Spontaneous Respiration Research Articles

Abstract 4137267: A novel reproducible low-cost model of acute myocardial infarction in swine

Background: Traditional open- and closed-chest methods for inducing acute myocardial infarction (AMI) in pigs typically require extensive and expensive instrumentation, including ventilators and inhalation anesthesia. This study aims to evaluate a reproducible and low-cost model for AMI in pigs using lower hemisternotomy. Methods: Twenty Yorkshire swine (15-20 kg, 45-50 days of age) underwent permanent ligation of the roots of the first and second diagonal branches of the left anterior descending coronary artery. The procedure was performed under intramuscular anesthesia (1ml 0.5mg/kg Zoletil™ and 2ml 10mg/kg xylazine hydrochloride) with spontaneous respiration. Cardiac function was assessed via echocardiography and cardiac PET/MRI scans at 1 and 4 weeks post-MI. Heart tissue was collected for pathological analysis to evaluate the establishment of the AMI model. Results: All animals exhibited ECG changes, including premature ventricular complexes and ST-segment elevation immediately after ligation. No ventricular tachycardia and fibrillation was observed during the operation. No animals (0%) died during infarct creation. The "Skin-to-Skin" procedure time was 18±3.3 minutes. this procedure produced an infarction that occupies ~10% of the left ventricular mass accompanied with the decrease of LV heart function and LV anterior wall thickness 4 weeks post-MI. Conclusions: This novel low-cost technique provides reproducible acute coronary artery occlusion at a selected location with subsequent AMI. It avoids ventilation, inhalation anesthesia, major surgery and does not require expensive instrumentation for intracoronary intervention.

Efficacy and safety of remimazolam tosilate in anesthesia for short otolaryngology surgery.

Remimazolam tosilate represents the novel ultrashort-acting benzodiazepine drug. This work focused on exploring whether remimazolam tosilate was effective and safe in anesthesia for short otolaryngology surgery in adults, and optimize its medication regimen, thus providing a theoretical basis for its widespread clinical application. The present unicentric, double-blind, randomized controlled study enrolled altogether 85 otolaryngology surgery patients aged 18-60 years, and they were divided as remimazolam (RM, 42 cases) or midazolam (MD, 43 cases) group. Efficacy outcomes included successful sedation time, sedation effect (Modified Observer's Assessment of Alertness/Sedation (MOAA/S) score), bispectral index values (BIS), and postoperative recovery. The safety outcomes were patient vital signs at each time point (before induction (T0), 2min and 5min after trial drug treatment (T1 and T2 separately), during successful intubation (T3), at the end of surgery (T4), during extubation (T5), and at the time of exiting the room (T6)), any adverse reactions (AEs) during perioperative period, and patient satisfaction with anesthesia experience. Demographics were not significantly different in both groups (P > 0.05). RM group had significantly decreased successful sedation time relative to MD group (P < 0.05), while increased successful sedation rate (100%) relative to MD group (90.70%, P = 0.116). RM group showed decreased MOAA/S score and BIS value compared with MD group at T1 and T2 (P < 0.05). The spontaneous respiration recovery time and extubation time were not significantly different in both groups (P > 0.05), but RM group exhibited decreased discharge time compared with MD group (P < 0.05). Compared with MD group, the RM group had lower blood pressure (BP) at T3 (P < 0.05); whereas higher heart rate (HR) and respiration rate (RR) at T1 and T2 (P < 0.05). Difference in AEs was not of statistical significance. Finally, RM group exhibited the increased satisfaction of anesthesia experience compared with MD group (P < 0.05). Remimazolam tosilate is effective on anesthesia for short otolaryngology surgery. Remimazolam shows the rapid onset, stable circulation, fast postoperative recovery, no increase in perioperative AEs, and high satisfaction with anesthesia experience compared with midazolam. https://www.chictr.org.cn/ (ChiCTR2200067123) on 27/12/2022. This study was consistent with CONSORT guidelines.

The Application and Pharmaceutical Development of Etomidate: Challenges and Strategies.

