Anesthesia providers are likely to see increasing numbers of geriatric patients in their practice. By 2030, 20% of the US population will be greater than 65 years old, and elderly patients are four times more likely to require surgery than younger individuals. It is beneficial to review pharmacologic considerations and dose adjustments for this patient population.

First of all, body composition changes with age, with a loss of lean muscle and an increase in adipose tissue. Hydrophilic drugs therefore see a decreased volume of distribution, while lipophilic drugs have a larger volume of distribution, leading to prolonged action of fat soluble agents such as propofol infusions. There is a 20-30% decrease in plasma volume and intracellular volume by the age of 75, causing a smaller volume of distribution in the central compartment and reduced bolus doses needed for the same effect.

Next, neurologic changes to the geriatric population include a reduction in brain volume by 5% per decade after age 40, decreased nerve conduction velocities, and altered neurotransmitter level and activity – all of which increase sensitivity to anesthetic agents. Decreasing presynaptic release of GABA may explain the increased sensitivity to benzodiazepines in elderly patients. They are also more likely to have baseline cognitive impairment, and are at higher risk for postoperative cognitive dysfunction and delirium.

Cardiovascularly, the decline of cardiac output with age leads to higher initial peak drug concentrations but longer time to reach the target site; this results in smaller doses of IV agents needed for induction, but the onset of action is slower. Inhalational agents have a faster onset due to decreased anesthetic washout from the lungs into the blood, leading to a faster equilibration of blood, brain and lung partial pressures of volatile gas.

Renal blood flow also decreases by 10% per decade after the age of 40, and renal cortical mass is reduced by 25% by age 80. The resultant 50% decrease in glomerular filtration rate by age 80 necessitates a dose reduction on any agent that depends on renal metabolism and elimination.

Furthermore, hepatic blood flow declines by 10% per decade. Decreased hepatic function primarily affects phase I reactions, and drugs dependent on this pathway for metabolism are considered to be flow-limited. Drugs that are metabolized by phase II reactions are not affected by declining hepatic function and are considered capacity-limited. More than 90% of patients older than 65 years take more than one drug regularly, 40% take 5 or more per week, and 12% use 10 or more per week. This polypharmacy may increase the likelihood of drug interactions, particularly with agents metabolized by the cytochrome P450 pathway.

In summary, anesthesia providers will often need to make dose adjustments based on altered drug metabolism in the elderly. Guidelines include reducing bolus and infusion rates for propofol by 20-50%, and fentanyl and remifentanil by 50% after age 80. Morphine, hydromorphone, and meperidine have active metabolites that may not be efficiently cleared with age, so their doses should also be reduced. Midazolam, though not recommended given increased risk of delirium in the geriatric population, should have a 25-75% dose reduction if necessary. Succinylcholine and cisatracurium are not affected by aging, though rocuronium doses should be reduced. Inhalational agents dosages should be reduced as MAC decreases by 6% per decade after age 40. A BIS monitor is often helpful to measure anesthetic depth.

References:

Rana MV, Bonasera LK, Bordelon GJ. Pharmacologic Considerations of Anesthetic Agents in Geriatric Patients. Anesthesioly Clin. 2017 Jun;35(2):259-271.

As health insurance reimbursement mechanisms become increasingly dense and complicated, it is essential for healthcare management companies to focus on a cornerstone of the practitioner experience in a medical episode: billing. Billing refers to the complex set of codes that a healthcare practitioner must submit to the hospital’s electronic medical records system in order to (a) record in a standardized system the services and procedures rendered during a patient’s stay in the facility and (b) submit for reimbursement from the patient’s insurer or, if uninsured, by the patient him/herself out of pocket. Medical billing is under increased focus from anesthesia management companies as the rules and regulations shift under Center for Medicare and Medicaid Services (CMS) for advising how to treat such issues. Similar to coverage policies, the standards for medical billing under CMS often directly influence that of commercial payers. Therefore, when delving into the issue of medical billing it is often helpful to base management on the foundation of national systems, in order to build from the most stringent criteria to that which may be less rigid in practice.

