Reply to Maxwell, A. Comment on "Miyamoto et al. Laryngopharyngeal Mucosal Injury Due to Nasogastric Tube Insertion during Cardiopulmonary Resuscitation: A Retrospective Cohort Study. J. Clin. Med. 2024, 13, 261".

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Laryngopharyngeal Mucosal Injury Due to Nasogastric Tube Insertion during Cardiopulmonary Resuscitation: A Retrospective Cohort Study.

BACKGROUND: Patients under cardiopulmonary resuscitation (CPR) are at high risk of aspirating gastric contents. Nasogastric tube insertion (NGTI) after tracheal intubation is usually performed blindly. This sometimes causes laryngopharyngeal mucosal injury (LPMI), leading to severe bleeding. This study clarified the incidence of LPMI due to blind NGTI during CPR. METHODS: We retrospectively analyzed 84 patients presenting with cardiopulmonary arrest on arrival, categorized them into a Smooth group (Smooth; blind NGTI was possible within 2 min), and Difficult group (blind NGTI was not possible), and consequently performed video laryngoscope-assisted NGTI. The laryngopharyngeal mucosal condition was recorded using video laryngoscope. Success rates and insertion time for the Smooth group were calculated. Insertion number and LPMI scores were compared between the groups. Each regression line of outcome measurements was obtained using simple regression analysis. We also analyzed the causes of the Difficult group, using recorded video laryngoscope-assisted videos. RESULTS: The success rate was 78.6% (66/84). NGTI time was 48.8 ± 4.0 s in the Smooth group. Insertion number and injury scores in the Smooth group were significantly lower than those in the Difficult group. The severity of LPMI increased with NGT insertion time and insertion number. CONCLUSIONS: Whenever blind NGTI is difficult, switching to other methods is essential to prevent unnecessary persistence.

A case of caffeine intoxication resulting in hypothermia.

A 30-year-old woman arrived at our hospital with polymorphic ventricular tachycardia and hypothermia. Later, it was found that the cause was an overdose of caffeine exceeding the lethal dose. Although it is common for toxidrome caused by caffeine intoxication to produce hyperthermia, here we report a case of hypothermia.

Obstructive shock due to right ventricular compression by a massively expanded reconstructed gastric tube.

Obstructive shock is often associated with poor right ventricular (RV) output and requires rapid obstruction release. A 54-year-old man was brought to our emergency department, presenting with shock. He had previously undergone esophagectomy with gastric interposition through the retrosternal route, after which he could not eat solid foods. After eating a ball of rice, he became critically ill, with a significantly increased lactate level, an indicator of shock. Though initial examinations showed no abnormalities, he was hospitalized for observation. The following day, he experienced similar discomfort while in the supine position, an hour after breakfast. Cardiac sonography revealed that the RV was remarkably compressed by a massively expanded gastric tube, causing diastolic dysfunction. After propping him into a sitting position, he recovered from shock. Upon a second examination of CT images, we recognized the massively dilated gastric tube compressing the RV. Anatomically, the retrosternal route is located directly in front of the RV. Thus, it is thought that the massively dilated gastric tube externally compressed the RV, preventing adequate RV filling and causing the obstructive shock. In such cases, the patient's position should be changed immediately to release the RV compression.

Effects of ANP and BNP on the generation of respiratory rhythms in brainstem-spinal cord preparation isolated from newborn rats.

Natriuretic peptides (NPs) are a family of peptide hormones produced in cardiac muscle cells and consist mainly of three types: atrial NP (ANP), B-type (or brain) NP (BNP), and C-type NP. We herein report the effects of ANP and BNP on central respiratory activity in brainstem-spinal cord preparation isolated from newborn rats. Bath application of these peptides (100 nM) induced a weak transient depression of the respiratory rhythm followed by recovery. Respiratory-related neurons in the rostral ventrolateral medulla showed a tendency for transient hyperpolarization followed by recovery during the application of ANP or BNP. The application of a membrane-permeable cGMP, 8-Br-cGMP (10 or 20 µM), did not induce significant effects on respiratory rhythm, suggesting no involvement of guanylyl cyclase in effects of ANP or BNP. We also examined effects of BNP on respiratory depression induced by the sedative dexmedetomidine, which exerts an inhibitory influence on respiratory rhythm. When pretreated with 50 nM BNP, the inhibitory effect of 100 nM dexmedetomidine was significantly reduced. Our findings suggest that ANP and BNP act as mild excitatory agents with sustained effects on respiratory rhythm after an initial transient depression.

A Case of Acute Non-ST Elevation Myocardial Infarction Later Revealed by Contrast-Enhanced Computed Tomography.

