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Background and aims

Dentists administer thousands of local anesthetic injections every day. Injection to a highly vascular area such as pterygomandibular space during an inferior alveolar nerve block has a high risk of intravascular needle entrance. Accidental intravascular injection of local anesthetic agent with vasoconstrictor may result in cardiovascular and central nervous system toxicity, as well as tachycardia and hypertension. There are reports that indicate aspiration is not performed in every injection. The aim of the present study was to assess the incidence of intravascular needle entrance in inferior alveolar nerve block injections.

Materials and methods

Three experienced oral and maxillofacial surgeons performed 359 inferior alveolar nerve block injections using direct or indirect techniques, and reported the results of aspiration. Aspirable syringes and 27 gauge long needles were used, and the method of aspiration was similar in all cases. Data were analyzed using t-test.

Results

15.3% of inferior alveolar nerve block injections were aspiration positive. Intravascular needle entrance was seen in 14.2% of cases using direct and 23.3% of cases using indirect block injection techniques. Of all injections, 15.8% were intravascular on the right side and 14.8% were intravascular on the left. There were no statistically significant differences between direct or indirect block injection techniques (P = 0.127) and between right and left injection sites (P = 0.778).

Conclusion

According to our findings, the incidence of intravascular needle entrance during inferior alveolar nerve block injection was relatively high. It seems that technique and maneuver of injection have no considerable effect in incidence of intravascular needle entrance.

This article presents a different method of venous cannulation. It has been used successfully to teach dental residents working on pediatric and developmentally disabled patients. The technique includes using a syringe of 1% lidocaine hydrochloride attached to a 25-ga needle to produce a skin wheal by "jet injection." This is accomplished by placing the bevel of the needle downward and forcing the syringe in a downward and backward direction, with pressure being continuously exerted on the plunger. A 20-ga, 1 1/4-inch catheter is then attached to the syringe containing the remaining lidocaine hydrochloride. The catheter is bent, with its bevel up, approximately three-fourths of the way from the tip to form a gradually sloping bend of approximately 40 degrees to 45 degrees. The catheter is then inserted into the skin wheal and advanced into the vein. The advantages of this technique are that it (1) can eliminate the pain associated with a subcutaneous infiltration of a local anesthetic solution, (2) provides a method of venous cannulation that is easier to master by the novice, and (3) gives a visual check on successful catheterization of the vein.

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The results of 101 pyloromyotomies performed from 1972 to 1980 have been analysed; 34 operations were performed using local anaesthesia and 67 using general anaesthesia. The use of local anaesthesia was not associated with any advantage related to postoperative or other complications. A high postoperative complication rate of 20% was found (excluding postoperative vomiting), and there were 2 deaths; 11 patients suffered wound infection, with Staphylococcus aureus isolated from 5 of these wounds. The use of prophylactic antibiotics active against Staphylococcus aureus is suggested.

Background

Epidural analgesia is commonly used to provide several types of pain relief. Although this technique has been widely used with many advantages, currently the complications appear to be increasing. Especially, inadvertent intravascular cannulation and intravascular local anesthetic administration can lead to fatal consequences.

Methods

Data was collected on 296 patients undergoing elective thoracic or abdominal surgery. Two detection methods were utilized to confirm the epidural intravascular cannulation; flashback and aspiration of indwelling catheter, and injection of a contrast agent through the catheter under fluoroscopy were used to guide the placement of the catheter and to examine the intravascular cannulation.

Results

Epidural intravascular cannulation was reported in 4 out of 296 cases (1.4%), and 1 patient underwent subdural cannulation. Among the 4 cases of epidural intravascular cannulation, two were confirmed by the flashback and aspiration methods, while the remaining cases were only detected by real time fluoroscopy.

Conclusions

In this study, inadvertent epidural intravascular cannulation occurred by as much as 1.4% of thoracic epidural catheterization. Utilizing real time fluoroscopy in addition to flashback and aspiration can enhance the sensitivity of detection.

