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Anesthesiology Mar 2024Lung protective ventilation aims at limiting lung stress and strain. By reducing the amount of pressure transmitted by the ventilator into the lungs, diaphragm...
BACKGROUND
Lung protective ventilation aims at limiting lung stress and strain. By reducing the amount of pressure transmitted by the ventilator into the lungs, diaphragm neurostimulation offers a promising approach to minimize ventilator-induced lung injury. This study investigates the physiologic effects of diaphragm neurostimulation in acute respiratory distress syndrome (ARDS) patients. The hypothesis was that diaphragm neurostimulation would improve oxygenation, would limit the distending pressures of the lungs, and would improve cardiac output.
METHODS
Patients with moderate ARDS were included after 48 h of invasive mechanical ventilation and had a left subclavian catheter placed to deliver bilateral transvenous phrenic nerve stimulation. Two 60-min volume-controlled mechanical ventilation (control) sessions were interspersed by two 60-min diaphragm neurostimulation sessions delivered continually, in synchrony with the ventilator. Gas exchange, lung mechanics, chest electrical impedance tomography, and cardiac index were continuously monitored and compared across four sessions. The primary endpoint was the Pao2/fraction of inspired oxygen (Fio2) ratio at the end of each session, and the secondary endpoints were lung mechanics and hemodynamics.
RESULTS
Thirteen patients were enrolled but the catheter could not be inserted in one, leaving 12 patients for analysis. All sessions were conducted without interruption and well tolerated. The Pao2/Fio2 ratio did not change during the four sessions. Median (interquartile range) plateau pressure was 23 (20 to 31) cm H2O and 21 (17 to 25) cm H2O, driving pressure was 14 (12 to 18) cm H2O and 11 (10 to 13) cm H2O, and end-inspiratory transpulmonary pressure was 9 (5 to 11) cm H2O and 7 (4 to 11) cm H2O during mechanical ventilation alone and during mechanical ventilation + neurostimulation session, respectively. The dorsal/ventral ventilation surface ratio was 0.70 (0.54 to 0.91) when on mechanical ventilation and 1.20 (0.76 to 1.33) during the mechanical ventilation + neurostimulation session. The cardiac index was 2.7 (2.3 to 3.5) l · min-1 · m-2 on mechanical ventilation and 3.0 (2.4 to 3.9) l · min-1 · m-2 on mechanical ventilation + neurostimulation.
CONCLUSIONS
This proof-of-concept study showed the feasibility of short-term diaphragm neurostimulation in conjunction with mechanical ventilation in ARDS patients. Diaphragm neurostimulation was associated with positive effects on lung mechanics and on hemodynamics.
Topics: Humans; Positive-Pressure Respiration; Diaphragm; Respiratory Mechanics; Respiration, Artificial; Respiratory Distress Syndrome
PubMed: 38088791
DOI: 10.1097/ALN.0000000000004873 -
Open Heart Dec 2023Cryoballoon ablation, especially Arctic Front Advance Pro (AFA-Pro) (Medtronic, Minneapolis, Minnesota, USA), has been widely recognised as a standard approach to atrial...
BACKGROUND
Cryoballoon ablation, especially Arctic Front Advance Pro (AFA-Pro) (Medtronic, Minneapolis, Minnesota, USA), has been widely recognised as a standard approach to atrial fibrillation (AF). Recently, Boston Scientific has released a novel cryoballoon system (POLARx). Despite comparable acute clinical outcomes of these two cryoballoons, the recent study reported a higher complication rate, especially for phrenic nerve palsy, with POLARx. However, their impact on biological tissue remains unclear.
OBJECTIVE
The purpose of our study is to evaluate temperature change of biological tissue during cryoablation of each cryoballoon using a porcine experimental model.
METHOD
A tissue-based pulmonary vein model was constructed from porcine myocardial tissue and placed on a stage designed to simulate pulmonary vein anatomy and venous flow. Controlled cryoablations of AFA-Pro and POLARx were performed in this model to evaluate the tissue temperature. A temperature sensor was set behind the muscle and cryoballoon ablation was performed after confirming the occlusion of pulmonary vein with cryoballoon.
RESULTS
The mean tissue nadir temperature during cryoablation with AFA-Pro was -41.5°C±4.9°C, while the mean tissue nadir temperature during cryoablation with POLARx was -58.4°C±5.9°C (p<0.001). The mean balloon nadir temperature during cryoablation with AFA-Pro was -54.6°C±2.6°C and the mean balloon nadir temperature during cryoablation with POLARx was -64.7°C±3.8°C (p<0.001).
