Smallest Clinically Meaningful Improvement in Amputation-Related Pain and Brief Pain Inventory Scores as Defined by Patient Reports of Global Improvement After Cryoneurolysis: a Retrospective Analysis of a Randomized, Controlled Clinical Trial.

BACKGROUND: The smallest meaningful improvement in pain scores (minimal clinically important difference [MCID]) after an analgesic intervention is essential information when both interpreting published data and designing a clinical trial. However, limited information is available for patients with chronic pain conditions, and what is published is derived from studies involving pharmacologic and psychological interventions. We here calculate these values based on data collected from 144 participants of a previously published multicenter clinical trial investigating the effects of a single treatment with percutaneous cryoneurolysis. METHODS: In the original trial, we enrolled patients with a lower-limb amputation and established phantom pain. Each received a single-injection femoral and sciatic nerve block with lidocaine and was subsequently randomized to receive either ultrasound-guided percutaneous cryoneurolysis or sham treatment at these same locations. Investigators, participants, and clinical staff were masked to treatment group assignment with the exception of the treating physician performing the cryoneurolysis, who had no subsequent participant interaction. At both baseline and 4 months (primary end point), participants rated their phantom limb pain based on a numeric rating scale (NRS) and their interference of pain on physical and emotional functioning as measured with the Brief Pain Inventory's interference subscale. They subsequently qualitatively defined the change using the 7-point ordinal Patient Global Impression of Change (PGIC). The smallest clinically meaningful improvements in phantom limb pain and Brief Pain Inventory scores were calculated using an anchor-based method based on the PGIC. RESULTS: The median (interquartile range [IQR]) phantom pain NRS (0-10) improvements at 4 months considered small, medium, and large were 1 [1-1], 3 [3-4], and 4 [3-6], respectively. The median improvements in the Brief Pain Inventory interference subscale (0-70) associated with a small, medium, and large analgesic changes were 16 [6-18], 24 [22-31], and 34 [22-46]. The proportions of patients that experienced PGIC ≥5 were 33% and 36% in the active and placebo groups, respectively. The relative risk of a patient experiencing PGIC ≥5 in the active group compared to the sham group with 95% confidence interval was 0.9 (0.6-1.4), P = .667. CONCLUSIONS: Amputees with phantom limb pain treated with percutaneous cryoneurolysis rate analgesic improvements as clinically meaningful similar to pharmacologic treatments, although their MCID for the Brief Pain Inventory was somewhat larger than previously published values. This information on patient-defined clinically meaningful improvements will facilitate interpretation of available studies and guide future trial design.

Ultrasound-guided Percutaneous Cryoneurolysis to Treat Chronic Postamputation Phantom Limb Pain: A Multicenter Randomized Controlled Trial.

BACKGROUND: Postamputation phantom pain is notoriously persistent with few validated treatments. Cryoneurolysis involves the application of low temperatures to reversibly ablate peripheral nerves. The authors tested the hypothesis that a single cryoneurolysis treatment would decrease phantom pain 4 months later. METHODS: The authors enrolled patients with a lower-limb amputation and established phantom pain. Each received a single-injection femoral and sciatic nerve block with lidocaine and was subsequently randomized to receive either ultrasound-guided percutaneous cryoneurolysis or sham treatment at these same locations. The primary outcome was the change in average phantom pain intensity between baseline and 4 months as measured with a numeric rating scale (0 to 10), after which an optional crossover treatment was offered. Investigators, participants, and clinical staff were masked to treatment group assignment with the exception of the treating physician performing the cryoneurolysis, who had no subsequent participant interaction. RESULTS: Pretreatment phantom pain scores were similar in both groups, with a median [quartiles] of 5.0 [4.0, 6.0] for active treatment and 5.0 [4.0, 7.0] for sham. After 4 months, pain intensity decreased by 0.5 [-0.5, 3.0] in patients given cryoneurolysis (n = 71) versus 0 [0, 3] in patients given sham (n = 73), with an estimated difference (95% CI) of -0.1 (-1.0 to 0.7), P = 0.759. Following their statistical gatekeeping protocol, the authors did not make inferences or draw conclusions on secondary endpoints. One serious adverse event occurred after a protocol deviation in which a femoral nerve cryolesion was induced just below the inguinal ligament-instead of the sensory-only saphenous nerve-which resulted in quadriceps weakness, and possibly a fall and clavicle fracture. CONCLUSIONS: Percutaneous cryoneurolysis did not decrease chronic lower extremity phantom limb pain 4 months after treatment. However, these results were based upon the authors' specific study protocol, and since the optimal cryoneurolysis treatment parameters such as freeze duration and anatomic treatment location remain unknown, further research is warranted.

