Inguinal herniorrhaphy

What the Anesthesiologist Should Know before the Operative Procedure

Elective inguinal hernia repair is one of the most common surgeries performed and can be done under a wide variety of anesthesia methods. It is also one of the most common ambulatory surgical procedures. Comorbidities are rare and mainly related to age and any associated cardiorespiratory, endocrine, and renal issues. Patients are normally evaluated by the surgical team and optimized before presenting for surgery. Strangulated or impacted hernia may present emergently with a more complex medical presentation, including fluid-electrolyte imbalance or abdominal sepsis.

1. What is the urgency of the surgery?

What is the risk of delay in order to obtain additional preoperative information?

Inguinal herniorrhaphy can be done as a planned elective procedure (direct or indirect inguinal hernia repair) or as an emergency that could even be life threatening (eg., strangulated intestine with or without necrosis). The patient could be of any age, although hernias arise most commonly in middle age. Most patients are healthy. However with a changing demographic, the elderly, with associated comorbidities, are presenting with increasing frequency.

Emergent: Strangulated inguinal hernia with a loop of bowel in the inguinal sac requires repair within 6 hours.

Urgent: Obstructed inguinal hernia can lead to strangulated hernia. However, there might be sufficient time to optimize any accompanying acute medical conditions, e.g., diabetic ketosis.

Elective: Many patients postpone hernia repair for years and the risks of delaying surgery are minimal. If there are more pressing conditions or investigations that need to be carried out, they should take precedence over repair of the hernia, including a CABG, coronary stent, or a cardiac valve replacement.

2. Preoperative evaluation

One needs to determine the suitability for same day surgery. The size of the hernia might involve extensive dissection necessitating admission, as postoperative pain could be significant. Sometimes patients present with poorly controlled diabetes or hypertension that might require optimization before anesthesia. It is important to bear in mind that patients could be living at a remote location where emergency medical care may not be easily available in the event of any complications.

Medically unstable conditions warranting further evaluation include hypertension, asthma, obesity smoking, gastrointestinal reflux disease, diabetes, cardiac arrhythmias, renal failure (with or without requiring dialysis). Sometimes hypertension is discovered for the first time on preoperative evaluation. We are seeing an increasing number of patients with stable organ transplants. Significant number of patients come with a pacemaker or pacemaker defibrillator. It is important to know the indications and the status of the pacemaker e.g, last time the cardiologist had evaluated the pacemaker. Patients with cardiac disease (e.g, ischemic cardiomyopathy with poor ejection fraction are increasingly seen. There is no specific contraindication to ambulatory surgery. However there should be always a plan of management including admission in the event of complications. Patients with significant lung disease including pulmonary hypertension are another category that many anesthesiologists may not be comfortable anesthetizing in an ambulatory surgery setting. However many of these patients are managing well and carrying on with their daily activities even on home oxygen, and with careful anesthetic management can do well in the ambulatory setting. For patients who are dialysis dependent, it is important to know the timing of previous dialysis. Although not mandatory, it might be advisable to get serum electrolytes before anesthesia. Peripheral vascular disease should be taken as a clue to look for evidence of any other vascular disease, as on its own it is not of much significance in deciding fitness for same day surgery. If the anesthesiologist is in any doubt about the postoperative recovery, it is advisable to admit them. However admission for preoperative optimization is rarely needed.

Delaying surgery may be indicated if: Apart from non-availability of a transport there are very few instances wherein the surgery needs to be delayed or cancelled. However if any of the co-morbidities need further investigation or treatment (for better optimization ) that would influence the outcome of the surgery/anesthesia, then a delay is justified. However in developed countries or developing countries with medical facilities, this is rarely required.

3. What are the implications of co-existing disease on perioperative care?

Perioperative evaluation

General-Anemia (sickle cell, occult bleeding, nutritional, chronic renal failure, thalassemia) is rare to be discovered in the preoperative check up in patients coming for elective herniorraphy. As obesity has already reached epidemic proportions in at least western countries, more and more of these patients will be encountered in the preoperative area. Also surgically they could be challenging. It is unlikely that morbidly obese patients will be done as day surgery.

