Incidence of Laryngospasm and Bronchospasm in Pediatric Adenotonsillectomy

Objectives/Hypothesis: To evaluate and describe airway complications in pediatric adenotonsillectomy. Study Design: Retrospective case-control study. Methods: A chart review of patients that underwent adenotonsillectomy between 2006 and 2010 was performed. Perioperative complications, patient characteristics, and surgeon and anesthesia technique were recorded. Results: A total of 682 charts were reviewed. Eleven cases (1.6%) of laryngospasm were identified: one was preoperative, seven occurred in the operating room postextubation, and three occurred in the recovery area. Four patients were given succinylcholine, one was reintubated, and the other cases were managed conservatively. Mean age of patients with laryngospasm was 5.87 years (standard deviation [SD], 4.01; 1.9–15.8 years). There were 12 cases (1.8%) of bronchospasm; all were treated with nebulized albuterol. Mean age of patients with bronchospasm was 5.81 years (SD, 4.17; 1.8–14.1 years). Overall, 22 patients required antiemetics (3.3%), 19 required albuterol (2.9%), and five required racemic epinephrine (0.8%). Compared to the children without airway complications, there was no difference in age, weight, American Society of Anesthesiologists status, length of surgery, need for admission, and anesthesia technique in those that had laryngospasm. Patients with bronchospasm, compared to the patients without complications, had faster surgeries (P \u3c .05), were more likely to have underlying asthma (P \u3c .05), and were more likely to be admitted (P \u3c .05). There were no unexpected admissions or other morbidities. Conclusions: The rates of laryngospasm (1.6%) and bronchospasm (1.8%) are significantly lower than reported in the literature, reflecting refinements in modern anesthesia/surgical technique. Knowledge of at-risk patients can facilitate planning to potentially reduce the incidence of perioperative airway complications during adenotonsillectomy

Superior laryngeal nerve injury

Purpose of reviewThe superior laryngeal nerve (SLN) provides motor innervation to the cricothyroid muscle. However, the functions of this muscle and the anatomic variations of the nerve that supplies it are not fully understood. SLN paresis and paralysis (SLNp) is difficult to diagnose because of a lack of consistent laryngeal findings, and its effects on the voice likely go beyond simple pitch elevation control.Recent findingsAlthough SLNp has traditionally been thought to lead to voice pitch limitation, recent research findings reveal multiple roles for this nerve in voice and speech. Cricothyroid muscles are the primary controls of fundamental frequency of voice. SLNp can lead to significant contraction of pitch range, vocal fold vibratory phase asymmetry, and acoustic aperiodicity, thus leading to an overall poor vocal quality. In addition, cricothyroid muscles may also play a role in pitch lowering and shifting from voiced to unvoiced sounds during speech.SummarySubtle signs, symptoms, and diagnostic findings associated with SLNp make this disorder difficult to characterize clinically. Lack of treatment methodologies to restore the dynamic action of the cricothyroid muscles poses difficulties in treating patients with this condition. A more thorough understanding of the effects of SLNp will improve diagnosis and treatment

Preliminary Study of the Open Quotient in an Ex Vivo Perfused Human Larynx

ImportanceScientific understanding of human voice production to date is a product of indirect investigations including animal models, cadaveric tissue study, or computational modeling. To our knowledge, direct experimentation of human voice production has previously not been possible owing to its invasive nature. The feasibility of an ex vivo perfused human phonatory model has recently allowed systematic investigation in virtually living human larynges with parametric laryngeal muscle stimulation.ObjectiveTo investigate the association between adductor muscle group stimulation and the open quotient (OQ) (the fraction of the cycle during which the glottis remains open) of vocal fold vibration.Design, setting, and participantsAn ex vivo perfused human tissue study was conducted at a physiology laboratory. Human larynx recovered from organ donors within 2 hours of cardiac death was used. The study was performed on May 19, 2014; data analysis took place from June 1, 2014, to December 15, 2014.InterventionsPerfusion with donated human blood was reestablished shortly after cardiac death. Ex vivo perfused human phonation was then achieved by providing subglottal airflow under graded neuromuscular electrical stimulation bilaterally to the intrinsic adductor groups and cricothyroid muscles.Main outcomes and measuresPhonation resulting from the graded states of neuromuscular stimulation was evaluated using high-speed vibratory imaging; the OQ was derived through digital kymography and glottal area waveform analysis.ResultsDuring constant glottal flow, a stepwise increase in adductor muscle group stimulation decreased the OQ. Quantitatively, OQ values decreased with increased stimulation levels from 2 V (OQ, 1) to 5 V (OQ, 0.68) and reached a lower limit of 8 V (OQ, 0.42). Increased stimulation above maximal muscle deformation was unable to affect OQ beyond this lower limit.Conclusions and relevanceTo our knowledge, a negative association between adductor muscle group stimulation and phonatory OQ has been demonstrated for the first time in a neuromuscularly activated human larynx. Further experience with the ex vivo perfused human phonatory model will aid in systematically defining this causal relationship

Phonatory effects of type I thyroplasty implant shape and depth of medialization in unilateral vocal fold paralysis