Etomidate is a synthetic imidazole anesthetic that exerts hypnotic effects by potentiating the action of the inhibitory neurotransmitter γ-aminobutyric acid (GABA) or directly activating the anionic GABA (GABAA) receptor. It stands out among many anesthetics because of its multiple advantages, such as good hemodynamic stability and minimal inhibition of spontaneous respiration. However, its low water solubility and side effects, such as adrenal cortex inhibition and myoclonus, have limited the clinical application of this drug. To address these issues, extensive research has been conducted on the drug delivery of etomidate in recent decades, which has led to the emergence of different etomidate preparations. Despite so many etomidate preparations, so far some of the toxic side effects have not yet been effectively addressed. Herein we discuss the pharmaceutical design of etomidate that may resolve the above problem. We also propose targeted strategies for future research on etomidate preparations and discuss the feasibility of different administration routes and dosage forms to expand the application of this drug. Through this review, we hope to draw more attention to the potential of etomidate and its application challenges and provide valuable insights into the development of new etomidate preparations.

First photon-counting detector computed tomography in the living crocodile: a 3D-Imaging study with special reference to amphibious hearing.

Crocodiles are semi-aquatic animals well adapted to hear both on land and under water. Currently, there is limited information on how their amphibious hearing is accomplished. Here, we describe, for the first time, the ear anatomy in the living crocodile using photon-counting detector computed tomography (PCD-CT) and 3D rendering. We speculate on how crocodiles, despite their closed ear canals, can use tympanic hearing in water that also provides directional hearing. A Cuban crocodile (Crocodylus rhombifer) underwent photon-counting detector computed tomography (PCD-CT), under anesthesia and spontaneous respiration. In addition two seven-month-old C. rhombifer and a juvenile Morelet´s crocodile (Crocodylus moreletii) underwent micro-computed tomography (µCT) and endoscopy. One adult Cuviérs dwarf caiman (Paleosuchus palpebrosus) was micro-dissected and video-recorded. Aeration, earflap, and middle ear morphology were evaluated and compared after 3D modeling. PCD-CT and µCT with 3D rendering and segmentation demonstrated the anatomy of the external and middle ears with high resolution in both living and expired crocodiles. Based on the findings and comparative examinations, we suggest that the superior earflap, by modulating the meatal recess together with local bone conduction, may implement tympanic hearing in submerged crocodiles, including directional hearing.

Comparison of Total Intravenous Anesthesia with Inhaler Anesthesia in Children Intubated with Remifentanil without Muscle Relaxant

Objective: The effects of remifentanil and muscle relaxant-free intubation as well as total intravenous anesthesia and inhaled anesthesia for tonsillectomy and/or adenoidectomy in children were compared. Materials and Methods: The study was conducted on 80 patients who were to undergo tonsillectomy and/or adenoidectomy between December 2014 and June 2015. Patients were randomized and divided into two groups. In the total intravenous anaesthesia group, 2.5 mg/kg propofol and 2 mcg/kg remifentanil were administered as induction within 90 seconds. In this group, 3 mg/kg/h propofol and 0.5 mcg/kg/min remifentanil were used for maintenance of anesthesia. In the sevoflurane group, 8% sevoflurane and 2 mcg/kg remifentanil were administered as induction within 90 seconds. In this group, 2.5% sevoflurane, 50% nitrogen protoxide and 50% oxygen were used at 6 l/min for maintenance of anesthesia. Results: Peak heart rate and systolic arterial pressure were significantly higher in Group I. Diastolic arterial pressure was significantly higher in Group T at 1 and 2 minutes after intubation and in Group 2 at 10 minutes postoperatively. Mean arterial pressure was higher in Group T at 2 minutes after intubation. In addition, Wong-Baker pain scale and agitation score were significantly higher in Group I. Spontaneous respiration and extubation time were significantly shorter in Group I. There was no difference between the groups in terms of side effects. Conclusion: Group total intravenous anaesthesia was thought to be a better choice in children because it had less impact on postoperative pain, agitation and recovery.

Decreased diaphragm moving distance measured by ultrasound speckle tracking reflects poor prognosis in amyotrophic lateral sclerosis