Systemic -Common cardiac problems encountered in these patients are likely to be related to past MI, recent past MI. Cardiac decompensattion may be as a result of old MI or any valvular abnormalities. Obviously they need to be assessed on an individual basis to evaluate risk and need for any more evaluation. If the patient is already scheduled for any cardiac evaluations that are more than routine (and are likely to affect the medical management) it makes sense to wait until such an evaluation is completed.

Common respiratory problems are either obstructive lung disease (asthma or emphysema) or a restrictive lung disease. Pulmonary sarcoidosis can be common in certain racial groups. If the patient is symptomatic at rest or on mild exertion, one must consider the possibility of acute exacerbation and if anything could be done tooptimize respiratory function. However if the condition is as good as it gets (or it is one of their normal day), then one should accept the risks and evaluate the potential benefit. With increasing safety of anesthesia and wide variety of techniques available, cancellation of surgery for respiratory problems should be rare.

End stage renal disease likewise is well managed on dialysis. It is important to know the timing of dialysis and if necessary obtain a set of serum electrolytes. Anemia resulting from ESRD is usually treated well with erythropoietin and as they are chronically anemic one should not aim for a normal hemoglobin.

Perioperative risk reduction strategies- *** Most of these are considered in the discussion above. Use of bronchodilators, chest physiotherapy might be considered to optimize respiratory status. In reality anesthesiologists are unlikely to be involved with the medical management apart from recognizing the need for this and advising the patient and the surgeon. The patients can be revaluated as an outpatient to avoid any future cancellation. Likewise we are limited in our scope to manage any cardiac de-compensation resulting from either ischemia or valvular abnormalities. More importantly we should be able to recognize the problem and see if anything can be done to make it better thereby reducing the perioperative risk.

b. Cardiovascular system

Acute/unstable conditions

Recent acute MI, unstable angina, uncontrolled cardiac arrhythmias (e.g., rapid atrial fibrillation), severe valvular stenosis especially aortic, pacemaker malfunction (detected at the preanesthetic examination) might be grounds for cancelling the surgery. Some of these conditions might require admission for further management while others can be managed on an outpatient basis. For example severe aortic stenosis might require aortic valvular replacement before an elective herniorraphy. Recent stroke and PE might also preclude any elective surgery. However if the patient is not a candidate for surgery one might do it local block and sedation (monitored anesthesia care)

Baseline coronary artery disease or cardiac dysfunction – Goals of management

As frequently stated it is how you do things rather than what you do that increases anesthesia safety. However depending on the severity of cardiac dysfunction resulting from coronary artery or disease, choosing a technique that causes least stress on the myocardium and minimally alters the loading conditions, or alters favorably (for example slight reduction in afterload without significant fall in blood pressure might improve the myocardial function) like local block with some sedation might be better than an uncontrolled spinal anesthesia. However for a laparoscopic repair or for an extensive hernia repair a full “cardiac anesthesia” might be the technique of choice. This includes monitoring of CVP (or even PCWP), ABP and opioid based anesthesia with ionotropes/vasoprressors ready to be deployed in the event of unexpected circulatory compromise. For mild dysfunction and small hernia with a skilled surgeon Total Intravenous Anesthesia (TIVA) using remifentanil and propofol might be the technique of choice. Experience with a particular technique and an understanding of the pathophysiology is paramount for a good outcome irrespective of the technique chosen.

c. Pulmonary

COPD: It is important to understand the degree of shortness of breath and lung reserve as judged by the pulmonary function tests. If there is no recent report one should go by the clinical criteria than requesting another battery of tests. Most patients can give a good picture of symptom control and any acute exacerbation. Any evidence of ongoing acute exacerbation (either on clinical examination or by patients own account) should be an indication for rescheduling. Not only the ongoing cough can influence the postop hernia repair, anesthesia induces (mainly airway manipulation) bronchospasm and can lead to further deterioration requiring unscheduled admission. It is also important to choose an anesthetic technique that avoids airway manipulation if possible.