Background:

In the contemporary dental practice, alleviation of pain is the most important factor to ameliorate patient's condition and to gain one's confidence towards the skills of the operator. Such confidence aids to the ultimate success of the treatment procedures.

Aims and Objectives:

This study compares the pain response of a group of 10 subjects to the Wand® with the response to traditional syringe injections and also compares the extent of the area anesthetized.

Materials and Methods:

10 subjects were selected for the study and 20 injections were given contralaterally to them, 10 with Wand®, and rest with the traditional aspirating syringe. Each subject received 2 injections on the palate, Left side with Wand® (test) and Right side with Traditional syringe (control). All injections were given by the same investigator without the use of topical anesthetic spray/gel. Pain perception levels were recorded with a visual analogue scale. Also the extent of area anesthetized with a single palatal injection was assessed by probing.

Results:

The results showed injections with the syringe were more painful than injections with the Wand® in 2 of 10 subjects. Also the extent of the area anesthetized by both the techniques was similar except in 2 patients.

Conclusion:

The Wand® results in less painful injections; however, mean ratings of pain for both the groups, were mostly below the annoying level of pain. Also, the areas covered by the anesthetic effect of both the injections were comparatively similar.

Background

Polymethylmethacrylate (PMMA) is commonly used for clinical applications. However, the short handling time increases the probability of a surgeon missing the crucial period in which the cement maintains its ideal viscosity for a successful injection. The aim of this article was to illustrate the effects a reduction in temperature would have on the cement handling time during percutaneous vertebroplasty.

Methods

The injectability of bone cement was assessed using a cement compressor. By twisting the compressor, the piston transmits its axial load to the plunger, which then pumps the bone cement out. The experiments were categorized based on the different types of hypothermic manipulation that were used. In group I (room temperature, sham group), the syringes were kept at 22°C after mixing the bone cement. In group 2 (precooling the bone cement and the container), the PMMA powder and liquid, as well as the beaker, spatula, and syringe, were stored in the refrigerator (4°C) overnight before mixing. In group 3 (ice bath cooling), the syringes were immediately submerged in ice water after mixing the bone cement at room temperature.

Results

The average liquid time, paste time, and handling time were 5.1 ± 0.7, 3.4 ± 0.3, and 8.5 ± 0.8 min, respectively, for group 1; 9.4 ± 1.1, 5.8 ± 0.5, and 15.2 ± 1.2 min, respectively, for group 2; and 83.8 ± 5.2, 28.8 ± 6.9, and 112.5 ± 11.3 min, respectively, for group 3. The liquid and paste times could be increased through different cooling methods. In addition, the liquid time (i.e. waiting time) for ice bath cooling was longer than for that of the precooling method (p < 0.05).

Conclusions

Both precooling (i.e. lowering the initial temperature) and ice bath cooling (i.e. lowering the surrounding temperature) can effectively slow polymerization. Precooling is easy for clinical applications, while ice bath cooling might be more suitable for multiple-level vertebroplasty. Clinicians can take advantage of the improved injectability without any increased cost.

Purpose

We measured dynamic biomechanics of loss-of-resistance (LOR) epidural placement in prone cadavers, focussing on the period immediately following LOR, to estimate forces acting on the tissue of the epidural space.

Methods

An epidural syringe with 17G Hustead needle was instrumented to track force on the plunger, pressure in the chamber, and movement of barrel and plunger. Insertions were attempted in five formalin-preserved cadavers from T2–3 to L4–5, using LOR with saline or air, and confirmed with X-ray.

Results

Sixteen insertions were successful. Soft tissues in formalin-preserved cadavers are much harder than in living humans. With continuous pressure on the plunger, fluid thrust through the needle at the point of LOR was significantly greater (P = 0.005) with saline (mean ± standard deviation [95% confidence intervals]: 19.3 ± 14.9 [8.3 to 30.3] N); than with air (0.17 ± 0.25 [0 to 0.39] N). Stress exerted on epidural tissue was similar (air = 7792 ± 920 [6986 to 8598] Pa; saline = 7378 ± 3019 [5141 to 9614] Pa); and in both cases was greater than the stress exerted by cerebrospinal fluid pushing outwardly on the dura (4800 Pa).