ObjectiveDecreased cephalocaudal diaphragm movement may indicate respiratory dysfunction in amyotrophic lateral sclerosis (ALS). We aimed to evaluate diaphragm function in ALS using ultrasound speckle tracking, an image-analysis technology that follows similar pixel patterns. MethodsWe developed an offline application that tracks pixel patterns of recorded ultrasound video images using speckle-tracking methods. Ultrasonography of the diaphragm movement during spontaneous quiet respiration was performed on 19 ALS patients and 21 controls to measure the diaphragm moving distance (DMD) in the cephalocaudal direction during a single respiration. We compared respiratory function measures and analyzed the relationship between the clinical profiles and DMD. ResultsDMD was significantly lower in ALS patients than in the control group (0.6 ± 1.4 mm vs 2.2 ± 2.2 mm, p < 0.01) and positively correlated with phrenic nerve compound motor action potential amplitude (R = 0.63, p = 0.01). DMD was negatively correlated with the change in the ALS Functional Rating Scale-Revised scores per month after the exam (R = −0.61, p = 0.02), and those with a larger rate of decline had a significantly lower DMD (p = 0.03). ConclusionsDiaphragm ultrasound speckle tracking enabled the detection of diaphragm dysfunction in ALS. SignificanceDiaphragm ultrasound speckle tracking may be useful for predicting prognosis.

Tracheobronchoplasty for severe tracheobronchomalacia: a case-series of patients with acute and chronic critical comorbidities.

There is little data within the literature regarding tracheobronchoplasty (TBP) in the setting of the acute and chronically ill, morbidly obese, or ventilator dependent patients with Tracheobronchomalacia (TBM). Short- and long-term outcomes are studied. The series represents 12 TBM patients with American Society of Anesthesiologists (ASA) physical status scores of 3 to 5. Candidacy was based on bronchoscopic findings during spontaneous respirations with >90% collapse of the trachea and both mainstem bronchi. We used dynamic CT scan as an adjunct in those not mechanically ventilated. Our operative approach was a complete portal robotic approach for those outpatients (wheelchair dependent) and right thoracotomy for those who were already mechanically ventilated with 100% fraction of inspired oxygen (FiO2) with high pressure. Extracorporeal support was used in 2 patients. Patients who underwent robotic repair, were discharged without complications. Two patients who were critically ill and required extracorporeal support for their surgeries, were separated from extracorporeal membrane oxygenation (ECMO) on postoperative day 2. Three patients died at the follow-up. In 1 patient, the prolene mesh migrated into trachea and caused obstruction of the trachea and required removal with endobronchial techniques. The repair of TBM in patients with multiple comorbidities and with severe life-threatening problems in or outside the ICU, may have improvement due to the ability to wean from positive pressure ventilation. Surgical technique and the utilization of mesh support in TBP operations may need to be debated due to duration of the surgery in patients with severe comorbidities.

Brain Death Scintigraphy: Do Not Blow the Flow.

Brain death denotes the loss of function in both the cerebrum and the brain stem, leading to coma, absence of spontaneous respiration in the setting of adequate stimulus, and the cessation of all brain stem reflexes. Although spinal reflexes such as deep tendon, plantar flexion, and withdrawal reflexes may persist, recovery is not possible. The cessation of brain function qualifies as death because of its central role in coordinating vital bodily functions. Although brain death is largely determined by a clinical and neurologic examination, confounding variables may necessitate ancillary testing such as cerebral brain perfusion imaging.

Postoperative Sedation in Free Microvascular Tissue Transfer in Head and Neck Cancer: A Comparison of Fentanyl and Morphine

Background and Aims: Head-and-neck cancer surgeries with microvascular free flap reconstruction require endotracheal tube retention for 24–48 h postoperatively. Many regimes have been used for analgesia and sedation. The efficacy of fentanyl and morphine for post-operative analgosedation was compared by evaluating the need for additional sedatives to achieve optimum sedation scores. The secondary objective included analgesia, haemodynamic stability and a re-exploration rate. Methods: This was an open-label prospective study. A sample size of 36 was calculated in each group with α = 0.05 and a power of 80% to detect a 50% difference between the groups. Ninety adult patients were allocated to receive either fentanyl (Group F) or morphine (Group M). The Richmond agitation sedation score, Behavioural pain scale score, requirement of rescue hypnotic drug, pulse rate, systolic and diastolic blood pressures and re-explorations were recorded postoperatively. Haemodynamic parameters and sedation were analysed by two-way repeated measures of analysis variances. Pain scores were analysed using the Chi-square test. Results: When titrating to optimal sedation, in Group M, more patients needed intravenous midazolam boluses (n = 42, 93.3%) as compared to Group F (n = 33, 73.3%) (P = 0.011). More subjects in Group M required propofol infusion (n = 15, 33.3%) than in Group F (n = 4, 8.9%) (P = 0.009). Mean behavioural pain scores were significantly higher in Group M (score 1: P = 0.005 and score 2: P =0.001). The difference in the mean systolic, diastolic blood pressure, pulse rate, respiratory rate and re-exploration rate between the two groups was statistically insignificant. Conclusion: For analgesia-based sedation of spontaneously breathing intubated patients after head-and-neck cancer reconstructive surgeries, fentanyl is more effective than morphine in terms of ease of titration, sedation quality and analgesia. Both are safe for post-operative sedation regarding haemodynamic stability, tube retention and maintenance of spontaneous respiration.

