Hospital Medicine

Complications of anesthesia

I. Problem/Challenge.

Managing postoperative complication: are you prepared for the challenge?

It is now commonplace for a hospitalist to manage patients beyond the traditional array of comorbid conditions for which internal medicine training has prepared us.

Postoperative nausea and vomiting, hypotension after a total knee replacement or post cholecystectomy fever have all become familiar issues hospitalists are dealing with each day.

The question stands however: are we prepared and competent to manage these issues? As surgical comanagement becomes more and more a staple in our medical practice, our ability to utilize evidence-based practice standards (or expert panel recommendations) to manage these issues is crucial. In order to best care for our new patient population we need to understand the inherent complications associated with anesthesia.

II. Identify the Goal Behavior

Treating the postoperative/anesthesia complication

Hospitalists must be able to actively manage their patient's medical complications arising from surgery. The vast majority of initial complications of surgery are due to anesthesia. The hospitalist must be able to understand, recognize and treat these early complications.

Complications can easily increase the risk of severe morbidity and possibly mortality. Early recognition of warning signs of patient demise will enable the hospitalist to care for his or her patient more efficiently and effectively. It is also important for the hospitalist to understand the potential complications associated with the type of anesthesia the patient will be receiving during surgery, i.e. general versus neuraxial versus nerve blocks versus moderate to conscience sedation.

III. Describe a Step-by-Step approach/method to this problem.

Managing the anesthetic choice (preventing the complications)

As hospitalists, managing the surgical patient remains a challenge. Part of this challenge is the management of medical complications of the anesthetic choice and surgery.

In order to best serve our patients we must be able to identify the anesthetic choice and recognize the side effects of each. The type of surgery and or a patient's comorbid conditions will eventually drive anesthesia choice.

The first step in the process is for there to be communication between the hospitalist and the surgeon (or anesthesiologist). Simply asking what type of anesthesia will be used during the procedure will greatly improve the outcome and the hospitalist's understanding of potential side effects. This step is often the most important and usually omitted.

There are four main types of anesthesia. The first, and most common, is general anesthesia. General anesthesia is usually reserved for patients requiring the most complex of surgical procedures. Complications include bronchospasm, myocardial infarction, aspiration pneumonia, deep vein thrombosis (DVT), and urinary tract infection (UTI) to name a few.

General anesthesia has three phases: induction, maintenance (usually in the form of volatile agents such as nitrous oxide or halothanes) and emergence. Postoperative issues that the hospitalist needs to recognize are pulmonary aspiration risk, bronchospasm, cardiac stress in patients with coronary artery disease (CAD) risk factors, DVT development given patients' immobility, and exacerbation of heart failure secondary to the increased fluid shifts during surgery.

General anesthesia should be avoided, if possible, in patients with severe end stage chronic obstructive pulmonary disease (COPD), or congestive heart failure (CHF) secondary to the increased morbidity and mortality.

A second type of anesthesia is neuraxial anesthesia. This includes both spinal and epidural approaches. These choices are most often utilized during orthopedic extremity procedures. They have decreased risk for cardiac and pulmonary complication; however they do carry small but significant complication risks: dural puncture, spinal hematoma or epidural abscess (all have been documented using these approaches of anesthesia).

Patients using antiplatelet therapy (clopidogrel etc.) should have their therapy delayed 1 week prior to this approach.

A third anesthetic choice, peripheral nerve block, is often used in conjunction with general anesthesia in order to decrease postoperative pain. Peripheral nerve blocks may also be used as standalone agents for certain local procedures or if the patient is high risk for cardiac or pulmonary complications.

Common sites for a peripheral nerve block include the brachial plexus or femoral nerve group. These approaches have extremely low complication rates especially when administered with a nerve stimulator or are ultrasound-guided. Nerve blocks are superior for postoperative pain control and therefore decrease complications such as aspiration pneumonia and over sedation from narcotics.

Peripheral nerve blocks are particularly useful in patients with severe obstructive sleep apnea as narcotic use should be minimized.