Conclusion

Formalin-preserved cadavers are too stiff to make them an experimental model from which we can generalize to live humans, although we were successful in entering the epidural space and testing the instrumentation for further studies on live animals or humans. Continuous pressure on the plunger while advancing the epidural needle may “blow” the dura away from the needle tip and help prevent dural puncture. Better results are seen with saline rather than air.

A syringe device for the injection and evacuation of highly viscous silicone oil was developed. The problem of removing the air interfering with these manoeuvres was solved by providing special outlets in the plunger and handle of a conventional glass syringe. A slightly modified commercial motor perfusor was chosen to power this device, which has proved to be good and fail-safe in more than 100 cases.

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The current work aimed to propose a system of scoring to rationalize and support the selection of the optimal diameter and length of needles. Four formulations at different viscosity and needles ranging from 21 to 26 G and length ranging from 16 to 40 mm were used. Plunger-stopper breakloose force, maximum force (Fmax), and dynamic glide force were measured by a texture analyzer at the crosshead speed of 1 mm/s. Testing was carried out into air or human subcutaneous tissue. The manual injectability of the highest viscosity product was assessed by ten evaluators. The comparison of the panel test score and the quantitative measurements of the forces permitted to score a given needle-syringe-formulation system keeping also in consideration the pressure created in the subcutaneous space and muscles at the injection site. In particular, the following relationship was drawn: at the Fmax up to 250 mPa, the injection was practically impossible; at Fmax ranging from 160 to 250 mPa, the injection was very difficult; at Fmax in the 125–160 mPa range, the injection was feasible, though with some difficulty; when the values of Fmax were lower 125 mPa, the injection went smoothly. On the basis of these preliminary data, a system of scoring the needle-syringe-formulation system is proposed to rationalize and support the selection of the optimal diameter and length of needles, keeping also in consideration the pressure created in the subcutaneous space and muscles at the injection site.

A simple nonsurgical technique of obtaining fat samples by aspiration from the gluteal prominence was developed by Hirsh in 1960 and has been in use in our Nutrition Clinic at the Mount Sinai Hospital for several years. We have modified it for field use and the analysis of fat-soluble hydrocarbon residues. All the materials which will contain the fat sample to be analyzed are washed with acetone and pesticide residue-free hexane, and a 15 gauge needle and 33 cc syringe are sterilized. Aspiration of fat from the lateral gluteal prominence is accomplished under local xylocaine anesthetic. The anesthetic also serves as the vehicle into which the fat is broken by the shearing action of the 15 gauge needle. Fat particles are sucked into the syringe by a constant vacuum kept on the syringe during lateral movement of the needle under (and parallel to) the skin within the gluteal fat pad; 200--500 ml of fat can be obtained for hydrocarbon residue analysis. The only complications have been some mild hematomas at the site of the aspiration. The method avoids surgical biopsy and sutures and takes about 7--8 min.

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Four college students were exposed to a Sidman avoidance procedure to determine if an avoidance contingency involving 20% carbon dioxide-enriched air (CO2) would produce and maintain responding. In Phase 1, two conditions (contingent and noncontingent) were conducted each day. These conditions were distinguished by the presence or absence of a blue or green box on a computer screen. In the contingent condition, CO2 presentation were delivered every 3 s unless a subject pulled a plunger. Each plunger pull postponed CO2 presentations for 10 s. In the noncontingent condition, CO2 presentations occurred on the average of every 5 min independent of responding. Following stable responding in Phase 1, condition-correlated stimuli were reversed. In both conditions, plunger response rate was high during the contingent condition and low or zero during the noncontingent condition. Furthermore, subjects avoided most CO2 presentations. However, CO2 presentations did not increase verbal reports of fear. Overall, the results from the present study suggest that CO2 can be used effectively in basic studies of aversive control and in laboratory analogues of response patterns commonly referred to as anxiety.

