Intubation Of Rats Research Articles

Simple Method Laryngoscope on Rat Intubation

Background: In research using rats as experimental animalsthat involve surgery and anesthetic procedures, it is often necessary to administer inhalation anesthetics and patency of the airway. In this condition, intubation in rats is required. Endotracheal intubation in rats is quite difficult because the size and structure of the airway is very small and smooth and there is no specific instrument designed for intubation in rats. Methods: The experimental animal used in this study was adult male Wistar rats weighing 250-350grams. The intubation equipment used is a commercially available otoscopy which has a light source and a camera that can be displayed on a mobile phone screen. The end of the otoscopy is a modified blunt-tipped plastic blade. The endotracheal tube that is used was a intravenous catheter size 16 G which was directed using an introducer made of blunt-tipped wire. The rat is positioned on its back dorsally with its head upward. Results: In this study, 32 rats were intubated. Fourteen of the 32 intubated rats were alive, awakened from anesthesia and extubation. There were no complications such as stridor or voice disturbances after this intubation procedure. The other eighteen rats were not extubated alive because this was part of the treatment in another study. Of the 32 rats that were subjected to intubation, 2 rats failed to intubate due to spasm and bradycardia. Conclusion: Methods that were given in this paper can be alternatives for rat intubation.

Micropipette tip intubation in rats as a replacement for conventional endotracheal tube intubation.

Endotracheal intubation is often necessary in the course of animal experiments, especially in craniofacial surgery. However, endotracheal intubation can be a major burden in this context. The authors performed simple and cost-saving method using a 200 μL yellow micropipette tip, and the success of this method was demonstrated by X-ray and autopsy. We used a total of 30 rats. After the rats were fixed with a plaster, the trachea and vocal cords were visualized with the tongue pulled back. Under direct visualization of the vocal cords, a curving micropipette tip was advanced into the trachea. This method can be learned quickly and applied successfully by general experimenters. We successfully intubated all 30 rats without any complications. The success rate of micropipette tip intubation was 100%. This procedure was performed by one experimenter within 2 to 3 minutes after induction of anesthesia. We demonstrated its superiority by X-ray and autopsy. Herein, we describe endotracheal intubation of rats using micropipette tips. To the best of our knowledge, this method is novel and represents the simplest and most efficient means of intubation in rats, providing an alternative to conventional endotracheal intubation.

Topiramate and Acetazolamide Combination a Comparative Study between High and Low Dose Profile of Side Effects on Metabolism

Background: Topiramate, with multiple putative anticonvulsant pathways, is a relatively recent antiepileptic drug. The ability to inhibit carbonic anhydrase, a property common with the acetazolamide anticonvulsant, is among them. Aim: The study refers to compare between the use of combinations of topiramate and acetazolamide high and low doses of drugs and which one is safer for the patients. Methods: Twenty stable adult males wistar rats three weeks after acclimatization and uniformly split into two groups (10 rats in each group) and 60 days of treatment: 9 mg/kg/B.W of Topiramate and 30 mg/kg/B.W of Acetazolamide in the high dose (Hd) group and 5 mg/kg B.W of Topiramate and 30 mg/kg B.W of Acetazolamide in the low dose (Ld) group, orally/day in the high dose (Hd) group. Results: No major differences in mean Glutamate pyruvate transaminase, Glutamic oxaloacetic transaminase, Alkaline phosphatase concentration were found in the statistical analysis of the results in all experimental groups compared with each other at the pretreated period, also revealed that intubation of rats in the 60-days Hd induced a substantial (P>0.05) rise in the mean Glutamate Pyruvate Transaminase and Glutamic Oxaloacetic Transaminase serum concentrations relative to the control and Ld classes. Treatment of low-dose rats showed a substantial (P<0.05) decrease in serum alanine aminotransferase, aspartate aminotransferase, blood urea nitrogen and creatinine enzyme concentrations at 30 and 60 days of the trial compared with the T1 group. Conclusion: The study showed that high-dose combinations of topiramate and acetazolamide had the same adverse effect somewhat in low-dose combinations.