CONCLUSION
POLARx could freeze the biological tissue more strongly than AFA-Pro.
Topics: Humans; Animals; Swine; Temperature; Catheter Ablation; Equipment Design; Atrial Fibrillation; Cryosurgery
PubMed: 38065585
DOI: 10.1136/openhrt-2023-002426 -
Cureus Nov 2023The interscalene block (ISB) is the standard regional anesthesia for shoulder arthroscopy. However, the superior trunk block (STB) is an alternative with a potentially... (Review)
Review
The interscalene block (ISB) is the standard regional anesthesia for shoulder arthroscopy. However, the superior trunk block (STB) is an alternative with a potentially safer profile. This meta-analysis aimed to compare the incidence and degree of hemidiaphragmatic paralysis and block efficacy of these techniques. We searched MEDLINE, EMBASE, Scopus, and Cochrane databases to identify randomized controlled trials (RCTs). The main outcome was total hemidiaphragmatic paralysis. We used the Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) framework to assess the certainty of evidence. Four RCTs and 359 patients were included. The STB group showed lower total hemidiaphragmatic paralysis (RR 0.07; 95% CI 0.04 to 0.14; <0.0001). The incidence of subjective dyspnea ( = 0.002) and Horner's syndrome (<0.001) was significantly lower with STB relative to ISB. There was no significant difference between groups in block duration (p = 0.67). There was a high certainty of evidence in the main outcome as per the GRADE framework. Our findings suggest that STB has a better safety profile than ISB, resulting in lower rates of hemidiaphragmatic paralysis and dyspnea while providing a similar block. Therefore, STB could be preferred to ISB, especially in patients susceptible to phrenic nerve paralysis complications.
PubMed: 38050517
DOI: 10.7759/cureus.48217 -
Cureus Oct 2023The typical clinical presentation of acute coronary syndrome (ACS) includes chest pain that may radiate to the left arm, shoulder, jaw, and neck, accompanied by...
The typical clinical presentation of acute coronary syndrome (ACS) includes chest pain that may radiate to the left arm, shoulder, jaw, and neck, accompanied by diaphoresis, dyspnea, nausea, vomiting, and hiccups, which have been observed as the sole symptom of presentation. The mechanism of hiccups involves the activation of the vagus and phrenic nerves, leading to the activation of the diaphragm and intercostal muscles. Several hypotheses link hiccups to ACS, associating irritation of the left anterior descending artery with activation of sympathetic phrenic and vagal nerves. This case report highlights the occurrence of hiccups in patients with inferior and right ventricular myocardial infarction (MI), indicating possible nerve synapse involvement. Timely recognition of hiccups as a possible atypical symptom of ACS can facilitate early evaluation and management, preventing delays in patient care and ensuring better outcomes.
PubMed: 38046484
DOI: 10.7759/cureus.48069 -
The Journal of International Medical... Dec 2023Persistent hiccups that occur after abdominal surgery seriously affect postoperative rehabilitation. Phrenic nerve block therapy has been recommended after failure of... (Review)
Review
Persistent hiccups that occur after abdominal surgery seriously affect postoperative rehabilitation. Phrenic nerve block therapy has been recommended after failure of medication or physical maneuvers. However, the phrenic nerve is often difficult to accurately identify because of its small diameter and anatomic variations. We combined ultrasound with the use of a nerve stimulator to quickly and accurately identify and block the phrenic nerve in a patient with postoperative persistent hiccups. The ongoing hiccups were immediately terminated with no adverse effects. The patient reported no recurrence during the 2-week follow-up period. We conclude that the combined use of real-time ultrasound guidance and a nerve stimulator for singular phrenic nerve block might be an effective intervention for terminating postoperative persistent hiccups, although further studies are needed to evaluate the safety and efficacy of this technique. The findings in this case suggest a potential clinical application for this technique in managing persistent hiccups, thereby contributing to improved patient care and outcomes.
Topics: Humans; Hiccup; Phrenic Nerve; Ultrasonography; Nerve Block
PubMed: 38041831
DOI: 10.1177/03000605231216616 -
Europace : European Pacing,... Dec 2023Pulsed-field ablation (PFA) has emerged as a novel treatment technology for patients with atrial fibrillation (AF). Cryoballoon (CB) is the most frequently used single...
AIMS
Pulsed-field ablation (PFA) has emerged as a novel treatment technology for patients with atrial fibrillation (AF). Cryoballoon (CB) is the most frequently used single shot technology. A direct comparison to a novel CB system is lacking. We aimed to compare pulmonary vein isolation (PVI) using PFA vs. a novel CB system regarding efficiency, safety, myocardial injury, and outcomes.
