A nomogram for predicting the need for sciatic nerve block after total knee arthroplasty

Purpose

Sciatic nerve block (SNB) is commonly performed in combination with femoral nerve block (FNB) for postoperative analgesia following total knee arthroplasty (TKA). Despite the fact that 10–20 % of TKA patients require SNB for postoperative posterior knee pain, there are no existing studies that suggest a model to predict the need for SNB. The aim of our study was to develop a prediction tool to measure the likelihood of patients undergoing TKA surgery requiring a postoperative SNB.

Methods

With institutional review board approval, we obtained data from the electronic medical record of patients who underwent TKA at the Cleveland Clinic. A multivariable logistic regression was used to estimate the probability of requiring a postoperative SNB. Clinicians selected potential predictors to create a model, and the potential nonlinear association between continuous predictors and SNB was assessed using the restricted cubic spline model.

Results

In total 6279 TKA cases involving 2329 patients with complete datasets were used for building the prediction model, including 276 (12 %) patients who received a postoperative SNB and 2053 (88 %) patients who did not. The estimated C statistic of the prediction model was 0.64. The nomogram is used by first locating the patient position on each predictor variable scale, which has corresponding prognostic points. The cut-off of 11.6 % jointly maximizes the sensitivity and specificity.

Conclusion

This is the first study to be published on SNB prediction after TKA. Our nomogram may prove to be a useful tool for guiding physicians in terms of their decisions regarding SNB.

     

Sufentanil sublingual tablet system for the management of postoperative pain

Introduction: Intravenous patient-controlled opioid analgesia has been an important improvement in addressing insufficient management of acute postoperative pain for over 40 years. However, there are number of weaknesses for intravenous patient-controlled analgesia, including operator and device error, intravenous line patency issues, and risk of catheter-related infection, all of which contribute to the complications and increase in cost of care. The sublingual sufentanil tablet system is a major evolution in both drug and technological management of postoperative pain.

Areas covered: We reviewed the use of the sublingual sufentanil tablet system in management of moderate to severe postoperative pain in hospitalized patients, with a particular focus on the pharmacological properties of sufentanil and clinical use in different surgical patients.

Expert opinion: The sublingual sufentanil tablet system can decrease intravenous opioid based patient-controlled analgesia related complications and safety issues. Current clinical studies have demonstrated this noninvasive-novel system to be safe and effective in management of acute pain in the postsurgical setting. Researchers should focus on comparing it with other available patient controlled analgesia modalities and evaluating the efficiency and cost effectiveness of the sublingual sufentanil tablet system.     

Pharmacokinetic and pharmacodynamic evaluation of sublingual sufentanil in the treatment of post-operative pain

Introduction: Intravenous patient-controlled analgesia using opioids is frequently used to provide perioperative analgesia. However, there are a number of drawbacks for intravenous patient-controlled analgesia. The sufentanil sublingual tablet system is a major evolution in technology and drug development for postoperative pain management.

Areas Covered: We reviewed the use of sublingual sufentanil in postoperative pain management, with a focus on chemistry, pharmacokinetics and clinical use in different surgical patients.

Expert Opinion: The sufentanil sublingual tablet system can decrease intravenous patient-controlled analgesia-related safety issues. Current clinical studies have demonstrated this novel system to be safe and effective in postoperative pain management.     

Comparative study of quantitative determination of amoxicillin in capsules by mercurimetry and liquid chromatography

Assay of amoxicillin in capsules performed in accordance with the US Pharmacopeia by liquid chromatography was compared with a method based on mercurimetric titration, developed by ourselves, in which the internal indicator was an azo derivative of theophylline, i.e., benzenesulfonamide, N-(2,6-dimethoxy-4-pyrimidinyl)- 4-[(4-methylamino-5-methylcarbamoyl)]azo [CA Index Name, i.e., chemical name according to the rules and conventions of the “9th Collective Index of the Chemical Abstracts Service.”]. The analysis results showed that mercurimetric assay was specific and easily performed in laboratory conditions and can be used as an alternative method.     

The Impacts of Super Obesity Versus Morbid Obesity on Respiratory Mechanics and Simple Hemodynamic Parameters During Bariatric Surgery

Background

This study was designed to determine the impact of the degree of obesity on respiratory mechanics and simple hemodynamic parameters at laparoscopic bariatric surgery.

Methods

The patients were divided into two groups, each of which included 24 patients (a morbidly obese group and a super obese group) undergoing laparoscopic bariatric surgery. Dynamic respiratory compliance, respiratory resistance, and peak inspiratory pressures were measured at four time points: 10 min after anesthesia induction (T1: induction), 10 min after pneumoperitoneum (T2: pneumoperitoneum), 10 min after terminating pneumoperitoneum (T3: end-pneumoperitoneum), and before extubation (T4: extubation). The systolic, diastolic, and mean arterial pressures and the heart rate values were measured noninvasively in T0 (10 min before operation).

Results

Obesity was found to cause a statistically significant increase in respiratory resistance and a peak inspiratory pressure and a decrease in dynamic respiratory compliance. In the morbidly obese group, the lowest dynamic respiratory compliance was 37?±?12 mL/cm H₂O, but it was 33?±?13 mL/cm H₂O in the super obese group. The systolic pressure, diastolic pressure, and mean arterial pressure were found to decrease significantly in both groups.

Conclusions

Morbid obesity and super obesity have negative effects on hemodynamics and respiratory mechanics.