Intraoperative Fluids and Fluid Management for Ambulatory Dental Sedation and General Anesthesia

Intravenous fluids are administered in virtually every parenteral sedation and general anesthetic. The purpose of this article is to review the physiology of body-water distribution and fluid dynamics at the vascular endothelium, evaluation of fluid status, calculation of fluid requirements, and the clinical rationale for the use of various crystalloid and colloid solutions. In the setting of elective dental outpatient procedures with minor blood loss, isotonic balanced crystalloid solutions are the fluids of choice. Colloids, on the other hand, have no use in outpatient sedation or general anesthesia for dental or minor oral surgery procedures but may have several desirable properties in long and invasive maxillofacial surgical procedures where advanced hemodynamic monitoring may assess the adequacy of intravascular volume.Key Words: Intravenous fluids, Ambulatory, Sedation, General anesthesia, Dentistry, Crystalloids, ColloidsIntravenous fluids are administered in almost every parenteral sedation and general anesthetic.¹ Historically, sedative medications were administered using a variety of methods that included barbotage, intramuscular injection, or inhalation of volatile agents. The goal of intravenous fluid therapy in anesthetic practice is to maintain adequate tissue perfusion and oxygen delivery,^1–3 and, in most cases, provide a fluid vehicle for drug administration. Decisions regarding the type and amount of fluids administered intraoperatively may affect postoperative outcomes.¹ This article reviews the physiology of body-water distribution and fluid dynamics at the vascular endothelium, evaluation of volume status, calculation of fluid requirements, and the clinical rationale for the use of various crystalloid and colloid solutions.     

Assessing the Need for Anesthesia and Sedation Services in Kuwaiti Dental Practice

The objective of this study was to examine the public health relevance of the prevalence of dental fear in Kuwait and the resultant barrier that it creates regarding access to dental care. The study analysis demonstrated a high prevalence of dental fear and anxiety in the Kuwaiti population and a perceived need for anesthesia services by dental care providers. The telephone survey of the general population showed nearly 35% of respondents reported being somewhat nervous, very nervous, or terrified about going to the dentist. In addition, about 36% of the population postponed their dental treatment because of fear. Respondents showed a preference to receive sedation and anesthesia services as a means of anxiety relief, and they were willing to go to the dentist more often when such services were available. People with high fear and anxiety preferred to receive some type of medication to relieve their anxiety. In conclusion, the significance and importance of the need for anesthesia services to enhance the public health of dental patients in Kuwait has been demonstrated, and improvements are needed in anesthesia and sedation training of Kuwaiti dental care providers.     

French Survey of Anesthesia in 1996

Background: To identify the growth in the number of anesthetic procedures since 1980 and the changes in the practice of anesthesia, the present survey was designed to collect and analyze the anesthetic activity performed in France in 1996, from a representative sample collected in all French hospitals and clinics.

Methods: This study, initiated by the French Society of Anesthesia and Intensive Care, collected information that included the characteristics of patients (age, sex, American Society of Anesthesiologists status), the techniques of anesthesia, and the nature of the procedure for which anesthesia was required. All French private, public, and military hospitals were asked to participate in the survey. In each hospital in the country, all anesthetic procedures were documented and collected during 3 consecutive days, chosen at random during a 12-month period, to obtain a representative sample of the annual activity. All data were analyzed at the INSERM (National Institute of Health and Medical Research). At the conclusion of the study, 5% of hospitals were randomly assigned to be audited to check for missing data and errors. The rate of anesthetic activity was calculated as the ratio between the annual number of anesthetic procedures and the number of the general population in the same age group.

Results: The participation rate of hospitals was 98%. The analysis of the 62,415 collected questionnaires allowed extrapolation of the anesthetic activity to 7,937,000 anesthetic procedures (95% confidence interval, +/- 387,000) performed in France in 1996. Thus, the annual rate of anesthetic procedures was 13.5 per 100 population, varying between 5.4 per 100 in girls aged 5-14 yr and 30.2 per 100 in men aged 75-84 yr. Surgery was involved in 71% of anesthesia cases. Regional anesthesia alone was performed in 20% of all surgical cases and was combined with general anesthesia in 3% of additional cases. Anesthesia for obstetric procedures represented 9% of all cases. Seventy-six percent of all anesthetic procedures started between 12:00 A.M. and 7:00 A.M. were related to obstetric activities.     