Three-Way Stopcock as Breathing Circuit in Anesthetic Procedures on Wistar Rats as Animal Models in Research

Introduction: General anesthesia in experimental animals is not limited in the field of anesthesia research. In Indonesia, ventilators and breathing circuit systems utilized in research involving anesthesia in rats are not widely available. The limitations in using ventilators and breathing circuit systems in research are one of the reasons why Indonesia is lacking complex and advanced animal experimental studies. Objective: This study aimed to examine a general anesthesia procedure for intubation in rats using tools and materials commonly discovered in clinical settings. Method: A search on the PubMed database using keywords consisting of animal study, rats, anesthesia, breathing circuit was performed. Review and Discussion: An endotracheal tube insertion procedure may utilize a Miller size 0 laryngoscope, while the endotracheal tube may use a 16 G intravenous cannula in which the needle is replaced by a small wire. The 3-way stopcock system may be considered as a replacement for the Mapleson E system for the breathing circuit system. The Fresh Gas Flow (FGF) source needs to be connected to the angled port, while the other two ports are connected to the reservoir and the intravenous cannula which would be delivered to the experimental animals. FGF three to five times as much as the minute ventilation may be used and the use of a reservoir capacity is similar to the tidal volume of spontaneous ventilation. Therefore, the oxygen flow rate is set to approximately 1-1.5 L per minute. A reservoir is not required for controlled ventilation. Conclusion: The use of a 3-way stopcock as a non-rebreathing circuit system is effective because it utilizes the similar principle as Mapleson E. The ability to use common tools and materials for general anesthesia procedures would significantly boost research of animal models in Indonesia to a further level.

Video laryngoscopic oral intubation in rats: a simple and effective method

Endotracheal intubation is a vital component of many rat in vivo experiments to secure the airway and allow controlled ventilation. Even in the hands of experienced researchers, however, the procedure remains technically challenging. The safest and most reliable way for human intubation is by video laryngoscopy. Previous attempts to apply this technique in rodents have been complicated and expensive. We, hereby, describe a novel, noninvasive method to safely intubate rats orally by video laryngoscopy, thus avoiding the need for a surgical tracheostomy. By repurposing a commercially available ear wax removal device, visualization of the rat larynx can be significantly enhanced. Because of its small diameter, integrated illumination, and a powerful camera with adequate focal length, the device has all of the necessary properties for exploring the upper airway of a rat. After identifying the vocal cords by video laryngoscopy, the insertion of an endotracheal tube (a 14G intravenous catheter) into the trachea under constant visual control is facilitated by using PE50 polyethylene tubing as a stylet (Seldinger technique). The procedure has been performed more than 60 times in our laboratory; all intubations were successful on the first attempt, and no adverse events were observed. We conclude that the described procedure is a simple and effective way to intubate a rat noninvasively, using inexpensive and commercially available equipment.

Comparison of the Effects of Endotracheal Intubation of Wistar Rats Using the Conventional Technique vs. a New Modified Technique Using a 3D Mouth-Piece

Aims Endotracheal intubation in rats is challenging due to the difficult anatomical characteristics of the airway. The success rate at first attempt is low and airway damage is a common complication. We aimed to compare and evaluate the conventional intubation method with a modified procedure using an inclined plate, headlamp (700-Lumen), and 3D mouth-piece designed with a 20° curvature. Both techniques were conducted by laboratory personnel with and without previous experience in airway management of laboratory rats. Material and methods In this study, we used 36 Wistar rats of both genders. Three groups of laboratory personnel (anesthesiologists, medical students, and laboratory technicians) performed both endotracheal intubation techniques, i.e., blind intubation at supine position and endotracheal intubation at 70° supine position with a 3D mouth-piece and direct illumination of the glottis. Results The modified technique had a significantly higher success rate and shorter procedure duration. Moreover, there was no significant difference in the procedure duration between personnel with and without previous training in airway management. Conclusion Previous knowledge and experience in airway management are required when performing conventional endotracheal intubation; moreover, its success rate is low. Contrastingly, using proper instruments and the 3D mouth-piece facilitated easier and quicker airway management regardless of previous experience.

Improved blind tracheal intubation in rats: a simple and secure approach.