BACKGROUND Acute coronary syndrome is life-threatening. The diagnosis can be confirmed by electrocardiography (ECG) and serum cardiac biomarkers. Early diagnosis and treatment of non-ST segment elevation myocardial infarction (NSTEMI) is important because delayed treatment is associated with poor prognosis, especially in older adults. CASE REPORT An 82-year-old woman presented to the Emergency Department (ED) with epigastric and back pain. Despite the symptoms, the electrocardiogram revealed no abnormality, and the high-sensitivity cardiac troponin (Hs-cTn) value was below the detection limit. Chest contrast-enhanced computed tomography (CT) performed to exclude fatal diseases such as aortic dissection revealed no obvious abnormalities. The patient's symptoms improved and she was discharged. On the following day, the radiologist reviewed the CT and noted reduced cardiac uptake of contrast medium, and so suspected a subendocardial infarction. The patient was immediately recalled to the ED. She had no symptoms, but her Hs-cTn level was markedly elevated and asynergy was found on echocardiography. Emergency coronary angiography revealed complete obstruction of the left anterior descending coronary artery. CONCLUSIONS Similar to patients with acute ST segment elevation myocardial infarction, those with unstable angina or NSTEMI should be treated early. Delayed diagnosis and treatment of acute coronary syndrome is associated with poor prognosis, especially in older adults. Therefore, in patients presenting to the ED with chest pain, careful attention should be paid to myocardial staining in addition to the aorta, pulmonary arteries, and abdominal organs, when performing contrast-enhanced CT.

Guillain-Barré syndrome diagnosed as central cervical spinal cord injury after hyperextension injury.

The clinical features of Guillain-Barré syndrome (GBS) are progressive, fairly symmetric muscle weakness, and patients present a few days to a week after onset of symptoms. A 63-y-old man strongly hit his forehead, and next day felt paresthesia in both upper limbs, with difficulty in walking. Spinal cord injury (SCI) was suspected; the cervical cord was severely compressed at the C4 level. He was diagnosed with central cervical SCI and transferred to a community hospital. Three days after the injury, oxygenation worsened, and the patient was transferred to our hospital for laminoplasty. After admission, we noticed bilateral ptosis-an atypical finding for SCI. Under analgesic sedation, he could only move his fingertips. Severe respiratory muscle weakness and absence of reflexes were observed. Moreover, albuminocytologic dissociation and decreased motor nerve conduction were observed, and GBS was suspected. Intravenous immunoglobulin was administered; thereby, the muscle weakness gradually improved, and the patient returned to work. Muscle weakness usually starts in the legs in GBS; however, in 10% of patients, it starts in the arms. In our patient, the symptoms started with paresthesia, followed by severe respiratory muscle weakness in a short period. Furthermore, intubation made history-taking and neurological examination difficult. The degree of inflammation in the acute GBS phase correlates with the severity of nerve injury. Therefore, early diagnosis and treatment of GBS is important. We should perform detailed history-taking and consider GBS as a differential diagnosis, especially when neurological examination cannot be performed at the emergency department.

Effects of acetylcholine on hypoglossal and C4 nerve activity in brainstem-spinal cord preparations from newborn rat.

Effects of acetylcholine (ACh) on respiratory activity have been an intriguing theme especially in relation to central chemoreception and the control of hypoglossal nerve activity. We studied the effects of ACh on hypoglossal and phrenic (C4) nerve activities and inspiratory and pre-inspiratory neurons in the rostral ventrolateral medulla in brainstem-spinal cord preparations from newborn rats. ACh application increased respiratory rhythm, decreased inspiratory hypoglossal and C4 nerve burst amplitude, and enhanced pre-inspiratory hypoglossal activity. ACh induced membrane depolarization of pre-inspiratory neurons that might be involved in facilitation of respiratory rhythm by ACh. Effects of ACh on hypoglossal and C4 nerve activity were partially reversed by a nicotinic receptor blocker, mecamylamine. Further application of a muscarinic receptor antagonist, oxybutynin, resulted in slight increase of hypoglossal (but not C4) burst amplitude. Thus, ACh induced different effects on hypoglossal and C4 nerve activity in the brainstem-spinal cord preparation.

Diagnosis of neurofibromatosis type 1 after rupture of aneurysm and consequent fatal hemothorax.

Patients with neurofibromatosis type 1 (NF1) can develop both benign and malignant tumors throughout their lives. A 49-year-old man was transferred to the emergency department with complaints of sudden right dorsal pain and respiratory discomfort. He was in shock on arrival. On finding significantly decreased permeability of the left lung field in chest X-ray, drainage was immediately performed. Subsequent computed tomography (CT; Lammert et al., 2005) angiography revealed the extravasation of contrast media from the deep carotid artery, a branch of subclavian artery. It suggested rupture of an aneurysm located at a rare site; the ruptured aneurysm penetrated the pleura, causing shock. The patient was resuscitated. Transcatheter arterial embolization (TAE; Evans et al., 2010) was successfully performed. Immediate drainage, resuscitation, and TAE 2 improved his condition. Most NF1 patients have café-au-lait macules; café-au-lait macules tend to fade with age. Importantly, café-au-lait macules, neurofibromas, and Lisch nodules were noticed at admission. NF1 patients are likely to have a malignant neoplasm when they are young. The patient had been diagnosed with thyroid cancer when he was young. As his deceased mother was an NF1 patient, we diagnosed him with NF1. Detailed patient history and early-stage examination led to the early diagnosis. NF1 should be considered as an early differential diagnosis to improve the outcome of patients in such cases.