Comparison of Dual-Dispatch Protocols on Return of Spontaneous Circulation in Patients with Out-of-Hospital Cardiac Arrest: A Nationwide Observational Study.

Objective: In South Korea, the National Fire Agency (NFA) conducted a pilot project on the advanced life support (ALS) protocol, including epinephrine administration, to improve the survival rate of out-of hospital cardiac arrest (OHCA). Therefore, this study aimed to evaluate the effect of the ALS protocol of NFA on prehospital return of spontaneous circulation (PROSC) in patients with OHCA. Methods: This study was conducted on patients with adult-presumed cardiac arrest between January and December 2020. The main factor of interest was ambulance type according to the ALS protocol, which was divided into dedicated ALS(DA), smartphone-based ALS(SALS), and non-dedicated ALS(Non-DA), and the main analysis factor was PROSC. Multivariate logistic regression analysis was performed. Results: During the study period, a total of 18,031 adult patients with OHCA were treated by the emergency medical service (EMS), including 7,520 (41.71 %) DA, 2,622 (14.54 %) SALS, and 7,889 (43.75 %) Non-DA. The prehospital ROSC ratio was 13.19% for the DA, 11.17% for the SALS, and 7.91% for the Non-DA ambulance (P < 0.01). Compared with that of the DA group, the odds ratio (95% confidence interval [CI]) for PROSC ratio in the SALS and Non-DA groups were 0.97 (0.82-1.15) and 0.57 (0.50-0.65), respectively. It was shown that the PROSC ratio of the DA group was higher than that of the Non-DA group and was not lower than that of the SALS group. Conclusion: ALS protocol intervention was associated with difference in PROSC rates. Therefore, continuous efforts on the systemic implementation of the ALS protocol to improve OHCA outcomes are necessary.

Smartphone AI vs. Medical Experts: A Comparative Study in Prehospital STEMI Diagnosis.

PURPOSE: Prehospital telecardiology facilitates early ST-elevation myocardial infarction (STEMI) detection, yet its widespread implementation remains challenging. Extracting digital STEMI biomarkers from printed electrocardiograms (ECGs) using phone cameras could offer an affordable and scalable solution. This study assessed the feasibility of this approach with real-world prehospital ECGs. MATERIALS AND METHODS: Patients suspected of having STEMI by emergency medical technicians (EMTs) were identified from a policy research dataset. A deep learning-based ECG analyzer (QCG™ analyzer) extracted a STEMI biomarker (qSTEMI) from prehospital ECGs. The biomarker was compared to a group of human experts, including five emergency medical service directors (board-certified emergency physicians) and three interventional cardiologists based on their consensus score (number of participants answering "yes" for STEMI). Non-inferiority of the biomarker was tested using a 0.100 margin of difference in sensitivity and specificity. RESULTS: Among 53 analyzed patients (24 STEMI, 45.3%), the area under the receiver operating characteristic curve of qSTEMI and consensus score were 0.815 (0.691-0.938) and 0.736 (0.594-0.879), respectively (p=0.081). Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of qSTEMI were 0.750 (0.583-0.917), 0.862 (0.690-0.966), 0.826 (0.679-0.955), and 0.813 (0.714-0.929), respectively. For the consensus score, sensitivity, specificity, PPV, and NPV were 0.708 (0.500-0.875), 0.793 (0.655-0.966), 0.750 (0.600-0.941), and 0.760 (0.655-0.880), respectively. The 95% confidence interval of sensitivity and specificity differences between qSTEMI and consensus score were 0.042 (-0.099-0.182) and 0.103 (-0.043-0.250), respectively, confirming qSTEMI's non-inferiority. CONCLUSION: The digital STEMI biomarker, derived from printed prehospital ECGs, demonstrated non-inferiority to expert consensus, indicating a promising approach for enhancing prehospital telecardiology.

Impact of COVID-19 on Out-of-Hospital Cardiac Arrest in Korea.

