What the Anesthesiologist Should Know before the Operative Procedure
Common bile duct procedures may cause problems for many practitioners because of the associated comorbidities. It is not uncommon that these patients present with significant cardiopulmonary issues. What raises the level of acuity is the presence of liver dysfunction and/or concomitant sepsis. Some of the patients will be asymptomatic, but every clinician must be aware of these risks associated with the procedures.
One must do a careful and complete physical examination and pay extra attention to a history that includes jaundice, prior surgeries that may have required blood transfusions, excessive use of alcohol and other recreational drugs, sexual history, as well as presence of pruritus, abdominal distention, weight loss, easy fatigability, and easy bruising after minor trauma. Clinical signs for liver dysfunction should be sought for such as: icterus, ascites, hepatomegaly, splenomegaly, palmar erythema, spider nevi, testicular atrophy and gynecomastia.
If suspicion for liver disease exists, testing for liver function, liver enzymes, coagulation studies, and electrolytes should be performed. While routine liver function tests are not indicated due to low prevalence in most preoperative patients, it is common that patients with biliary disease have already had a full laboratory evaluation.
1. What is the urgency of the surgery?
What is the risk of delay in order to obtain additional preoperative information?
In circumstances of biliary obstruction or biliary sepsis there is evidence that surgical intervention must proceed without delay. The clinical information or the lab work may be incomplete, but rapidity in resolving the issue may avoid overwhelming sepsis and worsening liver dysfunction. Most commonly this diagnosis was made after some imaging was performed, whether it was a CT scan, right upper quadrant ultrasound, or endoscopic retrograde cholangiopancreatography (ERCP).
The decision may be to proceed with either urgent/emergency surgical intervention or with ERCP to evacuate a stone or place a stent in a narrowed/strictured biliary tree due to pancreaticobiliary malignancy.
Emergency: Acute emergencies in biliary surgery are relatively uncommon. They mostly include biliary tract sepsis, acalculous cholecystitis with sepsis, or acute biliary tract perforation that may require biliary exploration and/or repair. Coexisting diseases in the setting of an acute inflammatory process are likely to be the major concern for the anesthesiologist. The requirement for invasive monitoring is individualized based on the procedure and the clinical presentation: that is, a septic patient may require invasive monitoring and vasopressor medication and may also need an ICU bed and prolonged intubation as part of the perioperative course.
Another important difference that needs to be taken into account is whether the procedure is being done by a surgeon in the operating room, or requires that the anesthesia team provide patient care in the GI suite and the procedure performed by a gastroenterologist. Unless the patient comes from the ICU and already has a secured airway it can be assumed that there is a “full stomach” risk for pulmonary aspiration. So even if in another circumstance one might consider MAC anesthesia for endoscopy, General anesthesia would be preferred by most clinicians.
Urgent: These are most of the gallbladder surgical procedures that are done while on call. Patients often present with biliary colic and cholethiasis confirmed on ultrasonography or abdominal CT scanning. Blood chemistries often show enzymatic evidence of biliary obstruction plus possible elevated bilirubin levels. If the patient is very unstable or has only sludge and no evidence of biliary tree obstruction a cholecystostomy tube is chosen as a viable alternative; otherwise, laparoscopic cholecystectomy with intraoperative cholangiogram is the usual course for this presentation. As gastrointestinal endoscopists become more and more aggressive, it is likely that the GI suite may replace the operating room for some of these cases.
Elective: This category includes all symptomatic patients with gallstones who require cholecystectomy. Most surgeons today want to provide these as outpatient procedures, but not all patients are good candidates, and evaluation and management should be individualized. Another category of patients are those with chronic pancreatitis or pancreaticobiliary malignancies who may require ERCP and placement of biliary/pancreatic stents in the GI suite. In many institutions, there is the concern that patients for GI endoscopy do not come to the preoperative clinic for medical evaluation and some information may be missed. Whether to administer GETA or MAC is a decision based on indications/contraindications, preference of the provider, and the skills of the gastroenterologist.
A third category are patients with suspected or known pancreaticobiliary malignancy who require either curative or palliative major surgical procedures. These patients often have laparoscopic evaluation prior to the open procedure, whether done in the same setting or not as is the preference of the surgeon. They are evaluated in the preadmission clinic, have all the lab work ready, and often benefit from regional anesthesia for postoperative pain control in addition to general anesthesia. The use of invasive monitoring depends on the planned extent of the surgical procedure and the surgeon’s skills in avoiding large blood losses.
