Influence of flow rate and different size of suction cannulas on splatter contamination in dentistry: results of an exploratory study with a high-volume evacuation system.

OBJECTIVES: SOPs recommend high-volume evacuation (HVE) for aerosol-generating procedures (AGPs) in dentistry. Therefore, in the exploratory study, the area of splatter contamination (SCON in %) generated by high-speed tooth preparation (HSP) and air-polishing (APD) was measured when different suction cannulas of 6 mm diameter (saliva ejector (SAE)), 11 mm (HC11), or 16 mm (HC16) were utilized versus no-suction (NS). MATERIALS AND METHODS: Eighty tests were performed in a closed darkened room to measure SCON (1m circular around the manikin head (3.14 m2) via plan metrically assessment through fluorescence technique. HSP (handpiece, turbine (Kavo, Germany)) or APD (LM-ProPowerTM (Finland), Airflow®-Prophylaxis-Master (Switzerland)) for 6 min plus 5 s post-treatment were performed either without suction or with low-flow (150 l/min for SAE) or high-flow rate (250 l/min/350 l/min for HC11/HC16) suction. All tests were two-tailed (p≤0.05, Bonferroni corrected for multi-testing). RESULTS: Irrespective the AGP, SCON was higher for NS (median [25th; 75th percentiles]: 3.4% [2.6; 5.4]) versus high-flow suction (1.9% [1.5; 2.5]) (p=0.002). Low-flow suction (3.5% [2.6; 4.3]) versus NS resulted in slightly lower but not statistically significantly lower SCON (p=1.000) and was less effective than high-flow suction (p=0.003). Lowest contamination values were found with HC16 (1.9% [1.5; 2.5]; p≤0.002), whereat no significant differences were found for HC11 (2.4% [1.7; 3.1]) compared to SAE (p=0.385) or NS (p=0.316). CONCLUSIONS: Within study's limitations, the lowest splatter contamination values resulted when HC16 were utilized by a high-flow rate of ≥250 l/min. CLINICAL RELEVANCE: It is strongly recommended to utilize an HVE with suction cannulas of 16mm diameter for a high-flow rate during all AGPs and afterwards also to disinfect all surface of patients or operators contacted.

Combination of a negative pressure suction device and endoscope can accurately locate the bleeding site of refractory epistaxis.

BACKGROUND: Selective endoscopic coagulation of a nasal bleeding vessel is an effective means of treating epistaxis. Precisely locating the bleeding site(s) is critical. OBJECTIVE: To investigate the utility of combining a negative pressure suction device and endoscope in locating bleeding sites of refractory epistaxis. METHODS: A total of 116 patients with refractory epistaxis, who underwent systematic endoscopic exploration under local anesthesia in the absence of identifiable sites of bleeding were randomizely divided into two groups via negative pressure group (NPG) and control group (CG): The negative pressure suction device combined with an endoscope was used to re-explore the epistaxis. Nasal bleeding was induced using this method to help the operator locate the site of epistaxis accurately; the bleeding was then stopped using electrocoagulation with the suction electrode. The CG was treated with endoscopic re-exploration and selective tamponade. RESULTS: Compared with the CG, there were statistically significant differences in length of hospital stay, rebleeding, and postoperative pain and complications (all p < .05). CONCLUSION AND SIGNIFICANCE: Combining a negative pressure suction device and endoscope was a safe and effective technique for accurately locating bleeding sites in patients with refractory epistaxis.

Tracheal suction at birth in non-vigorous neonates born through meconium-stained amniotic fluid.

