Anesthetic Success Using Nitrous Oxide and a Combination of Lidocaine/Clonidine for the Inferior Alveolar Nerve Block and the Effects on Blood Pressure and Pulse in Patients with Symptomatic Irreversible Pulpitis: A Prospective, Randomized, Double-blind Study

Physiology of pregnancy and oral local anesthesia considerations

Background

Safe and effective local anesthesia is a prerequisite for emergency oral surgeries and most dental treatments. Pregnancy is characterized by complex physiological changes, and increased sensitivity to pain. Pregnant women are particularly vulnerable to oral diseases, such as caries, gingivitis, pyogenic granuloma and third molar pericoronitis. Maternally administered drugs can affect the fetus through the placenta. Therefore, many physicians and patients are reluctant to provide or accept necessary local anesthesia, which leads to delays in the condition and adverse consequences. This review is intended to comprehensively discuss the instructions for local anesthesia in the oral treatment of pregnant patients.

Methodology

An in-depth search on Medline, Embase, and the Cochrane Library was performed to review articles concerned with maternal and fetal physiology, local anesthetic pharmacology, and their applications for oral treatment.

Results

Standard oral local anesthesia is safe throughout the pregnancy. At present, 2% lidocaine with 1:200,000 epinephrine is considered to be the anesthetic agent that best balances safety and efficacy for pregnant women. Maternal and fetal considerations must be taken into account to accommodate the physiological and pharmacological changes in the gestation period. Semi-supine position, blood pressure monitoring, and reassurance are suggested for high-risk mothers to reduce the risk of transient changes in blood pressure, hypoxemia, and hypoglycemia. For patients with underlying diseases, such as eclampsia, hypertension, hypotension, and gestational diabetes, the physicians should use epinephrine cautiously and control the dose of anesthetic. New local anesthesia formulations and equipment, which contribute to minimizing injection pain and relieving the anxiety, have and are being developed but remain understudied.

Conclusions

Understanding the physiological and pharmacological changes during pregnancy is essential to ensure the safety and efficiency of local anesthesia. Optimal outcomes for the mother and fetus hinge on a robust understanding of the physiologic alterations and the appropriate selection of anesthetic drugs and approaches.

Local Tramadol Improves the Anesthetic Success in Patients with Symptomatic Irreversible Pulpitis: A Meta-Analysis

Symptomatic irreversible pulpitis is a painful clinical condition with a broad inflammatory component. Dental anesthesia in these patients is affected by the inflammatory process, reporting a high incidence of anesthesia failure. The aim of this systematic review and meta-analytical evaluation was to determine the effect of pre-treatment with tramadol in patients with symptomatic irreversible pulpitis, as well as for pain control and adverse effects. This study was registered in PROSPERO (ID: CRD42021279262). PubMed was consulted to identify clinical investigations comparing tramadol and placebo/local anesthetics in patients with symptomatic irreversible pulpitis. Data about the anesthesia, pain control, and adverse effects were extracted. Both the anesthetic success index and the adverse effects of local tramadol and placebo were compared with the Mantel−Haenszel test and odds ratio. Data analysis showed that the local administration of tramadol increased the anesthetic success rate when compared to placebo in patients with symptomatic irreversible pulpitis (n = 228; I2 = 0; OR = 2.2; 95% CIs: 1.30 to 3.79; p < 0.004). However, local administration of tramadol increased the risk of adverse effects when compared to placebo/local anesthetics (n = 288; I2 = 0; OR = 7.72; 95% CIs: 1.37 to 43.46; p < 0.02). In conclusion, this study shows that the local administration of tramadol increases the anesthetic success index when compared to placebo in patients with symptomatic irreversible pulpitis.

Clonidine versus Adrenaline as an Adjunct to Lignocaine on Haemodynamic Parameters during Nerve Block for Third Molar Surgical Removal - A Systematic Review and Meta-Analysis

Background

Adrenaline or clonidine is used as adjuncts in conjunction with lignocaine to improve the depth of local anaesthesia in dental procedures.

Objectives

This systematic review and meta-analysis intends to compare the haemodynamic parameters when clonidine or adrenaline is used in conjunction with lignocaine for third-molar surgical removal.

Data Sources

Cochrane, PubMed and Ovid SP databases were searched using "MeSH" terms (((nerve block) OR (IANB)) AND ((clonidine) OR (adrenaline))) AND (lignocaine).

Study Eligibility Criteria

Clinical studies where Clonidine + lignocaine and Adrenaline + lignocaine were compared directly during nerve block administration exclusively for third molar surgical removal were selected.

Participants Study Appraisal

This current systematic review is registered in Prospero database CRD42021279446. Two independent reviewers were involved in collection, segregation and analysis of electronic data. The data were compiled in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Search was conducted till June 2021.

Synthesis Methods

Qualitative analysis of the selected articles was performed for systematic review. Meta-analysis is performed using RevMan 5 Software. Heterogeneity through the I2 statistics. Change in the haemodynamic parameters was the primary outcome evaluated, and secondary outcomes evaluated were onset and duration of anaesthesia in both the groups.

Results

In all databases, 1141 records were screened, out of which a total of 21 articles were included for the evaluation for full-text analysis. Out of these, 16 articles were excluded and 5 articles were included for the final systematic review. Meta-analysis was performed only for 4 studies.

Conclusion

Amongst the evaluated haemodynamic parameters, there was a significant reduction in the heart rate (baseline to intraoperative period) in clonidine and lignocaine groups than in adrenaline and lignocaine groups during nerve block administration for third molar surgical removal. There was no significant difference between other primary and secondary outcomes evaluated.

Limitations

Blinding was not performed in all the studies, randomisation was performed in only three studies. The volume of local anaesthesia deposited varied in the studies (2 mL in three studies and 2.5 mL in two studies). Most of the studies (n = 4) were evaluated on normal adults and only one study evaluated mild hypertensive patients.

Effect of a Combination of Nitrous Oxide and Intraligamentary Injection on the Success of the Inferior Alveolar Nerve Block in Patients with Symptomatic Irreversible Pulpitis

INTRODUCTION

The purpose of this prospective study was to determine the effect of a combination of nitrous oxide/oxygen and 1 set of supplemental intraligamentary/periodontal ligament (PDL) injections followed by a second set of PDL injections on anesthetic success in patients with symptomatic irreversible pulpitis (SIP).

METHODS

Ninety-four patients with a mandibular posterior tooth diagnosed with SIP received nitrous oxide/oxygen and an inferior alveolar nerve block (IANB) with 2% lidocaine with 1:100,000 epinephrine. Patients rated the pain of PDL injections and endodontic access on a visual analog scale. If moderate to severe pain was felt during treatment, the operator administered 1 set of supplemental PDL injections with 4% articaine with 1:100,000 epinephrine. If moderate to severe pain was felt again during treatment, the operator administered a second set of supplemental PDL injections. Anesthetic success was defined as having no to mild pain during endodontic treatment.

RESULTS

The success of the IANB with nitrous oxide was 44% (95% confidence interval [CI], 34%-54%). The overall anesthetic success rate (IANB with PDL injections) was increased from 69% (95% CI, 60%-78%) with 1 set of PDL injections to 80% (95% CI, 72%-88%) with a second set of PDL injections.

CONCLUSIONS

Although the second set of PDL injections increased anesthetic success, it was not sufficient to ensure complete pulpal anesthesia.