BACKGROUND: Coronavirus disease 2019 (COVID-19) is a global public health crisis that has had a significant impact on emergency medical services (EMS). Several studies have reported an increase in the incidence of out-of-hospital cardiac arrest (OHCA) and a decreased survival due to COVID-19, which has been limited to a short period or has been reported in some regions. This study aimed to investigate the effect of COVID-19 on OHCA patients using a nationwide database. METHODS: We included adult OHCA patients treated by EMS providers from January 19, 2019 to January 20, 2021. The years before and after the first confirmed case in Korea were set as the non-COVID-19 and COVID-19 periods, respectively. The main exposure of interest was the COVID-19 period, and the primary outcome was prehospital return of spontaneous circulation (ROSC). Other OHCA variables were compared before and after the COVID-19 pandemic and analyzed. We performed a multivariable logistic regression analysis to understand the independent effect of the COVID-19 period on prehospital ROSC. RESULTS: The final analysis included 51,921 eligible patients, including 25,355 (48.8%) during the non-COVID-19 period and 26,566 (51.2%) during the COVID-19 period. Prehospital ROSC deteriorated during the COVID-19 period (10.2% vs. 11.1%, P = 0.001). In the main analysis, the adjusted odds ratios (AORs) for prehospital ROSC showed no significant differences between the COVID-19 and non-COVID-19 periods (AOR [95% confidence interval], 1.02 [0.96-1.09]). CONCLUSION: This study found that the proportion of prehospital ROSC was lower during the COVID-19 period than during the non-COVID-19 period; however, there was no statistical significance when adjusting for potential confounders. Continuous efforts are needed to restore the broken chain of survival in the prehospital phase and increase the survival rate of OHCA patients.

Modification and Validation of a Complaint-Oriented Emergency Department Triage System: A Multicenter Observational Study.

PURPOSE: The objective of this study was to modify and validate an emergency department (ED) triage system with improved prediction performance on hospital outcomes by modifying the Korean Triage and Acuity Scale (KTAS). MATERIALS AND METHODS: We performed a retrospective observational study at three academic universities in South Korea. The KTAS code, determined by the chief complaint and the selected modifier of a patient, was used to derive the Modified KTAS (MKTAS). We calculated the area under the receiver operating characteristics curve (AUC) and the test characteristics to evaluate the performance of MKTAS to predict hospital mortality, critical outcome, and admission. RESULTS: A total of 272402 and 128831 ED visits were used for the derivation and validation of MKTAS, respectively. Compared to KTAS, MKTAS had significantly higher AUC values for the prediction of hospital mortality [MKTAS 0.826 (0.818-0.835) vs. KTAS 0.794 (0.784-0.803)], critical outcome [MKTAS 0.836 (0.830-0.841) vs. 0.798 (0.792-0.804)], and admission [MKTAS 0.725 (0.723-0.728) vs. KTAS 0.685 (0.682-0.688)]. The sensitivity for predicting hospital mortality and critical outcome, as well as the specificity for predicting admission, were significantly improved. CONCLUSION: MKTAS was derived by modifying the KTAS, and then validated. Compared with KTAS, MKTAS showed better discriminating ability to predict hospital outcomes. Continuous efforts to evaluate and modify widely used triage systems are required to improve their performance.

Association of Flow Rate of Prehospital Oxygen Administration and Clinical Outcomes in Severe Traumatic Brain Injury.

The goal of this study was to investigate the association of prehospital oxygen administration flow with clinical outcome in severe traumatic brain injury (TBI) patients. This was a cross-sectional observational study using an emergency medical services-assessed severe trauma database in South Korea. The sample included adult patients with severe blunt TBI without hypoxia who were treated by EMS providers in 2013 and 2015. Main exposure was prehospital oxygen administration flow rate (no oxygen, low-flow 1~5, mid-flow 6~14, high-flow 15 L/min). Primary outcome was in-hospital mortality. A total of 1842 patients with severe TBI were included. The number of patients with no oxygen, low-flow oxygen, mid-flow oxygen, high-flow oxygen was 244, 573, 607, and 418, respectively. Mortality of each group was 34.8%, 32.3%, 39.9%, and 41.1%, respectively. Compared with the no-oxygen group, adjusted odds (95% CI) for mortality in the low-, mid-, and high-flow oxygen groups were 0.86 (0.62-1.20), 1.15 (0.83-1.60), and 1.21 (0.83-1.73), respectively. In the interaction analysis, low-flow oxygen showed lower mortality when prehospital saturation was 94-98% (adjusted odds ratio (AOR): 0.80 (0.67-0.95)) and ≥99% (AOR: 0.69 (0.53-0.91)). High-flow oxygen showed higher mortality when prehospital oxygen saturation was ≥99% (AOR: 1.33 (1.01~1.74)). Prehospital low-flow oxygen administration was associated with lower in-hospital mortality compared with the no-oxygen group. High-flow administration showed higher mortality.