Successful tracheal intubation is the prerequisite for open-chest models. Tracheal intubation in small animal such as the rat is often challenging due to the small size and special anatomy. We investigated whether endotracheal intubation can be performed safely and reliably in rats employing only gesture fixation and a catheter. Rats were randomly classified into three groups: Improved blind intubation (B group) was performed with gestures fixed intubation position. Transillumination intubation (T group) utilized light to locate the larynx. Incision intubation (I group) was intubated after trachea incision. The feasibility, difficulty, complications of the three groups were compared. B group was faster than the other two groups. Completion time of the operation was recorded as follows: B group: 35.00 ± 9.86 sec; T group: 57.12 ± 6.54 sec; I group: 184.33 ± 25.49 sec (P≤0.001). B group has fewer attempts than Group T (P=0.001). The operational success rates of all three groups (B group 14 (93.3%) vs. T group 12 (80.0%) vs. I group 13 (86.7%)) were similar (P>0.05). In terms of operation difficult and operational complications, the differences between the three groups were not significant. The rate of endometrial damage under microscope were no difference, too. The Improved blind endotracheal intubation is a simple method, with a comparable safety profile to that of the transillumination and incision intubaton.

DIY Video Laryngoscopy in Rats–Safe, Fast and Reliable

IntroductionThe airway management of rats in the field of basic research is of great importance. Intubation is needed for general anesthesia, ventilation, and the use of neuromuscular blocking agents. For survival studies, especially, a less invasive intubation technique is preferred over tracheostomy. In the past, several different methods with high success rates have been described, but most need a high level of technical effort, training, and financial expenditure. In humans, video laryngoscopy for intubation is the most successful technique; it may also be feasible in rats with simple and cost‐effective devices.HypothesisBy using a commercial flexible video endoscope (VE), with small modifications for direct visualization, and the Seldinger‐Technique, intubation in rats can be quick, easy and reliable.MethodsA cost‐effective and waterproof VE (GiraffeCam, 5.5 mm diameter) with USB‐connection and an integrated light source was purchased. Due to its softness, and for fixation on the board, a 20 cm wire attached with surgical tape was added to the VE for more rigidity. After anesthesia was induced with an intraperitoneal injection of pentobarbital (45mg/kg), each rat was placed on its back on the board and fixed in position with surgical tape. The board was then secured in place on the bench at a 45° angle head up. The VE was hooked up to the board and connected to a computer. The tip of the VE was gently introduced into the mouth, on one side of the upper incisors, until the vocal cords could be identified on the video screen. A 14‐gauge catheter, used as endotracheal tube (ET), was prepared with a stylet (15 cm PE50 tubing) that was inserted and advanced 1 cm past the catheter tip. The ET was inserted into the trachea, and once past the vocal cords, the stylet was pulled back. One hundred (100) rats (30 Zucker Diabetic Fatty, 70 Sprague Dawley; weight between 350–450g) were intubated by this technique and used for experiments with cardiac arrest and resuscitation.ResultsAll intubation attempts were successful on the first attempt, with a proper placement of the ET. No complications, such as bleeding occurred, and all rats were ventilated without problems. Furthermore, this technique can be performed with little previous experience and in less than one minute.ConclusionWith estimated costs of approximately $30, this VL intubation procedure is a safe, fast and reliable technique for rat intubation.Support or Funding InformationDr. Balzer is funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – Project number 397561247. Additional support provided by institutional funds, NIH grant (5R01 HL123227), and a Merit Review Award (I01 BX003482) from the U.S. Department of Veteran Affairs Biomedical Laboratory R&D Service awarded to Dr. Riess. image imageThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Airway management using a supraglottic airway device without endotracheal intubation for positive ventilation of anaesthetized rats

Endotracheal intubation is often necessary for positive pressure ventilation of rats during open thoracic surgery. Since endotracheal intubation in rats is technically difficult and is associated with numerous complications, many techniques using various devices have been described in the scientific literature. In this study, we compared the effectiveness of airway management of a home-made supraglottic airway device (SAD), which is cheap to fabricate and easy to place with that of an endotracheal intubation tube in enflurane-anaesthetized rats. Twenty male Sprague-Dawley rats (200-300 g) were randomly assigned to two equal groups for positive pressure mechanical ventilation using either the SAD or an endotracheal intubation tube. The carotid artery of each rat was cannulated for continuous blood pressure measurements and obtaining blood samples for determination of oxygen tension, carbon dioxide tension, and blood acidity before, during and after SAD placement or endotracheal intubation. Proper placement of the SAD was confirmed by observing chest wall movements that coincided with the operation of the mechanical ventilator. No complications and adverse events were encountered in the rats in which the SAD was placed, during SAD placement and immediate removal, during their mechanical ventilation through the SAD, and one week after SAD removal. From the results of blood gas analyses, we conclude that anaesthetized rats can be successfully ventilated using an SAD for open thoracic surgery.