A Neural Basis for Mutant ATAXIN-1 Induced Respiratory Dysfunction in Mouse Models of Spinocerebellar Ataxia Type 1.

Spinocerebellar ataxia type 1 (SCA1), a dominantly inherited neurodegenerative disorder caused by an expanded trinucleotide repeat in the ATAXIN-1 (ATXN1) gene, is characterized by motor dysfunction, cognitive impairment, and death from compromised swallowing and respiration. To delineate specific cell types that contribute to respiratory dysfunction, we utilized the floxed conditional knock-in f-ATXN1 146Q/2Q mouse. Whole body plethysmography during spontaneous respiration and respiratory challenge showed that f-ATXN1 146Q/2Q mice exhibit a spontaneous respiratory phenotype characterized by elevated respiratory frequency, volumes, and respiratory output. Consequently, the ability of f-ATXN1 146Q/2Q mice to increase ventilation during the challenge is impaired. To investigate the role of mutant ATXN1 expression in neural and skeletal muscle lineages, f-ATXN1 146Q/2Q mice were bred to Nestin-Cre and Acta1-Cre mice respectively. These analyses revealed that the abnormal spontaneous respiration in f-ATXN1 146Q/2Q mice involved two aspects: a behavioral phenotype in which SCA1 mice exhibit increased motor activity during respiratory testing and functional dysregulation of central respiratory control centers. Both aspects of spontaneous respiration were partially ameliorated by removing mutant ATXN1 from neural, but not skeletal muscle, cell lineages.

The Flexible Rhino-Laryngoscope for Awake Nasotracheal Intubation.

Difficulties or failures in securing the airway still occur and can lead to permanent disabilities and mortality. Patients with head and neck pathologies obstructing airway access are at risk of airway management failure once they lose spontaneous respiration. Awake flexible scope intubation is considered the gold standard for controlling the airway in such patients. Following a feasibility trial involving 25 patients with challenging airways, this article presents a step-by-step protocol for awake nasotracheal intubation using a flexible video rhino-laryngoscope, which is significantly shorter than conventional intubating flexible scopes. The flexible video laryngoscope only exceeds the intubating tube length by a few centimeters, allowing the tube to closely follow the flexible scope during the procedure. Once the scope reaches the pharynx, it can be easily manipulated with one hand, enabling the operator to focus on the safe advancement of the scope-intubating tube assembly through the glottis. Based on previous results and experience gained, this article highlights the potential benefits of the technique: the opportunity for a minimally invasive "quick look" preoperatively to establish a final management plan, a more convenient and safer tool for navigating distorted anatomy with a lower chance of intubating tube impingement and airway injury, and a fast and smooth procedure resulting in improved patient satisfaction.

Thoracoscopic wedge resection of the upper lobe of the left lung achieved by a new approach of laryngeal mask general anesthesia with preservation of spontaneous breathing: A case report.

General laryngeal mask anesthesia with the preservation of spontaneous breathing has accelerated the advancement of the enhanced recovery after surgery concept in thoracoscopic surgery. However, the need for increased doses of anesthetic drugs to reduce laryngeal mask airway (LMA) stimulation poses challenges due to the increased risk of hypotension, respiratory depression, susceptibility to hypoxemia, and carbon dioxide retention, particularly in the lateral position. During the perioperative period, reducing the dose of anesthetic drugs while simultaneously improving LMA tolerance and preventing circulatory and respiratory depression poses a challenge. The patient was diagnosed with a nodule in the upper lobe of the left lung. In this case, we chose remimazolam sedation, which mildly inhibits circulatory respiration, and used mucosal surface anesthesia in the pharynx. This approach improved the patient's tolerance to LMA, reduced the dose of anesthetic drugs, and facilitated the successful thoracoscopic wedge resection of the upper lobe of the left lung with preservation of spontaneous respiration. During 2 weeks follow-up, the patient recovered satisfactorily and did not report any discomfort. We used pharyngeal mucosal surface anesthesia and thoracic paravertebral nerve block in combination with remimazolam sedation to provide precise analgesia, moderate sedation, and successful LMA general anesthesia with preservation of spontaneous respiration in patients undergoing thoracoscopic pulmonary wedge resection.