Adjuvant chemotherapy as a risk factor for chronic postoperative pain after video-assisted thoracoscopic surgery: a 10-year single-centre retrospective study.

OBJECTIVES: The association between adjuvant chemotherapy (AC) and chronic postoperative pain (CPP) after video-assisted thoracoscopic surgery (VATS) for lung cancer resection has not yet been reported. We, therefore, investigated the association between AC and the long-term incidence of CPP after VATS. METHODS: We retrospectively reviewed 3015 consecutive patients who underwent VATS for lung cancer between 2007 and 2016. The patients were divided into 2 groups: those who received (AC group) and those who did not receive (non-AC group) AC within 3 months after VATS. Propensity score analysis was performed to adjust for baseline differences between the 2 groups. The cumulative incidence of CPP at the intervals of 3 months, over 36 months, was compared before and after matching. A Cox proportional hazards regression analysis was used to investigate the predictors of CPP after VATS. RESULTS: We included and assessed 2222 patients in this study. Of these, 320 patients (14.4%) received AC within 3 months post-VATS. The cumulative incidence of CPP during 36 months post-surgery was significantly higher in the AC group than in the non-AC group, before and after matching (log-rank test; P = 0.002 and 0.027, respectively). Cox proportional hazards regression analysis also showed that AC was a significant risk factor for CPP (hazard ratio 1.62, 95% confidence interval 1.16-2.28; P = 0.005). CONCLUSIONS: Our results indicate that AC is an important risk factor for CPP after VATS. Further understanding of the risk factors for CPP may facilitate its prediction and treatment.

Long-term incidence of chronic postsurgical pain after thoracic surgery for lung cancer: a 10-year single-center retrospective study.

BACKGROUND: The long-term incidence of chronic postsurgical pain (CPSP) after thoracic surgery has not yet been reported. METHODS: We retrospectively reviewed the electronic medical records of 4218 consecutive patients who underwent thoracic surgery for lung cancer between 2007 and 2016. We evaluated the long-term incidence of CPSP after thoracic surgery at intervals of 3 months for 36 months. A Cox proportional hazard regression analysis was performed to investigate the predictors of CPSP after thoracic surgery. RESULTS: A total of 3200 patients were included in the analysis. Of these, 459 (14.3%) and 558 (17.4%) patients were diagnosed with CPSP within 3 and 36 months after surgery, respectively. Furthermore, the incidence of CPSP decreased over time. Additionally, 99 (3.1%) patients were newly diagnosed with CPSP at least 6 months after surgery. Female sex (HR 1.20, 95% CI 1.00 to 1.43; p=0.04), longer duration of surgery (HR 1.11, 95% CI 1.03 to 1.20; p<0.01), higher 11-point Numeric Rating Scale score at first outpatient visit after surgery (HR 1.29, 95% CI 1.24 to 1.34; p<0.001), postoperative chemotherapy (HR 1.55, 95% CI 1.26 to 1.90; p<0.001), and postoperative radiation therapy (HR 1.35, 95% CI 1.05 to 1.74; p=0.02) were significant predictors of CPSP for 36 months after surgery. CONCLUSION: Our study showed a decreasing trend in the incidence of CPSP as well as delayed-onset or recurrent CPSP after thoracic surgery. A better understanding of the progression of CPSP after thoracic surgery may provide important information on its prediction and treatment.

Association Between Post-Resuscitation Coronary Angiography With and Without Intervention and Neurological Outcomes After Out-of-Hospital Cardiac Arrest.

Objective: This study aimed to investigate the association between coronary angiography (CAG) with and without percutaneous coronary intervention (PCI) after out-of-hospital cardiac arrest (OHCA) and neurological recovery and to determine the influence of primary electrocardiogram or patient age on the effects of CAG. Methods: Adult patients with OHCA with cardiac etiology who were admitted to PCI-capable hospitals from 2016 to 2017 were enrolled in this study from the nationwide OHCA registry of Korea. Coronary intervention was categorized into three groups: No CAG, CAG without PCI, and CAG with PCI. The endpoint was good neurological recovery. Multivariable logistic regression and interaction analyses (intervention × electrocardiogram and intervention × age) were conducted by calculating adjusted odds ratios (aORs) and 95% confidence intervals (CI). Results: Of a total of 6,802 eligible OHCA patients, 1,218 (17.9%) underwent CAG without PCI and 1,136 (16.7%) underwent CAG with PCI. The CAG without PCI and CAG with PCI groups were more likely to have good neurological recovery than the No CAG group (57.4% vs. 61.6% vs. 16.3%; 3.39 [2.83-4.06] for CAG without PCI and 3.32 [2.74-4.01] for CAG with PCI). Interaction analysis showed that although the effect size differed according to patient characteristics, both CAG groups were associated with an increased likelihood of good neurological recovery, regardless of primary electrocardiogram and age group. In younger patients, CAG with PCI had greater outcome benefits than CAG without PCI (8.54 [4.31-16.95] vs. 4.10 [2.69-6.24]), whereas CAG without PCI had a larger effect size than CAG with PCI in elderly patients (4.46 [2.59-7.68] vs. 2.92 [1.80-4.73]) (p value for interaction 0.02). Conclusions: Post-resuscitation CAG with and without PCI are associated with better neurological recovery in patients with OHCA, regardless of primary electrocardiogram and patient age.