Assisted Ventilation without Endotracheal Intubation in Rats

ABSTRACTThis technique was performed to allow for an additional approach to assist in ventilation. A modified ventilation nose cone was placed over the nose, which allowed the animal to not require endotracheal intubation. This method was effective in ventilating the animals during thoracic and abdominal procedures without requiring endotracheal intubation.

Blind oral endotracheal intubation of rats using a ventilator to verify correct placement

Endotracheal intubation in rats is challenging due to difficulties visualizing the epiglottis and vocal cords. No visualization of these structures results in repeated intubation attempts which can cause trauma to the oral cavity and/or oesophagus, and death of the animal due to respiratory failure. Here, we describe a simple blind oral tracheal intubation technique in the rat that decreases the frequency of repeated intubations using an intubation device that comprises a 16 G intravenous catheter and a modified 18 G epidural needle, and a rodent ventilator. The epidural needle is bent in such a way that it curves in conformity with the rat's oral airway in order to direct the catheter into the larynx, and the rodent ventilator is used to verify its correct placement. The first attempt success rate of endotracheal intubation using the blind oral tracheal intubation technique with a rodent ventilator was greater than the first attempt success rate using the blind oral tracheal intubation technique without using a rodent ventilator. Although this method is a simple modification of a previously described method of blind oral endotracheal intubation, our method is easy to learn, inexpensive and does not require specialized equipment.

Drug-eluting stents are associated with a high rate of stent thrombosis compared to bare metal stents in an underserved Hispanic population presenting with acute ST segment myocardial infarction

Endotracheal intubation in rats is a challenging problem. This is a difficult procedure due to the narrow oral cavity and the difficulty in visualizing the vocal cord. It is associated with high complication rate. We have developed a very safe and simple method using a 0.035-in. straight tip wire as a guide and the small infantile laryngoscope for intubation in rats.Seventy Sprague-Dawley rats weighing between 100 and 450 g were used for endotracheal intubation, utilizing a 0.035-in. straight-tip wire, infantile laryngoscope blade Miller size 0 and conventional cutdown 18-gauge catheter. Rats were anesthetized using a mixture of ketamine (50 mg/kg), xylazine (4 mg/kg) and acepromazine (1 mg/kg). The upper incisors were fixed with a rubber band. With the laryngoscope, the trachea and vocal cords were visualized with the tongue pulled back. Under direct visualization of the vocal cords, a 0.035-in. straight-tip wire was advanced into the trachea and an 18-gauge cutdown catheter was advanced over the wire into the trachea. The wire was removed and the catheter was attached to the respirator. With this method, the use of atropine was not necessary.We successfully intubated all 70 rats without any complications. The successful rate was 100% with no mortality related to the intubation. This was performed within 1 to 2 min after induction of anesthesia without using atropin. There was no intra-esophageal or soft tissue intubation.With a 0.035-in. straight-tip wire as a guide and a small infant laryngoscope blade Miller size 0, endotracheal intubations in rats can be safely performed with high success rate without the use of atropine, which makes it better suitable for cardiovascular research.