The degree of respiratory depression according to the effect-site concentration in remimazolam target-controlled infusion: A randomised controlled trial.

Remimazolam is not only associated with a lower incidence of respiratory depression than propofol but also in itself has the risk of respiratory depression. We investigated respiratory depression following remimazolam infusion, targeting different effect-site concentrations using target-controlled infusion. A prospective, double-blind, randomised controlled study. Tertiary hospital, Suwon, South Korea, from April 2022 to November 2022. One hundred and seven patients scheduled for general anaesthesia were randomised into three groups targeting remimazolam effect-site concentrations of 500 (RMZ-500) ( n = 36), 1000 (RMZ-1000) ( n = 35) and 1500 ng ml -1 (RMZ-1500) ( n = 36). Remimazolam was solely infused for 10 min according to target effect-site concentrations. According to the degree of SpO 2 decrease, oxygen desaturations were managed with the following respiratory supports: jaw-thrust for SpO 2 less than 97%, 100% oxygen delivery for SpO 2 less than 93% and assisted ventilation for SpO 2 less than 90%. The incidence of each respiratory support, along with respiratory variables (at baseline, 5 min and 10 min after remimazolam infusion) and loss of consciousness were observed for 10 min after remimazolam target-controlled infusion. Both RMZ-1000 and RMZ-1500 required more frequent respiratory support than RMZ-500 (both P < 0.001), with nearly identical frequencies between RMZ-1000 and RMZ-1500. In terms of respiratory support, the incidence of assisted ventilation was significantly lower in RMZ-500 (2.8%) than RMZ-1000 (48.6%) and RMZ-1500 (50%) ( P < 0.001). RMZ-1000 and RMZ-1500 achieved loss of consciousness in all patients; RMZ-500 only achieved loss of consciousness in 86.1% of patients ( P = 0.010). In patients who maintained spontaneous respiration, tidal volume decreased by 41 to 48% and respiratory rate increased by 118 to 158% at 5 and 10 min, significantly compared to baseline in all groups ( P < 0.001). Remimazolam infusion, like that of other benzodiazepines, led to respiratory depression, which was more prominent at higher target effect-site concentrations. Therefore, appropriate countermeasures should be developed to prevent oxygen desaturation. CRIS ( https://cris.nih.go.kr ), identifier: KCT0006952.

Videolaryngoscope as a rescue to fiber-optic intubation in a pediatric patient

We report a case of 6-year-old child posted for excision of a large fragile tumor over the face compromising mask application for ventilation. Fiber-optic intubation with preserved spontaneous respiration was attempted. However, unfortunately, the fiber-optic endoscope stopped functioning, before entering the glottic opening. We assisted the endoscope with a videolaryngoscope to achieve successful intubation without disturbing the mass. This combination technique can be used as a rescue strategy if the fiber-optic endoscope malfunctions.

Respiratory internal kinematics of the tongue base and soft palate in obese minipigs with obstructive sleep apnea.

It is largely unknown how the tongue base and soft palate deform to alter the configuration of the oropharyngeal airway during respiration. This study is to address this important gap. After live sleep monitoring of five Yucatan and two Panepinto minipigs to verify obstructive sleep apnea (OSA), eight and four ultrasonic crystals were implanted into the tongue base and soft palate to circumscribe a cubic and square region, respectively. The 3D and 2D deformational changes of the circumscribed regions were measured simultaneously with electromyographic activity of the oropharyngeal muscles during spontaneous respiration under sedated sleep. The results indicated that both obese Yucatan and Panepinto minipigs presented spontaneous OSA, but not in threenonobese Yucatan minipigs. During inspiration, the tongue base showed elongation in both dorsal and ventral regions but thinning and thickening in the anterior and posterior regions, respectively. The widths showed opposite directions, widening in the dorsal but narrowing in the ventral regions. The soft palate expanded in both length and width. Compared to normal controls, obese/OSA ones showed similar directions of deformational changes, but the magnitude of change was two times larger in the tongue base and soft palate, and obese/OSA Panepinto minipigs presented 10 times larger changes in all dimensions of both the tongue base and the soft palate. The distance changes between the dorsal surface of tongue base and soft palate during inspiration increased in normal but decreased in obese OSA minipigs.

