As a veterinary dentist with nearly 5 decades of experience, I’ve amassed more than 53,000 dental and oral cavity images in storage on my laptop. At my wife’s encouragement this past November, I ventured beyond my comfort range to focus on a 5-day landscape nature photography trip in Utah’s Badlands. The experience broadened my photographic skills and provided unexpected insights into veterinary anesthesia practices.
The transition from handheld dental macrophotography to landscape photography using a tripod and long lenses required adjustments in technique and approach. (Figure 1) This adaptability is necessary in veterinary medicine, where embracing new technologies and equipment is crucial for optimal patient care.
The tripod analogy: Strength in photography and anesthesia
Using a tripod in nature photography can be likened to the foundational principles of successful veterinary anesthesia. Just as a tripod provides stability and support for capturing clear, sharp images, the 3 critical synergistic components of anesthesia—patient evaluation, tailored anesthesia protocols, and vital sign monitoring—form a stable base for safe and effective anesthetic procedures. Client communication is equally important in achieving happy anesthesia results. We need to take the time to explain the necessity of anesthesia for proper dental care, potential risks and benefits, expected recovery time, and postoperative care instructions. This open dialogue helps alleviate owner anxiety and sets realistic expectations for the procedure and recovery process.
Patient evaluation
Similar to assessing the landscape before setting up a shot, thorough preanesthetic evaluation is crucial for identifying potential risks and tailoring the anesthetic approach. The American Veterinary Medical Association and American Animal Hospital Association mandate that all dental procedures be performed under general anesthesia. This makes sense, but how can you transform the anxiety caused by general anesthesia in dentistry into a blissful experience for you and your patients? Start with the physical examination and testing to determine the American Society of Anesthesiologists (ASA) scoring. In addition to the physical examination and history, the ASA score helps you decide what additional testing is indicated before anesthesia. (Figure 2)
The patient assessment may include comprehensive blood work (complete blood cell count, chemistry panel, and electrolytes), urinalysis, chest radiographs for older patients or those with suspected cardiopulmonary issues, and N-terminal pro b-type natriuretic peptide (NT-proBNP). This detailed evaluation helps identify any underlying health concerns affecting anesthesia safety.
One example is our dog KC, a 4-year-old Polish lowland sheepdog, which we had since a puppy and had no clinical signs of kidney disease. It was time for his first professional comprehensive oral prevention, assessment, and treatment visit. His blood tests revealed end-stage kidney disease. The procedure was canceled and he passed 6 months later.
A study evaluated more than 2000 dogs who underwent anesthesia. A death rate of just over 1% (26 patients) was recorded. A direct correlation was found between the patients’ ASA score and the death rate1:
- A total of 0.3% of fatalities involved ASA 1 and 2 scores.
- A total of 1.7% of fatalities involved ASA 3 scores.
- A total of 13% of fatalities involved ASA 4 or 5 scores.
- Approximately one-fourth of the deaths happened during surgery, whereas the others occurred in the postoperative period. This is a good reminder that patients should be monitored closely after extubation.
Tailored anesthesia protocol
Evaluating your dental patient
American Society of Anesthesiologists classifications
Class 1: Minimal risk in an average healthy patient with no underlying disease
Class 2: Slight to mild risk of systemic disease, especially in neonates, older patients, and those with obesity
Class 3: Moderate risk and apparent systemic disease involving anemia, moderate dehydration, fever, low-grade heart murmur, or cardiac disease
Class 4: High risk with severe, systemic, life-threatening disease involving severe dehydration, shock, uremia, toxemia, high fever, uncompensated heart disease, uncompensated diabetes, pulmonary disease, and emaciation
Class 5: Extreme risk of moribund state, with patient facing likely death with or without surgery, involving advanced cases of heart, kidney, liver, or endocrine disease; profound shock; severe trauma; pulmonary embolus; and terminal malignancy
Resembling adjustments of camera International Organization for Standardization sensitivity, f-stop, and speed settings adjustments for specific lenses and lighting conditions, anesthesia protocols must be customized to each patient’s unique physiological needs and anticipated procedure duration.
This is a good starting point, which may need modification for dental procedures:
- For premedication, a combination of an opioid (eg, hydromorphone 0.05-0.1 mg/kg intramuscular [IM] or fentanyl 3 μg/kg) and a benzodiazepine (eg, midazolam 0.2-0.3 mg/kg IM) can provide excellent sedation and analgesia.
- Preoxygenation is performed using a maskvto deliver medical oxygen for 5 minutes.
- Propofol (4-6 mg/kg intravenous [IV]) orvalfaxalone (2-3 mg/kg IV) is excellent for smooth induction. These agents allow for rapid, controlled induction with minimal cardiovascular effects.