Ultrasound-Guided Suprazygomatic Nerve Blocks to the Pterygopalatine Fossa: A Safe Procedure.

OBJECTIVES: Large-scale procedural safety data on pterygopalatine fossa nerve blocks (PPFBs) performed via a suprazygomatic, ultrasound-guided approach are lacking, leading to hesitancy surrounding this technique. The aim of this study was to characterize the safety of PPFB. METHODS: This retrospective chart review examined the records of adults who received an ultrasound-guided PPFB between January 1, 2016, and August 30, 2020, at the University of Florida. Indications included surgical procedures and nonsurgical pain. Clinical data describing PPFB were extracted from medical records. Descriptive statistics were calculated for all variables, and quantitative variables were analyzed with the paired t test to detect differences between before and after the procedure. RESULTS: A total of 833 distinct PPFBs were performed on 411 subjects (59% female, mean age 48.5 years). Minor oozing from the injection site was the only reported side effect, in a single subject. Although systolic blood pressure, heart rate, and oxygen saturation were significantly different before and after the procedure (132.3 vs 136.4 mm Hg, P < 0.0001; 78.2 vs 80.8, P = 0.0003; and 97.8% vs 96.3%, P < 0.0001; respectively), mean arterial pressure and diastolic blood pressure were not significantly different (96.2 vs 97.1 mm Hg, P = 0.1545, and 78.2 vs 77.4 mm Hg, P = 0.1314, respectively). Similar results were found within subgroups, including subgroups by sex, race, and indication for PPFB. DISCUSSION: We have not identified clinically significant adverse effects from PPFB performed with an ultrasound-guided suprazygomatic approach in a large cohort in the hospital setting. PPFBs are a safe and well-tolerated pain management strategy; however, prospective multicenter studies are needed.

Diagnostic Value of MAML2 Rearrangements in Mucoepidermoid Carcinoma.

Mucoepidermoid carcinoma (MEC) is often seen in salivary glands and can harbor MAML2 translocations (MAML2+). The translocation status has diagnostic utility as an objective confirmation of the MEC diagnosis, for example, when distinction from the more aggressive adenosquamous carcinoma (ASC) is not straightforward. To assess the diagnostic relevance of MAML2, we examined our 5-year experience in prospective testing of 8106 solid tumors using RNA-seq panel testing in combinations with a two-round Delphi-based scenario survey. The prevalence of MAML2+ across all tumors was 0.28% (n = 23/8106) and the majority of MAML2+ cases were found in head and neck tumors (78.3%), where the overall prevalence was 5.9% (n = 18/307). The sensitivity of MAML2 for MEC was 60% and most cases (80%) were submitted for diagnostic confirmation; in 24% of cases, the MAML2 results changed the working diagnosis. An independent survey of 15 experts showed relative importance indexes of 0.8 and 0.65 for "confirmatory MAML2 testing" in suspected MEC and ASC, respectively. Real-world evidence confirmed that the added value of MAML2 is a composite of an imperfect confirmation test for MEC and a highly specific exclusion tool for the diagnosis of ASC. Real-world evidence can help move a rare molecular-genetic biomarker from an emerging tool to the clinic.

Pterygopalatine Fossa Blockade as Novel, Narcotic-Sparing Treatment for Headache in Patients with Spontaneous Subarachnoid Hemorrhage.