BACKGROUND: Neonates born through meconium-stained amniotic fluid (MSAF) are at risk of developing meconium aspiration syndrome (MAS). Neonates who are non-vigorous due to intrapartum asphyxia are at higher risk of developing MAS. Clearance of meconium from the airways below the vocal cords by tracheal suction before initiating other steps of resuscitation may reduce the risk of development of MAS. However, conducting tracheal suction may not only be ineffective, it may also delay effective resuscitation, thus prolonging and worsening the hypoxic-ischaemic insult.  OBJECTIVES: To evaluate the efficacy of tracheal suctioning at birth in preventing meconium aspiration syndrome and other complications among non-vigorous neonates born through meconium-stained amniotic fluid. SEARCH METHODS: We used the standard search strategy of Cochrane Neonatal to search Cochrane Central Register of Controlled Trials (CENTRAL 2020, Issue 11) in the Cochrane Library; Ovid MEDLINE(R) and Epub Ahead of Print, In-Process & Other Non-Indexed Citations, Daily and Versions(R) (1946 to 25 November 2020) for randomised controlled trials (RCTs) and quasi-randomised trials. We also searched clinical trials databases and the reference lists of retrieved articles for RCTs and quasi-randomised trials (up to November 2020). SELECTION CRITERIA: We included studies enrolling non-vigorous neonates born through MSAF, if the intervention being tested included tracheal suction at the time of birth with an intent to clear the trachea of meconium before regular breathing efforts began. Tracheal suction could be performed with an endotracheal tube or a wide-gauge suction catheter. Neonates in the control group should have been resuscitated at birth with no effort made to clear the trachea of meconium. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trial quality and extracted data, consulting with a third review author about any disagreements. We used standard Cochrane methodological procedures, including assessment of risk of bias for all studies. Our primary outcomes were: MAS; all-cause neonatal mortality; and incidence of hypoxic-ischaemic encephalopathy (HIE). Secondary outcomes included: need for mechanical ventilation; incidence of pulmonary air leaks; culture-positive sepsis; and persistent pulmonary hypertension. We used the GRADE approach to assess the certainty of evidence. MAIN RESULTS: We included four studies (enrolling 581 neonates) in the review. All four studies were conducted in tertiary care hospitals in India. Three of the four studies included neonates born at and beyond term gestation, whereas one included neonates born at and beyond 34 weeks of gestation. Due to the nature of the intervention, it was not possible to blind the healthcare personnel conducting the intervention. Tracheal suction compared to no suction in non-vigorous neonates born through MSAF In non-vigorous infants, no differences were noted in the risks of MAS (RR 1.00, 95% CI 0.80 to 1.25; RD 0.00, 95% CI -0.07 to 0.08; 4 studies, 581 neonates) or all-cause neonatal mortality (RR 1.24, 95% CI 0.76 to 2.02; RD 0.02, 95% CI -0.03 to 0.07; 4 studies, 575 neonates) with or without tracheal suctioning. No differences were reported in the risk of any severity HIE (RR 1.05, 95% CI 0.68 to 1.63; 1 study, 175 neonates) or moderate to severe HIE (RR 0.68, 95% CI 0.43 to 1.09; 1 study, 152 neonates) among non-vigorous neonates born through MSAF. We are also uncertain as to the effect of tracheal suction on other outcomes such as incidence of mechanical ventilation (RR 0.99, 95% CI 0.68 to 1.44; RD 0.00, 95% CI -0.06 to 0.06; 4 studies, 581 neonates), pulmonary air leaks (RR 1.22, 95% CI 0.38 to 3.93; RD 0.00, 95% CI -0.02 to 0.03; 3 studies, 449 neonates), persistent pulmonary hypertension (RR 1.29, 95% CI 0.60 to 2.77; RD 0.02, 95% CI -0.03 to 0.06; 3 studies, 406 neonates) and culture-positive sepsis (RR 1.32, 95% CI 0.48 to 3.57; RD 0.01, 95% CI -0.03 to 0.05; 3 studies, 406 neonates). All reported outcomes were judged as providing very low certainty evidence. AUTHORS' CONCLUSIONS: We are uncertain about the effect of tracheal suction on the incidence of MAS and its complications among non-vigorous neonates born through MSAF. One study awaits classification and could not be included in the review. More research from well-conducted large trials is needed to conclusively answer the review question.

Double-sheath vacuum suction versus vacuum-assisted sheath minimally invasive percutaneous nephrolithotomy for management of large renal stones: single-center experience.