2. Preoperative evaluation
The most important aspects of the medical condition of nonseptic biliary tract patient are the presence and severity of liver dysfunction, along with the expected difficulty of the surgical procedure and the type of anesthetic planned. While coagulopathy is not common with biliary tract disease, its presence is a serious risk factor. Classifications of liver dysfunction have been implemented to aid clinicians with risk assessment (Table I).
|Measure||1 point||2 points||3 points|
|Total bilirubin, μmol/L (mg/dL)||<34 (<2)||34-50 (2-3)||>50 (>3)|
|Serum albumin, g/L||>35||28-35||<28|
|Hepatic encephalopathy||None||Grade I-II (or suppressed with medication)||Grade III-IV (or refractory)|
A. Child-Pugh-Turcotte classification of chronic liver disease
This classification has limitations because it is based on subjective data such as degree of ascites and encephalopathy, which are observer-dependent quantification and was developed before the ultrasound evaluation of ascites was possible.
Chronic liver disease is classified in Child-Pugh Class A to C (Table II) by adding the points from Table I.
|Points||Class||One-year survival||Two-year survival|
Another prognostic model for estimating the severity of liver disease is becoming popular, the Model for End-stage Liver Disease (MELD). Initially developed for patients who underwent elective transjugular intrahepatic portosystemic shunt (TIPS), and shown to be an accurate predictor of survival after this procedure, it is hypothesized that MELD can be used as a prognostic tool for broader range of liver disease and severity.
Briefly, an increasing MELD score is associated with an increased severity of liver dysfunction and 3-month mortality risk. Due to its accuracy for predicting short-term survival it has been used especially by the transplant community. Due to its predictive value, the MELD system has now been expanded beyond the transplant patient and applied to a larger variety of patients with liver disease like patients undergoing TIPS, patients with alcoholic hepatitis, hepatorenal syndrome, cirrhosis with sepsis unrelated to spontaneous bacterial peritonitis, acute variceal hemorrhage, and, relevant here, for assessment of surgical mortality risk in liver disease.
The initial MELD score model took into consideration the etiology of the liver disease whether cholestatic or alcoholic or due to other etiologies.
The original formula used is: 3.8[Ln serum bilirubin (mg/dl)] + 11.2[Ln INR] +9.6[Ln serum creatinine (mg/dl)] + 6.4[etiology: 0 if cholestatic or alcoholic, 1 if other etiologies], where Ln is the natural logarithm. There are several calculators available online slightly different for various etiologies. As far as the tool utilized for determining the risk of postoperative mortality after major surgical procedures including gastrointestinal, orthopedic, and cardiac surgery there is an online calculator that takes into consideration the etiology of liver dysfunction and therefore it resembles the initial MELD formula, and can be found at: www.mayoclinic.org/meld/mayomodel9.html
It has been suggested that patients with a MELD score below 10 can undergo elective surgery, those with a score between 10 and 15 may undergo elective surgery with caution, and patients with MELD score above 15 should not have elective surgery.
The current MELD used by the United Network for Organ Sharing (UNOS) with the goal in prioritizing allocation of donor organs for liver transplantation is different in terms of not including the etiology of liver dysfunction:
C. Measures of hepatic function
Measures have been proposed including dynamic tests of liver function; unfortunately, they do not seem to provide additional prognostic information when compared to Child-Pugh classification.
The APACHE score can predict survival in patients admitted to the ICU, but they are not specifically evaluated for patients with cirrhosis undergoing surgery.
Elective or semi-urgent procedures should not be performed in patients with acute or fulminant hepatitis, alcoholic hepatitis, severe chronic hepatitis, Child class C or MELD >15 cirrhosis, severe coagulopathy, or severe extrahepatic manifestations of liver dysfunction such as hypoxia, cardiomyopathy, or acute renal failure. Elective procedures are well tolerated in patients with Child’s class A or MELD <10 cirrhosis and those with mild chronic liver disease, and is tolerable in patients with Child’s class B or MELD 10-15 cirrhosis except those undergoing extensive hepatic resection or cardiac surgery.
Medically unstable conditions warranting further evaluation in addition to assessing the surgical risk include presence of jaundice, coagulopathy, ascites, electrolyte abnormalities, renal dysfunction, and encephalopathy, all of which will require specific treatment prior to surgery.