BACKGROUND: Severe headache is a hallmark clinical feature of spontaneous subarachnoid hemorrhage (SAH), affecting nearly 90% of patients during index hospitalization, regardless of the SAH severity or presence of a culprit aneurysm. Up to 1 in 4 survivors of SAH experience chronic headaches, which may be severe and last for years. Data guiding the optimal management of post-SAH headache are lacking. Opioids, often in escalating doses, remain the guideline-recommended mainstay of acute therapy, but pain relief remains suboptimal. METHODS: This study is a case series of adult patients who received bilateral pterygopalatine fossa (PPF) blockade for the management of refractory headaches after spontaneous SAH (aneurysmal and non-aneurysmal) at a single tertiary care center. We examined pain scores and analgesic requirements before and after block placement. RESULTS: Seven patients (median age 54 years, 3 men, four aneurysmal and three non-aneurysmal) received a PPF-block between post-bleed day 6-11 during index hospitalization in the neurointensive care unit. The worst pain recorded in the 24-h period before the block was significantly higher than in the period 4 h after the block (9.1 vs. 3.1; p = 0.0156), and in the period 8 h after the block (9.1 vs. 2.8; p = 0.0313). The only complication was minor oozing from the needle insertion sites, which subsided completely with gauze pressure within 1 min. CONCLUSIONS: PPF blockade might constitute a promising opioid-sparing therapeutic strategy for the management of post-SAH headache that merits further prospective controlled randomized studies.

Trigeminal Nerve Blockade in the Pterygopalatine Fossa for the Management of Postoperative Pain in Three Adults Undergoing Tonsillectomy: A Proof-of-Concept Report.

SETTING: Post-tonsillectomy pain in adults can be severe and is often poorly controlled. Pain can lead to decreased oral intake, bleeding, longer hospital stays, emergency department visits, dehydration, and weight loss. Due to persistent pain despite scheduled medications, other methods for pain control are needed. Local/regional anesthetic options have been previously studied in this population. Unfortunately, neither the injection of local anesthetics into the tonsillar fossa nor the postoperative topical application of local anesthetics to the tonsillar bed has demonstrated efficacy in large systematic reviews. PATIENTS: Here we report on the post-tonsillectomy pain experience of three patients who were treated with perioperative nerve blocks placed in the pterygopalatine fossa. This represents an as-yet unexplored option for post-tonsillectomy pain control. INTERVENTION: After induction of general anesthesia, before surgical incision, a 25-gauge spinal needle was advanced into the pterygopalatine fossa using a suprazygomatic, ultrasound-guided approach. Ropivacaine and dexamethasone were deposited into the pterygopalatine fossa. RESULTS: All three patients experienced excellent pain control for the duration of their recovery and required ≤10 mg of oxycodone over the two weeks after surgery. CONCLUSIONS: Our case series of three patients provides proof of concept that use of nerve blocks in the pterygopalatine fossa can be useful for the control of post-tonsillectomy pain. Further study is needed to confirm these initial results.

Refractory primary and secondary headache disorders that dramatically responded to combined treatment of ultrasound-guided percutaneous suprazygomatic pterygopalatine ganglion blocks and non-invasive vagus nerve stimulation: a case series.

In 1981, Devoghel achieved an 85.6% success rate in treating patients with treatment-refractory cluster headaches with alcoholization of the pterygopalatine ganglion (PPG) via the percutaneous suprazygomatic approach. Devoghel's study led to the theory that interrupting the parasympathetic pathway by blocking its transduction at the PPG could prevent or treat symptoms related to primary headache disorders (PHDs). Furthermore, non-invasive vagus nerve stimulation (nVNS) has proven to treat PHDs and has been approved by national regulatory bodies to treat, among others, cluster headaches and migraines.In this case series, nine desperate patients who presented with 11 longstanding treatment-refractory primary headache disorders and epidural blood patch-resistant postdural puncture headache (PDPH) received ultrasound-guided percutaneous suprazygomatic pterygopalatine ganglion blocks (PPGB), and seven also received nVNS. The patients were randomly selected and were not part of a research study. They experienced dramatic, immediate, satisfactory, and apparently lasting symptom resolution (at the time of the writing of this report). The report provides the case descriptions, briefly reviews the trigeminovascular and neurogenic inflammatory theories of the pathophysiology, outlines aspects of these PPGB and nVNS interventions, and argues for adopting this treatment regime as a first-line or second-line treatment rather than desperate last-line treatment of PDPH and PHDs.

Molecular characterization of inhibiting biochar water-extractable substances using electrospray ionization fourier transform ion cyclotron resonance mass spectrometry.