Sedation during Spinal Anesthesia

Background: Central neuraxial anesthesia has been reported to decrease the dose of both intravenous and inhalational anesthetics needed to reach a defined level of sedation. The mechanism behind this phenomenon is speculated to be decreased afferent stimulation of the reticular activating system. The authors performed a two-part study (nonrandomized pilot study and a subsequent randomized, double-blind, placebo-controlled study) using the Bispectral Index (BIS) monitor to quantify the degree of sedation in unmedicated volunteers undergoing spinal anesthesia.

Methods: Twelve volunteers underwent BIS monitoring and observer sedation scoring (Observer's Assessment of Alertness/Sedation Scale [OAA/S]) before and after spinal anesthesia with 50 mg hyperbaric lidocaine, 5%. Subsequently, 16 volunteers blinded to the study were randomized to receive spinal anesthesia with 50 mg hyperbaric lidocaine, 5% (n = 10) or placebo (n = 6) and underwent BIS and OAA/S monitoring.

Results: In part I, significant changes in BIS scores of the volunteers occurred progressively (P = 0.003). The greatest variations from baseline BIS measurement occurred at 30 and 70 min. In part II, there were significant decreases in OAA/S and self-sedation scores for patients receiving spinal anesthesia versus control patients (P = 0.04 and 0.01, respectively). The greatest decrease in OAA/S scores occurred at 60 min. BIS scores were similar between groups (P = 0.4).     

Airway Assessment for Office Sedation/Anesthesia

Whenever a patient is about to receive sedation or general anesthesia, no matter what the technique, the preoperative assessment of the airway is one of the most important steps in ensuring patient safety and positive outcomes. This article, Part III in the series on airway management, is directed at the ambulatory office practice and focuses on predicting the success of advanced airway rescue techniques.Key Words: Airway management, Airway evaluation, Emergency rescue, Sedation, AnesthesiaA thorough and focused assessment of the airway prior to the planned administration of moderate sedation or deep sedation/general anesthesia (GA) is of vital importance. Over the years, studies of closed claims have focused on the association of respiratory and airway issues with mortality and severe morbidity in hospital and off-site locations.^1–3 The Closed Claims Project of the American Society of Anesthesiologist (ASA) evaluated adverse anesthetic outcomes obtained from the closed claim files of 35 U.S. liability insurance companies. This database dates from 1985 and accrues about 300 cases per year. One of the first reviews of this data evaluated respiratory events, the most common cause of adverse outcomes.⁴ This study found that respiratory events were the single largest class of injury and accounted for 34% of all claims. Eighty-five percent of these adverse outcomes resulted in death or brain damage. Critical review found that most could have been prevented. It is not surprising that 30% of the mortalities in these claims were attributable to anesthetic malpractice and were the result of an inability to establish an airway, ventilate, and/or oxygenate patients when airway loss occurred. More recent examination of the data looked at outcomes from perioperative airway claims filed between 1985 and 1999. In this series, 57% of claims resulted in brain damage or loss of life, with the difficult airway being encountered upon induction.In an effort to improve management of the difficult airway, the ASA released their original difficult airway algorithm in 1993 and have updated it more than once to include newer advanced airway adjuncts.^5–7 This algorithm is recognized as a national standard and begins by stressing the importance of assessing the likelihood and clinical impact of basic airway management problems during the induction of anesthesia. It systematically provides alternative pathways for airway rescue for both known and unsuspected difficult airways (Figure). Positive findings during this preoperative examination will determine whether the patient is suitable for treatment in the outpatient setting, the risk/benefit ratio of various sedative/anesthetic techniques including airway maintenance adjuncts available to the clinician, and the skill set required of the professional necessary to rescue the patient if the airway becomes obstructed or compromised (​through55).⁸Open in a separate windowAmerican Society of Anesthesiologists difficult airway algorithm.⁷

Table 1.