End stage renal disease modifies the effect of targeted temperature management after out-of-hospital cardiac arrest.

INTRODUCTION: Kidney function can affect the permeability of the blood-brain barrier; thus, end-stage renal disease (ESRD) may alter the effects of targeted temperature management (TTM) on the neurological outcomes of out-of-hospital cardiac arrest (OHCA) patients. We aimed to investigate whether the interaction effect of TTM on outcomes after OHCA was observed among patients with and without ESRD. METHODS: Adult OHCA patients with presumed cardiac etiology who attained sustained return of spontaneous circulation from 2013 to 2017 were included using nationwide OHCA registry. The main exposure variable was TTM. The primary endpoint was survival with good neurological recovery. Multivariable logistic regression analysis was performed after adjustment for potential confounders. To compare the effect of ESRD on TTM, an interaction term (TTM × ESRD) was added to the model. RESULTS: A total of 21,250 patients were included in the analysis; 2693 (12.7%) patients underwent TTM. ESRD was observed in 128 (4.8%) in the TTM group and 767 (4.1%) in the no-TTM group. The TTM group showed better outcomes than the no-TTM group (32.4% vs. 17.2%, p < 0.01). The adjusted odds ratio of TTM for good neurological recovery in the entire study group was 1.15 (95% CI, 1.03-1.29). In the interaction model, the adjusted odds ratio of TTM for good neurological recovery was 0.47 (95% CI, 0.23-0.98) in the ESRD group vs. 1.54 (95% CI, 1.00-2.39) in the no-ESRD group. CONCLUSIONS: The interaction effect between ESRD and TTM on neurologic outcome was positive in adult OHCA initial survivors with presumed cardiac etiology.

The effect of sevoflurane versus desflurane on postoperative catheter-related bladder discomfort in patients undergoing transurethral excision of a bladder tumour: a randomized controlled trial.

PURPOSE: Catheter-related bladder discomfort (CRBD) due to an indwelling urinary catheter can cause postoperative distress, and the mechanism underlying CRBD is linked to the activation of muscarinic receptors. Inhalation of anesthetic agents, such as sevoflurane and desflurane, has differential inhibitory effects on muscarinic receptors. We aimed to compare the effect of intraoperative sevoflurane vs desflurane inhalation on postoperative CRBD. METHODS: Eighty-nine patients undergoing transurethral resection of a bladder tumour (TURBT) were randomly allocated to two groups. The sevoflurane group (n = 45) and the desflurane group (n = 44) received the respective inhalational agents for maintenance of general anesthesia. The incidence and severity (mild/moderate/severe) of CRBD were assessed at zero, one, six, and 24 hr postoperatively. RESULTS: Catheter-related bladder discomfort during the first 24 hr postoperatively occurred in 34/45 (76%) patients receiving sevoflurane compared with 41/44 (93%) patients receiving desflurane [absolute difference 18%; 95% confidence interval [CI], 2 to 33; P = 0.039]. The differences in the rate of CRBD between the sevoflurane and desflurane groups at zero, one, and six hours postoperatively were 24% (95% CI, 7 to 40; P = 0.012), 33% (95% CI, 15 to 49; P = 0.001), and 26% (95% CI, 6 to 43; P = 0.019), respectively. The incidence of moderate to severe CRBD and the number of patients treated with tramadol for CRBD were comparable between the two groups. CONCLUSIONS: As a maintenance agent of general anesthesia, sevoflurane reduced the incidence of early postoperative CRBD in patients undergoing TURBT when compared with desflurane. The protocol for this clinical trial was registered at ClinicalTrials.gov (NCT02096224).

