Risk-adjusted policies to minimise perioperative staffing shortages during a pandemic: An agent-based simulation study.

Healthcare workers' (HCWs) safety and availability to care for patients are critical during a pandemic such as the one caused by severe acute respiratory syndrome coronavirus 2. Among providers of different specialities, it is critical to protect those working in hospital settings with a high risk of infection. Using an agent-based simulation model, various staffing policies were developed and simulated for 90 days using data from the largest health systems in South Carolina. The model considers staffing policies that include geographic segregation, interpersonal contact limits, and a combination of factors, including the patient census, transmission rates, vaccination status of providers, hospital capacity, incubation time, quarantine period, and interactions between patients and providers. Comparing the existing practices to various risk-adjusted staffing policies, model predictions show that restricted teaming and rotating schedules significantly (p-value <0.01) reduced weekly HCW unavailability and the number of infected HCWs by 22% and 38%, respectively, when the vaccination rates among HCWs were lower (<75%). However, as the vaccination rate increases, the benefits of risk-adjusted policies diminish; and when 90% of HCWs were vaccinated, there were no significant (p-value = 0.09) benefits. Although these simulated outcomes are specific to one health system, our findings can be generalised to other health systems with multiple locations.

Effect of near real-time feedback tool in the electronic medical record on protocol compliance during laparoscopic cholecystectomy: a single-center retrospective analysis.

Implementation of evidence-based medicine has proved difficult across medical fields. Leveraging the electronic medical record may improve clinician compliance to published best practices. Our hypothesis was that the use of a near real-time feedback tool would improve compliance to the protocol steps. In order to test this hypothesis, we performed a retrospective chart review to compare compliance to a proprietary enhanced recovery protocol for patients undergoing laparoscopic cholecystectomy with and without a near real-time feedback tool embedded in the electronic medical record. Deviations to the care pathway were quantified and classified as allowable or as errors of commission, omission, or dose. During the study period, 2625 laparoscopic cholecystectomies were performed. A total of 16,972 protocol steps were evaluated. Complete protocol compliance improved from 10.3 to 61.5% (p < 0.001) with the use of the feedback tool. Individual protocol component compliance increased from 4994/8418 (59.3%) to 7669/8554 (89.7%) (p < 0.001). The near real-time feedback tool reduced the number of cases with every number of deviations (except zero) at p < 0.001. The near real-time feedback tool significantly improved protocol compliance for patients undergoing laparoscopic cholecystectomy.

Assisted Fluid Management Software Guidance for Intraoperative Fluid Administration.

BACKGROUND: Excessive or inadequate fluid administration causes complications, but despite this, fluid administration during noncardiac surgery is highly variable. Goal-directed management helps optimize the amount and timing of fluid administration; however, implementation is difficult because algorithms are complex. The authors therefore tested the performance of the Acumen Assisted Fluid Management software (Edwards Lifesciences, USA), which is designed to guide optimal intravenous fluid administration during surgery. METHODS: In this multicenter, prospective, single-arm cohort evaluation, the authors enrolled 330 adults scheduled for moderate- to high-risk noncardiac surgery that required arterial catheter insertion and mechanical ventilation. Clinicians chose a fluid strategy based on a desired 10%, 15%, or 20% increase in stroke volume (SV) in response to a fluid bolus. Dedicated fluid management software prompted "test" or "recommended" boluses, and clinicians were free to initiate a "user" bolus of 100 to 500 ml of crystalloid or colloid. Clinicians were free to accept or decline the software prompts. The authors primarily compared the fraction of software-recommended boluses that produced suitable increases in SV to a 30% reference rate. On an exploratory basis, we compared responses to software-recommended and clinician-initiated boluses. RESULTS: Four hundred twenty-four of 479 (89%) software-recommended fluid boluses and 508 of 592 (86%) clinician-initiated fluid boluses were analyzed per protocol. Of those, 66% (95% CI, 62 to 70%) of delivered fluid boluses recommended by the software resulted in desired increases in SV, compared with the 30% reference rate, whereas only 41% (95% CI, 38 to 44%) of clinician-initiated boluses did (P < 0.0001). The mean ± SD increase in SV after boluses recommended by the software was 14.2 ± 13.9% versus 8.3 ± 12.1% (P < 0.0001) for those initiated by clinicians. CONCLUSIONS: Fluid boluses recommended by the software resulted in desired SV increases more often, and with greater absolute SV increase, than clinician-initiated boluses. Automated assessment of fluid responsiveness may help clinicians optimize intraoperative fluid management during noncardiac surgery.