Effects of Dexmedetomidine on the Recovery Quality of Donors Undergoing Pure Laparoscopic Donor Hepatectomy

To investigate the effects of intraoperative intravenous administration of dexmedetomidine (DEX) on the recovery quality of donors undergoing pure laparoscopic donor hepatectomy. A total of 56 liver donors who were going to undergo scheduled pure laparoscopic donor hepatectomy were enrolled and randomly assigned to two groups, a DEX group ( n=28) and a control group ( n=28). Donors in the DEX group received DEX infusion at a dose of 1 μg/kg over 15 minutes through a continuous pump, which was followed by DEX at 0.4 μg/(kg·h) until the disconnection of the portal branch. Donors in the control group were given an equal volume of 0.9% normal saline at the same infusion rate and over the same period of time as those of the dex infusion in the DEX group. The primary outcome was the incidence of emergence agitation (EA). The Aono's Four-point Scale (AFPS) score was used to assess EA. The secondary observation indicators included intraoperative anesthesia and surgery conditions, spontaneous respiration recovery time, recovery time, extubation time, scores for the Ramsay Sedation Scale, the incidence of chills, numeric rating scale (NRS) score for pain, and blood pressure and heart rate after extubation. The incidence of EA was 10.7% and 39.3% in the DEX group and the control group, respectively, and the incidence of EA was significantly lower in the DEX group than that in the control group ( P=0.014). The APFS scores after extubation in the DEX group were lower than those in the control group (1 [1, 1] vs. 2 [1, 3], P=0.005). Compared to the control group, the dosages of intraoperative propofol and remifentanil were significantly reduced in the DEX group ( P<0.05). During the recovery period, the number of donors requiring additional boluses of analgesia, the blood pressure, and the heart rate were all lower in the DEX group than those in the control group ( P<0.05). No significant differences between the two groups were observed in the spontaneous respiration recovery time, recovery time, extubation time, the incidence of chills, NRS score, scores for the Ramsay Sedation Scale, and the length-of-stay in postanesthesia care unit (PACU) ( P>0.05). DEX can reduce the incidence of EA after pure laparoscopic donor hepatectomy and improve the quality of recovery without prolonging postoperative recovery time or extubation time.

Analysis of the application effect and safety of transnasal humidified rapid insufflation ventilatory exchange technique in hysteroscopic diagnostic and therapeutic surgery

Objective: To investigate the effect and safety of transnasal humidified rapid insufflation ventilatory exchange (THRIVE) technique in hysteroscopic diagnostic and therapeutic surgery. Methods: This study was a randomized controlled trial. A total of 100 female patients undergoing hysteroscopy surgery at Beijing Tongren Hospital from September to December 2023 were selected and randomly divided into two groups by the random number table method: the THRIVE group and the mask oxygen group, with 50 patients in each group. Patients in both groups were given total intravenous anesthesia with propofol combined with remifentanil and preserved spontaneous respiration. The THRIVE group was given oxygen by the THRIVE device with an oxygen flow rate of 50 L/min, while the mask oxygen group was given oxygen by the mask with an oxygen flow rate of 5 L/min; the oxygen concentration of both groups was set at 100%. The general condition of the patients, vital signs during the operation, the amount of anesthesia drugs used and the operation time were recorded. The primary observation index was the incidence of hypoxic events in the two groups; the secondary observation indexes were the incidence and time of intraoperative apnea as well as the corresponding oxygenation interventions and the incidence of non-hypoxic adverse events. Results: The age of the THRIVE group was (42±14) years, and the age of the mask oxygen group was (43±15) years. The duration of surgery in the THRIVE group was (15.9±3.4) min, which was statistically lower than that of the mask oxygen group (16.3±4.5) min (P=0.041), and there were no differences observed in the duration of awakening time and anesthesia time (both P>0.05). There was no significant difference in the dosage of propofol, remifentanil, and intraoperative vasoactive drugs between the two groups (all P>0.05). The SpO2 of the patients in the THRIVE group at the end of the operation was (99.7±1.1) %, which was higher than that of the mask-oxygen group (99.1±1.1) % (P<0.05). There was no difference in SpO2 of the two groups at the other time points (all P>0.05). There were no differences in HR and MAP of two group patients at each time point (all P>0.05). The incidence of hypoxic events in the THRIVE group was 12.0% (6/50), which was lower than that of 28.0% (14/50) in the mask oxygen group (P=0.045). The difference in the incidence and duration of apnea between the two groups was not statistically significant (all P>0.05). There were no cases of temporary need for laryngeal mask or tracheal intubation during surgery in both groups. There was no statistically significant difference in the incidence of intraoperative body movement, dizziness, nausea and vomiting between the two groups (all P>0.05), and no cardiac, cerebral, renal or other important organ insufficiency occurred in the two weeks after surgery. Conclusion: THRIVE technology can provide effective oxygenation for patients undergoing hysteroscopic diagnosis and treatment, maintain patients' circulatory stability, and improve the safety and efficiency of surgery.