Finally, monitored anesthesia care (MAC) is a spectrum of anesthetic services including intraoperative monitoring, analgesia and supportive care. MAC does not involve complete loss of consciousness. Often agents such as propofol are utilized in conjunction with a peripheral nerve block when MAC is implemented.

MAC is often utilized for patients for patients requiring less invasive procedures. MAC has decreased episodes of nausea and vomiting, postoperatively. A disadvantage of MAC is the inability to control a patient's airway and potentially increasing the risk of aspiration. Careful monitoring should be shown during a procedure using MAC.

Before any surgical procedure communication between all three parties should occur - the hospitalist, surgeon and anesthesiologist. The choice of anesthesia should be made based on the patient’s procedure and medical risk. It is important that as hospitalists we have a working understanding of each method and when to medically recommend one versus another.

Hospitalists do have a critical role in the influence of anesthetic choice but also the management of the complications of all types of anesthesia. These complications are often immediately following the procedure. A standardized approach to the patient in the acute postoperative period will decrease variability in care and also improve outcomes. Some of the most common complications include: postoperative nausea and vomiting, respiratory depression, acute myocardial infarction, delirium, and fever. See below for specific management strategies for each.

Postoperative nausea and vomiting

Postoperative nausea and vomiting is a major issue for not only the patient (aspiration risk) but also financially as it has been shown to increase the total cost of care and length of stay (LOS) for the hospital. Factors influencing nausea and vomiting include type of anesthesia uses (use of nitrous oxide), duration of surgery (increased risk with each 30 minute increment) and type of surgery (increased with laparoscopic, ENT and neurosurgery).

Despite best intentions nausea and vomiting frequently occurs postoperatively. Strategies to treat these symptoms include initially raising the head of the bed more than 30 degrees (if surgically stable) to decrease aspiration risk, use of ondansetron 4mg, supplemental oxygen (O2), and intravenous (IV) fluids to improve symptoms until the effects of the anesthesia abate. In patients with increased risk of heart disease a postoperative electrocardiogram (ECG) must be obtained to rule out postoperative ischemia as a source of the nausea and vomiting. Also be mindful of surgical complications contributing to nausea and vomiting such as ileus or luminal perforation.

Delirium in the postoperative patient

The management of postoperative delirium is a team approach. This approach requires constant contact with not only the patient but also nursing and family. After ruling out infection and cardiac causes of this new mental status change, the most important step in treating postoperative delirium is non-chemical.

Some estimates have the percentage of patients suffering from postoperative delirium ranging from 10-50%. It is a major issue complicating patient care (failure to extubate and increased risk of long term dementia) and it increases the economic burden to healthcare systems via increased intensive care unit (ICU) resources and LOS.

An initial approach to the patient with delirium should be non-pharmacologic. Reorienting the patient to their current situation and circumstance, calling in family members and mild stimuli such as a room close to the nursing station should all be utilized if possible.

If delirium persists after all reversible causes have been excluded then chemical agents may be used. Haloperidol or respiradone may be beneficial for management of behaviours that pose a risk for the patient's safety. Haloperidol must be avoided in patients with a prolonged QT or allergy, and in these circumstances respiradone may be substituted. Including nursing in the treatment plans is also critical given they will be able to intervene when physicians or family are not available. A total team approach must be utilized.

Myocardial infarction

The management of an actual myocardial infarction goes beyond the scope of this chapter. However, it should be mentioned that patients with increased risk of preoperative morbidity and mortality should have a through physical examination pre and postoperatively. A postoperative ECG should also be ordered for high risk patients. The key to treating postoperative myocardial infarction is prevention through the appropriate selection of anesthesia with the anesthesia/surgical team.

Management of respiratory depression

This complication usually occurs in patients with underlying pulmonary pathology, commonly COPD or obstructive sleep apnea (OSA). Again, preoperative screening for these diseases represents the best approach with the correct use of preoperative anesthesia.

A through history and physical along with communication is the best. However, in the event that a patient does have this complication, initial strategies for management include: maintenance of airway protection and the use of beta agonists via nebulizers, avoidance of over sedation with basal or as needed narcotics (early recognition and pain management consult should be considered), use of supplemental O2 or continuous positive airway pressure (CPAP), and finally correct positioning to decrease risk of aspiration.