Biochar has gained significant interest worldwide for its potential use as both a carbon sequestration technique and soil amendment. Recently, research has shown that pinewood-derived biochar water extracts inhibited the growth of aquatic photosynthetic microorganisms, both prokaryotic and eukaryotic algae, while chicken litter- and peanut shell-derived biochar water extracts showed no growth inhibition. With the use of electrodialysis, the pinewood-derived biochar water extract is separated into 3 fractions (anode-isolated, center chamber retained, and cathode-isolated substances) all with varying toxic effects. Because of its ultrahigh resolution and mass precision, electrospray ionization (ESI) coupled to Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) is utilized in this study to analyze biochar water extracts at a molecular level to enhance our understanding of the toxic nature of pinewood-derived biochar water extracts as compared to benign peanut shell-derived biochar water extracts. The molecular composition of pinewood-derived biochar water extracts shows unique carbohydrate ligneous components and sulfur containing condensed ligneous components that are both absent from the peanut shell water extracts and more prevalent in the anode-isolated substances. Using Kendrick mass defect analysis, we also determine that the most likely inhibitor species contain carboxyl and hydroxyl homologous series, both of which are characteristic functional groups hypothesized in our previous research for the inhibitor species. We have suggested that inhibition of aquatic photosynthetic microorganism growth is most likely due to degraded lignin-like species rich in oxygen containing functionalities. From the study conducted here, we show the potential of ultrahigh resolution FTICR-MS as a valuable analytical technique for determining whether certain biochars are safe and benign for use as carbon sequestration and soil amendment.

Comparing Spinal Chloroprocaine to Hyperbaric and Isobaric Bupivacaine for Total Hip and Knee Arthroplasties: A Retrospective Study.

INTRODUCTION: Spinal anesthesia is commonly used for total knee and hip arthroplasties (TKA/THA). The rising popularity of ambulatory TKA and THAs require anesthetic techniques that provide rapid recovery of motor and sensory function while minimizing side effects like postoperative urinary retention. This single-center retrospective observational study compares the recovery profile of patients undergoing TKA and THA under chloroprocaine spinals compared to hyperbaric and isobaric bupivacaine spinals. METHODS: One hundred and twelve patients undergoing primary TKA and THA under spinal anesthesia at University of Florida Health were identified between September 1, 2019 and February 21, 2020. Their electronic medical records were reviewed. Patients were categorized based on the local anesthetic used in the spinal. Various demographic, intraoperative, and postoperative data were compiled and compared, including duration of surgery, time to physical therapy, time to post-anesthesia care unit (PACU) discharge, and time to spontaneous micturition. RESULTS: Time to spontaneous micturition and PACU discharge were significantly lower in the chloroprocaine spinal group compared to the hyperbaric bupivacaine group by 193 minutes and 42 minutes, respectively. Fewer patients receiving chloroprocaine spinals had their first physical therapy session limited by residual motor weakness compared to those in both bupivacaine groups. Additionally, mean duration of surgery was shorter in the chloroprocaine group compared to both bupivacaine groups (89 minutes compared to 111 minutes). Time to physical therapy completion was not different. All groups had <10% conversion to general anesthesia. CONCLUSION: Chloroprocaine spinals can be feasible options for TKAs and THAs with improved postoperative recovery profiles compared to bupivacaine spinals.

Staying proper with your personal protective equipment: How to don and doff.

INTRODUCTION: The global COVID-19 pandemic highlighted the importance of protecting frontline healthcare workers from novel respiratory infections while also exposing the limited instruction that medical students receive on proper donning of personal protective equipment (PPE) and more importantly the safe doffing of contaminated PPE to minimize their risk of nosocomial infection. The best methods of providing this kind of instruction have not yet been determined. METHODS: Anesthesiology interns and CA-1 residents were trained on proper PPE donning and doffing for AGPs using a methodology based on Miller's pyramid and following a "knows-knows how-shows-does" progression. Participants donned PPE without instruction and were sprayed with Glo Germ® to identify areas of contamination, after which they received both video and in-person instruction on best practices for donning and doffing PPE for AGPs. Following instruction, they again donned PPE and were sprayed with Glo Germ® to identify areas of contamination. RESULTS: 54 participants completed the study. Before training, overall donning compliance was 60% and overall doffing compliance was 48%. Overall, 70% were contaminated after PPE doffing, with 46% having multiple sites of contamination. After training, donning compliance increased by nearly 30% (P < 0.001), doffing compliance increased by over 20% (P < 0.001), and overall contamination decreased by nearly 30% (P = 0.029), with multiple-site contamination decreasing to only 6% (P = 0.013). DISCUSSION: While best methods for providing instruction regarding topics such as PPE donning and doffing have not yet been determined, we have demonstrated that the underlying knowledge base from medical school regarding proper donning and doffing for respiratory isolation is insufficient for preventing self-contamination, and that Miller's pyramid-based training using both video and in-person instruction combined with task execution by learners can improve compliance with PPE donning and doffing protocols and more importantly decrease skin contamination among a group of early training anesthesiology residents.