Intraoperative vasopressors in head and neck free flap reconstruction.

INTRODUCTION: Historically, there were concerns vasopressors impair free flap outcomes, but recent studies suggest vasopressors are safe. Here we investigate this controversy by (1) evaluating vasopressors' effect on head and neck free-flap survival and surgical complications, and (2) performing soft tissue and bony subset analysis. PATIENTS AND METHODS: Post hoc analysis was performed of a single-blinded, prospective, randomized clinical trial at a tertiary care academic medical center involving patients ≥18 years old undergoing head and neck free flap reconstruction over a 16-month period. Patients were excluded if factors prevented accurate FloTrac™ use. Patients were randomized to traditional volume-based support, or goal-directed support including vasopressor use. Primary data was obtained by study personnel through intraoperative data recording and postoperative medical record review. RESULTS: Forty-one and 38 patients were randomized to traditional and pressor-based algorithms, respectively. Flap survival was 95% (75/79). There was no significant difference between the pressor-based and traditional protocols' flap failure (1/38 [3%] vs. 3/41 [7%], RR 0.36, 95% CI of RR 0.04-3.31, p = .63) or flap-related complications (12/38 [32%] vs. 18/41 [44%], RR 0.72, 95% CI 0.40-1.29, p = .36) Soft tissue flaps had surgical complication rates of 12/30 (40%) and 9/27 (33%) for traditional and pressor-based protocols, respectively. Bony flaps had surgical complication rates of 6/11 (55%), and 3/11 (27%) for traditional and pressor-based protocols, respectively. CONCLUSIONS: Intraoperative goal-directed vasopressor administration during head and neck free flap reconstruction does not appear to increase the rate of flap complications or failures.

Opioid Addiction and Opioid Receptor Dimerization: Structural Modeling of the OPRD1 and OPRM1 Heterodimer and Its Signaling Pathways.

Opioid addiction is a complex phenomenon with genetic, social, and other components. Due to such complexity, it is difficult to interpret the outcome of clinical studies, and thus, mutations found in individuals with these addictions are still not indisputably classified as opioid addiction-causing variants. Here, we computationally investigated two such mutations, A6V and N40D, found in the mu opioid receptor gene OPRM1. The mutations are located in the extracellular domain of the corresponding protein, which is important to the hetero-dimerization of OPRM1 with the delta opioid receptor protein (OPRD1). The hetero-dimerization of OPRD1-OPRM1 affects the signaling pathways activated by opioids and natural peptides and, thus, could be considered a factor contributing to addiction. In this study, we built four 3D structures of molecular pathways, including the G-protein signaling pathway and the ß-arrestin signaling pathway of the heterodimer of OPRD1-OPRM1. We also analyzed the effect of mutations of A6V and N40D on the stability of individual OPRM1/OPRD1 molecules and the OPRD1-OPRM1 heterodimer with the goal of inferring their plausible linkage with opioid addiction. It was found that both mutations slightly destabilize OPRM1/OPRD1 monomers and weaken their association. Since hetero-dimerization is a key step for signaling processes, it is anticipated that both mutations may be causing increased addiction risk.

Safety and Effectiveness of a Novel Facemask for Positive Pressure Ventilation.

