Pre-hospital emergency cricothyrotomy in dogs part 2: Airway sealing and ventilation using cricothyrotomy tubes.

Cricothyrotomy (CTT) has been recommended for use in the pre-hospital setting for military working dogs and Operational K9s during airway emergencies. Although the CTT can establish a patent airway for spontaneous ventilation, the ability to seal the airway and provide positive pressure ventilation (PPV) using tubes designed for humans has not been determined. Using various CTT tubes placed in cadaver dog airways, this study aimed to determine: (1) Whether the tube cuff could create a functional airway seal with safe intra-cuff pressures; (2) The magnitude of delivered tidal volume (TV) loss during a standard breath to assess the possibility of delivering an adequate tidal volume with a bag-valve device (BVM); (3) The best performing tubes for either test; (4) The reasons behind the findings using observations from upper airway endoscopy, dissection, and measurements. Cadaver dogs of similar weights to MWD and Operational K9 breeds had various CTT tubes placed including three from commercial kits, a standard endotracheal tube, and a tracheostomy tube. The minimum occlusive volume technique was used to inflate the tube cuff and a pressure ≤ 48 cm H2O with an adequate seal was considered successful. Individual TVs were calculated for each dog and added to the volume lost during delivery of a standard breath from an ICU ventilator. Endoscopy and airway dissection were performed to assess the relationship between tubes cuffs and the airway. The tubes from the CTT kits performed poorly with regards to producing an airway seal with the H&H tube failing to seal the airway all tests. Tracheal dimensions were significantly associated with successful airway sealing (P = 0.0004). Tidal volume loss could be compensated using a BVM in 34/35 tests with the H&H tube in cadaver 8 the only to fail. Tracheal airway sealing is influenced by airway anatomy when tube cuffs are inflated to a target pressure and larger tubes do not always provide a better seal. The CTT tubes tested have the potential to facilitate ventilation with a BVM under the conditions set in this study. The 8.0 mm endotracheal tube performed the best and the H&H the worst in both tests.

A proposed improvised pleural drainage system for veterinary use.

BACKGROUND: Active pleural suction devices may be required for continuous drainage of pleural fluid or air. Such devices may not always be available or economical to stock at all veterinary hospitals. Three designs of pleural drainage systems adapted from standard suction canisters are proposed. KEY FINDINGS: The designs were constructed from readily available materials from the veterinary hospital and consist of (1) a 1-bottle system intended for use with pneumothoraces, (2) a 2-bottle system, which can be used for draining air and fluid, and (3) an abbreviated 2-bottle system. The suction pressure was tested using a water manometer for each design. The suction pressure was consistently accurate with designs 1 and 2, with mild fluctuations, intermittently increasing suction pressure in design 1 due to bubbling through the air vent. Design 3 demonstrated a greater degree of pressure fluctuations, which was attributed to having the least water volume, reaching suction pressures up to 1 cm H2 O above what was set. SIGNIFICANCE: The improvised devices appear effective, allow accurate delivery of a set suction pressure, and can be rapidly constructed from inexpensive and readily available equipment.

A Proposed Guideline for Performance of Emergency Surgical Airways in Small Animals: Analysis of Five Unsuccessfully Managed Cannot Intubate, Cannot Oxygenate Cases.

Objective-To describe three dogs and two cats diagnosed with a cannot intubate, cannot oxygenate (CICO) condition, and discuss the appropriateness and timing of emergency front-of-neck airway access (eFONA). The authors aim to increase awareness of CICO events and effective management strategies, which may result in faster airway access and improve patient outcomes. Case series summary-Three dogs and two cats could not be easily intubated resulting in the inability to deliver oxygen and contributing to their death. Emergency front-of-neck airway access was attempted in three cases, it could not be performed in one when indicated, and it was not considered in managing another. Conclusions-This is the first report of small animals suffering CICO emergencies and tracheostomy attempts without a concurrently secured airway. Cannot intubate, cannot oxygenate events and eFONA attempts were managed sub-optimally in all cases, which likely contributed to the poor outcomes. Rapid diagnosis of CICO and early eFONA using appropriate techniques has the potential to improve the management of difficult airways in small animals.

