Dexmedetomidine (DEX) has a minimal respiratory depressive effect, which is beneficial for dentistry; however, it has the disadvantage of permitting an intraoperative arousal response such that the patient appears to be suddenly no longer sedated, and it has a variable amnestic effect. Since midazolam (MDZ) in an appropriate dose has a profound amnesic effect, we investigated whether additional MDZ compensates for the disadvantage of DEX and enables a better quality of sedation. Forty-three subjects were randomly divided into 4 groups. In group 1, MDZ (0.02 mg/kg) was administered intravenously, followed by a dose of 0.01 mg/kg every 45 minutes. After the first dose of MDZ, preloading with DEX (2 µg/kg/h for 10 minutes) was started and maintained with a dosage of 0.5 µg/kg/h. In group 2, MDZ was infused in the same manner as in group 1, followed by preloading with DEX (1 µg/kg/h for 10 minutes) and maintenance (0.3 µg/kg/h). In group 3, MDZ was infused 0.03 mg/kg, and a dose of 0.01 mg/kg was given every 30 minutes; DEX was administered at the same as in group 2. In group 4, DEX was infused using the same method as in group 1 without MDZ. The sedation levels, amnesia, and patient satisfaction were also investigated. Group 2 had a lower sedation level and a poor evaluation during the first half of the operation. Group 4 did not exhibit an amnesic effect at the beginning of the operation. An evaluation of the degree of patient satisfaction did not reveal any differences among the groups. Optimal sedation was achieved through the combined use of MDZ (0.02 mg/kg with the addition of 0.01 mg/kg every 45 minutes) and DEX (2 µg/kg/h for 10 minutes followed by 0.5 µg/kg/h).
Dexmedetomidine; Midazolam; Sedation; Dental treatment; Implant; Amnesia
We audited the recovery characteristics of 51 patients who had undergone orthognathic maxillofacial surgery at a single center. Patients whose anesthesia had been maintained with intravenous propofol and remifentanil (n = 21) had significantly higher pain scores during the first 4 hours after surgery than those whose anesthesia was maintained with volatile inhalational agents and longer-acting opioids (n = 30) (P = .016). There was a nonsignificant trend towards shorter recovery times in the former group, while there were no differences in early postoperative opioid usage, hemodynamic parameters, or postoperative nausea and vomiting . Given that our data were collected retrospectively and without the ability to control for potential confounders, we interpret the results with caution. Notwithstanding these limitations, we believe this is the first report comparing the effects of different opioid-based anesthetic regimens on early recovery from orthognathic surgery, and we believe this report may be used as the starting point for a controlled study.
Propofol; Remifentanil; Inhalation anesthesia; Orthognathic surgery
The effects of infiltration anesthesia with ropivacaine on the dental pulp are considered to be weak. This may be partly associated with its permeation into the oral tissue. With the objective of investigating the local pharmacokinetics of ropivacaine and lidocaine following infiltration anesthesia, we injected 3H-ropivacaine or 14C-lidocaine to the palatal mucosa in rats, measured distributions of radioactivity in the maxilla, and compared the local pharmacokinetics of these agents. The animals were sacrificed at various times and the maxillas were removed. The palatal mucosa and maxillary nerve were resected, and the bone was divided into 6 portions. We measured radioactivity in each tissue and calculated the level of each local anesthetic (n = 8). Lidocaine diffused to the surrounding tissue immediately after the injection, whereas ropivacaine tended to remain in the palatal mucosa for a longer period. Lidocaine showed a higher affinity for the maxillary bone than ropivacaine. There was a correlation between the distribution level of local anesthetics in the maxillary bone and that in the maxillary nerve. The lower-level effects of infiltration anesthesia with ropivacaine on the dental pulp may be because ropivacaine has a high affinity for soft tissue, and its transfer to bone is slight.
Ropivacaine; Lidocaine; Infiltration anesthesia; Local pharmacokinetics
We report an unexpected failed laryngeal mask airway in a patient with unrecognized lingual tonsil hypertrophy (LTH). A 19-year-old obese woman presented for extraction of multiple teeth via intravenous general anesthesia. Surgery was interrupted due to a laryngospasm midway through the procedure. The laryngospasm required the existing laryngeal mask airway to be removed so the patient could be suctioned. Although it is unclear the extent of obstruction caused by LTH, the surgery had to be postponed due to the discovery of enlarged lingual tonsils, which prevented endotracheal intubation. One reason for unexpected difficult airways is attributed to LTH. It is recognized that LTH is more common in patients with obstructive sleep apnea; however, LTH also has an increased prevalence in obese children with prior palatine tonsillectomies or adenoidectomies. Unexpected LTH can complicate general anesthesia by making placement of a laryngeal mask airway difficult. Thus, further research needs to be conducted to gain a deeper understanding on how to reduce the risks presented by LTH during sedation surgeries.