Delaying surgery may be indicated if medical therapy is indicated to optimize the above mentioned conditions, such as:
Patients with elevated prothrombin time correction with vitamin K and fresh frozen plasma should be attempted prior to surgery. There is not enough experience to make recommendations regarding the use of recombinant factor VIIA that can temporarily correct prothrombin time, but its use is somewhat restricted due to high cost.
Prolonged bleeding time is corrected with diamino-8-D-arginine vasopressin (DDAVP).
Treatment of ascites is important in order to minimize the risk of abdominal dehiscence or hernias, and it should be done aggressively with either diuretics or direct drainage during laparotomy.
Electrolyte abnormalities, especially metabolic alkalosis and hypokalemia, should be corrected in order to reduce the risk of cardiac arrhythmias.
Renal function should be evaluated prior to surgery; however, patients with chronic liver disease have reduced creatinine and urea production and therefore normal values may be misleading.
Gastroesophageal varices should receive the appropriate prophylactic treatment at least with beta-blockers, if other more advanced methods like TIPS or variceal banding are not indicated.
Patients with portal hypertension should be evaluated for TIPS, but its role in the perioperative period has not been studied.
Perioperative nutritional support is essential in patients with cirrhosis who are chronically malnourished, which may reduce postoperative complications.
3. What are the implications of co-existing disease on perioperative care?
b. Cardiovascular system:
Patients with coronary disease should be managed in a similar manner as for any other surgical procedure. For patients with liver dysfunction a hyperdynamic state with increased cardiac output and reduced vascular resistance is characteristic.
Patients are encouraged to continue their chronic medication treatment, and for any exacerbations, the use of inhaled bronchodilators is usually sufficient in the perioperative period.
Patients with liver disease may develop a multitude of pulmonary complications such as restrictive disease, intrapulmonary shunts, ventilation/perfusion mismatches, and pulmonary hypertension.
Patients with biliary pathology most often than not present with symptoms of nausea, bloating, and vomiting, or even ascites; therefore a rapid sequence induction is advisable when these are prominent.
Renal dysfunction is not an uncommon occurrence in patients with liver dysfunction, most commonly due to impairment of renal autoregulation and the renin-angiotensin-aldosterone axis, which induce vasoconstriction of the afferent arterioles, and decreased glomerular filtration rate, all leading to decreased urine output. The extreme is hepatorenal syndrome characterized by severe renal dysfunction, azotemia, hyperosmolar urine, and decreased urinary sodium excretion.
In circumstances of significant liver dysfunction, patients may present with encephalopathy manifested with asteritis, hyper-reflexia, progressing to delirium, and coma. In such cases, hypokalemia and alkalosis should be corrected because it may accentuate the ammonia-related central venous dysfunction, and minimal use of all sedatives is also recommended.
g. Additional systems/conditions which may be of concern in a patient undergoing this procedure and are relevant for the anesthetic plan (e.g., musculoskeletal in orthopedic procedures, hematologic in a cancer patient)
Hematology and coagulation status
Patients with liver insufficiency have an increased risk for perioperative bleeding due coagulopathy secondary to inadequate levels of clotting factors, thrombocytopenia and platelet dysfunction, hyperfibrinolysis, and production of heparinoids such as glycosaminoglycans in sepsis or endotoxemia. These disturbances are identifiable through different studies like thromboelastography, platelet count, bleeding time, fibrinogen, and D-dimer, but most commonly and easily accessible being an evident prolongation of PT and INR.
If bleeding dominates the clinical picture a multitude of products can be used, but one must be aware that their effect is only temporary: vitamin K, fresh frozen plasma, cryoprecipitate, platelet transfusion, recombinant factor VIIa, antifibrinolytics such as aminocaproic acid, tranexamic acid, desmopressin, and prothrombin complex concentrates.
Recently a new concept has emerged, namely hypercoagulability. Therefore, the balance between pro- and anticoagulation is impaired toward either bleeding or toward clotting and the result is difficult to predict. Patients with advanced liver disease have a procoagulation tendency due to reduction of the anticlotting factors such as protein C, protein S, and antithrombin, while other factors like factor VIII and von Willebrand are increased. This procoagulant status, which leads to macro- and microthrombi, is evident in some patients who present with deep vein thrombosis, pulmonary embolism, portal vein thrombosis, intrahepatic or intralung microthrombi, and nonalcoholic fatty liver disease that is associated with obesity, insulin resistance, and thrombotic disorders including coronary disease.