Using a 0.035-in. straight-tip wire and a small infant laryngoscope for safe and easy endotracheal intubations in rats for cardiovascular research

Endotracheal intubation in rats is a challenging problem. This is a difficult procedure due to the narrow oral cavity and the difficulty in visualizing the vocal cord. It is associated with high complication rate. We have developed a very safe and simple method using a 0.035-in. straight tip wire as a guide and the small infantile laryngoscope for intubation in rats. Seventy Sprague-Dawley rats weighing between 100 and 450 g were used for endotracheal intubation, utilizing a 0.035-in. straight-tip wire, infantile laryngoscope blade Miller size 0 and conventional cutdown 18-gauge catheter. Rats were anesthetized using a mixture of ketamine (50 mg/kg), xylazine (4 mg/kg) and acepromazine (1 mg/kg). The upper incisors were fixed with a rubber band. With the laryngoscope, the trachea and vocal cords were visualized with the tongue pulled back. Under direct visualization of the vocal cords, a 0.035-in. straight-tip wire was advanced into the trachea and an 18-gauge cutdown catheter was advanced over the wire into the trachea. The wire was removed and the catheter was attached to the respirator. With this method, the use of atropine was not necessary. We successfully intubated all 70 rats without any complications. The successful rate was 100% with no mortality related to the intubation. This was performed within 1 to 2 min after induction of anesthesia without using atropin. There was no intra-esophageal or soft tissue intubation. With a 0.035-in. straight-tip wire as a guide and a small infant laryngoscope blade Miller size 0, endotracheal intubations in rats can be safely performed with high success rate without the use of atropine, which makes it better suitable for cardiovascular research.

A simple device for intubation of rats

Endotracheal intubation of rats is often necessary for lengthy survival surgeries, but the animal's small size and the lack of suitable equipment may complicate the procedure. The authors describe the construction and use of a simple device for the easy intubation of rats, requiring no expensive, specialized equipment.

Farnesol Is Not the Nonsterol Regulator Mediating Degradation of HMG-CoA Reductase in Rat Liver

A recent report, in which cultured tumor cells were used, identified farnesol as the nonsterol mevalonate-derived metabolite required for the accelerated degradation of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase (C. C. Correll, L. Ng, and P. A. Edwards, 1994,J. Biol. Chem.269, 17390–17393). We examined this proposed linkage in animals by measuring hepatic farnesol levels and rates of HMG-CoA reductase degradation under conditions previously shown to alter the stability of the reductase. In normal rats, the hepatic farnesol level, quantified by high-pressure liquid chromatography, was 0.10 ± 0.08 μg/g and the half-life of HMG-CoA reductase was 2.5 h. Administration of mevalonolactone at 1 g/kg body wt to provide all nonsterol metabolites in addition to cholesterol increased farnesol levels 6-fold without significantly affecting the half-life of the reductase. Treatment of rats with zaragozic acid A, an inhibitor of squalene synthase, raised hepatic farnesol levels 10-fold and decreased the half-life of HMG-CoA reductase to 0.25 h. However, feeding lovastatin to rats did not lower hepatic farnesol levels despite a marked stabilization of HMG-CoA reductase protein. Moreover, intubation of rats with 500 mg/kg body wt of farnesol failed to decrease the half-life of HMG-CoA reductase protein, alter the levels of enzyme activity, or change of the levels of immunoreactive protein despite an increase of 1000-fold in hepatic farnesol levels. These observations indicate that farnesol per se does not induce accelerated degradation of HMG-CoA reductase in rat liver.

Transoral Tracheal Intubation for Gastroscopy in Rats

Abstract: A new method of orotracheal intubation in rats which was developed to prevent apnea during upper gastrointestinal endoscopiy is described. After the anesthetized animals are relaxed with an I. V. injection of Vecuronium, orotracheal intubation was performed with a thin endoscope under complete visual control. After relaxation is achieved the glottis is wide open and intubation can be performed carefully without any medianical irritation of the larynx. After placement of the tube in the trachea, the fiberoptic was removed and pressure–controlled ventilation occurred.This technique can be widely applied in any kind of rat experiment, where controlled ventilation is required.