Lingual tonsil hypertrophy; Endotracheal intubation; Laryngospasm; Anesthesia; Sedation; Complication; Intubation
We read with great interest the anesthetic technique of using a gum elastic bougie (GEB) for nasal intubation in a recent issue of Anesthesia Progress. The authors recommend the use of GEB for the first attempt of nasotracheal intubation in patients with a difficult airway. We agree that this is an excellent alternative. We also have found an excellent variation of this method that utilizes a double bougie technique for insertion of a nasotracheal tube if the difficult airway can be secured initially with an orotracheal tube.
Dual bougie technique; Nasotracheal intubation
Masticatory muscle tendon-aponeurosis hyperplasia (MMTAH) is a new disease entity characterized by limited mouth opening due to contracture of the masticatory muscles, resulting from hyperplasia of tendons and aponeuroses. In this case series, we report what methods of airway establishment were conclusively chosen after rapid induction of anesthesia. We had 24 consecutive patients with MMTAH who underwent surgical release of its contracture under general anesthesia. Rapid induction of anesthesia with propofol and rocuronium was chosen for all the cases. In 7 cases, intubation using the Macintosh laryngoscopy was attempted; however, 2 of those cases failed to be intubated on the first attempt. Finally, intubation using the McCoy laryngoscopy or fiber-optic intubation was alternatively used in these 2 cases. In 7 cases, the Trachlight was used. In the remaining 10 cases, fiber-optic intubation was used. Limited mouth opening in patients with MMTAH did not improve with muscular relaxation. “Square mandible” has been reported to be one of the clinical features in this disease; however, half of these 24 patients lacked this characteristic, which might affect a definitive diagnosis of this disease for anesthesiologists. An airway problem in patients with MMTAH should not be underestimated, which means that other intubation methods rather than direct laryngoscopy had better be considered.
Masticatory muscle tendon-aponeurosis hyperplasia; Square mandible; Difficult airway management
Local anesthetics have an impressive history of efficacy and safety in medical and dental practice. Their use is so routine, and adverse effects are so infrequent, that providers may understandably overlook many of their pharmacotherapeutic principles. The purpose of this continuing education article is to provide a review and update of essential pharmacology for the various local anesthetic formulations in current use. Technical considerations will be addressed in a subsequent article.
Local anesthetics; Pharmacology; Drug toxicity; Dentistry
The purpose of this study is to explore the use of office-based sedation by board-certified pediatric dentists practicing in the United States. Pediatric dentists have traditionally relied upon self-administered sedation techniques to provide office-based sedation. The use of dentist anesthesiologists to provide office-based sedation is an emerging trend. This study examines and compares these two models of office-based sedations. A survey evaluating office-based sedation of diplomates of the American Board of Pediatric Dentistry (ABPD) based on gender, age, years in practice, practice types, regions, and years as a diplomate of the ABPD was completed by 494 active members. The results were summarized using frequencies and percentages. Relationships of dentist age, gender, and number of years in practice with the use of intravenous (IV) sedation was completed using two-way contingency tables and Mantel-Haenszel tests for ordered categorical data. Relationships of office-based sedation use and the type of one's practice were examined using Pearson chi-square tests. Of the 1917 surveys e-mailed, 494 completed the survey for a response rate of 26%. Over 70% of board-certified US pediatric dentists use some form of sedation in their offices. Less than 20% administer IV sedation, 20 to 40% use a dentist anesthesiologist, and 60 to 70% would use dentist anesthesiologists if one were available.