Determination of chemical constituent yields in e-cigarette aerosol using partial and whole pod collections, a comparative analysis.

Literature reports the chemical constituent yields of electronic nicotine delivery systems (ENDS) aerosol collected using a range of aerosol collection strategies. The number of puffs to deplete an ENDS product varies widely, but collections often consist of data from the first 50-100 puffs. However, it is not clear whether these discrete puff blocks are representative of constituent yields over the life of a pod. We aimed to assess the effect of differing aerosol collection strategies on reported yields for select chemical constituents in the aerosol of closed pod-based ENDS products. Constituents analyzed were chosen to reflect important classes of compounds from the Final Premarket Tobacco Product Application Guidance. Yields were normalized to total device mass loss (DML). Collection strategies that consisted of partial pod collection were valid for determining yields of constituents whose DML normalized yields were consistent for the duration of pod life. These included primary aerosol constituents, such as propylene glycol, glycerol, and nicotine, and whole pod yields could be determined from initial puff blocks. However, changes were observed in the yields of some metals, some carbonyl compounds, and glycidol over pod life in a chemical constituent and product dependent manner. These results suggest that collection strategies consisting of initial puff block collections require validation per chemical constituent/product and are not appropriate for chemical constituents with variable yields over pod life. Whole pod collection increased sensitivity and accuracy in determining metal, carbonyl, and glycidol yields compared to puff block-based collection methodologies for all products tested.

Gastric Emptying of Orange Juice With and Without Pulp: A Point-of-Care Ultrasound Study.

Purpose The American Society of Anesthesiologists (ASA) preoperative fasting recommendations regarding fruit juice with pulp is unclear. In addition, it is debatable whether orange juice without pulp should be treated as a clear liquid. Our objective is to determine the gastric emptying time of orange juice with and without pulp. Methods This is an observational study of gastric emptying time using point-of-care ultrasound (POCUS). Thirty-five adult volunteers were enrolled in this study. Exclusion criteria included pregnancy, diabetes, body mass index > 40 kg/m2, previous lower esophageal or upper abdominal surgery, hiatal hernia, and upper gastrointestinal bleed. The study was carried out on three separate days for each volunteer. After fasting a minimum of 8 h, the volunteers were asked to drink 240 ml of water on day 1, orange juice without pulp on day 2, and orange juice with pulp on day 3. Gastric volumes were estimated using gastric antrum cross-sectional area at fasting state, and then 30, 60, 90 120, 180, and 240 min after drinking until the gastric volume returned to baseline. Results A gastric volume of 1.5 mL/kg was defined as a baseline. All subjects' gastric volume returned to baseline 90 min after drinking water. More than 97% of the subjects who drank orange juice without pulp and 93.9% of the subjects who drank orange juice with pulp reached a gastric volume of less than 1.5 mL/kg after 2 h. All subjects' gastric volume returned to baseline 3 h after drinking orange juice with pulp. Conclusions Orange juice without pulp can be treated as a clear liquid in a majority of patients who do not have conditions that would cause delayed gastric emptying. Orange juice with pulp required 3 h to empty.

Role of an Intercostobrachial Nerve Block in Alleviating Tourniquet Pain: A Randomized Clinical Trial.