Siah proteins induce the epidermal growth factor-dependent degradation of phospholipase Cepsilon.

Phospholipase Cepsilon (PLCepsilon) is activated by various growth factors or G-protein-coupled receptor ligands via different activation mechanisms. The Ras association (RA) domain of PLCepsilon is known to be important for its ability to bind with Ras-family GTPase upon growth factor stimulation. In the present study, we identified Siah1 and Siah2 as novel binding partners of the PLCepsilon RA domain. Both Siah1 and Siah2 interacted with the RA2 domain of PLCepsilon, and the mutation of Lys-2186 of the PLCepsilon RA2 domain abolished this association. Moreover, Siah induced the ubiquitination and degradation of PLCepsilon upon epidermal growth factor (EGF) stimulation, and Siah proteins were phosphorylated on multiple tyrosine residues via an Src-dependent pathway upon EGF treatment. The Src inhibitor abolished the EGF-dependent ubiquitination of PLCepsilon, and the Siah1 phosphorylation-deficient mutant could not increase the EGF-dependent ubiquitination and degradation of PLCepsilon. The EGF-dependent degradation of PLCepsilon was blocked in mouse embryonic fibroblast (MEF) cells derived from Siah1a/Siah2 double knockout mice, and the extrinsic expression of wild-type Siah1 restored the degradation of PLCepsilon, whereas the phosphorylation-deficient mutant did not. Siah1 expression abolished PLCepsilon-dependent potentiation of EGF-dependent cell growth. In addition, the expression of wild-type Siah1 in Siah1a/Siah2-double knockout MEF cells inhibited EGF-dependent cell growth, and this inhibition was abolished by PLCepsilon knockdown. Our results suggest that the Siah-dependent degradation of PLCepsilon plays a role in the regulation of growth factor-dependent cell growth.

Phospholipase C-epsilon augments epidermal growth factor-dependent cell growth by inhibiting epidermal growth factor receptor down-regulation.

The down-regulation of the epidermal growth factor (EGF) receptor is critical for the termination of EGF-dependent signaling, and the dysregulation of this process can lead to oncogenesis. In the present study, we suggest a novel mechanism for the regulation of EGF receptor down-regulation by phospholipase C-epsilon. The overexpression of PLC-epsilon led to an increase in receptor recycling and decreased the down-regulation of the EGF receptor in COS-7 cells. Adaptor protein complex 2 (AP2) was identified as a novel binding protein that associates with the PLC-epsilon RA2 domain independently of Ras. The interaction of PLC-epsilon with AP2 was responsible for the suppression of EGF receptor down-regulation, since a perturbation in this interaction abolished this effect. Enhanced EGF receptor stability by PLC-epsilon led to the potentiation of EGF-dependent growth in COS-7 cells. Finally, the knockdown of PLC-epsilon in mouse embryo fibroblast cells elicited a severe defect in EGF-dependent growth. Our results indicated that PLC-epsilon could promote EGF-dependent cell growth by suppressing receptor down-regulation.

Grb2 negatively regulates epidermal growth factor-induced phospholipase C-gamma1 activity through the direct interaction with tyrosine-phosphorylated phospholipase C-gamma1.

Phospholipase C-gamma1 (PLC-gamma1) plays pivotal roles in cellular growth and proliferation. Upon the stimulation of growth factors and hormones, PLC-gamma1 is rapidly phosphorylated at three known sites; Tyr771, Tyr783 and Tyr1254 and its enzymatic activity is up-regulated. In this study, we demonstrate for the first time that Grb2, an adaptor protein, specifically interacts with tyrosine-phosphorylated PLC-gamma1 at Tyr783. The association of Grb2 with PLC-gamma1 was induced by the treatment with epidermal growth factor (EGF). Replacement of Tyr783 with Phe completely blocked EGF-induced interaction of PLC-gamma1 with Grb2, indicating that tyrosine phosphorylation of PLC-gamma1 at Tyr783 is essential for the interaction with Grb2. Interestingly, the depletion of Grb2 from HEK-293 cells by RNA interference significantly enhanced increased EGF-induced PLC-gamma1 enzymatic activity and mobilization of the intracellular Ca2+, while it did not affect EGF-induced tyrosine phosphorylation of PLC-gamma1. Furthermore, overexpression of Grb2 inhibited PLC-gamma1 enzymatic activity. Taken together, these results suggest Grb2, in addition to its key function in signaling through Ras, may have a negatively regulatory role on EGF-induced PLC-gamma1 activation.