As a precondition for selecting the correct code in medical billing, it is necessary to identify the practitioner who enacted the service or procedure on the patient. Moreover, the billing code should also distinguish between the practitioner — including an anesthesiologist, certified registered nurse anesthetist (CRNA), anesthesiologist assistant (AA), registered nurse (RN), or nurse practitioner (NP) — who enacted the procedure. CMS provides several categories to assist anesthesia administrators with forming such a distinction, based upon input from the clinicians themselves. The predominant categories are: teaching, personally performed, medically directed, and medically supervised. The first two are fairly self-explanatory. But, the difference between medically directed and medically supervised is often confused, leading to differences in billing and thus reimbursement outcomes for the patients and hospital. According to CMS, the “medically directed” designation indicates a more significant level of involvement from the most senior practitioner than that of the “medically supervised” category. For example, an anesthesiologist who performs the preoperative exam and evaluation, prescribes the medications that will be utilized during surgery, and/or personally performs the most complicated parts of the anesthesia procedure during surgery would clearly have worked above his/her role as supervisor. Therefore, in this case the billing code would fall under “medical direction”. However, consider another example: an anesthesiologist and CRNA are working on the same case team and the anesthesiology is highly staffed (defined as participating or leading on more than four cases). The anesthesiologist may advise on the anesthesia plan, but the CRNA would be responsible for enacting all the parts of the project plan, including administration of anesthesia. In turn, this case would be defined in the medical billing scenario as a medical supervision case, reflecting the lack of physician involvement in every step of the anesthesia episode.

Along with distinction of clinician roles in the medical side, a prime component of accurate medical billing rests with meeting rigorous documentation requirements. Documentation should include timing, clinician notes, dosage and administration, medical equipment usage, and a medical assessment at minimum. Furthermore, any documentation requires a verified signature from the surgeon or most senior clinician present during the surgery. In the event that an insurance claim is rejected, medical billing administrative professionals will often refer back to the verified case notes to elucidate the specifics of a case. Thus, it is critical for the documentation to be comprehensive, specific, accurate, and up-to-date.

Fortunately for anesthesiologists, CRNAs, AAs, and other anesthesia providers, innovations in healthcare technology are actively working to facilitate the documentation process for clinicians. A study in the peer-reviewed journal Anesthesiology described a computer software which can automatically examine electronic medical records and alert clinicians if there appears to be an error, with a targeted response for resolution. The researchers found that the system not only reduced the number of unbilled records and median time to address documentation errors, but it also increased the anesthesiology department revenue by approximately 400,000 USD as a result of re-captured reimbursement. The efficacy and cost benefits of bolstered documentation, and thus more accurate billing and reimbursement as illustrated in this study, highlights the importance of high standards in billing from the anesthesia management perspective.

Anesthesia management companies should emphasize a focus on billing in their administrative and clinical staff alike in order to continue moving forward, providing high-quality and cost-effective compassionate care for all patients who undergo procedures nationwide.

Sources:

1. https://www.everyusb.com/ebooks/tulane/#648
2. https://www.ncbi.nlm.nih.gov/pubmed/17197858
3. https://www.cms.gov/Medicare/Medicare-Fee-for-Service-Payment/HomeHealthPPS/coding_billing.html

A recent topic of interest is the utilization of “deep” neuromuscular blockade and its improvement of surgical conditions, particularly during laparoscopic cases where the surgical workspace is limited and subtle movements of the diaphragm may affect visibility and technical performance. Deep neuromuscular blockade is often compared to “moderate” neuromuscular blockade, however the definitions of both seems somewhat variable depending on whom you talk to. Some define deep blockade as zero twitch in train of four monitoring, others use it to designate 1-2 twitches. Moderate blockade is even less consistently defined, with some simply characterizing it as the administration of neuromuscular blockers without consistent monitoring.