OBJECTIVE

Children and adults with type 1 diabetes who receive insulin pump therapy have reported hypoglycemia during air travel. We studied the effects of atmospheric pressure on insulin pump delivery.

RESEARCH DESIGN AND METHODS

Ten insulin pumps were connected to capillary tubes. The effects of changes in ambient pressure on insulin delivery, bubble formation, bubble size, and cartridge plunger movement were analyzed.

RESULTS

During a flight (200 mmHg pressure decrease), excess insulin delivery of 0.623% of the cartridge volume occurred (P < 0.001, Student t test). In hypobaric chamber studies, bubbles developed in the insulin when the pressure decreased and displaced the insulin out of the cartridge. Pre-existing bubbles changed in size consistent with Boyle law. Cartridge plunger movement did not occur in normal flight conditions but did occur when catastrophic plane depressurization was mimicked.

CONCLUSIONS

Atmospheric pressure reduction causes predictable, unintended insulin delivery in pumps by bubble formation and expansion of existing bubbles.

In the present study, novel dry-contact sensors for measuring electro-encephalography (EEG) signals without any skin preparation are designed, fabricated by an injection molding manufacturing process and experimentally validated. Conventional wet electrodes are commonly used to measure EEG signals; they provide excellent EEG signals subject to proper skin preparation and conductive gel application. However, a series of skin preparation procedures for applying the wet electrodes is always required and usually creates trouble for users. To overcome these drawbacks, novel dry-contact EEG sensors were proposed for potential operation in the presence or absence of hair and without any skin preparation or conductive gel usage. The dry EEG sensors were designed to contact the scalp surface with 17 spring contact probes. Each probe was designed to include a probe head, plunger, spring, and barrel. The 17 probes were inserted into a flexible substrate using a one-time forming process via an established injection molding procedure. With these 17 spring contact probes, the flexible substrate allows for high geometric conformity between the sensor and the irregular scalp surface to maintain low skin-sensor interface impedance. Additionally, the flexible substrate also initiates a sensor buffer effect, eliminating pain when force is applied. The proposed dry EEG sensor was reliable in measuring EEG signals without any skin preparation or conductive gel usage, as compared with the conventional wet electrodes.

The problem of glass breakage in the local anesthetic cartridge system was evaluated under laboratory conditions with a mechanical testing machine. The anticipated breakage of the glass did not occur with any frequency, as the rubber stopper produced more uniform failures of the system. The glass cartridge appeared to be quite reliable and resistant to breakage.

Local anesthetics have been used for many years to provide patients temporary freedom from pain. Local anesthetic solutions are in wide use in both dentistry and medicine and are the most frequently used drugs in dentistry. Various estimates place the number of injections at approximately one half million daily or 125 million injections per year.

These drugs and the armamentarium necessary to administer them have proven to be safe and reliable. Only rarely are there reports of sensitivity to the anesthetic solution or breakage of needles.. Sterility of the solutions has not been a problem as they are carefully processed and evaluated at the factory. Although there are sporadic reports of loss of sterility, this has been attributed to the reuse of the anesthetic cartridges on more than one patient. Monheim states “The success of the cartridge system in dentistry has been due to the sincerity, honesty, and high standards of the manufacturers in giving the profession a near-perfect product.” However, on occassion a glass cartridge will break or shatter when inserting the harpoon into the rubber stopper or even during injection. Cooley et al reported on eye injuries occurring in the dental office, one of which was due to glass from a local anesthetic cartridge that exploded and propelled particles into the patient's eye. Forrest evaluated syringes, needles, and cartridges and reported that one brand (made in Britain) fractured more often than any other, but that the fracture rate was too low to be of any consequence.

It is apparent that glass cartridges will fracture or burst from time to time. This study evaluates the cartridge system with carefully controlled laboratory procedures. The cartridges were tested under various pressures and conditions in an attempt to determine the causes of failure and when such failure may be anticipated.