BACKGROUND: Manual positive pressure ventilation is an essential skill in a variety of clinical situations. The C&E technique is commonly used with standard facemasks to provide effective ventilation. The Tao mask is a novel design that allows a more ergonomic grip. A seal between the mask and face is made with downward pressure of the palm, centered on the mask, and jaw lift is achieved with 4 fingers centered under the mandible. The purpose of this study was to evaluate the safety and effectiveness of the Tao mask compared to a standard mask before and after the administration of neuromuscular blockade (NMB) using 2 previously established ventilation scales. METHODS: One hundred fifty-two patients >18 years of age who were scheduled for general anesthesia were recruited. All care team members were shown a brief instructional video on the use of the Tao mask. After induction of general anesthesia with a standardized protocol, each patient was ventilated with both the standard (Vital Signs #082510) and Tao masks and effectiveness was measured using the Han and Warters scales. This process was repeated after NMB. The sequence of masks was determined with a random-number generator. RESULTS: Tao mask ventilation scores were significantly better than standard mask scores on both the Han scale and the Warters scale before the administration of NMB (P < .001 for both). Tao mask scores were also significantly better than standard mask scores on the Warters scale after the administration of NMB (P < .001). However, there was no significant difference on the Han scale between the 2 mask types after NMB (P = .180). On the Warters scale, there were significantly fewer patients who were difficult to ventilate with the Tao mask than the standard mask before NMB (18 vs 40; P < .001) and after NMB (8 vs 17; P = .005). No adverse events were reported with either mask. CONCLUSIONS: Our results indicate that the Tao mask demonstrated equivalent safety and superior effectiveness compared to a standard mask. The study design favored the standard mask because all participating practitioners had multiple years of experience with the standard mask and no prior experience with the Tao mask. Since the incidence of inadequate mask ventilation goes up significantly with inexperienced operators, the improved effectiveness of the Tao mask could be even more profound with novice operators.

A Smartphone-based Decision Support Tool Improves Test Performance Concerning Application of the Guidelines for Managing Regional Anesthesia in the Patient Receiving Antithrombotic or Thrombolytic Therapy.

BACKGROUND: The American Society of Regional Anesthesia and Pain Medicine (ASRA) consensus statement on regional anesthesia in the patient receiving antithrombotic or thrombolytic therapy is the standard for evaluation and management of these patients. The authors hypothesized that an electronic decision support tool (eDST) would improve test performance compared with native physician behavior concerning the application of this guideline. METHODS: Anesthesiology trainees and faculty at 8 institutions participated in a prospective, randomized trial in which they completed a 20-question test involving clinical scenarios related to the ASRA guidelines. The eDST group completed the test using an iOS app programmed to contain decision logic and content of the ASRA guidelines. The control group completed the test by using any resource in addition to the app. A generalized linear mixed-effects model was used to examine the effect of the intervention. RESULTS: After obtaining institutional review board's approval and informed consent, 259 participants were enrolled and randomized (eDST = 122; control = 137). The mean score was 92.4 ± 6.6% in the eDST group and 68.0 ± 15.8% in the control group (P < 0.001). eDST use increased the odds of selecting correct answers (7.8; 95% CI, 5.7 to 10.7). Most control group participants (63%) used some cognitive aid during the test, and they scored higher than those who tested from memory alone (76 ± 15% vs. 57 ± 18%, P < 0.001). There was no difference in time to completion of the test (P = 0.15) and no effect of training level (P = 0.56). CONCLUSIONS: eDST use improved application of the ASRA guidelines compared with the native clinician behavior in a testing environment.

Hydroxyethyl starch and acute kidney injury in orthotopic liver transplantation: a single-center retrospective review.

BACKGROUND: Acute kidney injury (AKI) is a frequent complication of orthotopic liver transplantation (OLT). Hepatic failure pathophysiology and intraoperative events contribute to AKI after OLT. Colloids are routinely used to maintain intravascular volume during OLT. Recent evidence has implicated 6% hydroxyethyl starch (HES) (130/0.4) with AKI in critically ill patients. METHODS: We performed a retrospective cross-sectional analysis of electronic anesthesia records, surgical dictations, and perioperative laboratory results. Postoperative AKI incidence was determined by RIFLE (Risk Injury Failure Loss End-Stage) criteria. AKI was staged into Risk, Injury, and Failure based on change in serum creatinine from preoperative baseline to peak level by postoperative day 7. Uni- and multivariate analysis was used to evaluate the association between type of intraoperative colloid administered and AKI. RESULTS: One hundred seventy-four adult patients underwent OLT and had complete records for review. Of these, 50 received only 5% albumin, 25 received both 5% albumin and HES, and 99 received only HES. Albumin-only, albumin and HES, and HES-only groups were otherwise homogeneous based on patient characteristics and intraoperative variables. There was a statistically significant linear-by-linear association between type of colloid(s) administered and AKI (Rifle Criteria-Injury Stage). Patients administered HES were 3 times more likely to develop AKI within 7 days after OLT compared with albumin (adjusted odds ratio 2.94, 95% confidence interval, 1.13-7.7, P = 0.027). The linear trend between colloidal use (5% albumin only versus albumin/HES versus HES only, ranked ordering) and "injury" was statistically significant (P = 0.048). A propensity-matched analysis also showed a significant difference in the incidence of AKI between the patients receiving albumin compared with HES (P = 0.044). CONCLUSIONS: Patients receiving 6% HES (130/0.4) likely had an increased odds of AKI compared with patients receiving 5% albumin during OLT. These retrospective findings are consistent with recent clinical trials that found an association between 6% HES (130/0.4) and renal injury in critically ill patients.