METHODS AND RESULTS
One hundred and eighty-one consecutive patients underwent PVI and were included (age 64 ± 9.7 years, ejection fraction 0.58 ± 0.09, left atrial size 40 ± 6.4 mm, paroxysmal AF 64%). 106 patients (59%) underwent PFA (FARAPULSE, Boston Scientific) and 75 patients (41%) underwent CB ablation (PolarX, Boston Scientific). The median procedure time, left atrial dwell time and fluoroscopic time were similar between the PFA and the CB group with 55 [interquartile range (IQR) 43-64] min vs. 58 (IQR 48-69) min (P < 0.087), 38 (30-49) min vs. 37 (31-48) min, (P = 0.871), and 11 (IQR 9.3-14) min vs. 11 (IQR 8.7-16) min, (P < 0.81), respectively. Three procedural complications were observed in the PFA group (two tamponades, one temporary ST elevation) and three complications in the CB group (3× reversible phrenic nerve palsies). During the median follow-up of 404 days (IQR 208-560), AF recurrence was similar in the PFA group and the CB group with 24 vs. 30%, P = 0.406.
CONCLUSION
Procedural characteristics were very similar between PFA and CB in regard to procedure duration fluoroscopy time and complications. Atrial fibrillation free survival did not differ between the PFA and CB groups.
Topics: Humans; Middle Aged; Aged; Atrial Fibrillation; Pulmonary Veins; Cryosurgery; Treatment Outcome; Catheter Ablation; Recurrence
PubMed: 38036293
DOI: 10.1093/europace/euad329 -
Cureus Oct 2023Background It has been postulated that sodium bicarbonate can reduce postoperative pain by neutralizing the acidic peritoneal environment created by carbon dioxide. It...
Background It has been postulated that sodium bicarbonate can reduce postoperative pain by neutralizing the acidic peritoneal environment created by carbon dioxide. It also prevents phrenic nerve damage and peritoneal irritation. The present study is a randomized controlled trial aimed at studying the effects of sodium bicarbonate in reducing postoperative pain in laparoscopic gynecological surgeries. Materials and methods This was a single-center, prospective, two-arm, double-blinded randomized control trial in which intraperitoneal irrigation with sodium bicarbonate was compared with normal saline in operative laparoscopy. Group I (intervention group) consisted of 40 patients who received intraperitoneal sodium bicarbonate, and Group II (control group) consisted of 40 patients who received normal saline. All procedures were conducted under general anesthesia. Postoperative pain scores were compared between intervention and control groups. Results The most common indication of laparoscopy was infertility. There was no difference in the duration of surgery between the two arms (p=0.27). The mean value of the visual analog scale (VAS) score at the shoulder tip was found to be significantly reduced in the intervention group at two hours (p=0.02), four hours (p=0.0009), and 12 hours (p=0.0002) after surgery. The mean VAS score at the abdomen and port sites was also found to be significantly reduced in the intervention group in the first 24 hours after surgery (p<0.05). With the increase in the time period from surgery, the mean VAS scores decreased in both intervention and control groups. Conclusion Intraperitoneal irrigation with sodium bicarbonate is beneficial in reducing postoperative pain in operative laparoscopy. However, multicenter randomized trials with a greater number of participants will be helpful to confirm the findings.
PubMed: 38021625
DOI: 10.7759/cureus.47686 -
Medicina (Kaunas, Lithuania) Nov 2023: Cryoablation is an established treatment method for atrial fibrillation (AF). We present the long-term results of cryoablation in 94 patients with paroxysmal and... (Observational Study)
Observational Study
: Cryoablation is an established treatment method for atrial fibrillation (AF). We present the long-term results of cryoablation in 94 patients with paroxysmal and persistent AF treated in our center. : This was an observational, retrospective study of 94 patients who underwent a cryoablation procedure for paroxysmal or persistent AF from 2015 to 2017. The follow up was 51 ± 3 months. The absence of arrhythmia was checked at 6, 12, 24, and 48 months after the procedure with 24 h Holter monitoring. We evaluated echocardiography parameters before and 48 months after cryoablation. The quality of life was assessed by calculating EHRA scores at each visit. : The mean history of pre-procedural AF duration was 55.3 ± 8.6 months. Paroxysmal AF was present in 42% of patients and persistent AF in 58%. Comparing the EHRA classes, a statistically significant difference was observed between the score assessed before the procedure and the score after one year, as well as when comparing the rates before the procedure and four years after the procedure ( < 0.000). The recurrence of AF was observed in 22.3% of patients 1 year after the procedure, in 26.6% of patients 2 years after the procedure, and in 34% of patients 4 years after the procedure; 9.3% of them were left in permanent AF. During the observation period, 28% of patients underwent a repeated pulmonary vein isolation procedure, and 6% of patients had a permanent pacemaker implanted. Five hematomas (5%) and one instance of phrenic nerve palsy (1%) were observed during the procedure. : The rate of arrhythmia recurrence increased every year after cryoablation. Quality of life improved after the procedure, despite the recurrence of AF. A quarter of patients had to undergo a repeat pulmonary vein isolation procedure.