Objectives/hypothesisMedialization thyroplasty (MT) is commonly used to treat glottic insufficiency. In this study, we investigated the phonatory effects of MT implant medialization depth and medial surface shape.MethodsRecurrent laryngeal nerve (RLN) and vagal paralysis were simulated in an in vivo canine. A type 1 MT was performed using a silicone elastomer implant with variable medialization depths and medial surface shapes: rectangular, V-shaped, divergent, and convergent. The effects on phonation onset flow/pressure relationships and acoustics were measured.ResultsIncreasing depth of medialization led to improvements in fundamental frequency (F0) range and normalization of the slope of pressure/flow relationship toward baseline activation conditions. The effects of implant medial shape also depended on depth of medialization. Outcome measures were similar among the implants at smaller medialization depths. With large medialization depths and vagal paralysis conditions, the divergent implant maintained pressure/flow relationship closer to baseline. The vagal paralysis conditions also demonstrated decreased fundamental frequency range and worse flow/pressure relationship compared to RLN paralysis.ConclusionsThe depth and medial shape of a medialization laryngoplasty (ML) implant significantly affect both the F0 range and aerodynamic power required for phonation. These effects become more notable with increasing depth of medialization. The study also illustrates that ML is less effective in vagal paralysis compared to RLN paralysis.Level of evidenceN/A

Intraoperative red blood cell transfusion, delayed graft function, and infection after kidney transplant: an observational cohort study

Background: Kidney transplant patients are frequently anemic and at risk for red blood cell (RBC) transfusion. Previous studies suggest that pre-transplant RBC transfusion may improve kidney transplant outcomes; however, RBC transfusion is also associated with infection. The purpose of our study was to characterize the relationships between intraoperative RBC transfusion, delayed graft function (DGF), postoperative surgical site infection (SSI), and sepsis. Methods: Analysis was performed on a historical cohort of adult kidney transplant patients from a single medical center during a two-year period. Crude odds ratios for DGF, superficial and deep SSI, and sepsis were calculated for transfused patients and multivariate regression was used to control for potential confounders when significant relationships were identified. Results: Four hundred forty-one patients had kidney transplant during the study period; 27.0% had RBC transfusion, 38.8% had DGF, 7.0% had superficial SSI, 7.9% had deep SSI, and 1.8% had sepsis. High dose RBC transfusion was associated with improved graft function, but this was negated after adjusting for confounders (OR = 0.86, 95% CI 0.26 to 2.88). There was no association between RBC transfusion and SSI. RBC transfusion was independently associated with sepsis (OR = 8.98, 95% CI 1.52 to 53.22), but the confidence interval was wide. Conclusions: Intraoperative RBC transfusion during kidney transplant is not associated with improved allograft function or incisional SSI, but is associated with postoperative sepsis. RBCs should not be liberally transfused during kidney transplant surgery to improve graft outcomes

Intraoperative Use of Albumin in Major Noncardiac Surgery: Incidence, Variability, and Association With Outcomes.

BACKGROUND: The impact of albumin use during major surgery is unknown, and a dearth of evidence governing its use in major noncardiac surgery has long precluded its standardization in clinical guidelines. OBJECTIVE: In this study, we investigate institutional variation in albumin use among medical centers in the United States during major noncardiac surgery and explore the association of intraoperative albumin administration with important postoperative outcomes. METHODS: The study is an observational retrospective cohort analysis performed among 54 U.S. hospitals in the Multicenter Perioperative Outcomes Group and includes adult patients who underwent major noncardiac surgery under general anesthesia between January 2014 and June 2020. The primary endpoint was the incidence of albumin administration. Secondary endpoints are acute kidney injury (AKI), net-positive fluid balance, pulmonary complications, and 30-day mortality. Albumin-exposed and albumin-unexposed cases were compared within a propensity score-matched cohort to evaluate associations of albumin use with outcomes. RESULTS: Among 614,215 major surgeries, predominantly iso-oncotic albumin was administered in 15.3% of cases and featured significant inter-institutional variability in use patterns. Cases receiving intraoperative albumin involved patients of higher American Society of Anesthesiologists physical status and featured larger infused crystalloid volumes, greater blood loss, and vasopressor use. Overall, albumin was most often administered at high-volume surgery centers with academic affiliation, and within a propensity score-matched cohort (n=153,218), the use of albumin was associated with AKI (aOR 1.24, 95% CI 1.20-1.28, P <0.001), severe AKI (aOR 1.45, 95% CI 1.34-1.56, P <0.001), net-positive fluid balance (aOR 1.18, 95% CI 1.16-1.20, P <0.001), pulmonary complications (aOR 1.56, 95% CI 1.30-1.86, P <0.001), and 30-day all-cause mortality (aOR 1.37, 95% CI 1.26-1.49, P <0.001). CONCLUSIONS: Intravenous albumin is commonly administered among noncardiac surgeries with significant inter-institutional variability in use in the United States. Albumin administration was associated with an increased risk of postoperative complications

Hydrophilic polymer emboli: an under-recognized iatrogenic cause of ischemia and infarct

With the increased use of percutaneous intravascular diagnostic and therapeutic devices, there is potential for embolization of materials introduced into the vasculature. We report nine cases of foreign body emboli in patients who underwent vascular procedures using hydrophilic-coated medical devices. The procedures performed included cardiac catheterization (four cases), diagnostic cerebral angiography (two cases), therapeutic cerebral angiography with coil embolization of intracerebral aneurysm (one case), lower extremity angiography (one case), and/or orthotopic cadaveric organ transplantation (three cases). Other procedures in these patients included hemodialysis and peripheral arterial or central venous catheterization. Clinical sequelae ranged from undetectable (no symptoms) to pulmonary infarction, stroke, ongoing gangrene, and/or death occurring within days to weeks of suspected embolization of foreign material. Microscopic findings in biopsy or autopsy tissue revealed aggregates of amorphous or lamellated, non-refractile, non-polarizable, predominantly basophilic foreign substances occluding intrapulmonary, intracerebral, or peripheral arteries. This is the largest series documenting embolization of polymer gel materials. Polymer gel is now widely used on several devices for interventional procedures worldwide, and we suspect that complications associated with iatrogenic embolization of this substance are under-recognized