Tracheostomy - A Comparative Study of Decannulation with Gradual Blocking of the Tube vs. Reduction of the Size of Tube - A Prospective Study.

Tracheostomy is one of the most common procedures done in intensive care unit (ICU) patients. Decannulation is the weaning off from tracheostomy to maintain spontaneous respiration and/or airway protection. However, this step needs a near perfect coordination of brain, swallowing, coughing, phonation, and respiratory muscles. However, despite its perceived importance, there is no universally accepted protocol for this vital transition. In this systematic review of decannulation we focus attention to this important aspect of tracheostomy care. To compare the two methods of decannulation, with gradual blocking of the tube and reducing the size of the tube and also study and compare the incidental complications associated with both methods. This longitudinal, open label, randomized, observational study of 50 patients who were tracheostomized for more than 7 days was carried out in a tertiary health care Centre in central India. Over the course of 2 years demographic data, clinical information was collected and patients divided into 2 groups according to the method of decannulation done by a simple randomization method. The outcomes and the complications associated with the two techniques in the study groups were also be noted down and then compared. Maximum number of patients in both the study groups were males (56% in group with tube blocking, and 52% in group with tube size reduction). 48% cases in group with tube blocking, and 60% in group with tube size reduction were noted to be between 51 and 70 years' age group. The mean duration between tracheostomy and decannulation in group with tube blocking was 16.63 + 8.44 days, and while it was 16.71 + 8.79 days in group with tube size reduction. 36% patients in group with tube blocking had tracheostomy tube number 7.5, while 32% had tube number 8. 36% in group with tube size reduction had tube number 7.5 while 32% had tube size 7. 4 patients in group with tube blocking, and 3 patients in group with tube size reduction required reinsertion of tube. 40% patients in group with tube blocking, and 44% in group with tube size reduction underwent tracheostomy following prolonged intubation. 4 patients in group with tube blocking, and 3 patients in group with tube size reduction required reinsertion of tube. 1 patient in group with tube blocking had trachea-esophageal fistula as post decannulation complication. 1 patient each in group with tube size reduction had granule formation over stoma and tracheal stenosis as complications. The two decannulation methods, viz., gradual blocking of tube and reduction of tube size, showed comparable outcomes in terms of tube reinsertion rate, mechanical ventilation rate after decannulation, successful decannulation, and complications.

Comparison of Response First Technique with Reversal First Technique for Quality of Extubation in Patients Undergoing Transsphenoidal Pituitary Surgery: A Randomized Clinical Trial.

Early and smooth extubation following anesthesia is an important concern in patients undergoing transsphenoidal pituitary surgery to permit early neurological evaluation and prevent complications. The aim was to compare the RESPONSE FIRST and REVERSAL FIRST techniques for quality of extubation (QOE) in patients undergoing endoscopic transsphenoidal pituitary surgery. Fifty-six patients aged 18-60 years, with American Society of Anesthesiologists Physical Statuses I-II, and undergoing transsphenoidal surgery for pituitary tumors were randomized into either the RESPONSE FIRST group, in which neuromuscular reversal was given following the patient's response to oral commands, or the REVERSAL FIRST group, in which reversal of neuromuscular blockade (NMB) was given at the return of spontaneous respiration. QOE was the primary outcome. Hemodynamic response, jugular venous oxygen saturation (SjVO2), time to extubation, and awareness during emergence were assessed as secondary outcomes. The QOE in the RESPONSE FIRST group was significantly better than the REVERSAL FIRST group (mean (interquartile range (IQR)), 18 (17-19) vs 14 (12-14.75), P < 0.001). Heart rate (HR) and mean arterial pressure (MAP) were better in the RESPONSE FIRST group when compared to the REVERSAL FIRST group at the time of extubation, at 5 minutes, and 15 minutes following extubation (P < 0.05). SjVO2values were higher in the REVERSAL FIRST group as compared to the RESPONSE FIRST group during extubation and at 5 minutes after extubation (P < 0.01). There was no significant difference in the time to extubation between the groups (P = 0.73). The RESPONSE FIRST technique is associated with better QOE and preservation of systemic and cerebral hemodynamics during extubation in patients undergoing transsphenoidal pituitary surgery when compared to the REVERSAL FIRST technique.