If thrombosis is the main issue, anticoagulation should be sought, but the use of antiplatelet agents as well as warfarin is difficult due to baseline coagulopathy. Probably the best indicator of therapeutic anticoagulation levels is measurement of antifactor Xa activity.
Some patients have anemia either due to chronic disease, malnutrition, or bleeding. Thrombocytopenia may be present due to splenic sequestration.
4. What are the patient's medications and how should they be managed in the perioperative period?
Patients may be taking nothing or they may have a long list of medications for different diseases from coronary disease, diabetes, lung disease, heartburn, chronic pain, liver disease, and neurologic and psychiatric diseases and less essential diseases such as gout, arthritis, and thyroid disease. The use of herbals and/or OTC medications with aspirin or NSAIDs should be pursued.
If one is examining the patient in a preadmission clinic, careful evaluation of medications and recommendations toward withholding some of them the day of the procedure should be made.
Aspirin should be held in most cases, but in a special instance of a patient with drug-eluding stents that is chronically on aspirin and clopidrogrel, a discussion with the patient’s cardiologist may be necessary in order to minimize the risk for stent thrombosis and resultant myocardial ischemia in the perioperative period.
The same consideration applies for anticoagulation medication used in patients with mechanical valves, medication that have to be stopped prior to surgical procedures, and may require transitory anticoagulation with a shorter-acting agent like intravenous heparin.
Most cardiac medication should be continued throughout surgery. There is debate regarding the continuation or not of ACE inhibitors due to significant perioperative hypotension, but also others consider it riskier to stop them due to rebound hypertension that may remain untreated for longer periods of time. An institution policy may be useful in such circumstances. One may also consider telling patients to avoid diuretics the day of surgery due to inherent hypovolemia that ensues. Of course this decision should be individualized, since some patients with severe cardiomyopathy may not tolerate prolonged periods of fluid overload and may develop congestive heart failure in the perioperative period. Even if inadvertently despite recommendation, the diuretic has been taken by the patient, careful fluid administration may be done intraoperatively and attention to electrolyte abnormalities and possible cardiac arrhythmias should follow.
Neurologic and psychiatric medications should be continued but attention of the drug classes like MAOIs and possible interactions with anesthetics should be carefully addressed.
Pulmonary medications should be continued. Gastroesophageal reflux treatment should be enforced even for patients with rare symptoms.
Renal medication should be continued in the perioperative period. The chelating agents and in some cases bicarbonate ensure maintenance of acid-base equilibrium that the kidney alone is incapable of providing.
For patients with diabetes, usually avoiding the oral hypoglycemics is recommended the day of surgery. For a patient who is insulin-dependent, half of the morning dose of insulin is a good standard regimen. For a patient with an insulin pump, a consultation with the hospital diabetologist is extremely useful regarding the rate of insulin that should be continued perioperatively. Most commonly the pump should be used at approximately half of the regular rate to avoid significant glucose swings in either direction. In any case frequent blood sugar verifications and prompt usage of an insulin infusion are necessary and extremely useful maneuvers that a modern clinician should employ.
h. Are there medications commonly seen in patients undergoing this procedure and for which should there be greater concern?
i. What should be recommended with regard to continuation of medications taken chronically?
See above discussion.
j. How to modify care for patients with known allergies
Avoid the substances that are inducing allergies in the patient.
k. Latex allergy – If the patient has a sensitivity to latex (e.g., rash from gloves, underwear, etc.) versus anaphylactic reaction, prepare the operating room with latex-free products.
l. Does the patient have any antibiotic allergies – Common antibiotic allergies and alternative antibiotics
If patient has antibiotic allergies, one may choose an acceptable alternative for this purpose.
m. Does the patient have a history of allergy to anesthesia?
A trigger-free anesthetic should be used.
5. What laboratory tests should be obtained and has everything been reviewed?
When patients come for ERCP or biliary stent placement the lab work may not be updated. For surgical exploration of the right upper quadrant, most commonly lab results are available. Nevertheless a thorough physical exam with emphasis on symptoms of liver disease and especially signs of worsening clinical status together with communication with the gastroenterologist regarding concerns for active liver disease should allow the anesthesiologist to decide whether more testing is needed and specifically what would be useful for determining patient’s status and perioperative risk.