It is also important to bear in mind that a chronic smoker with COPD may have other smoke induced damage to systems/organs. Attention should be paid to any evidence of coronary artery disease, lung cancer, peripheral vascular disease and cerebrovascular disease.Reactive airway disease (Asthma): The implications are similar to those for COPD. There is likely to be more reversible component in bronchospsm induced by asthma in contrast to COPD. By the same token, asthmatic intraoperative exacerbations might be easier to manage than those of COPD.

d. Renal-GI:

As the field of nephrology has made significant strides, more and more patients are seen in outpatient surgery and on dialysis. In a well treated patient with EDRD (end stage renal disease) there is little reason to change anything in terms of preoperative evaluation. A history of last dialysis, review of serum electrolytes is important. However for patients in CRF (but not on dialysis yet) it is important to avoid any nephrotoxic drugs during perioperative period. For patients on dialysis fluid management should be cautious.

Hepatitis C is common in certain geographic areas and certain races. Most of them are otherwise normal. Some may be progressing to liver failure (due to cirrhosis). Avoidance of any hepatotoxic drugs and taking universal precautions are important in the management. Increasing number of patients with hepatitis induced hepatoma or cirrhosis undergo liver transplantation. These patients will be on immunosuppressants. Again there is little reason to deny the benefits of same day surgery in these patients. Other chronic Gastrointestinal problems that might be present in patients presenting for inguinal hernia repair are crohn’s disease and ulcerative colitis. It is sensible to delay any elective surgery if they are in a period of exacerbation and wait until they go into a remission.

e. Neurologic:

Acute issues: It is unlikely that anyone with acute neurological illness will present for an elective outpatient inguinal hernia repair. It is also unlikely that treatment of hernia takes precedence over the acute neurological problems unless for example it is a life threatening strangulated hernia, even then the extent and type of surgical intervention has to be balanced against any neurological problems. There is no specific neurological illness that has any association with inguinal hernia.

ii. Chronic disease: Patients with chronic coexisting neurological illness can present for an elective inguinal hernia repair. These can include

Cerebrovascular diseases- history of stroke or subarachnoid hemorrhage with varying degrees of recovery. Things to bear in mind are hyperkalemia in response to sucuinylcholine, problems with positioning and IV access. There is no contraindication to spinal, local or block anesthesia. However this could be technically challenging. A history of recent TIA should prompt to look at any carotid artery disease. If the carotid disease is diffuse or not amenable for surgical management, it is important to maintain the blood pressure within tight limits of baseline as they could be dependent on collateral circulation.

Inflammatory diseases –Multiple sclerosis can present at any stage. Many patients present for surgery during a remission. Spastic paraparesis is usually a result of plaque in the cervical and thoracic cord and obviously, positioning issued need to be addressed. Suxamethonium induced hyperkalemia, sensitivity to non-depolarizing muscle relaxants are other potential complications to be borne in mind while anesthetizing these patients.

Epilepsy can be of various types usually well controlled with one or more medications. There is no contraindication for propofol use. They can be safely anesthetized in same day surgery units.

Degenerative disorders like Parkinson’s are more common in elderly. Dopamine agonists are more likely to be prescribed in this age group, any drug interactions should be borne in mind both with dopa agonists and anticholinergics.

Peripheral neuropathy is common in chronic diabetics and should not pose any major problems in inguinal hernia repair.

f. Endocrine:

Diabetes and hypothyoroidism are encountered frequently in same day surgery patients and are usually well controlled. A history and recent hydroxylated hemoglobin levels give a good indication of the control. A value of above 8% indicates poor control and the blood sugar is likely to be above 180mg%. History should also focus on any end organ damage. Acceptable blood sugar for day surgery varies. However many centers do not undertake ambulatory surgery if blood sugar is above 230 mg percent. In well controlled diabetics there is no need of any additional precautions during the perioperatibve period. However if the surgery is an emergency or extensive, close monitoring and insulin administration may be the correct management option.

g. Additional systems/conditions which may be of concern in a patient undergoing this procedure and are relevant for the anesthetic plan (eg. musculoskeletal in orthopedic procedures, hematologic in a cancer patient)

There are no associated co-morbidities conditions that are particularly common in patients coming for inguinal hernia

4. What are the patient's medications and how should they be managed in the perioperative period?

Consistent with the associated conditions that can be present, patients can be on a wide array of medications. Although there are no medications that are associated with hernia as such, many patients routinely take dietary supplements like multivitamins, omega-3 fatty acids, vitamin E and D Etc.

h. Are there medications commonly seen in patients undergoing this procedure and for which should there be greater concern?