PURPOSE: To compare double-sheath vacuum suction minimally invasive percutaneous nephrolithotomy (DS-mini-PCNL) with vacuum-assisted mini-PCNL (VS-mini-PCNL) and to better define the potential benefits of DS-mini-PCNL. METHODS: Between July 2019 and May 2020, 117 patients with large radiopaque renal stones underwent mini-PCNL. Of these, 63 underwent DS-mini-PCNL and 54 underwent VS-mini-PCNL. For VS-mini-PCNL, a F20 Y-shaped sheath was used and the oblique arm of the sheath was connected to the vacuum suction. For DS-mini-PCNL, the oblique arm of a F20 Y-shaped sheath (the outer sheath) and a F16 Y-shaped sheath (the inner sheath) was connected to the perfusion inflow and the vacuum suction, respectively. A 550-µm holmium-YAG laser was used for stone fragmentation. RESULTS: Compared with VS-mini-PCNL group, DS-mini-PCNL group had significantly shorter operative time (35.78 ± 7.77 min vs. 44.56 ± 13.19 min; P = 0.000) and significantly lower fever rate (1.6% vs. 11.1%; P = 0.048). It was not significantly different between the two groups despite the higher initial stone-free rate seen for DS-mini-PCNL group relative to VS-mini-PCNL group (87.7% vs. 81.5%, P = 0.346). Auxiliary procedure rates were 4.8% (three patients) in DS-mini-PCNL group and 16.7% (nine patients) in VS-mini-PCNL group, with a significant difference (P = 0.034). The difference in the final stone-free rate between the two groups was rendered insignificant (93.8% vs. 89.1%, P = 0.510). CONCLUSIONS: DS-mini-PCNL is a safe and effective modality for large renal stones, which could increase the efficiency of stone extraction and decrease infectious complications compared with VS-mini-PCNL.

Effectiveness of paranasal air suction on acute migraine using portable air sucker - a randomized, double blind study.

BACKGROUND: Migraine is a primary headache disorder and is the most common disabling primary headache disorder that occurs in children and adolescents. A recent study showed that paranasal air suction can provide relief to migraine headache. However, in order to get the maximum benefit out of it, an easy to use effective air sucker should be available. Aiming to fulfil the above requirement, a randomized, double blind control clinical trial was conducted to investigate the efficacy of a recently developed low-pressure portable air sucker. METHODS: Eighty-six Sri Lankan school children of age 16-19 years with migraine were enrolled for the study. They were randomly allocated into two groups, and one group was subjected to six intermittent ten-second paranasal air suctions using the portable air sucker for 120 s. The other group was subjected to placebo air suction (no paranasal air suction). The effect of suction using portable air sucker was the primary objective but side of headache, type of headache, and gender were also studied as source variables. The primary response studied was severity of headache. In addition, left and right supraorbital tenderness, photophobia, phonophobia, numbness over the face and scalp, nausea and generalized tiredness/weakness of the body were studied. The measurements on all those variables were made before and after suction, and the statistical analysis was performed based on before and after differences. As a follow-up, patients were monitored for 24-h period. RESULTS: There was a significant reduction in the severity of headache pain (OR = 25.98, P < 0.0001), which was the primary outcome variable, and other migraine symptoms studied, tenderness (left) (OR = 289.69, P < 0.0001), tenderness (right) (OR > 267.17, P < 0.0001), photophobia (OR = 2115.6, P < 0.0001), phonophobia (OR > 12.62, P < 0.0001) nausea (OR > 515.59, P < 0.0001) and weakness (OR = 549.06, P < 0.0001) except for numbness (OR = 0.747, P = 0.67) in the treatment group compared to the control group 2 min after the suction. These symptoms did not recur within 24-h period and there were no significant side effects recorded during the 24-h observation period. CONCLUSION: This pilot study showed that low-pressure portable air sucker is effective in paranasal air suction, and suction for 120 s using the sucker can provide an immediate relief which can last for more than 24-h period without any side effects. TRAIL REGISTRATION: Clinical Trial Government Identification Number - 1548/2016. Ethical Clearance Granted Institute - Medical Research Institute, Colombo, Sri Lanka (No 38/2016). Sri Lanka Clinical Trial Registration No: SLCTR/2017/018 . Date of registration = 29/ 06/2017. Approval Granting Organization to use the device in the clinical trial- National Medicines Regulatory Authority Sri Lanka (16 Jan 2018), The device won award at Geneva international inventers exhibition in 2016 and President award in 2018 in Sri Lanka. It is a patented device in Sri Lanka and patent number was SLKP/1/18295. All methods were carried out in accordance with CONSORT 2010 guidelines.

Aerosol and Droplet Risk of Common Otolaryngology Clinic Procedures.