It is not recommended to routinely order liver function tests prior to surgical procedures due to low prevalence. In any case one must be aware that these patients do carry a high risk for coexisting liver disease and therefore some additional testing may be necessary.
The most common liver function tests (LFTs) are enzyme tests: alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase. The AST and ALT are present in the hepatocytes, therefore their elevation serves as a marker of hepatocellular destruction rather than its function. Also, in severe end-stage cirrhosis there may be too few hepatocytes left to release the liver enzymes, which appear to be falsely normal, or only mildly elevated.
Elevation of alkaline phosphatase is a marker for cholestasis and biliary obstruction. However this enzyme is present in other tissues, and not specific for liver dysfunction.
Direct bilirubin may also be elevated and suggests liver disease including cirrhosis, obstruction of biliary tree, hepatitis viral or alcoholic, or drug reactions.
More valuable in assessing hepatic dysfunction are coagulation studies like PT/PTT/INR. All liver-synthesized clotting factors, including vitamin K–dependent factors (II, VII, IX, X), are decreased in liver disease, and subsequently all coagulation studies are abnormal. One must be cautious in interpreting these results because malnutrition, malabsorption or recent antibiotic therapy may also decrease the absorption of vitamin K.
Levels of albumin are useful in interpreting hepatic function. If these values are decreased shows decrease in synthetic function. Again, chronic disease states and malnutrition will decrease the value of albumin. Due to its long half-life of 2 to 3 weeks, acute hepatic dysfunction may still be associated with normal albumin levels.
Common laboratory normal values will be same for all procedures, with a difference by age and gender.
Hemoglobin levels: It is important to evaluate and have a baseline for a patient who comes for a procedure that may entail significant blood loss. At the same time, a type and cross is usually requested by most clinicians before proceeding with the anesthetic.
Electrolytes: Electrolytes are checked routinely for a surgical procedure that may involve liver dysfunction or even sepsis. Glucose and BUN/creatinine determinations offer additional information related to coexisting disease such as diabetes and preexisting renal dysfunction.
Coagulation panel: See above.
Imaging: Include stress tests, renal imaging tests, etc. Imaging studies are ordered by surgeons to clarify exactly the extent of disease and to decide which is the best approach for this specific disease. Most of the time, they include right upper quadrant ultrasound and/or CT scan of the abdomen. MRI is not routine but may be used to better evaluate the biliary tree.
Other tests: LFTs; see above.
Intraoperative Management: What are the options for anesthetic management and how to determine the best technique?
If it is suspected that the patient has significant liver dysfunction, extreme care toward choosing the appropriate anesthetic is essential, not only due to impaired drug metabolism, but also because the liver and kidneys respond poorly to even modest decreases in blood pressure.
Commonly, narcotic use is minimized because of a prolonged duration of effect and cistaracurium, with no need for hepatic metabolism, is used for muscle relaxation. With the exception of halothane, all inhalational agents have similar hepatic protection. Euvolemia should be maintained with crystalloids and colloids. If there is a requirement for blood products, these should be administered judiciously, and consideration toward possible preexisting coagulopathy with early administration of fresh frozen plasma is an important aspect of these patients’ resuscitation. If hypotension persists despite small doses of vasopressors, in order to maintain organ perfusion, the pure alpha-agonist phenylephrine as an infusion can be useful.
There are at least four types of procedures that involve the biliary tree. Naturally, variations can be found in everyday clinical practice, but we believe that one can find the root in one of those described here:
Cholecystectomy laparoscopic or open
Cholecystectomy is the most common abdominal surgical procedure, since approximately 750,000 are performed in the US annually. The standard of care has become a laparoscopic approach for this disease, especially since the cost is reduced due to decreased time off work for the patients, and many centers offer this as an ambulatory procedure for uncomplicated cases and healthy patients.
The common option for anesthetic management in this case is a choice of general anesthesia. Rapid sequence induction should be used based on patient’s symptoms of nausea and vomiting that suggest acute cholecystitis or the presence of GERD. The specifics of GETA (general endotracheal anesthesia) are individualized based on anesthesiologist’s preference, patient’s coexisting diseases, and surgeon’s ability.
If the laparoscopic procedure is being converted to an open procedure, pain relief and avoidance of splinting with low tidal volumes and reduced FRC become more significant issues in the immediate postoperative period and should be handled in a similar way as any open abdominal procedure that does not benefit from an epidural analgesia.