N/A

i. What should be recommended with regard to continuation of medications taken chronically?

• Cardiac: All antihypertensives are normally continued except ACE inhibitors and AT antagonists. However it is common for the patient either having taken all (including ACE inhibitors and AT antagonists) or nonel. Either way both are not sufficient reasons for cancellation of hernia repair unless the blood pressure is found to be unacceptably high (over 150/100). If the ACE and AT group are taken, one should watch out for the development of significant intraoperative hypotension. However it responds to fluids and vasopressors and never resistant to treatment. Significant beta blockade with heart rate in 40s could be a reason for better optimization of beta blockade therapy. Digoxin therapy is usually continued, but one should avoid any situations that might predispose to toxicity.

• Pulmonary It is good idea to ask the patients who are on regular bronchodilators to take 2-3 doses of their Metered Dose Inhalers (MDI) before the procedure. Other regular bronchodialators are continued on the morning of the surgery

• Renal: An effort should be made to schedule surgery as soon as possible after the dialysis. The rate of rise of potassium during interdialysis interval is unpredictable. However it is important to get serum electrolytes especially if the dilalysis is more than 48 hours before.

• Neurologic: Medications for conditions like Parkinsons and multiple sclerosis are continued as normal and there should not be any major modification of anesthesia to accommodate this. Again antiepileptics are continued.

• Anti-platelet. Most surgeons would stop anti-platelet medications before the surgery for varying periods as per the manufacturer’s recommendation. This is especially applicable to clopidopgrel. If one is planning a regional technique particular attention should be paid to this.

• Psychiatric. Again all psychiatric medications including MAOIs are normally continued. Interaction between anesthesia and MAOI’s should be kept in mind. As the MAOIs are not preferred drugs for depression, if patients are on them, it is an indication of severe depression and before recommending discontinuation, this should be balanced against any anesthesia interaction. With many choices for anesthesia discontinuation for hernia repair might not be necessary.

j. How To modify care for patients with known allergies –

N/A

k. Latex allergy- If the patient has a sensitivity to latex (eg. rash from gloves, underwear, etc.) versus anaphylactic reaction, prepare the operating room with latex-free products.

Latex contributes to about 20 percent of all anaphylaxis reactions in the operating room. The incidence of latex allergy in patients coming for inguinal hernia should be no different than general population and the management is the same. A distinction has to be made between latex sensitivity and latex allergy. The former is seen in about 8 percent of the population (10) while allergy is seen in only 1.4 percent. Patient groups with high are those with atopy, severe dermatitis of the hands, working in health care, allergy to fruits (esp. banana, chestnut and avocado), industrial workers using protective gear and occupational exposure to latex. Most hospitals have guidelines in scheduling and managing the patients with history of latex allergy.

l. Does the patient have any antibiotic allergies- [Tier 2- Common antibiotic allergies and alternative antibiotics]

Penicillins and cephalosporins which share the beta lactam ring are responsible for the 70% of antibiotic induced anaphylaxis (10). Approximately 15% of all anesthesia related anaphylactic episodes are antibiotic related. Common beta lactum antibiotics are Benzylpenicillin, phenoxymethylpenicillin,Flucloxacillin, temocillin’ Amoxicillin, ampicillin, co-amoxiclav,Co-fluampicil,Piperacillin, ticarcillin,Pivmecillinam HCl,Cephalosporins,Aztreonam, Ertapenem, imipenem with cilastatin and meropenem. Patients who are allergic to pencillins can have cross reactivity to cephalosporins(11)

m. Does the patient have a history of allergy to anesthesia?

• Documented- avoid all trigger agents such as succinylcholine and inhalational agents:

  Proposed general anesthetic plan: Total Intravenous anesthesia without succinylcholine can be easily used for inguinal hernia repair and eliminates the risk of malignant hyperthermia. However if there is a known risk of MH one can also think of regional/blocks for most inguinal hernias. Irrespective of the technique and the patient’s sensitivity, it is important to be aware of the MH cart availability and the protocol.