Thoracolumbar interfascial plane (TLIP) block: a pilot study in volunteers.

PURPOSE: Regional anesthesia has been shown to improve outcomes in several recent studies. The transversus abdominis plane (TAP) block provides anesthesia to the abdominal wall by introducing local anesthetic to the ventral rami of the thoracolumbar nerves. This work quantifies the area of anesthesia obtained after performing the novel thoracolumbar interfascial plane block (analogous to the TAP block but intended for the back) which targets the sensory component of the dorsal rami of the thoracolumbar nerves. METHODS: Ten participants underwent bilateral ultrasound-guided injections of 0.2% ropivacaine 20 mL into the fascial plane between the multifidus and longissimus muscles. After five and 20 min, respectively, the area of anesthesia was plotted on the participant's back. Anesthesia was defined as loss of point discrimination to pinprick. RESULTS: Participants reported a mean (SD) area of anesthesia surrounding the needle injection site of 137.4 (71.0) cm(2) and 217.0 (84.7) cm(2) at five and 20 min after injection, respectively. The mean (SD) cephalad and caudal spread of local anesthetic from the site of injection was 6.5 (1.8) cm and 3.9 (1.2) cm, respectively. There were no complications or adverse events reported. CONCLUSION: This report shows that a reproducible area of anesthesia can be obtained by ultrasound-guided injection of local anesthetic in the fascial plane between the multifidus and longissimus muscles of the thoracolumbar spine. The area of anesthesia consistently covered the midline and had a predictable spread. This project was registered with clinicaltrials.gov (NCT02297191).

Effect of a cognitive aid on adherence to perioperative assessment and management guidelines for the cardiac evaluation of noncardiac surgical patients.

BACKGROUND: The 2007 American College of Cardiologists/American Heart Association Guidelines on Perioperative Cardiac Evaluation and Care for Noncardiac Surgery is the standard for perioperative cardiac evaluation. Recent work has shown that residents and anesthesiologists do not apply these guidelines when tested. This research hypothesized that a decision support tool would improve adherence to this consensus guideline. METHODS: Anesthesiology residents at four training programs participated in an unblinded, prospective, randomized, cross-over trial in which they completed two tests covering clinical scenarios. One quiz was completed from memory and one with the aid of an electronic decision support tool. Performance was evaluated by overall score (% correct), number of incorrect answers with possibly increased cost or risk of care, and the amount of time required to complete the quizzes both with and without the cognitive aid. The primary outcome was the proportion of correct responses attributable to the use of the decision support tool. RESULTS: All anesthesiology residents at four institutions were recruited and 111 residents participated. Use of the decision support tool resulted in a 25% improvement in adherence to guidelines compared with memory alone (P < 0.0001), and participants made 77% fewer incorrect responses that would have resulted in increased costs. Use of the tool was associated with a 3.4-min increase in time to complete the test (P < 0.001). CONCLUSIONS: Use of an electronic decision support tool significantly improved adherence to the guidelines as compared with memory alone. The decision support tool also prevented inappropriate management steps possibly associated with increased healthcare costs.

The Impact of Virtual Reality on Anxiety and Pain During US-Guided Breast Biopsies: A Randomized Controlled Clinical Trial.