Intraoperative issues that can arise include difficult ventilation with increase in the ETCO2 (end-tidal carbon dioxide) due to CO2 insufflation during procedure. This may become a hindrance especially in patients that already require high pressures (such as obese patients) or increased minute volumes to ensure an adequate minute ventilation such those who have COPD (chronic obstructive pulmonary disease). Tolerating permissive hypercapnia together with increasing the I:E (inspiratory/expiratory) ratio, adding PEEP (positive end-expiratory pressure), and even switching to pressure controlled ventilation are means that can aid with this issue. At times, however, the surgical port is not well positioned and the ETCO2 becomes dangerously high. An arterial blood gas should be performed to verify results and confirm that significant acidosis has ensued.
Obviously, ruling out other conditions such as malignant hyperthermia and thyrotoxicosis are important at this juncture. Temporary evacuation of the intra-abdominal CO2 by surgeon with almost immediate improvement of the ETCO2 confirms this diagnosis. Presence of subcutaneous emphysema is usually diagnostic, at which point if combined with significant acidosis, a decision to further the completion of cholecystectomy as an open procedure should be made after discussion with surgeon.
Other possible more significant complications that amount to a total of 2.6% include bile leak, biliary injury, venous embolism due to gas insufflation into the venous system when inserting the trocar, which can be followed almost immediately by cardiac arrest, liver and bowel injury, pneumothorax, or even occult bleeding; the latter diagnosis that can be missed entirely but should always be suspected in any laparoscopic procedure with persistent and profound yet inexplicable hypotension. Point of care rapid measurement of hemoglobin, such as blood gas, I-STAT, etc., should be employed to make this latter diagnosis rather than waiting for a classic CBC (complete blood count) to arrive from the laboratory, which can take in most institutions a long time.
There are several types of biliary tree injuries that will either be asymptomatic and resolve itself within few days or may lead to complete obstruction of the extrahepatic biliary tree that will be obvious in a few days. Segmental biliary tree obstruction may not be diagnosed until years after the procedure. Postoperative mortality for patients with biliary injury is 1.7% and incidence of postoperative complications is 43% (Figure 1).
Type A includes injuries that involve leakage into the gallbladder bed from either minor hepatic ducts or cystic duct without loss in continuity of the biliary tree. Types B and C are occlusions (Type B), and transection (Type C) injuries of aberrant right hepatic ducts, and are frequently are associated with injuries to right hepatic artery. Type D present as lateral damage to common bile duct resulting in bile leak. Type E injuries are subclassified according to the level of injury of the biliary tree into five subtypes. These patients present years after cholecystectomy with jaundice and require surgical repair via hepaticojejunostomy.
In general complications after laparoscopic cholecystectomy are due to patient selection, surgical inexperience, and technical constraints of the minimally invasive procedures. If biliary injuries are recognized at the time of surgery a T-tube drainage of the common bile duct is indicated and primary repair is contraindicated due to higher rates of breakdown or strictures. Major biliary leaks present within 2 to 10 days after cholecystectomy with fever, abdominal pain, and/or bilious ascites, mild jaundice, leukocytosis, abnormal liver function tests, and mildly elevated bilirubin.
ERCP is an important diagnostic tool, and also can be followed by stent placement or even sphincterotomy to allowing free flow of bile. If symptoms improve, the stent can be either removed or replaced in 2 to 4 weeks’ time, although most will require hepaticojejunostomy. For patients who continue to have severe abdominal pain or peritonitis or progressive intra-abdominal sepsis, operative exploration with wash-out may be needed. Occlusive injury to the right hepatic lobe results in atrophy of the right lobe, which ultimately requires hepaticojejunostomy with possible segmental liver resection if atrophy is significant. There are multiple types of operative procedures to correct a bile duct injury, a Roux-en-Y bypass being the most commonly used.
ERCP (endoscopic retrograde cholangiopancreatography)
ERCP is a procedure performed routinely in the GI suite initially developed as a nonsurgical approach for diseases of pancreaticobiliary system. The purpose is either diagnostic for biliary or sphincter of Oddi pathology or therapeutic when stents are placed to aid with bile drainage in either benign strictures or malignancies of hepatobiliary system.