Regardless of definition, there now exists a compelling body of evidence that surgeons can tell the difference between deep and moderate neuromuscular blockade in terms of improved surgical conditions, though the effect is not the same across all surgery types and is not unanimously reflected in all studies.

An interesting perspective was presented by anesthesiologists from the Netherlands at Anesthesiology 2017, and subsequently published in their paper: Boon et al described a retrospective study of retroperitoneal laparoscopic urology procedures examining whether deep neuromuscular blockade affected postoperative outcomes. Patients either received high dose rocuronium (1mg/kg followed by a continuous infusion targeting 1-2 twitches on train of four monitoring) or low dose rocuronium (0.4mg/kg at induction, no continuous infusion, no consistent train of four monitoring). In the former, all patients received sugammadex for reversal, while the latter received either sugammadex or neostigmine. The high dose rocuronium group (deep neuromuscular blockade) had significantly lower rates of unplanned readmission in the first 30 days following surgery.

In their discussion, the authors addressed that the mechanism for deep neuromuscular blockade reducing 30-day unplanned readmission was unclear. The readmissions in question did not involve the pulmonary system, therefore lending less credence to the hypothesis that the difference was due to superior reversal by sugammadex or better monitoring of depth of neuromuscular blockade in the high dose rocuronium group. Rather, the readmissions involved were largely due to postoperative surgical complications, including infections or anastomosis leak. The authors theorized that the improved surgical conditions offered by deep neuromuscular blockade resulted in better technical performance and therefore fewer surgical complication resulting in readmission.

Notably, the researchers found no difference between the deep and moderate neuromuscular blockade groups in terms of duration of anesthesia, duration of procedure, use of vasoactive medications, vital signs, or bispectral index.

It is compelling to suggest that deep neuromuscular blockade intraoperatively can lead to cost-saving measures and lower readmission rates postoperatively. Further study is needed to elucidate the mechanism of these benefits.

Reference

https://www.anesthesiologynews.com/Multimedia/Article/04-18/Deep-Neuromuscular-Block-Leads-to-Fewer-Readmissions-Lower-Overall-Costs/48483

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0197036

Drug shortages across disciplines of medicine are not uncommon and can occur for many reasons, including difficulties in obtaining raw materials, shifts in manufacturing companies, government regulations, and more. However, a few years into the 21^st century, the United States began to suffer from a prolonged drug shortage, especially in anesthesia. In response, in 2012, Congress passed the Food and Drug Administration Safety and Innovation Act (FDASIA), which gave the FDA more authority to act on the issue. FDASIA mandated manufacturers to notify the FDA of almost any potential issues that may affect their production output. Shortly after, in 2013, the FDA released its Strategic Plan for Preventing and Mitigating Drug Shortages, which had two goals: 1) to mitigate drug shortages and 2) to develop strategies for long-term prevention.

Despite governmental action, anesthesiology remains one of the most affected areas of practice. A 2014 report released by the Government Accountability Office (GAO) found anesthetic and central nervous system drugs to be among the class of drugs that accounted for 17 percent of all shortages in the United States. The shortages resulted in anesthesiologists citing less than optimal anesthetic outcomes, an increase in minor complications, and prolonged surgical and recovery times.

When brands and concentrations of available drugs continuously change, the burden on anesthesiologists to develop and adhere to new protocols without jeopardizing patient safety significantly increases. As a result, some facilities and personnel hoard drugs that are susceptible to shortages. In turn, this causes many potential shortages to swiftly become actual, nation-wide shortages.²

Today, the 2017 nationwide shortage of lidocaine with epinephrine persists, as there continues to be an epinephrine shortage and only 2 pharmaceutical companies (Pfizer and Fresnius Kabi USA) still produce it. Additionally, over the past several months, several medication shortages in North America have been exacerbated by Hurricane Maria and its effect on Puerto Rican manufacturing plants. The shortages are now affecting health care facilities in new ways, as this is an issue whose landscape changes on a weekly basis. Care facilities are now receiving drugs in varying volumes and concentrations (including that of epinephrine), which further complicates standard anesthesia protocols.