Topics: Humans; Atrial Fibrillation; Follow-Up Studies; Treatment Outcome; Cryosurgery; Quality of Life; Retrospective Studies; Pulmonary Veins; Catheter Ablation; Recurrence
PubMed: 38004085
DOI: 10.3390/medicina59112036 -
Journal of Cardiothoracic Surgery Nov 2023Re-opening the chest is an unwanted and potentially morbid complication after open heart surgery, most commonly required for refractory bleeding or tamponade. In this...
BACKGROUND
Re-opening the chest is an unwanted and potentially morbid complication after open heart surgery, most commonly required for refractory bleeding or tamponade. In this report, we present a unique case of a postoperative coronary artery bypass patient, demonstrating clinical features of cardiac tamponade of the right atrium and ventricle with inconclusive findings on imaging.
CASE PRESENTATION
A 62 year-old male presented to hospital with exertional angina and a coronary angiogram found severe three-vessel coronary artery disease with preserved left ventricular function. He underwent an uncomplicated triple coronary artery bypass surgery. Over the following hours in the cardiac intensive care unit, the patient had a climbing serum lactate level and increasing vasopressor requirements. On investigations, there was evidence of compression of the right heart. The patient was taken back to the operating room where very little clot or bleeding was identified, rather there was significant amounts of mediastinal fat surrounding the heart which was subsequently resected with wide margins. The patient had complete resolution of their symptoms and an uncomplicated postoperative course thereafter.
CONCLUSIONS
To our knowledge, this case is the first reported occurrence of cardiac constriction from excessive mediastinal fat after open heart surgery. Identifying patients at high-risk for excessive pericardial fat, as well as considering alternative modalities of imaging appear to be the main stay in diagnosis at this point. Current treatment is a mediastinal lipectomy with wide margins, avoiding injury to surrounding structures such as the phrenic nerve and innominate vein. Future study might consider the value of prophylactic mediastinal lipectomy at time of surgery, and methods to improve detection with current and future imaging modalities.
Topics: Humans; Male; Middle Aged; Cardiac Surgical Procedures; Cardiac Tamponade; Coronary Artery Bypass; Lipectomy; Pericardium
PubMed: 37990270
DOI: 10.1186/s13019-023-02421-z -
Scientific Reports Nov 2023Organophosphorus poisoning kills individuals by causing central apnea; however, the underlying cause of death remains unclear. Following findings that the pre-Bötzinger...
Organophosphorus poisoning kills individuals by causing central apnea; however, the underlying cause of death remains unclear. Following findings that the pre-Bötzinger complex impairment alone does not account for central apnea, we analyzed the effect of paraoxon on the brainstem-spinal cord preparation, spanning the lower medulla oblongata to phrenic nucleus. Respiratory bursts were recorded by connecting electrodes to the ventral 4th cervical nerve root of excised brainstem-spinal cord preparations obtained from 6-day-old Sprague-Dawley rats. We observed changes in respiratory bursts when paraoxon, neostigmine, atropine, and 2-pyridine aldoxime methiodide were administered via bath application. The percentage of burst extinction in the paraoxon-poisoning group was 50% compared with 0% and 18.2% in the atropine and 2-pyridine aldoxime methiodide treatment groups, respectively. Both treatments notably mitigated the paraoxon-induced reduction in respiratory bursts. In the neostigmine group, similar to paraoxon, bursts stopped in 66.7% of cases but were fully reversed by atropine. This indicates that the primary cause of central apnea is muscarinic receptor-mediated in response to acetylcholine excess. Paraoxon-induced central apnea is hypothesized to result from neural abnormalities within the inferior medulla oblongata to the phrenic nucleus, excluding pre-Bötzinger complex. These antidotes antagonize central apnea, suggesting that they may be beneficial therapeutic agents.
Topics: Rats; Animals; Antidotes; Paraoxon; Rats, Sprague-Dawley; Neostigmine; Sleep Apnea, Central; Atropine; Pralidoxime Compounds; Pyridines
PubMed: 37990100
DOI: 10.1038/s41598-023-47745-x