For this procedure patients need to be prone with the head turned toward the endoscopist. The decision to provide MAC vs. GETA is dependent upon the anesthesiologist’s preference, patient’s coexisting diseases, and the endoscopist’s experience. It seems that anesthesiologists that work with the same team for many of these cases feel more comfortable in providing MAC anesthesia. On the other hand when most of these procedures are performed with nursing sedation and the anesthesia team is called for a very complicated case, general anesthesia is the expectation. If MAC is the desired anesthetic good topical anesthesia of the hypopharynx should be done by the endoscopist. A minimal anesthetic may be ideal for sicker patients; nevertheless, it is more cumbersome to provide MAC in a prone patient. Small doses of medications such as fentanyl with only modest boluses of propofol while the probe is inserted can be used; infusions of remifentanyl or dexmedetomidine may also be used. Most important is the avoidance of apnea in a prone patient since mask ventilation or insertion of a LMA may be very challenging. Some of these patients come repeatedly for stent revisions, and are therefore well known to the anesthesia teams.
The advantage of MAC is rapid turnover and fast track toward discharge home, but it requires a cooperative patient. Disadvantages are obvious, first related to difficulty in maintaining a patent airway if large doses of sedation are being administered, prolonged procedure duration if the anesthetic is inadequate, and imperfect relaxation with limited tolerance for very long procedures.
Post-ERCP complications include cholangitis, cholecystitis, and pancreatic sepsis. The most important risk factor for developing cholangitis is failed endoscopic drainage, in which case antibiotic treatment may be indicated, because subsequently patients may develop fever, right upper quadrant pain, and jaundice. If adequate drainage cannot be achieved, percutaneous or surgical decompressive procedures should be promptly performed.
Gastric reduction surgeries are now considered an established treatment for bariatric patients. There are several types, including biliopancreatic diversion (BPD). BPD is considered a malabsorptive procedure and, due to its side effects that include both macro- and micronutrient deficiencies, can be followed by significant complications, some of which can be life-threatening. Another point of interest is that some surgeons perform cholecystectomy at the time of gastric bypass procedures. This is obviously associated with different risk factors due to preexisting diseases, including morbid obesity.
Whipple procedure also known as pancreaticoduodenectomy is a major surgical procedure utilized for treatment of cancers of head of pancreas, common bile duct, duodenum near the pancreas, or duodenal papilla; it consists of resection of gastric antrum, first and second portion of duodenum, head of the pancreas, common bile duct and gallbladder. Since radiographic studies like CT scan may underestimate subtle aspects of the disease, some surgeons elect to perform a laparoscopic examination prior to this procedure, either in the same setting or at a different time, and biopsy lymph nodes, liver or peritoneum that might look suspicious for cancer; the goal is to select only the candidates with localized disease that are amenable to surgical resection.
A pylorus-sparing pancreaticoduodenectomy has recently emerged and appears to be more popular especially in Europe. It seems that this newer technique offers the benefit of shorter surgical time and required less blood transfusion when compared to the classic Whipple, but there seem to be no difference in morbidity, hospital mortality, and postoperative complications between them. (See Pancreaticoduodenectomy chapter.)
Monitored anesthesia care
6. What is the author's preferred method of anesthesia technique and why?
What prophylactic antibiotics should be administered?
Any cephalosporins are acceptable.
What do I need to know about the surgical technique to optimize my anesthetic care?
What can I do intraoperatively to assist the surgeon and optimize patient care?
See above, intraoperative management and issues.
What are the most common intraoperative complications and how can they be avoided/treated?
Blood loss is one of the most significant complications in this case and should be watched and replaced with colloids and/or blood products when a certain threshold is met. This threshold is based on a multitude of factors including coronary disease and other comorbid pathologies, hemodynamic instability, assessment of intravascular volume, the rapidity with which the blood is being lost just to name a few. Commonly, cell saver techniques are not a viable option because of neoplastic disease. Low urine output should be also carefully observed and euvolemia should be pursued. Although a poor prognostic marker for renal dysfunction it may be the harbinger for worse outcome, and fluid administration should ensue; if relative euvolemia does not correct the issue of low urine output in the setting of hypotension, one may consider low does vasopressors to optimize renal perfusion pressure.
b. If the patient is intubated, are there any special criteria for extubation?