Observation of Tracheal Mucosa Following Intratracheal Intubation in Rats

Observation of Tracheal Mucosa Following Intratracheal Intubation in Rats

Comparison of end-tidal carbon dioxide, oxygen saturation and clinical signs for the detection of oesophageal intubation

The reliability of various methods for detecting oesophageal intubation was assessed by means of a single blind study in rats. Both oesophagus and trachea were simultaneously intubated. The presence or absence of various clinical signs was noted during tracheal or oesophageal ventilation and arterial blood gases and end-tidal CO2 were measured. Oesophageal ventilation for one minute was associated with significant decreases (P less than 0.001) in pH, PaO2 and SaO2 and a significant (P less than 0.001) increase in PaCO2. Although mean PaO2 decreased by 70 per cent and mean SaO2 decreased by 31 per cent, 43 percent of rats failed to demonstrate a decrease in SaO2 below 85 per cent. Oxygen saturation was the least reliable method for detecting oesophageal intubation (sensitivity = 0.5, specificity = 0.9, positive predictive value (PPV) = 0.8). Chest movement was the most reliable clinical sign for detecting oesophageal intubation (sensitivity = 0.9, specificity = 1.0, PPV = 1.0). Oesophageal rattle was the second most reliable clinical sign (PPV = 0.9). Moisture condensation in the tracheal tube (PPV = 1.0) and abdominal distension (PPV = 0.9) were judged to be the least reliable because each had a high false negative rate of 0.3. The most reliable method for the early detection of oesophageal intubation in rats was end-tidal, CO2 (sensitivity 1.0, specificity = 1.0, PPV = 1.0). In addition, end-tidal CO2 when used in conjunction with the four clinical signs improved the reliability of these signs.

Characterization of immune response to oral administration of Streptococcus sobrinus ribosomal preparations in liposomes

Gnotobiotic rats gastrically intubated with a total of 12.5 micrograms of Streptococcus sobrinus ribosomal protein incorporated into cholesterol-based liposomes had significantly (P less than or equal to 0.01) fewer carious lesions on their molar surfaces than did nonimmunized infected controls after challenge with a virulent organism. The immunized animals had significantly (P less than or equal to 0.01) lower numbers of molar-adherent S. sobrinus cells and higher levels of salivary immunoglobulin A antibodies to S. sobrinus whole cells and ribosomes than did the control group. Dose-response studies indicated that 12.5 micrograms of S. sobrinus ribosomal protein in liposomes induced slightly higher immune responses than did 62.5, 125.0, and 250.0 micrograms of ribosomal protein incorporated into liposomes. Intubation of rats with up to 250.0 micrograms of S. sobrinus ribosomal protein alone was no more effective in reducing the numbers of molar-adherent S. sobrinus cells than were nonimmunized infected controls, establishing that insertion of ribosomes into liposomes was required for inducing an effective immune response. These results indicate that oral administration of as little as 12.5 micrograms of S. sobrinus ribosomal protein incorporated into liposomes can protect rats from caries formation after challenge with the virulent organism by inducing specific salivary immunoglobulin A antibodies which can inhibit colonization by the challenged S. sobrinus.

Asphyxia, cardiac arrest and resuscitation in rats. II. Long term behavioral changes.

This study in 53 rats was conducted to investigate a mild insult, sensitive parameter model in contrast to a severe insult, severe damage model of brain resuscitation. Up to now, the latter approach, which causes neuropathologic changes and neurological abnormalities, has not provided unequivocal data on pharmacological measures to ameliorate post-anoxic brain damage, because of logistical difficulties and many extracranial complicating factors. As tracheotomy and oral intubation in rats proved impractical in studies on recovery from asphyxia, transtracheal jet ventilation was tested in 14 rats as a measure for effective prolonged and reversible control of airway and ventilation. Subsequently, in 37 other rats we studied, during the first post-insult week, the effects of anesthesia, with or without 6 min asphyxia, on behavior, i.e. unrestrained spontaneous locomotor activity and two sessions of one-trial passive avoidance. Transtracheal jet ventilation proved a reliable method for reversible and prolonged controlled ventilation in rats. Spontaneous locomotor activity was affected for at least 48 h after anesthesia and differently so after asphyxia. Passive avoidance was affected only after asphyxia. The recovery of behavior was delayed for days, whereas the recovery of neurologic deficits was only delayed for several post-asphyxia hours. The asphyxiated rats showed hyper-excitability for at least 2 weeks. The existence of abnormal behavior during recovery from mild anoxic-ischemic insults to the brain provides parameters for evaluation of therapies of the post-resuscitation disease in a model without the difficulties encountered in models with severe insults, which made post-insult intensive care necessary. The mild insult, sensitive parameter model is promising and further work in this direction is indicated.