Now more than ever, with no imminent solution in sight, increased public and governmental attention and action is critical to resolving the issue and ensuring patient safety. Furthermore, anesthesiologists and other care providers must collaborate to develop a new school of thought when it comes to developing adaptive drug administration protocols.

References

Orlovich, D. S., & Kelly, R. J. (2015, February). Drug Shortages in the U.S. ­ A Balanced Perspective. Retrieved May 15, 2018, from https://www.apsf.org/article/drug-shortages-in-the-u-s-%C2%AD-a-balanced-perspective/

Vaidya, A. (2014, October 16). Anesthesia drug shortages are a reality: 5 options for ASCs. Retrieved May 15, 2018, from https://www.beckersasc.com/anesthesia/anesthesia-drug-shortages-are-a-reality-5-options-for-ascs.html

Bodie, B., Brodell, R. T., & Helms, S. E. (2018). Shortage of lidocaine with epinephrine: Causes and solutions. Journal of the American Academy of Dermatology.

Carniol, E. T., Gantous, A., & Adamson, P. A. (2018). Local Anesthesia Shortages—Adapting to a New Way of Life. JAMA Facial Plastic Surgery.

Obesity is a nationwide epidemic, affecting over 30% of Americans. Over 50% of pregnant women in the United States are overweight or obese. Neuraxial anesthesia is often a good choice for this population for appropriate surgeries as well as for labor, avoiding airway instrumentation and complications of general anesthesia that are often exacerbated by obesity.

It remains a topic of debate whether the dosage of local anesthetics for neuraxial blocks needs to be adjusted for obese patients. Traditional teaching based on earlier studies recommends decreasing the dose of local anesthetics for spinal and epidural blocks, citing a positive correlation between cephalad spread of sensory blockade and BMI. However newer data calls this correlation into question.

MRI studies demonstrate a smaller cerebrospinal fluid volume in the lumbar subarachnoid space of obese patients, as well as an inverse relationship between lumbar CSF volume and cephalad block extension. The epidural space in these patients is also smaller. The mechanism is thought to be compression and increased abdominal pressure by abdominal fat, which causes caval compression, epidural vein engorgement, and displacement of soft tissue through the intervertebral foramina.

Despite these confirmed physiological differences between obese and non-obese patients, several recent clinical studies have shown no significant difference in the ED50 and ED95 of hyperbaric spinal bupivacaine in obese parturients and those with normal BMI when undergoing cesarean section. There is little data on super-obese patients (BMI >50 kg/m2). Some argue based on these studies that intrathecal dosing of local anesthetics need not be reduced for obese patients, however there is no expert consensus on the topic.

Less controversy exists in the epidural dosing of obese patients, with most studies showing a decreased requirement for local anesthetics in this population.

The fact that block overdose, block failure and inadequate block duration in obese patients may lead to undesirable emergency airway instrumentation in a population with increased incidence of difficult airway raises the stakes of accurate dosing. Options such as combined spinal epidurals allow for dosage reduction in the initial intrathecal component, with the ability to titrate together with the epidural component. This and intrathecal catheters both guard against the possibility of longer surgical duration in patients with high BMI.

While it remains unclear whether obesity warrants a reduction in local anesthetic dosing for neuraxial anesthesia, a prudent approach may be to start on the side of safety and begin with smaller dosages while employing a catheter-based technique.

References

Brodsky JB, Lemmens HJ. Regional anesthesia and obesity. Obes Surg. 2007 Sep;17(9):1146-9.

Lamon AM, Habib AS. Managing anesthesia for cesarean section in obese patients: current perspectives. Local Reg Anesth. 2016 Asug 16;9:45-57. doi: 10.2147/LRA.S64279.

Panni MK, Columb MO. Obese parturients have lower epidural local anaesthetic requirements for analgesia in labour. Br J Anaesth. 2006 Jan;96(1):106-10.