For rare unexpected cases with significant blood loss that require massive blood-fluid resuscitation, careful assessment of respiratory peak and plateau pressures should be done when abdominal fascia is being closed. If pressures increase significantly followed by a dramatic decrease in the tidal volumes, while switching to pressure control ventilation may alleviate the problem, it is doubtful that such a patient will be able to sustain adequate unsupported spontaneous minute ventilation, therefore maintaining intubation may be a wiser decision. The decision to extubate the patient will be similar to standard ICU care.
c. Postoperative management
What analgesic modalities can I implement?
For ambulatory patients who come for ERCP or laparoscopic cholecystectomy small doses of intravenous narcotics are adequate. Patient-controlled analgesia (PCA) may be useful for patients who undergo cholecystectomy and due to either more complicated procedure, or due to objective (e.g., hypertension) or subjective (nausea) symptoms that do not allow discharge the same day. Extreme care should be used when recommending PCA to very obese postsurgical patients, especially after bariatric procedures. For patients who had a Whipple procedure epidural analgesia or regional supplemental analgesia are ideal, but if not a viable option, PCA can be used as an alternative.
What level bed acuity is appropriate?
The decision to upgrade a patient to a higher level of care should primarily be based upon the patient’s comorbid diseases. For the patients after a Whipple procedure it is advisable that a high level care or even ICU bed be considered because they may require continuous and careful fluid resuscitation due to large fluid shifts, possibly followed by hypotension which only in part can be secondary to epidural analgesics. Careful neurologic monitoring as for any patient who has an epidural catheter is essential also. If PCA is employed respiratory depression and or inadequate ventilation due to splinting and inadequate pain relief are only a few of complications associated with this technique. Obviously patients who remained intubated at the end of the case will require an ICU for further care.
What are common postoperative complications, and ways to prevent and treat them?
The most common postoperative complications are related to the type of procedure. See above.
What's the Evidence?
Garg, RK. “Anesthetic consideration in patients with hepatic failure”. Intern Anesth Clin. vol. 43. 2005. pp. 45-63.
Wamsteker, E-J. “Updates in biliary endoscopy”. Curr Opin Gastroenterol. vol. 22. 2006. pp. 300-4.
Jabonska, B, Lampe, P. “Iatrogenic bile duct injuries”. World J Gastroenterol. vol. 15. 2009. pp. 4097-104.
Rizvon, MK, Chou, CL. “Surgery in the patient with liver disease”. Med Clin N Am. vol. 87. 2003. pp. 211-27.
Nguyen, K, Sing, JT. “Review of endoscopic techniques in the diagnosis and management of cholangiocarcinoma”. World J Gastroenterol. vol. 14. 2008. pp. 2995-9.
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- What the Anesthesiologist Should Know before the Operative Procedure
- 1. What is the urgency of the surgery?
- What is the risk of delay in order to obtain additional preoperative information?
- 2. Preoperative evaluation
- 3. What are the implications of co-existing disease on perioperative care?
- b. Cardiovascular system:
- c. Pulmonary:
- d. Renal-GI:
- e. Neurologic:
- f. Endocrine:
- g. Additional systems/conditions which may be of concern in a patient undergoing this procedure and are relevant for the anesthetic plan (e.g., musculoskeletal in orthopedic procedures, hematologic in a cancer patient)
- 4. What are the patient's medications and how should they be managed in the perioperative period?
- h. Are there medications commonly seen in patients undergoing this procedure and for which should there be greater concern?
- i. What should be recommended with regard to continuation of medications taken chronically?
- j. How to modify care for patients with known allergies
- k. Latex allergy - If the patient has a sensitivity to latex (e.g., rash from gloves, underwear, etc.) versus anaphylactic reaction, prepare the operating room with latex-free products.
- l. Does the patient have any antibiotic allergies - Common antibiotic allergies and alternative antibiotics
- m. Does the patient have a history of allergy to anesthesia?
- 5. What laboratory tests should be obtained and has everything been reviewed?
- Intraoperative Management: What are the options for anesthetic management and how to determine the best technique?
- 6. What is the author's preferred method of anesthesia technique and why?
- What prophylactic antibiotics should be administered?
- What do I need to know about the surgical technique to optimize my anesthetic care?
- What can I do intraoperatively to assist the surgeon and optimize patient care?
- What are the most common intraoperative complications and how can they be avoided/treated?
- a. Neurologic:
- b. If the patient is intubated, are there any special criteria for extubation?
- c. Postoperative management