- Inhalation anesthesia with isoflurane or sevoflurane is typically used for maintenance. It is recommended that the concentration should be 2% to 3% and that the number should be adjusted based on patient response and monitoring parameters.
- Fentanyl constant-rate infusion (3-10 μg/kg/h) should be used for specific cases where minimum alveolar concentration reduction is desired and there is a need to alter analgesia throughout the procedure.
- Incorporating local anesthesia techniques can significantly enhance pain management and reduce the required depth of general anesthesia.
Consider the following nerve blocks for dental procedures. Long-acting local anesthetics such as bupivacaine 0.5% (0.1-0.5 mL per site) can provide extended operative and postoperative pain relief for 6 to 8 hours.
- Infraorbital nerve block for same-sided maxillary incisors, canines, and premolars
- Maxillary nerve block for same-sided maxillary teeth
- Mandibular nerve block for same-sided mandibular teeth
- Mental nerve block for samesided mandibular incisors, canines, and premolars
Ventilators or not?
Incorporating a ventilator into the anesthesia protocol offers benefits and can significantly ease the management of patients under general anesthesia, particularly in its ability to provide precise ventilation control. These devices allow for accurate delivery of tidal volumes and respiratory rates, ensuring optimal gas exchange and oxygenation. Precise control is especially beneficial for patients with compromised respiratory function. Ventilators with ascending bellows technology provide immediate visual feedback on proper ventilation and allow for quick detection of leaks or disconnections on a breath-by-breath basis. This enhanced patient safety feature enables prompt identification and resolution of potential issues, significantly reducing risks associated with mechanical ventilation. The use of ventilators in anesthesia practice also leads to a reduced workload for anesthesia providers. Automatic ventilation frees the anesthesiologist to focus on other aspects of patient care, medication administration, and monitoring. Ventilators offer various ventilation modes, including pressure-controlled, volume-controlled, and support modes for spontaneously breathing patients. This flexibility allows for tailored ventilation strategies based on individual patient needs and dental requirements.
Vital sign monitoring
Continuous monitoring during anesthesia is akin to constantly checking composition and exposure in photography, allowing for real-time adjustments to ensure optimal outcomes. Effective monitoring is crucial for patient safety during dental procedures. A portable multiparameter monitor is ideal, providing essential physiological readings, including electrocardiogram, pulse oximetry, capnography, blood pressure, and patient temperature. These monitors typically feature a touch screen interface and compact design, making them well suited for dental procedures across various clinical settings. The comprehensive data provided allow us to respond quickly to changes in patient status.
Customizable alarms allow us to set patient-specific limits, ensuring prompt alerts to potential issues. Trend analysis enables the review of physiological data over time, helping identify subtle patient status changes that might go unnoticed. Some models offer network connectivity, facilitating remote monitoring and consultation with specialists when needed. Capnography offers end-tidal, inspired, and real-time CO2 waveforms and crucial information about the patient’s ventilation status. Temperature monitoring is facilitated by calibrated modules with flexible probes for easy rectal or esophageal placement. Pulse oximetry technology delivers accurate readings of saturation of peripheral oxygen even in challenging conditions such as low perfusion or patient movement. These features collectively enhance the monitor’s ability to provide reliable, real-time data, supporting safe and effective patient care during dental procedures.
Get help
Happy anesthesia is achievable in virtually all situations. We are fortunate to have excellent advice from our vendors, boarded anesthesiologists, and veterinary technician specialists certified in anesthesia (VTS-anesthesia) available for the asking.
The results achieved through tripod based landscape photography demonstrate the importance of a stable foundation, much like the outcomes of well-managed anesthesia. In both scenarios, preparation, proper equipment use, and vigilance lead to superior results, be it in capturing stunning landscapes or ensuring patient safety through anesthesia during dental procedures. (Figure 3)
The journey toward happy anesthesia is ongoing, requiring dedication, continuous learning, and a commitment to excellence. By combining our clinical expertise with advanced monitoring technologies, we can elevate the standard of care in veterinary dental anesthesia, ensuring safer procedures, more comfortable patients, and more satisfied clients. This foray into landscape photography expanded my photographic skills and reinforced the principles of excellence in veterinary anesthesia. The parallels between these seemingly disparate fields underscore the universal importance of preparation, adaptability, and attention to detail in achieving optimal outcomes, whether in capturing images or providing veterinary care.
REFERENCE
1. Gil L, Redondo JI. Canine anaesthetic death in Spain: a multicentre prospective cohort study of 2012 cases. Vet Anaesth Analg. 2013;40(6):e57-e67. doi:10.1111/vaa.12059