OBJECTIVE: To investigate the efficacy of immersive virtual reality (VR) in combination with standard local anesthetic for mitigating anxiety and pain during US-guided breast biopsies compared to local anesthetic alone. METHODS: Patients scheduled for US-guided biopsy were invited to participate. Eligible patients were females 18 years of age or older. Patients were randomized to VR or control group at a 1:1 ratio. Patients in the VR group underwent biopsy with the addition of a VR experience and patients in the control group underwent usual biopsy. Patient-perceived levels of anxiety and pain were collected before and after biopsy via the State-Trait Anxiety Inventory (STAI) and Visual Analog Scale (VAS). Physiological data were captured during biopsy using a clinically validated wristband. Differences in anxiety, pain, and physiologic data were compared between the VR and control group. RESULTS: Sixty patients were enrolled. After excluding 2 patients with VR device malfunction, there were 29 patients in the VR and 29 patients in the control group for analysis. The VR group had reduced anxiety compared to the control group based on postintervention STAI (P <.001) and VAS (P = .036). The VR group did not have lower pain based on postintervention VAS (P = .555). Physiological measures showed higher RR intervals and decreased skin conductance levels, which are associated with lower anxiety levels in the VR group. CONCLUSION: Use of VR in addition to standard local anesthetic for US-guided breast biopsies was associated with reduced patient anxiety. Virtual reality may be a useful tool to improve the patient biopsy experience.

Surgery for constipation in patients with prior spinal cord injury: the Department of Veterans Affairs experience.

OBJECTIVE: Patients with spinal cord injury (SCI) typically have difficulty with constipation. Some undergo surgery for bowel management. We predicted that SCI patients would have higher mortality and/or morbidity rates following such surgery than neurally intact patients receiving the same procedures. We sought to evaluate this using a large population-based data set. METHODS: Patients receiving care at Department of Veterans Affairs Medical Centers (DVAMCs) with computer codes for SCI and constipation who later underwent colectomy, colostomy, or ileostomy during fiscal years 1993-2002 were identified. Charts were requested from the VAMCs where the surgery had been performed and a retrospective chart review of these charts was done. We collected data on patient demographics, six specific pre-operative co-morbidities, surgical complications, and post-operative mortality. Comparisons were made to current literature evaluating a population receiving total abdominal colectomy and ileorectal anastomosis for constipation but not selected for SCI. RESULTS: Of 299 patients identified by computer search, 43 (14%) had codes for SCI and 10 of 43 (24%) met our inclusion criteria. All were symptomatic and had received appropriate medical management. Co-morbid conditions were present in 9 of 10 patients (90%). There were no deaths within 30 days. The complication rate was zero. The mean post-operative length of stay was 17 days. CONCLUSIONS: Patients with SCI comprise about 14% of the population who receive surgery for severe constipation in the Department of Veterans Affairs system. The mortality and morbidity rates in these patients are similar to those reported in other constipated patients who have surgery for intractable constipation. Our data suggest that stoma formation ± bowel resection in patients with SCI is a safe and effective treatment for chronic constipation.

Grassroots and Youth-Led Climate Solutions From The Gambia.

Climate change and environmental degradation are among the greatest threats to human health. Youth campaigners have very effectively focused global attention on the crisis, however children from the Global South are often under-represented (sometimes deliberately) in the dialogue. In The Gambia, West Africa, the impacts of climate change are already being directly experienced by the population, and this will worsen in coming years. There is strong government and community commitment to adapt to these challenges, as evidenced by The Gambia currently being the only country on target to meet the Paris agreement according to the Nationally Determined Contributions, but again children's voices are often missing-while their views could yield valuable additional insights. Here, we describe a "Climate Change Solutions Festival" that targeted and engaged school children from 13 to 18 years, and is to our knowledge, the first peer-to-peer (and student-to-professional) learning festival on climate change solutions for students in The Gambia. The event gave a unique insight into perceived climate change problems and scalable, affordable and sometimes very creative solutions that could be implemented in the local area. Logistical and practical methods for running the festival are shared, as well as details on all solutions demonstrated in enough detail to be duplicated. We also performed a narrative review of the most popular stalls to explore the scientific basis of these solutions and discuss these in a global context. Overall, we find extremely strong, grass-roots and student engagement in the Gambia and clear evidence of learning about climate change and the impacts of environmental degradation more broadly. Nevertheless, we reflect that in order to enact these proposed local solutions further steps to evaluate acceptability of adoption, feasibility within the communities, cost-benefit analyses and ability to scale solutions are needed. This could be the focus of future experiential learning activities with students and partnering stakeholders.

Post-Reperfusion Syndrome in Liver Transplantation: Does a Caval Blood Flush Vent Help?