Office-based; Dentist-anesthesiologist; Pediatric dentist
The purpose of this study was to examine how submucosal injection of a clinically relevant dose of a lidocaine hydrochloride solution containing epinephrine affects the muscle relaxant effects of rocuronium bromide. Sixteen patients scheduled for orthognathic surgery participated in this study. All patients were induced with fentanyl citrate, a target-controlled infusion of propofol and rocuronium bromide. Anesthesia was maintained by total intravenous anesthesia. After nasotracheal intubation, an infusion of rocuronium bromide was started at 7 µg/kg/min, and the infusion rate was then adjusted to maintain a train of four (TOF) ratio at 10 to 15%. The TOF ratio just prior to oral mucosal injection of a 1% lidocaine hydrochloride solution containing 10 µg/mL epinephrine (LE) was taken as the baseline. TOF ratio was observed for 20 minutes, with 1-minute intervals following the start of injection. Mean epinephrine dose was 85.6 ± 18.6 µg and mean infusion rate of rocuronium bromide was 6.3 ± 1.6 µg/kg/min. TOF ratio began to decrease 2 minutes after the injection of LE, reached the minimum value at 3.1 ± 3.6% 12 minutes after the injection, and then began to recover. We conclude that oral mucosal injection of LE enhances the muscle relaxant effects of rocuronium bromide.
Rocuronium; Lidocaine with epinephrine; Muscle relaxant effects
Facial nerve palsy, as a complication of an inferior alveolar nerve block anesthesia, is a rarely reported incident. Based on the time elapsed, from the moment of the injection to the onset of the symptoms, the paralysis could be either immediate or delayed. The purpose of this article is to report a case of delayed facial palsy as a result of inferior alveolar nerve block, which occurred 24 hours after the anesthetic administration and subsided in about 8 weeks. The pathogenesis, treatment, and results of an 8-week follow-up for a 20-year-old patient referred to a private maxillofacial clinic are presented and discussed. The patient's previous medical history was unremarkable. On clinical examination the patient exhibited generalized weakness of the left side of her face with a flat and expressionless appearance, and she was unable to close her left eye. One day before the onset of the symptoms, the patient had visited her dentist for a routine restorative procedure on the lower left first molar and an inferior alveolar block anesthesia was administered. The patient's medical history, clinical appearance, and complete examinations led to the diagnosis of delayed facial nerve palsy. Although neurologic occurrences are rare, dentists should keep in mind that certain dental procedures, such as inferior alveolar block anesthesia, could initiate facial nerve palsy. Attention should be paid during the administration of the anesthetic solution.
Inferior alveolar nerve block; Facial nerve palsy
Moderate and deep sedation can be provided using various classes of drugs, each having unique mechanisms of action. While drugs within a given classification share similar mechanisms and effects, certain classes demonstrate superior efficacy but added concern regarding safety. This continuing education article will highlight essential principles of pharmacodynamics and apply these to drugs commonly used to produce moderate and deep sedation.
Pharmacodynamics; Drug actions; Drug mechanisms; Sedation
This study describes what training programs in pediatric dentistry and dental anesthesiology are doing to meet future needs for deep sedation/general anesthesia services required for pediatric dentistry. Residency directors from 10 dental anesthesiology training programs in North America and 79 directors from pediatric dentistry training programs in North America were asked to answer an 18-item and 22-item online survey, respectively, through an online survey tool. The response rate for the 10 anesthesiology training program directors was 9 of 10 or 90%. The response rate for the 79 pediatric dentistry training program directors was 46 of 79 or 58%. Thirty-seven percent of pediatric dentistry programs use clinic-based deep sedation/general anesthesia for dental treatment in addition to hospital-based deep sedation/general anesthesia. Eighty-eight percent of those programs use dentist anesthesiologists for administration of deep sedation/general anesthesia in a clinic-based setting. Pediatric dentistry residency directors perceive a future change in the need for deep sedation/general anesthesia services provided by dentist anesthesiologists to pediatric dentists: 64% anticipate an increase in need for dentist anesthesiologist services, while 36% anticipate no change. Dental anesthesiology directors compared to 2, 5, and 10 years ago have seen an increase in the requests for dentist anesthesiologist services by pediatric dentists reported by 56% of respondents (past 2 years), 63% of respondents (past 5 years), and 88% of respondents (past 10 years), respectively. Predicting the future need of dentist anesthesiologists is an uncertain task, but these results show pediatric dentistry directors and dental anesthesiology directors are considering the need, and they recognize a trend of increased need for dentist anesthesiologist services over the past decade.
