive pulmonary care and positioning. Abdominal pain may restrict ventilation and ambulation. analgesia is paramount. Obese patients must have sequential compression devices on their lower extremities or Prophylactic anticoagulation to prevent pulmonary emboli (five to 12 per cent obese patients)7.
Age related physiological and pathological changes and age related concomitant diseases Narrow margin of safety decrease in organ reserve Lead to high incidence of Peri operative complications
Positioning the patient: 1.Fragile osteoporotic & spondylytic changes in vertebrae 2.Protect from nerve injury 3.Prevention of venous stasis 4.Careful tilting (increment of 5° )
During intra-op period: -CV to maintain EtCO2 – 35mm.Hg. - Isoflurane less arrhythmogenic - IAP maintained below 15mm.Hg - Atropine to counteract ref.vagal tone - Monitor urine out put & Electrolytes - Careful titration of all anaesthetic agents -
-During recovery— -Exaggerated hypotension on correcting lithotomy - Expected delay in recovery Inc.sensitivity to drugs. Imp.metabolism Delayed excretion
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
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
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
Small abdominal surface and organs demand small telescopes for laparoscopy. The abdominal surface / cavity ratio in infants and children is less than that of adults. The abdominal wall in children is pliable and attention is needed while placing the cannulas and trocars to prevent intraabdominal injuries. The trans umbilical open laparoscopic technique for insufflation under direct vision is recommended to prevent complications with veress-needle Gasless laparoscopic surgery can now be performed in these children and smaller infants .
In infants less than 5 kg weight, peri umbilical area should not be used for port access because of risk of puncture of umbilical vessels. Cold, non-humidified CO2 directly in to the abdominal cavity also contributes to a major risk of hypothermia A fluid bolus of 20 ml.kg-1 can be used to offset hemodynamic effects
In neonates, the foramen ovale or the ductus arteriosus is potentially patent and may reopen during the procedure. The pulmonary arterial resistance is relatively high, predisposing to reverse flow through a patent ductus arteriosus or foramen ovale. There is a risk of reopening of right-to-left shunts, cardiac insufficiency and gas embolism into the systemic circulation which may result in cardiac ischemia and neurological damage.
CO2 absorption is more intense and faster in infants Volume of gas for creation of pneumo peritoneum is less IAP should be limited to 5 – 10 mm Hg in neonates and infants and 10 – 12 mm Hg in older children. risk of injuries to vitals is higher, so care is must. Prone for hypothermia & PONV
CO2 peritoneum results in ventilatory /respiratory changes PaCO2 rise will aggravate cardio respiratory disturbances Increase in EtCO2 >25% later than 30mts after beginning, suspect CO2 sub.cut.emphysema Haemodynamic changes decrease CO and this is more in haemo dynamically compromised patients Preload augmentation, use of vaso dilators, clonidine and Dexmedetomedine, high dose opioids, & beta blockers – will attenuate pathophysiologic hemodynamic changes
In pregnancy, lap surgery can be safely performed before23 wks (avoid hypercarbia) & open laparoscopic approach to avoid injury to gravid uterus. Gasless laparoscopy may be helpful but technical difficulty is more Laparoscopy has proven benefits allowing quick recovery, shorter hospital stay, less p.o.pain General anesthesia with controlled ventilation has proved to be clinically superior anesthetic technique Improved knowledge of pathophysiology and good perimoperative monitoring permit safe management in patient with severe cardio respiratory disease
Laparoscopy surgery presents new challenges to the anaesthesiologist. A thorough knowledge of the patho physiological changes during laparoscopy along with vigilant monitoring is the backbone for an uneventful and complete success.
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