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Phentolamine mesylate accelerates recovery from oral soft tissue anesthesia in patients who have received local anesthetic injections containing a vasoconstrictor. The proposed mechanism is that phentolamine, an alpha-adrenergic antagonist, blocks the vasoconstriction associated with the epinephrine used in dental anesthetic formulations, thus enhancing the systemic absorption of the local anesthetic from the injection site. Assessments of the pharmacokinetics of lidocaine and phentolamine, and the impact of phentolamine on the pharmacokinetics of lidocaine with epinephrine were performed to characterize this potentially valuable strategy. The blood levels of phentolamine were determined following its administration intraorally and intravenously. Additionally, the effects of phentolamine mesylate on the pharmacokinetics of intraoral injections of lidocaine with epinephrine were evaluated. Sixteen subjects were enrolled in this phase 1 trial, each receiving 4 drug treatments: 1 cartridge lidocaine/epinephrine followed after 30 minutes by 1 cartridge phentolamine (1L1P), 1 cartridge phentolamine administered intravenously (1Piv), 4 cartridges lidocaine/epinephrine followed after 30 minutes by 2 cartridges phentolamine (4L2P), and 4 cartridges lidocaine/epinephrine followed by no phentolamine (4L). Pharmacokinetic parameters estimated for phentolamine, lidocaine, and epinephrine included peak plasma concentration (Cmax), time to peak plasma concentration (Tmax), area under the plasma concentration-time curve from 0 to the last time point (AUClast) or from time 0 to infinity (AUCinf), elimination half-life (t1/2), clearance (CL), and volume of distribution (Vd). The phentolamine Tmax occurred earlier following the intravenous administration of 1Piv (7 minutes than following its submucosal administration in treatment 1L1P (15 minutes) or 4L2P (11 minutes). The phentolamine t1/2, CL, and Vd values were similar for 1L1P, 1Piv, and 4L2P. The Tmax for lidocaine occurred later and the Cmax for lidocaine was slightly higher when comparing the 4L2P treatment and the 4L treatment. The phentolamine-induced delay of the lidocaine Tmax likely represents phentolamine's ability to accelerate the systemic absorption of lidocaine from oral tissues into the systemic circulation.

The purpose of the present study is to determine the cardiovascular effects produced by intravascular injection of 2% lidocaine with 20 μg/mL of norepinephrine on systolic, diastolic, and mean arterial pressures and heart rate of rats at the following times: control period, during the injection (first 15 seconds), during the first minute, and at the end of 1, 2, 3, 4, 5, 10, 15, 20, 25, and 30 minutes after drug administration. The study was performed on 13 male Wistar rats with weights between 200 grams and 220 grams that were awake during the recording of these parameters. The dose administered was proportional to 1 cartridge of local anesthetic (1.8 mL) in an average-size human, which is equivalent to 0.51 mg/kg of lidocaine hydrochloride and 0.51 μg/kg of norepinephrine hydrochloride. The average time of injection was 15.7 seconds. The results of this study showed significant increases in systolic, diastolic, and mean arterial pressure and a noticeable decrease in heart rate. The greatest variation occurred in the systolic blood pressure. The greatest alterations occurred during injection and within the first minute following administration of the anesthetic solution. We would anticipate these changes in the parameters analyzed to be clinically significant. Thus, dentists using 2% lidocaine with norepinephrine 20 μg/mL should be very careful to avoid intravascular injection.

Ketamine, a dissociative anesthetic, has emerged as an increasingly common drug among subgroups of young injection drug users (IDUs) in cities across the United States. In-depth qualitative interviews were conducted with 213 young IDUs aged 16–28 years recruited in New York, New Orleans, and Los Angeles between 2004 and 2006. While some initiated injection drug use with ketamine, the drug was more frequently injected by IDUs with extensive polydrug using histories. IDUs initiating with ketamine commonly self-injected via an intramuscular mode of administration. The injection group provided crucial knowledge and material resources that enabled the injection event to occur, including ketamine, syringes, and injection skills. Injection paraphernalia was commonly shared during the first injection of ketamine, particularly vials of pharmaceutically-packaged liquid ketamine. Injection events infrequently occurred in a rave or club and more typically in a private home, which challenges ketamine’s designation as a ‘club’ drug. The first injection of ketamine was a noteworthy event since it introduced a novel drug or new mode of administration to be further explored by some, or exposed others to a drug to be avoided in the future. Risk reduction messages directed towards young IDUs should be expanded to include ketamine.