Introduction Tourniquet pain may have cutaneous and ischemic components. It is questionable whether blockade of a sensory nerve will help reduce ischemic pain. In addition, complete anesthesia of the axilla in the intercostobrachial nerve (ICBN) distribution is challenging to execute, and ICBN blockade has an inherently higher failure rate because of its variable anatomic location and source of innervation. We sought to determine the utility of an ICBN block for the prevention of tourniquet pain. Methods We conducted a single-center randomized controlled trial at a major academic medical center involving patients scheduled to undergo distal upper extremity surgery under ultrasound-guided supraclavicular brachial plexus block. Forty patients were randomized to receive an additional ICBN block or no ICBN block, with 22 allocated to the intervention and 18 to control. We collected data on the incidence of tourniquet pain and systemic anesthetic requirements. Results Initial contingency analysis examining the relationship between ICBN block placement and the development of pain using the two-tailed Fisher exact test failed to show that the presence or absence of ICBN block was associated with the development of tourniquet pain. χ2 analysis failed to show that tourniquet time was significantly related to the development of tourniquet pain. Conclusions The overall incidence of tourniquet pain in the setting of a dense supraclavicular brachial plexus block for surgical anesthesia was low even without an ICBN block and even with tourniquet times greater than 90 min. Tourniquet pain was easily managed with small amounts of systemic analgesics.

Visceral versus somatic pain: an educational review of anatomy and clinical implications.

Somatic and visceral nociceptive signals travel via different pathways to reach the spinal cord. Additionally, signals regulating visceral blood flow and gastrointestinal tract (GIT) motility travel via efferent sympathetic nerves. To offer optimal pain relief and increase GIT motility and blood flow, we should interfere with all these pathways. These include the afferent nerves that travel with the sympathetic trunks, the somatic fibers that innervate the abdominal wall and part of the parietal peritoneum, and the sympathetic efferent fibers. All somatic and visceral afferent neural and sympathetic efferent pathways are effectively blocked by appropriately placed segmental thoracic epidural blocks (TEBs), whereas well-placed truncal fascial plane blocks evidently do not consistently block the afferent visceral neural pathways nor the sympathetic efferent nerves. It is generally accepted that it would be beneficial to counter the effects of the stress response on the GIT, therefore most enhanced recovery after surgery protocols involve TEB. The TEB failure rate, however, can be high, enticing practitioners to resort to truncal fascial plane blocks. In this educational article, we discuss the differences between visceral and somatic pain, their management and the clinical implications of these differences.

Predicting long-term postsurgical pain by examining the evolution of acute pain.

BACKGROUND: Increased acute postoperative pain intensity has been associated with the development of persistent postsurgical pain (PPP) in mechanistic and clinical investigations, but it remains unclear which aspects of acute pain explain this linkage. METHODS: We analysed clinical postoperative pain intensity assessments using symbolic aggregate approximations (SAX), a graphical way of representing changes between pain states from one patient evaluation to the next, to visualize and understand how pain intensity changes across sequential assessments are associated with the intensity of postoperative pain at 1 (M1) and 6 (M6) months after surgery. SAX-based acute pain transition patterns were compared using cosine similarity, which indicates the degree to which patterns mirror each other. RESULTS: This single-centre prospective cohort study included 364 subjects. Patterns of acute postoperative pain sequential transitions differed between the 'None' and 'Severe' outcomes at M1 (cosine similarity 0.44) and M6 (cosine similarity 0.49). Stratifications of M6 outcomes by preoperative pain intensity, sex, age group, surgery type and catastrophising showed significant heterogeneity of pain transition patterns within and across strata. Severe-to-severe acute pain transitions were common, but not exclusive, in patients with moderate or severe pain intensity at M6. CONCLUSIONS: Clinically, these results suggest that individual pain-state transitions, even within patient or procedural strata associated with PPP, may not alone offer good predictive information regarding PPP. Longitudinal observation in the immediate postoperative period and consideration of patient- and surgery-specific factors may help indicate which patients are at increased risk of PPP. SIGNIFICANCE: Symbolic aggregate approximations of clinically obtained, acute postoperative pain intraday time series identify different motifs in patients suffering moderate to severe pain 6 months after surgery.

Complete Tracheal Transection in a 3-Year-Old After Blunt Neck Trauma: a Case Report.