  Local anesthetics/ muscle relaxants: Anaphylaxis reactions to local anesthetic drugs are uncommon, esters more likely than amides to produce type IV hypersensitivity (10). Approximately 60 percent of anesthesia-related anaphylaxis are thought to be due to neuromuscular blocking agents. Succinylcholine is most likely to be associated with allergic anaphylaxis although rocuronium seems to have a similar incidence. Cross sensitivity between muscle relaxants is common and the prevalence of sensitization to these drugs in the population is about 10 percent. The use of muscle relaxants can be altogether avoided in the majority of the patients coming for inguinal hernia repair by choosing the appropriate technique.

5. What laboratory tests should be obtained and has everything been reviewed?

As mentioned earlier no specific laboratory tests are required for proceeding with inguinal hernia repair. The necessity of the test is based upon any associated co-morbidity

Intraoperative Management: What are the options for anesthetic management and how to determine the best technique?

Inguinal hernia repair can be done under a wide variety of anesthesia techniques (1,2). These include general anesthesia (inhalational or total intravenous anesthesia) with or without local would infiltration, Inguinal field block, spinal or epidural anesthesia and paravertebral block. However many factors need to be considered in choosing the correct technique viz age, anxiety levels, size and type of inguinal hernia, surgeons expertise and experience, anesthesiologists expertise and experience, associated co-morbidity, suitability of the patient for a given anesthetic technique..

a. Regional anesthesia

Spinal anesthesia is arguably the commonest anesthesia for hernia repair worldwide although not a popular technique in USA and UK. With adequate levels,it provides excellent muscle relaxation and, repair of even large hernia can be carried out. A mid-thoracic dermatomal level blockade is adequate and the volume of local anesthetic required for such a spread depends mainly on the patient’s height. Hyperbaric bupivacaine is the most popular choice as it provides anesthesia for sufficient duration. If the duration is likely to exceed that of bupivacaine, combined spinal-epidural might be an option. Although spinal anesthesia provides post operative analgesia for varying duration, it also delays discharge. Urinary retention requiring catherisation occurs occasionally.

Peripheral Nerve Blocks:The surgery can be done under unmonitored local anesthesia (3) regardless of co-morbidity. However it is not a popular technique in a university hospital setup. The analgesia might be insufficient and requires expertise on the part of the surgeon. One should be prepared to convert to a full general anesthetic.

As a sole anesthetic technique, Inguinal field bock is frequently performed by the surgeons themselves and supplemented with mild sedation. In selected patients the technique provides better postoperative analgesia, recovery function and patient satisfaction than general anesthesia supplemented with local would infiltration (4).The technique either on its own or with local wound infiltration (5) is also useful for postoperative analgesia. Transient femoral nerve palsy can be annoying and can delay discharge after field block (9). Some surgeons would prefer wound infiltration for this reason alone.

Paravetrebral blockade with sedation is described as a useful technique better than general anesthesia supplemented with inguinal field block (6,7). However many anesthesiologists are unfamiliar with the technique, complication/failure rates are higher and there are better alternatives are available (8).

b. General Anesthesia

Majority of the patients coming for inguinal hernia repair in the Western world are done under general anesthesia with a field block or local infiltration for postoperative analgesia. With significant advances in airway management, monitoring and increasing safety of general anesthesia, it is a popular technique for ambulatory surgery. Use of TIVA has greatly increased turnover times, reduced the incidence of postoperative nausea and vomiting, and improved patient satisfaction. Most cases can be done with a laryngeal mask airway with or without muscle relaxation depending on the surgeon’s preference and surgical conditions (that also depends on the size of the hernia).

c. Monitored Anesthesia Care

Propofol sedation supplemented with nerve blocks and/or local would infiltration is useful in patients unfit for general anesthesia and too anxious for nerve block and conscious sedation. The presence of anesthesiologist with allows the surgeon to concentrate of the operation. It also allows the patient to be converted to a general anesthetic in the event of any unexpected complications.