Demand for services; Dental anesthesiologist; Pediatric dentist
The purpose of this prospective, randomized, single-blind study was to determine the anesthetic efficacy of lidocaine with epinephrine compared to lidocaine with epinephrine plus 0.5 M mannitol in inferior alveolar nerve (IAN) blocks. Forty subjects randomly received an IAN block in 3 separate appointments spaced at least 1 week apart using the following formulations: a 1.8 mL solution of 36 mg lidocaine with 18 µg epinephrine (control solution); a 2.84 mL solution of 36 mg lidocaine with 18 µg epinephrine (1.80 mL) plus 0.5 M mannitol (1.04 mL); and a 5 mL solution of 63.6 mg lidocaine with 32 µg epinephrine (3.18 mL) plus 0.5 M mannitol (1.82 mL). Mandibular teeth were blindly electric pulp tested at 4-minute cycles for 60 minutes postinjection. No response from the subject to the maximum output (80 reading) of the pulp tester was used as the criterion for pulpal anesthesia. Mean percent total pulpal anesthesia was defined as the total of all the times of pulpal anesthesia (80 readings) over the 60 minutes. Pain of solution deposition and postoperative pain were also measured. The results demonstrated that 2.84 mL of lidocaine with epinephrine plus 0.5 M mannitol was significantly better than 1.8 mL of lidocaine with epinephrine for the molars and premolars. The 5 mL of lidocaine with epinephrine plus 0.5 M mannitol was statistically better than 1.8 mL of lidocaine with epinephrine and 2.84 mL of lidocaine with epinephrine plus 0.5 M mannitol for all teeth except the central incisor. Solution deposition pain and postoperative pain were not statistically different among the mannitol formulations and the lidocaine formulation without mannitol. We concluded that adding 0.5 M mannitol to lidocaine with epinephrine formulations significantly improved effectiveness in achieving a greater percentage of total pulpal anesthesia compared with a lidocaine formulation without mannitol for IAN block.
Inferior alveolar nerve block; Lidocaine; Mannitol
Moderate and deep sedation can be provided using several routes of drug administration including oral (PO), inhalation, and parental injection. The safety and efficacy of these various techniques is largely dependent on pharmacokinetic principles. This continuing education article will highlight essential principles of absorption, distribution, and elimination of commonly used sedative agents.
Pharmacokinetics; Drug administration; Sedation
The death of a patient under sedation in New South Wales, Australia, in 2002 has again raised the question of the safety of dental sedation. This study sought answers to 2 questions: Can safe oxygen saturation levels (≥94%) be consistently maintained by a single operator/sedationist? Does the additional use of propofol, in subanesthetic doses, increase the risk of exposure to hypoxemia? Three thousand five hundred cases generated between 1996 and 2006 were randomly examined and divided into 2 subcohorts: 1750 patients were sedated with midazolam and fentanyl, and 1750 patients received propofol, in subanesthetic increments, in addition to midazolam and fentanyl. Initial sedation was established using midazolam and fentanyl in both subcohorts. The second subcohort received propofol during times of noxious stimulation. Patient exposure to 2 or more oxygen desaturations below 94% was uncommon. The variables that were significantly associated with low saturations were age, gender, and weight. Neither the dose of midazolam nor the additional use of propofol was a significant risk factor. ASA classification (I or II) was not a determinant of risk. The data, within the limitations of the study, showed that a single operator/sedationist, supported by a well-trained team of nurses, can consistently maintain safe oxygen saturation levels. The additional use of propofol did not increase exposure to hypoxemia.
Dental sedation; Safe oxygen saturation levels; Propofol
Nasal foreign bodies may result from the abundant availability of tiny objects in our society and a curious child exploring his or her nasal cavities. An inserted object that is not witnessed or retrieved can remain relatively asymptomatic or cause local tissue damage and potentially yield more serious consequences. An unusual case of a young child who presented for dental rehabilitation under general anesthesia is described. Immediately prior to the nasotracheal intubation, an unanticipated foreign body was detected and safely removed before any injury occurred. This case report discusses the presentation and pathophysiology of nasal foreign bodies. Moreover, applicable suggestions are provided to aid in the prevention and management of the unexpected discovery of a nasal foreign body after the induction of general anesthesia.
The risk for cardiovascular complications while providing any level of sedation or general anesthesia is greatest when caring for patients already medically compromised. It is reassuring that significant untoward events can generally be prevented by careful preoperative assessment, along with attentive intraoperative monitoring and support. Nevertheless, providers must be prepared to manage untoward events should they arise. This continuing education article will review cardiovascular complications and address their appropriate management.
Medical emergencies; Sedation; Anesthesia; Complications