Pediatric laryngotracheal injuries from blunt force trauma are rare but can lead to significant morbidity and mortality. In pediatric patients with severe laryngotracheal disruption, extracorporeal membrane oxygenation has been used to improve oxygenation and ventilation until definitive repair can be performed. We describe the case of a 3-year-old girl with blunt neck trauma secondary to an all-terrain vehicle accident in which her neck was clotheslined against a fence, leading to a complete tracheal transection at the C7-T1 level. Emergent extracorporeal membrane oxygenation cannulation was initiated. We discuss the evaluation and management of tracheal injuries and the requisite multidisciplinary team approach. Pediatric patients with laryngotracheal trauma require definitive airway management, which should be performed by skilled personnel.

A Flexible Enclosure to Protect Respiratory Therapists During Aerosol-Generating Procedures.

BACKGROUND: Exposure of respiratory therapists (RTs) during aerosol-generating procedures such as endotracheal intubation is an occupational hazard. Depending on the hospital, RTs may serve as laryngoscopist or in a role providing ventilation support and initiating mechanical ventilation. This study aimed to evaluate the potential exposure of RTs serving in either of these roles. METHODS: We set up a simulated patient with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection in an ICU setting requiring endotracheal intubation involving a laryngoscopist, a nurse, and an RT supporting the laryngoscopist. All participants wore appropriate personal protective equipment (PPE). A fluorescent marker was sprayed by an atomizer during the procedure using 3 different methods for endotracheal intubation. The 3 techniques included PPE alone, a polycarbonate intubating box, or a coronavirus flexible enclosure, which consisted of a Mayo stand with plastic covering. The laryngoscopist and the supporting RT were assessed with a black light for contamination with the fluorescent marker. All simulations were recorded. RESULTS: When using only PPE, both the laryngoscopist and the RT were grossly contaminated. When using the intubating box, the laryngoscopist's contamination was detectable only on the gloves: the gown and face shield remained uncontaminated; the RT was still grossly contaminated on the gloves, gown, neck, and face shield. When using the coronavirus flexible enclosure system, both the laryngoscopist and the RT were better protected, with contamination detected only on the gloves of the laryngoscopist and the RT. CONCLUSIONS: Of the 3 techniques, the coronavirus flexible enclosure contained the fluorescent marker more effectively during endotracheal intubation than PPE alone or the intubating box based on exposure of the laryngoscopist and supporting RT. Optimizing containment during aerosol-generating procedures like endotracheal intubation is a critical component of minimizing occupational and nosocomial spread of SARS-CoV-2 to RTs who may serve as either the laryngoscopist or a support role.

Effects of perfluorocarbon infusion in an anesthetized swine decompression model.

INTRODUCTION: Decompression illness (DCI) results from sudden changes in ambient pressure leading to super-saturation and bubble formation in tissues and the blood stream. Perfluorocarbon emulsions (PFC) increase both oxygen and nitrogen solubility when infused into the blood stream. This study hypothesized that PFC would increase N(2) removal as well as O(2) delivery to tissues. MATERIALS AND METHODS: Juvenile swine (20 kg) were anesthetized and highly instrumented with arterial monitoring, pulmonary artery catheterization, EDAC ultrasound bubble detection, and end tidal N(2) by mass spectrometry. Blood gases were monitored in both the mixed venous and arterial circulation. Full hemodynamics were calculated using standard equations. Four groups of animals were randomized to be either sham controls or compressed and to receive either saline or PFC at 4.5 ml/kg. Animals were dry compressed to 6.8 ATA for 30 minutes of time on the bottom and then rapidly decompressed. Animals were monitored for 120 minutes after surfacing, then euthanized. RESULTS: DCI was created by the dive profile but the severity was variable. Sham animals had no significant changes except that those who received PFC developed significant pulmonary hypertension and decreased cardiac output. This held true for those that also underwent DCI. Respiratory N(2) washout was not significantly different with and without PFC. However, O(2) delivery to tissues was improved with PFC and EDAC bubble count was dramatically less with PFC. CONCLUSIONS: PFC decreased bubble generation but the data was confounded by a species specific pulmonary hypertensive response. Even with this as a problem O(2) delivery to tissues was enhanced by PFC. Future work with PFC in different species will help to further understand the contribution of these two mechanisms to treatment efficacy by PFC in DCI.