6. What is the author's preferred method of anesthesia technique and why?

• My preference is TIVA using Propofol and Remifentanil infusion (bolus and maintenance) with local would infiltration of bupivacaine for postop analgesia followed by fentanyl for immediate post-op pain relief as necessary. A laryngeal mask airway is adequate for most cases, although occasionally intubation and muscle relaxation might be necessary. This technique has minimal post op nausea vomiting, facilitates earlier discharge and has negligible pot-op airway complications.

  A single dose of appropriate antibiotic is administered before incision if a mesh repair is planned. Other than that there is no indication for a routine prophylactic antibiotic for inguinal hernia repair.

  As per the current SCIP 2010 recommendations preferred antibiotic is Cefazolin 1-2 g IV. If ß-Lactam Allergy: Clindamycin 600-900 mg IV or Vancomycin 1 g IV. If known history of MRSA: Vancomycin 1 g IV

  Sometimes, traction on the hernia sac with inadequate anesthesia can cause bradycardia, ask the surgeon to stop the traction and deepen the anesthesia (a small bolus of propofol). Sometimes an anti-cholinergic administration may be required.

  If the surgery is technically challenging, administration of a muscle relaxant might facilitate the repair. An inguinal field block can be done by the surgeon before the incision that can be supplemented with local would infiltration. Injecting the hernia sac might also help to prevent the bradycardia response.

  There are no other complications that are peculiar to the inguinal hernia repair.

a. Neurologic

N/A

b. If the patient is intubated, are there any special criteria for extubation?

Patients coming for emergency laparatomy for a strangulated inguinal hernia especially if septic and hemodynamically unstable might benefit from a period of respiratory support depending on the surgery performed. However for a common day surgery inguinal hernia repair, intubation should not be required and if required, extubation should not pose any problems.

c. Postoperative management

• An inguinal filed block with or without local wound infiltration is all that is necessary in majority of the cases. Supplemental doses of a short acting analgesic might be necessary in the recovery. An antiemetic needs to be prescribed. Occasionally the patient needs overnight admission either because of intractable pain or nausea/vomiting. Post-operative bleeding is very uncommon and may be an indication for re-exploration

What's the Evidence?

Kehlet, H, White, PF. “Optimizing anesthesia for inguinal herniorrhaphy: general, regional, or local anesthesia?”. Anesth Analg. vol. 93. 2001 Dec. pp. 1367-9.

Callesen, T. “Inguinal hernia repair: anaesthesia, pain and convalescence”. Dan Med Bull. vol. 50. 2003 Aug. pp. 203-18.

Callesen, T, Bech, K, Kehlet, H. “One-thousand consecutive inguinal hernia repairs under unmonitored local anesthesia”. Anesth Analg. vol. 93. 2001 Dec. pp. 1373-6.

Aasbø, V, Thuen, A, Raeder, J. “Improved long-lasting postoperative analgesia, recovery function and patient satisfaction after inguinal hernia repair with inguinal field block compared with general anesthesia”. Acta Anaesthesiol Scand. vol. 46. 2002 Jul. pp. 674-8.

Andersen, FH, Nielsen, K, Kehlet, H. “Combined ilioinguinal blockade and local infiltration anaesthesia for groin hernia repair–a double-blind randomized study”. Br J Anaesth. vol. 94. 2005 Apr. pp. 520-3.

Hadzic, A, Kerimoglu, B, Loreio, D, Karaca, PE, Claudio, RE, Yufa, M, Wedderburn, R, Santos, AC, Thys, DM. “Paravertebral blocks provide superior same-day recovery over general anesthesia for patients undergoing inguinal hernia repair”. Anesth Analg. vol. 102. 2006 Apr. pp. 1076-81.

Weltz, CR, Klein, SM, Arbo, JE, Greengrass, RA. “Paravertebral block anesthesia for inguinal hernia repair”. World J Surg. vol. 27. 2003 Apr. pp. 425-9.

White, PF. “Choice of peripheral nerve block for inguinal herniorrhaphy: is better the enemy of good?”. Anesth Analg. vol. 102. 2006 Apr. pp. 1073-5.

Ghani, KR, McMillan, R, Paterson-Brown, S. “Transient femoral nerve palsy following ilio-inguinal nerve blockade for day case inguinal hernia repair”. J R Coll Surg Edinb. vol. 47. 2002 Aug. pp. 626-9.

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