OBJECTIVES: Define aerosol and droplet risks associated with routine otolaryngology clinic procedures during the COVID-19 era. METHODS: Clinical procedures were simulated in cadaveric heads whose oral and nasal cavities were coated with fluorescent tracer (vitamin B2) and breathing was manually simulated through retrograde intubation. A cascade impactor placed adjacent to the nares collected generated particles with aerodynamic diameters ≤14.1 µm. The 3D printed models and syringes were used to simulate middle and external ear suctioning as well as open suctioning, respectively. Provider's personal protective equipment (PPE) and procedural field contamination were also recorded for all trials using vitamin B2 fluorescent tracer. RESULTS: The positive controls of nebulized vitamin B2 produced aerosol particles ≤3.30 µm and endonasal drilling of a 3D model generated particles ≤14.1 µm. As compared with positive controls, aerosols and small droplets with aerodynamic diameter ≤14.1 µm were not detected during rigid nasal endoscopy, flexible fiberoptic laryngoscopy, and rigid nasal suction of cadavers with simulated breathing. There was minimal to no field contamination in all 3 scenarios. Middle and external ear suctioning and open container suctioning did not result in any detectable droplet contamination. The clinic suction unit contained all fluorescent material without surrounding environmental contamination. CONCLUSION: While patients' coughing and sneezing may create a baseline risk for providers, this study demonstrates that nasal endoscopy, flexible laryngoscopy, and suctioning inherently do not pose an additional risk in terms of aerosol and small droplet generation. An overarching generalization cannot be made about endoscopy or suctioning being an aerosol generating procedure. LEVEL OF EVIDENCE: 3.

Effects of disusing closed suction drainage in simultaneous bilateral total hip arthroplasty: A retrospective cohort study.

PURPOSE: Increased blood loss remains a major drawback of simultaneous bilateral total hip arthroplasty (SBTHA). We examined the effects of disusing closed suction drainage (CSD) on postoperative blood loss and transfusion requirement in cementless SBTHA. METHODS: A retrospective cohort study was conducted with a consecutive series of cementless SBTHAs performed by a single surgeon between January 2014 and March 2017. The surgeon routinely used CSD until May 2015 and refrained from CSD in all primary THAs thereafter. This study included SBTHAs with intravenous administration of tranexamic acid (TXA). Postoperative hemoglobin drop, blood loss, transfusion rate, pain scores, complication rates, and implant survivorships were compared between the groups of SBTHA with and without CSD. The minimum follow-up duration was 1 year. RESULTS: Among the 110 patients (220 hips), 46 (92 hips) and 64 (128 hips) underwent SBTHA with and without CSD, respectively. Maximum hemoglobin drop (mean, 4.8 vs. 3.9 g/dL; P = 0.001), calculated blood loss (mean, 1530 vs. 1190 mL; P<0.001), transfusion rate (45.7% vs. 21.9%; P = 0.008), and length of hospital stay (mean, 6.6 vs. 5.8 days; P = 0.004) were significantly lower in patients without CSD. There were no significant differences in postoperative pain scales and wound complication rates. The mean Harris Hip scores at final follow-up (92.5 vs. 92.1; P = 0.775) and implant survivorships with an end-point of any revision at 4 years (98.9% vs. 98.4%; log-rank, P = 0.766) were similar between groups. CONCLUSIONS: Disusing CSD significantly reduced postoperative blood loss and transfusion requirement without increasing postoperative pain and surgical wound complications in cementless SBTHA with concurrent administration of intravenous TXA.

Easy Suction Technique During Robotic-Assisted Thoracoscopic Lobectomy.

In robotic-assisted thoracoscopic surgery, surgeons may encounter bleeding issues requiring compression techniques and time to achieve hemostasis. During this time, surgeons cannot use the robot arm and may require an assistant to perform suction, thus increasing the cost of the procedure. This report describes an alternative suction device, Dobon (Senko Medical Instrument Mfg, Tokyo, Japan), which is usually used for pediatric cardiac surgery, for use in robotic-assisted thoracoscopic surgery. The report presents the technique for using this device and comments on the advantages, including decreased cost and an improved surgical visual field.

Factors Affecting the Efficacy of Suction Curettage Using an Arthroscopic Shaver for Bromhidrosis.