Prehospital Emergency Cricothyrotomy in Dogs Part 1: Experiences With Commercial Cricothyrotomy Kits.

The surgical cricothyrotomy (CTT) has been recommended for emergency front of neck airway access (eFONA) during a cannot intubate, cannot oxygenate scenario for military working dogs (MWD) and civilian law enforcement working dogs (operational K9s). In prehospital and austere environments, combat medics and emergency medical service providers are expected to administer emergency medical care to working dogs and may only have emergency airway kits designed for humans at their disposal. The objective of this article is to provide a detailed description of the application of such devices in cadaver dogs and highlight potential alterations to manufacturer guidelines required for successful tube placement. The kits evaluated included the Portex® PCK, Melker universal cricothyrotomy kit and H&H® emergency cricothyrotomy kit. A novel technique for awake cricothyrotomy in the dog is also described, which can also be considered for in-hospital use, together with the open surgical method described for the H&H® kit. To the authors' knowledge, this is the first publication documenting and providing instruction on the application of commercial cricothyrotomy kits in dogs.

Cricothyrotomy Is Faster Than Tracheostomy for Emergency Front-of-Neck Airway Access in Dogs.

Objectives: In novice final year veterinary students, we sought to: (1) compare the procedure time between a novel cricothyrotomy (CTT) technique and an abbreviated tracheostomy (TT) technique in canine cadavers, (2) assess the success rate of each procedure, (3) assess the complication rate of each procedure via a damage score, (4) evaluate the technical difficulty of each procedure and (5) determine the preferred procedure of study participants for emergency front-of-neck access. Materials and Methods: A prospective, cross-over, block randomised trial was performed, where veterinary students completed CTT and TT procedures on cadaver dogs. Eight students were recruited and performed 32 procedures on 16 dogs. A generalised estimating equation approach to modelling the procedure times was used. Results: The procedure time was significantly faster for the CTT than the TT technique, on average (p < 0.001). The mean time taken to complete the CTT technique was 49.6 s (95% CI: 29.5-69.6) faster on average, with a mean CTT time of less than half that of the TT. When taking into account the attempt number, the procedure time for a CTT was 66.4 s (95% CI: 38.9-93.9) faster than TT for the first attempt, and for the second attempt, this was 32.7 s (95% CI: 15.2-50.2) faster, on average. The success rate for both procedures was 100% and there was no difference detected in the damage or difficulty scores (P = 0.13 and 0.08, respectively). Seven of eight participants preferred the CTT. Clinical Significance: CTT warrants consideration as the primary option for emergency front-of-neck airway access for dogs.

A pilot study evaluating the utility of a novel tube cricothyrotomy technique in providing ventilation in small animals using a live porcine model.

BACKGROUND: Tube cricothyrotomy has been suggested as a first-choice for emergency surgical airway access in small animals, rather than the more commonly accepted procedures of tracheotomy and needle cricothyrotomy. METHODS: A small pilot study of tube cricothyrotomy in a live porcine model was conducted to evaluate this method. The technique was modified to permit the use of commonly available equipment and ease of application. Following ethics approval, a tube cricothyrotomy was performed on 9 live pigs. The endpoints were the efficacy of ventilation through the tube as measured by end-tidal carbon dioxide, successful placement of the tube and the time taken for placement. RESULTS: Of the nine pigs, eight had a tube placed successfully, with the median procedure time being 111.5 seconds (range: 35-240 seconds). After 10 mins, the mean end-tidal carbon dioxide was 58.3 mmHg (95% CI: 55.2-61.3 mmHg), with a range of 54-64 mmHg. Tube cricothyrotomy holds promise as a means of rapidly obtaining tracheal access in small animals and temporarily sustaining ventilation in an emergency. CONCLUSION: Further detailed investigation is warranted to assess the use of this technique in the small animal emergency setting.