BACKGROUND Post-reperfusion syndrome (PRS) during liver transplantation can range from a benign event to a profound hemodynamic excursion from baseline with significant morbidity. Multiple variables can be responsible for the diverse presentations. Over time, our group noticed that a blood flush of the liver graft via a caval vent (in addition to a standard chilled flush via the portal vein) appeared to result in a milder reperfusion effect. Attenuation of PRS via caval vent seemed to minimize hemodynamic instability and reduce metabolic derangements associated with reperfusion. MATERIAL AND METHODS This was a prospective observational pilot study of standard practice with the addition of lab values and hemodynamic evaluations. We methodically observed normal clinical flow in 20 adult orthotopic liver transplant recipients. We analyzed blood and fluid samples at set time intervals during the peri-reperfusion phase. RESULTS Sixteen out of 20 patients received a blood flush via caval venting. Mean arterial pressure (MAP) and heart rate were better preserved in the patient population that received a caval blood flush vent. Elevations in central venous pressure (CVP) were similar between the 2 groups. Lab values (blood gas, electrolyte, and hemoglobin) of the patients' blood were similar, with no notable differences. Analysis of the initial blood flushed through the liver graft proved to be hypothermic, acidotic, and hyperkalemic. CONCLUSIONS Pre-reperfusion caval venting in liver transplantation (in addition to a portal vent and a chilled LR/albumin portal flush solution) appears to have favorable hemodynamic effects. The literature on this technique is sparse and larger studies are needed.

Length of Stay and Opioid Dose Requirement with Transversus Abdominis Plane Block vs Epidural Analgesia for Ventral Hernia Repair.

BACKGROUND: Major abdominal operations often requires postoperative opioid analgesia. However, there is growing recognition of the potential for abuse. We previously reported a significant reduction in opioid consumption after implementation of an Enhanced Recovery after Surgery protocol after ventral hernia repair focusing on opioid reduction. Epidural use was routine for postoperative pain control in this protocol. Recently, we have transitioned to transversus abdominis plane (TAP) block instead of epidural analgesia. We hypothesize that this modification reduces length of stay and lowers opioid use in ventral hernia repair. METHODS: All patients undergoing open ventral hernia repair were recorded prospectively in the Americas Hernia Society Quality Collaborative database. All patients receiving either TAP or epidural between February 2015 and March 2018 were identified. Additional review was performed to quantify opioid use in morphine milligram equivalents (MMEs). Primary outcomes were length of stay and opioid use. RESULTS: Epidural was used in 172 patients and TAP block in 74. There were no significant comorbidity differences between groups. The TAP group had a slightly higher BMI (33.6 kg/m2 vs 28.3 kg/m2) and slightly smaller hernias (8.8 cm vs 10.8 cm). There was no difference in 30-day surgical site infections. Hospital length of stay was significantly shorter with TAP block (2.4 vs 4.5 days; p < 0.001). Total MME requirements for patients receiving TAP block were lower than those with epidural during postoperative days 1 and 2 (mean 40 vs 54.1 MMEs; p = 0.033 and 36.1 vs 52.5 MMEs; p = 0.018). CONCLUSIONS: Use of TAP block significantly reduces length of stay and decreases opioid dose requirements in the early postoperative period compared with epidural analgesia.

Partial anomalous pulmonary venous return: Scimitar vein.

Scimitar syndrome is a rare association of congenital cardiopulmonary anomalies characterized by partial anomalous pulmonary venous return, in which an abnormal right pulmonary vein drains into the inferior vena cava. This case exemplifies the role of transesophageal echocardiography in perioperative management and surgical decision-making.

Intraoperative goal-directed hemodynamic management in free tissue transfer for head and neck cancer.

BACKGROUND: The purpose of this study was to determine the effect of algorithmic physiologic management on patients undergoing head and neck free tissue transfer and reconstruction. METHODS: Ninety-four adult patients were randomized to treatment and control groups. The blood pressure of the control group was managed consistent with contemporary standards. The treatment group was managed using an algorithm based on blood pressure and calculated physiologic values derived from arterial waveform analysis. Primary outcome was intensive care unit (ICU) length of stay. RESULTS: ICU length of stay was decreased in the treatment group (33.7 vs 58.3 hours; p = .026). The complication rate was not increased in the treatment group. CONCLUSION: The goal-directed hemodynamic management algorithm decreased the ICU length of stay. Judicious use of vasoactive drugs and goal-directed fluid administration has a role in improving perioperative outcomes for patients undergoing head and neck free tissue transfer. © 2016 Wiley Periodicals, Inc. Head Neck 38: E1974-E1980, 2016.