BACKGROUND: Suction-curettage using an arthroscopic shaver is the most effective surgical treatment for bromhidrosis; however, information regarding the procedure is limited. This study investigated the factors that affect the efficacy of suction-curettage. PATIENTS AND METHODS: We retrospectively evaluated data for 215 patients (430 axillae) with bromhidrosis treated with suction-curettage using an arthroscopic shaver between 2011 and 2019. RESULTS: Excellent or good efficacy with improved malodor was achieved in 418 axillae (97.21%). Secondary suction-curettage was performed for 11 (2.56%), with excellent results. Efficacy and need for secondary suction-curettage were not associated with age, sex, shaving time, and tumescent infiltration use. Complications were observed in 52 (12.09%) axillae, including hematoma or seroma, epidermis decortication, skin necrosis, and infections; 10 (2.33%) required local debridement for wounds. Complications showed a significant difference with respect to age (p < .001). Pain scores on postoperative Day 2 were significantly lower for patients treated using tumescent infiltration than those for the others (1.65 ± 0.84 vs 4.57 ± 1.16; p < .001). CONCLUSION: The results suggest that 7 to 15 minutes of suction curettage using an arthroscopic shaver is sufficient to achieve good efficacy for bromhidrosis with few complications. Older age was a risk factor for complications, and tumescent infiltration use achieved good postoperative pain control. LEVELS OF EVIDENCE: II.

Effect of Active Aspiration and Sheath Location on Intrapelvic Pressure During Miniaturized Percutaneous Nephrolithotomy.

OBJECTIVE: To evaluate the effects of location of the tip of percutaneous sheath and nephroscope in the collecting system together with active aspiration on the Intrapelvic pressure measurements (IPP) during miniaturized percutaneous nephrolithotomy (miniPNL). MATERIALS AND METHODS: The data of 20 patients underwent miniPNL in supine position was collected prospectively. IPP measurements were done with an 8 Fr urodynamic pressure measurement catheter in 4 different settings with respect to location of tip of sheath and nephroscope. All 4 settings were repeated with active aspiration. Totally measurements were done and compared in 8 different settings for 90 seconds in each patient. RESULTS: Highest mean IPP measurements were recorded in setting II (35.3 ± 11.8 cm H2O) where the sheath was located in the calyx and the tip of the nephroscope was in the renal pelvis. When active aspiration was applied, the mean pressure measurements were significantly lower than the counterpart settings without aspiration (all P values <.0001). When the active aspiration was applied, intrarenal pressure measurements did not exceed 40 cm H2O in any settings in any of the patients. CONCLUSION: Location of the tip of the sheath and the nephroscope has significant effect on IPP measurements. Active aspiration significantly lowers the IPP and keeps it <40 cm H2O. Endourologists should be aware of possible alterations in IPP during miniPNL and active aspiration should be kept in mind as an effective solution to decrease the risk of complications related to high IPP.

Water-slider method reduced colonic polyp fragmentation compared with conventional suction retrieval: A prospective randomized controlled study.

OBJECTIVES: After resecting colonic polyps, retrieval through the scope channel may lead to polyp fragmentation, making pathologic evaluation challenging. An easy and reliable method for complete polyp retrieval is needed. METHODS: We developed the water-slider method (WSM), in which the resected polyp is surrounded by water from an auxiliary water channel during suctioning. We prospectively randomized patients who underwent endoscopic resection for colonic polyps in our institute into WSM and non-WSM groups, and evaluated the polyp fragmentation rate. RESULTS: Analysis of the data regarding small polyps (≤10 mm in size) revealed that the WSM group had a significantly lower polyp fragmentation rate (8.2%) than the non-WSM group (23.8%, p < 0.001). Polyp retrieval time did not differ significantly between groups. The rate of a clear-cut end on neoplastic polyps was significantly higher in the WSM group (63.8%) than in the non-WSM group (50.0%; p = 0.029). CONCLUSIONS: The WSM achieved a significantly lower polyp fragmentation rate, allowing for more accurate histologic evaluation than the conventional method. The WSM did not influence the polyp retrieval time.

Proposal for a novel elliptical ultrasonic aspirator and its fundamental performance in cartilage removal.