Suprapubic bladder aspiration in neonates is a simple, safe, and useful technique for collection of sterile urine. The procedure can be performed in the hospital or office. Neither sedation nor local anesthetic is required. Suprapubic bladder aspiration of urine is the preferred method of collecting urine for culture in septic neonates. The technique is also indicated to verify urinary tract infection in neonates. Suprapubic bladder aspiration is contraindicated in the presence of abdominal distension or an empty bladder. Carefully and properly performed, the risk of complications should be negligible, and the success rate in obtaining urine is 90%.

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The literature is reviewed to demonstrate the significant amount of contamination on the external surface of the anesthetic cartridge diaphragm. Current methods of cartridge diaphragm decontamination to prevent injection of pathogens are discussed. A series of bacteriologic tests were conducted to determine the probability of transfer of pathogens from the diaphragm surface through the needle lumen of three different sizes to the deposition site. Results of needle purging suggest that a significant reduction in the transfer of microorganisms is possible using this technique.

The aim of the present study was to assess injection flow rates of metal syringes, with an emphasis on injection speed and the generation of flow pulsations. A cohort of 64 operators (32 practitioners and 32 students) performed 3 consecutive ex vivo simulated injections (SIs) of 1.8-mL cartridges of anesthetic solution. Two needle diameters were tested (27-gauge and 30-gauge). Each SI was filmed and analyzed using a computer. In most cases, the SI lasted longer than 60 seconds with the 30-gauge needle (75%) but not with the 27-gauge needle (47.9%) (P < .0001). Practitioners and men delivered a full cartridge significantly faster than students and women, respectively (P  =  .0007 in both cases). All operators generated 1 pulse in at least 1 of the 3 SIs with both types of needles, especially during the first 3 seconds (254/384; 66.1%). Pulses occurred more frequently with practitioners (P  =  .0176) and with the 27-gauge needle (P  =  .005). Within its methodological limits, the present study showed how difficult it is to control injection pressure when using a metal syringe, especially at the beginning of the injection. Computerized systems may help overcome this problem.

The most common complication after abdominoplasty is seroma formation. The incidence of seroma formation in abdominal procedures as a whole, including abdominoplasty, panniculectomy and transverse rectus abdominis myocutaneous flap abdominal donor sites, ranges from 1% to 38%. A recent concern among surgeons is the possibility of a causal relationship between the use of continuous infusion devices such as local anesthetic pain pumps and the development of seromas. A case of postoperative, persistent, recurrent seroma formation after abdominoplasty with the use of continuous infusion local anesthetic pain pump is presented. After several attempts at aspiration and drain catheter placement, only open surgical excision of the seroma cavity was found to be definitively effective in treating the development of seroma.

A total of 182 percutaneous trans-thoracic aspiration biopsies were performed in 164 patients over a three-year period. In malignant neoplasms arising in the lung the diagnostic accuracy rate was 84%. In the non-malignant localized parenchymal lesions the accuracy drops considerably unless the lesion is cystic or cavitary. Some patients with non-parenchymal lesions were selected to assess further the value of this procedure. It proved much less rewarding in lesions of the chest wall, diaphragm and also in diffuse parenchymal disease. These lesions may be more accurately identified by other methods of biopsy. Lesions presenting as a mediastinal mass are an intermediate group and in selected cases helpful information can often be obtained by small-bore needle aspiration, particularly if a pericardial, bronchogenic or thymic cyst is suspected. Recent reports have shown that the aspiration of pulmonary lesions can be utilized to obtain viable tumour cells for chemosensitivity testing. The aspiration of nodular pulmonary lesions should be considered when a diagnosis is not forthcoming from the usual investigative means, since there has been little morbidity and no mortality in the series.