Liquid respiratory desaturation. The first experience of application on large biological objects

Introduction. This article is a continuation of the publication of the experimental studies results of prevention of acute decompression sickness (aDCS) in laboratory animals by the method of liquid respiratory desaturation (LRDS). LRDS is a method of preventing decompression disorders by the excretion of metabolically indifferent gases (in particular nitrogen) from the body during spontaneous respiration with liquid or artificial liquid lung ventilation (ALLV), by dissolved gas concentration gradient "from tissues to respiratory fluid". The method allows to provide rapid desaturation of the body from metabolically indifferent gases in the process of liquid respiration before and/or during decompression, thereby creating conditions for application of ultra-fast decompression profiles without the risk of decompression disorders.&#x0D; The aim of the study was to confirm the possibility of LRDS being a method of DCS prevention on large laboratory animals (minipigs).&#x0D; Materials and methods. The studies were performed on Wiessenau minipigs (n=8) — male and female, aged 4–5.5 months and weighing 7.1–11.2 kg. Animals of the control (n=4) and experimental (n=4) groups were subjected by compression by keeping in an air environment under high pressure (absolute 0.5 MPa for 60 minutes) to saturate tissues with indifferent gas (nitrogen). After compression experimental group was exposed to 30-minute ALLV with a liquid (perfluorodecalin) saturated with an oxygen under normobaric conditions. Air environment pressure during procedure of artificial lung ventilation was kept at 0.5 MPa. Decompression of the control and experimental groups was carried out in non-stop manner for 80 and 40 seconds respectively. The investigation of severity of clinical manifestations of DCS (changes in hemodynamic and respiratory parameters) including ultrasonic examination of gas bubbles in the heart and large vessels of the liver and as well as survival of animals in groups and pathoanatomical changes was performed.&#x0D; Results of the study. Clinical manifestations, ultrasonic scanning of the heart and venous vessels of the liver, as well as morphological examination data indicated the development of severe acute post-decompression disorders (PDD) in animals of the control group, which caused deaths in 100% of cases. Meanwhile all animals in experimental group survived and their state was stable. According to ultrasonic examination, the presence of small number of gas bubbles in the right-side heart chambers and liver's venous vessels being noted, but they disappeared after several hours. Deviations of the respiration's parameters function from background values (shortness of breath of a mixed type with the participation of auxiliary muscles, etc.) observed from the 2nd to the 4th day after ALLV, as well as compensatory reactions from the cardiovascular system (heart rate variability and instability of hemodynamic parameters) were caused by ALLV.&#x0D; Conclusions. Compressed air exposure 0.5 MPa for 60 minutes followed by 80 seconds of non-stop decompression allows to provoke the severe acute PDD minipigs model, manifested by pronounced intravascular gas formation, the development of acute respiratory and cardiovascular insufficiency causing the development of adverse outcomes.&#x0D; The ultrasound method of visual assessment of intravascular gas formation severity, adapted for minipigs, together with the dynamics of changes in the indicators of respiratory and cardiovascular systems makes possible to assess not only state of animal under anesthesia, but also the effectiveness of PDD prevention measures.&#x0D; The usage of ALLV with PFC liquid completely saturated with 100% oxygen under normobaric conditions makes possible partial removal of indifferent gas (nitrogen) dissolved in tissues of experimental animals during exposition in a compressed air environment before decompression and thereby carry out the prevention of DCS by LRDS method. It makes possible to implement successfully ultra-fast decompression profiles, incompatible with life in the control group.&#x0D; The state of animals from experimental group after LRDS is characterized by lung impairment caused by ALLV in hyperbaric conditions accompanied by temporary changes of external respiration function and compensatory reactions of cardiovascular system, observed during first 4 days.&#x0D; Ethics. The study was conducted in accordance with the ethical principles of the Declaration of Helsinki. The Clinical Study Protocol was approved by local Ethics Committee of The Federal State Budgetary Scientific Institution «Izmerov Research Institute of Occupational Health».