All patients who are unable to maintain a sufficient airway or are felt to be clinically decompensating should have reintubation for airway control. Obviously, a chest x-ray (CXR) must be ordered if the physical exam reveals any finding suggestive of pneumonia or pneumothorax.

Fever

One of the most common occurrences in the hospital setting is often an area of angst for hospitalists. A very common approach to fever is not always the most prudent. Postoperative fever should be approached similarly to medical school training: "Wind, Water, Walking, Wound, Wonder Drugs".

Postoperative fevers are extremely common, occurring in up to 60% of patients regardless of anesthesia utilized. Postoperative day 1-3 the differential should include atelectasis (controversial) pneumonia or pulmonary embolism. UTIs, DVTs, wound infections, and drugs etc. as described by the five W mnemonic usually present fever postoperatively day 3-7 and therefore go beyond the scope of this article.

Fever, should be initially treated conservatively in the immediate postoperative period and the reflex of obtaining blood cultures, CXR and a urinalysis should be avoided unless there are signs of an overwhelming infection or sepsis. Most causes of fever in the first 24 hours postsurgical procedure are inflammatory secondary to the surgery itself.

IV. Common Pitfalls.

Avoiding the postoperative pitfall - communication

The management of complications occurring postanesthesia are well within the hospitalist's scope of practice. However, one of the most common mistakes a hospitalist can make is lack of understanding of the procedure and anesthetic choice.

It is imperative that communication occurs "prior" to the surgery. Simply ask the surgeon and or anesthesiologist what approach they plan on implementing. Often times input from the hospitalist can improve the outcome of the surgery or decrease the complications postoperatively.

For example, discussing the severity of a patient's OSA can educate the surgeon/anesthesiologist and therefore influence the choice of anesthesia. Each hospital medicine group will have a unique set of circumstances regarding the operations of preoperative clearance and interaction with anesthesiologists/surgeons. However, it is imperative that a common goal exists.

The goal should be the appropriate risk stratification and communication of that information to the anesthesiologist and/or surgeon. An initial approach to this process should begin with standardizing the process. Whether a daily communication system is needed via multispecialty team rounds or simply an agreed upon approach whereby no patient may proceed to the operating room prior to the hospitalist and anesthesiologist communicating, a system must be implemented. The system of communication will allow for greater satisfaction among all physicians and improved patient outcomes.

V. National Standards, Core Indicators and Quality Measures.

Surgical Care Improvement Project measures and hospital medicine

The relationship between the surgeon and hospitalist is in evolution. The value equation begins with data measurement. In order to best demonstrate value of the comanagement, relationship-specific goals or quality measures should be discussed.

While there exist no specific comanagement national standards, the Surgical Care Improvement Project (SCIP) is a core measure that surgeons equate high value with.

Targeted areas of collaboration could be the UTI/Foley, DVT prophylaxis or glycemic control measures. Although none of these metrics directly relate to the complication of anesthesia, it is important to recognize the global view of the hospitalist/surgeon relationship and how best to leverage its benefit. By determining pre-established goals with the surgeon a clearer picture of value can be placed on the hospitalist's role in this process.

VI. What's the evidence?

Apfel, CC, Roewer, N. "Risk assement of postoperative nausea and vomiting". Int Anesthesiology Clinics. vol. 41. 2003. pp. 13-31.

Fiesher, LA, Beckman, JA. "2007 Guideline on perioperative cardiovascular evaluation and care for the non-cardiac patient". Journal American College of Cardiology. vol. 50. 2007. pp. 1707-1737.

Michota, F, Frost, S. "The preoperative evaluation. Use the history and physical rather than routine testing". Cleveland Clinc Journal of Medicine. vol. 17. 2004. pp. 63-70.

Jin, F, Chung, F. "Minimizing perioperative adverse events in the elderly". British Journal of Anesthesia. vol. 87. 2001. pp. 608-624.

Liu, LL, Wiener-Kronsih, JP. "Perioperative anesthesia issues in the elderly". Critical Care Clinics. vol. 19. 2003. pp. 641-656.

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