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Abstract

Needleless devices have been developed to provide anesthesia without injections. Little controlled research has examined the acceptability of needleless devices in pediatric patients. The aims of the study were to compare children’s acceptance and preference for one type of needleless jet injection with classical local infiltration as well as to evaluate the efficacy of the needleless anesthesia. Eighty-seven nonfearful children with no previous experience of dental anesthesia were studied using a split-mouth design. The first dental procedure was performed with the classical infiltration anesthesia. The same amount of anesthetic was administered using the INJEX needleless device in a second session 1 week later, during which a second dental procedure was performed. Patients rated their acceptance and preference for the 2 methods, and the dentist recorded data about the need for additional anesthesia. More negative experiences were reported for the INJEX method. Most (73.6%) of the children preferred the traditional method. Among the 87 treatment procedures attempted following the use of INJEX, 80.5% required additional anesthesia, compared with 2.3% of those attempted following traditional infiltration. Traditional infiltration was more effective, acceptable, and preferred, compared with the needleless INJEX.

Differences in ethnic beliefs about the perceived need for local anesthesia for tooth drilling and childbirth labor were surveyed among Anglo-Americans, Mandarin Chinese, and Scandinavians (89 dentists and 251 patients) matched for age, gender, and occupation. Subjects matched survey questionnaire items selected from previously reported interview results to estimate (a) their beliefs about the possible use of anesthetic for tooth drilling and labor pain compared with other possible remedies and (b) the choice of pain descriptors associated with the use of nonuse of anesthetic, including descriptions of injection pain. Multidimensional scaling, Gamma, and Chi-square statistics as well as odds ratios and Spearman's correlations were employed in the analysis. Seventy-seven percent of American informants reported the use of anesthetics as possible remedies for drilling and 51% reported the use of anesthetics for labor pain compared with 34% that reported the use of anesthetics among Chinese for drilling and 5% for labor pain and 70% among Scandinavians for drilling and 35% for labor pain. Most Americans and Swedes described tooth-drilling sensations as sharp, most Chinese used descriptors such as sharp and "sourish" (suan), and most Danes used words like shooting (jagende). By rank, Americans described labor pain as cramping, sharp, and excruciating, Chinese used words like sharp, intermittent, and horrible, Danes used words like shooting, tiring, and sharp, and Swedes used words like tiring, "good," yet horrible. Preferred pain descriptors for drilling, birth, and injection pains varied significantly by ethnicity. Results corroborated conclusions of a qualitative study about pain beliefs in relation to perceived needs for anesthetic in tooth drilling. Samples used to obtain the results were estimated to approach qualitative representativity for these urban ethnic groups.

Liposuction is one of the most popular treatment modalities in aesthetic surgery with certain unique anaesthetic considerations. Liposuction is often performed as an office procedure. There are four main types of liposuction techniques based on the volume of infiltration or wetting solution injected, viz dry, wet, superwet, and tumescent technique. The tumescent technique is one of the most common liposuction techniques in which large volumes of dilute local anaesthetic (wetting solution) are injected into the fat to facilitate anaesthesia and decrease blood loss. The amount of lignocaine injected may be very large, approximately 35-55 mg/kg, raising concerns regarding local anaesthetic toxicity. Liposuction can be of two types according to the volume of solution aspirated: High volume (>4,000 ml aspirated) or low volume (<4,000 ml aspirated). While small volume liposuction may be done under local/monitored anaesthesia care, large-volume liposuction requires general anaesthesia. As a large volume of wetting solution is injected into the subcutaneous tissue, the intraoperative fluid management has to be carefully titrated along with haemodynamic monitoring and temperature control. Assessment of blood loss is difficult, as it is mixed with the aspirated fat. Since most obese patients opt for liposuction as a quick method to lose weight, all concerns related to obesity need to be addressed in a preoperative evaluation.