An ultrasonic aspirator with elliptical vibration on the end face is presented in this paper. The ultrasonic vibration relied on a specially designed Langevin transducer. The end face of the transducer was screwed into a surgical tool capable of changing amplitude, which requires resonance to provide sufficient vibration amplitude for cutting cartilage or other biological tissues. Based on the coupling of two vertical bending vibrations, the new design produced the elliptical ultrasonic vibration on the end face of the surgical tool, which differed from the axial vibration of a traditional ultrasonic aspirator. The design greatly increased the mechanical effect of the aspirator. A specially designed blade was employed to remove the cartilage tissue. A prototype device was designed to operate at 20 kHz with a displacement amplitude of 150 µm at 200 V. The measurements of the vibrational and impedance responses showed the mechanical and electrical characteristics of the aspirator. Cutting tests on mice costal cartilage were subsequently conducted. Histological analysis displayed a higher proportion of live cells in the region around the cut site, which exhibited a higher removal efficiency.

The impact of roller pump-assisted cardiotomy suction unit on hemolysis.

Hemolysis in cardiac surgery is often related to the contact of blood with air or artificial surfaces. Variations of negative pressure in the suction cannulas may represent an additional factor. Limited data exist on the contribution of a roller pump-assisted (RPA) cardiotomy suction unit to hemolysis. Elevation of free hemoglobin (fHb) following air suction (AS) or suction tip occlusion (STO) events of a pump-assisted cardiotomy suction unit was investigated in a mock circuit filled with blood from slaughtered domestic pigs. AS-associated hemolysis was measured over 240 minutes with 2 minutes of AS occurring every 10 minutes. STO-associated hemolysis was analyzed over 80-minute periods: configuration 1 (c1) comprised a cycle of 20 minutes (min) occlusion and 60 minutes RPA flow (20/60 minutes); c2 comprised 20 cycles of 1/3 minutes; c3 comprised 40 cycles of 0.5/1.5 minutes; and c4 comprised 80 cycles of 0.25/0.75 minutes. The AS setup did not lead to significant hemolysis after 2 (P = .97), 3 (P = .40) or 4 (P = .11) hours. The STO setup showed the greatest hemolysis (ΔfHb of 30 mg/dL) in c1 after 20 minutes. ΔfHb was different in c1 from all other configurations at 20 minutes (P < .0001) and 80 minutes (P < .05). Ex vivo generation of large negative pressures by STO events is the main cause of cardiotomy suction-associated hemolysis. The clinical relevance of this mechanism needs further investigations.

Metagenomic analysis of the dust particles collected from the suction tube and the suction funnel of a dermatological laser smoke evacuator system.

In the last few decades, there has essentially been an explosion in the use of lasers in medicine, especially in the area of cosmetic dermatology. Potentially harmful substances are liberated when tissues are vaporized with laser. This creates numerous risks, including the spread of infectious disease. Smoke evacuators are devices that capture and filter laser plume, thereby maintaining a safe environment for the surgical team and patient. Our aim was to characterize the microbial community structure within the suction tube and funnel of the smoke evacuator system, identify their origin, and evaluate pathogenicity. Dust particles were collected from the instruments with a cotton swab. DNA was extracted from the swabs and the transport media, and sequencing was performed using the Illumina HiSeq Xplatform. Metagenomic analysis was conducted using the Empowering the Development of Genomics Expertise (EDGE) Bioinformatics pipeline and custom Python scripts. The most abundant bacterial species were Micrococcus luteus and Brevibacterium casei in the suction tube, and Dermacoccus sp. Ellin 185 and Janibacter hoylei in the suction funnel. A total of 15 medium- to high-quality metagenome-assembled genomes (MAGs) were constructed where we found 104 antibiotic-resistant genes (ARGs) and 741 virulence factors. Findings indicate that the suction tube and funnel are likely a reservoir of virulence factor genes and ARGs, which can possibly be passed on to other bacteria via horizontal gene transfer. We would like to emphasize the health risk these microorganisms pose and the need to reevaluate the current hygiene standards with regard to the smoke evacuator system.

[Design of Integrated Suction Detection System for Pediatric Oral Secretion].

According to the actual requirements of pediatric intensive care, a suction detection system of pediatric oral secretions integrated with monitoring function is designed. The system has the function of adjustable intermittent attraction. The duration and proportion of intermittent attraction can be adjusted according to the individualized needs of pediatric intensive care. The suction head of pacifier can reduce the mechanical damage to pediatric oral mucosa as much as possible. Meanwhile, the system can detect and monitor the real-time biochemical indexes of the collected oral secretions, which can be used to help the judgement of aspiration and quantitatively evaluate the microcirculation dysfunction.