Sorting nexin 16 regulates EGF receptor trafficking by phosphatidylinositol-3-phosphate interaction with the Phox domain.

Sorting nexins (SNXs) containing the Phox (PX) domain are implicated in the regulation of membrane trafficking and sorting processes of epithelial growth factor receptor (EGFR). In this study, we investigated whether SNX16 regulates EGF-induced cell signaling by regulating EGFR trafficking. SNX16 is localized in early and recycling endosomes via its PX domain. Mutation of the PX domain disrupted the association between SNX16 and phosphatidylinositol 3-phosphate [PtdIns(3)P]. Treatment with wortmannin, a PtdIns 3-kinase inhibitor, abolished the endosomal localization of SNX16, suggesting that the intracellular localization of SNX16 is regulated by PtdIns 3-kinase activity. SNX16 was found to associate with EGFR after stimulation with EGF in COS-7 cells. Moreover, overexpression of SNX16 increased the rate of EGF-induced EGFR degradation and inhibited the EGF-induced up-regulation of ERK and serum response element (SRE). In addition, mutation in the PX domain significantly blocked the inhibitory effect of SNX16 on EGF-induced activation of ERK and SRE. From these results, we suggest that SNX16 directs the sorting of EGFR to the endosomal compartment and thus regulates EGF-induced cell signaling.

Phospholipase C-gamma1 is a guanine nucleotide exchange factor for dynamin-1 and enhances dynamin-1-dependent epidermal growth factor receptor endocytosis.

Phospholipase C-gamma1 (PLC-gamma1), which interacts with a variety of signaling molecules through its two Src homology (SH) 2 domains and a single SH3 domain has been implicated in the regulation of many cellular functions. We demonstrate that PLC-gamma1 acts as a guanine nucleotide exchange factor (GEF) of dynamin-1, a 100 kDa GTPase protein, which is involved in clathrin-mediated endocytosis of epidermal growth factor (EGF) receptor. Overexpression of PLC-gamma1 increases endocytosis of the EGF receptor by increasing guanine nucleotide exchange activity of dynamin-1. The GEF activity of PLC-gamma1 is mediated by the direct interaction of its SH3 domain with dynamin-1. EGF-dependent activation of ERK and serum response element (SRE) are both up-regulated in PC12 cells stably overexpressing PLC-gamma1, but knockdown of PLC-gamma1 by siRNA significantly reduces ERK activation. These results establish a new role for PLC-gamma1 in the regulation of endocytosis and suggest that endocytosis of activated EGF receptors may mediate PLC-gamma1-dependent proliferation.

Changes of esophageal motility after total laryngectomy.

OBJECTIVE: Total laryngectomy completely interrupts the continuity of the proximal digestive tract and may lead to derangement in esophageal motility. The purpose of this investigation was to find out how total laryngectomy changes the resting and the maximum contracting pressures of the upper esophageal sphincter muscle and how it affects the coordination of the contraction and the relaxation between the pharynx and the upper esophageal sphincter muscles. If changes in the function of the upper esophageal sphincter muscle should occur, this study will also demonstrate how it affects the motility of the esophagus and the lower esophageal sphincter muscle. METHODS: In an attempt to explain postoperative motility changes, the stationary pull through method of manometric evaluation was used to quantify the alteration in esophageal motility. For the manometric evaluation of the esophagus, a polyethylene catheter with 8 internal tubes was used. The study was performed on a group of 15 patients with total laryngectomy and 15 people without esophageal disease or symptoms as the control group. RESULTS: There was a statistically significant difference between the laryngectomy group and the control group for both the resting and maximum contraction pressures as well as for coordination and relaxation of the upper esophageal sphincter. (P < 0.05) In the laryngectomy group, 3 patients who complained of postoperative dysphasia showed more severe functional changes. The proximal esophageal body pressure and peristaltic waves were significantly decreased in the laryngectomy group. No significant difference between the laryngectomy group and the control group was noted in terms of the lower esophageal resting sphincter pressure and the postdeglution pressure. There also was no significant difference between the two groups in the degree of lower esophageal sphincter coordination and relaxation. CONCLUSION: From these results, it may be concluded that interruption of the cricopharyngeal muscle and pharyngeal plexus after laryngectomy not only may produce local derangement of upper esophageal sphincter function but also may produce abnormalities in peristalsis of the proximal esophageal body. However, the function of lower esophageal sphincter did not show any significant difference between the laryngectomy group and the control group.