Airway Evaluation Considerations*Open in a separate window

Table 5.

Physical Findings Suggestive of Difficult Airway ManagementOpen in a separate window     

Use of Local Anesthesia During Dental Rehabilitation With General Anesthesia: A Survey of Dentist Anesthesiologists

The purpose of this study was to document current practices of dentist anesthesiologists who are members of the American Society of Dentist Anesthesiologists regarding the supplemental use of local anesthesia for children undergoing dental rehabilitation under general anesthesia. A survey was administered via e-mail to the membership of the American Society of Dentist Anesthesiologists to document the use of local anesthetic during dental rehabilitations under general anesthesia and the rationale for its use. Seventy-seven (42.1%) of the 183 members responded to this survey. The majority of dentist anesthesiologists prefer use of local anesthetic during general anesthesia for dental rehabilitation almost always or sometimes (90%, 63/70) and 40% (28/70) prefer its use with rare exception. For dentist anesthesiologists who prefer the administration of local anesthesia almost always, they listed the following factors as very important: “stabilization of vital signs/decreased depth of general anesthesia” (92.9%, 26/28) and “improved patient recovery” (82.1%, 23/28). There was a significant association between the type of practice and who determines whether or not local anesthesia is administered during cases. The majority of respondents favor the use of local anesthesia during dental rehabilitation under general anesthesia.Key Words: Local anesthesia, Hospital dentistry, General anesthesia, Restorative dentistryGeneral anesthesia is a form of advanced behavior management utilized by dentists to provide quality dental care for children otherwise unable to tolerate dentistry in an outpatient setting.¹ The use of local anesthesia in conjunction with general anesthesia is an area with conflicting research.The addition of local anesthesia during dental rehabilitations has some potential benefits: decreased postoperative pain, improved hemorrhage control, and reduced need for anesthesiologist intervention. In regards to postoperative pain, Noble et al found in a randomized controlled trial that patients undergoing extractions under general anesthesia in the absence of systemic analgesics were less likely to be distressed upon recovery if local anesthetic infiltration was also utilized.² Atan et al also found a significant decrease in pain at the operation site in patients who received supplemental local anesthesia.³ In a randomized controlled study, Sammons et al showed a statistically significant decrease in pain following extractions if local anesthesia was added; however, this difference was significant only after 5 minutes.⁴The use of local anesthesia with general anesthesia has been advocated to improve physiological parameters during general anesthesia. Watts et al found the heart rate and end-tidal carbon dioxide stayed stable for patients undergoing dental treatment with supplemental local anesthesia versus children under general anesthesia without local anesthesia. In addition, patients with local anesthesia required less frequent anesthesiologist intervention. The change in heart rate and end-tidal CO₂ was statistically lower in children with local anesthesia versus children without it.⁵ Although these physiologic changes are statistically significant, the temporary increase in heart rate and respiratory rate following extraction or crown placement may not be clinically meaningful in the treatment of a healthy child.^5,6Conflicting studies have shown no difference in postoperative pain with the use of local anesthetic in conjunction with general anesthesia.^7–9 Al-Bahlani et al did not study postoperative pain but did report a “clear and marked increased in the measures of distress post-operatively” in anesthetized children who received infiltration with local analgesic.¹⁰ Topical anesthetics have also been suggested to reduce postoperative pain following general anesthesia, but Gazal et al did not find a difference compared to when topical anesthetics were not used.¹¹ Although some authors have expressed concern that the addition of local anesthesia would increase lip and cheek biting, a statistically significant association between lip and cheek biting and local anesthesia has not been shown.^7,8A recent survey of pediatric dentist and general dentist members of the American Academy of Pediatric Dentistry (AAPD) about their use of local anesthesia on children undergoing dental rehabilitations under general anesthesia found a spectrum of practices and rationales.¹²The purpose of this study was to document the current practices of dentists who are members of the American Society of Dentist Anesthesiologists (ASDA) regarding their use of local anesthesia on children undergoing dental rehabilitations under general anesthesia.