Does endogenous testosterone mediate the lower preconditioning threshold in males?

BACKGROUND: Preconditioning is injury-induced protection from subsequent insult. Recent data indicates that males have lower preconditioning thresholds compared to females. Therefore, we hypothesized that testosterone may mediate the lower preconditioning threshold observed in males. MATERIALS AND METHODS: Adult normal and castrated male Sprague-Dawley rats (n = 4-5) were given intraperitoneal (i.p.) injections of 125 or 500 microg/kg Salmonella typhimurium lipopolysaccharide (ETX) or 0.4 ml normal saline (NS). Another i.p. injection of 500 microg/kg ETX (injury dose) was given 24 h later. After 6 h, myocardial function was evaluated via the Langendorff perfusion model. Shams received only NS, while non-preconditioned rats (PC-) received NS followed by the 500 microg/kg ETX injury dose. Preconditioned rats received injections of 125 mug/kg ETX (PC +125) or 500 microg/kg ETX (PC +500), followed by the 500 microg/kg ETX injury dose. RESULTS: Normal PC +125 and PC +500 males were preconditioned and maintained cardiac function similar to shams (P > 0.05). Castrated PC +125 and PC +500 males were also preconditioned and maintained cardiac function similar to castrated shams (P > 0.05). Conversely, both normal and castrated PC-males showed significantly decreased cardiac function compared to shams (P < 0.05). CONCLUSIONS: Endogenous testosterone does not mediate the lower preconditioning threshold in males.     

Does stress mediate the association between personal relative deprivation and gambling?

Evidence has linked subjective feelings of personal relative deprivation with general gambling involvement and problem gambling tendencies. In turn, problem gambling tendencies have been linked with a wide array of damaging physical and mental health consequences. It has been theorized that the deleterious effects of perceived inequality on mental and physical health operate at the individual level through the experience of personal relative deprivation leading to psychosocial stress. We empirically examined whether the experience of perceived stress contributes to explaining the deprivation‐gambling link using cross‐sectional, self‐reported survey data collected from a crowdsourced population of adults (n = 565). Results indicate that personal relative deprivation is associated with problem gambling tendencies (but not general gambling involvement) and that this association is mediated by perceived stress. These associations were particularly strong among participants who reported non‐zero levels of problem gambling tendencies. Together, our results further emphasize the importance of individual‐level social comparison reactions in the context of health.     

Does a digital regional nerve block improve the accuracy of noninvasive hemoglobin monitoring?

Background

Blood hemoglobin (Hb) can be continuously monitored utilizing noninvasive spectrophotometric finger sensors (Masimo SpHb). SpHb is not a consistently accurate guide to transfusion decisions when compared with laboratory Co-Oximetry (tHb). We evaluated whether a finger digital nerve block (DNB) would increase perfusion and, thereby, improve the accuracy of SpHb.

Methods

Twenty adult patients undergoing spinal surgery received a DNB with lidocaine to the finger used for the monitoring of SpHb. SpHb–tHb differences were determined immediately following the DNB and approximately every hour thereafter. These differences were compared with those in our previously reported patients (N = 20) with no DNB. The SpHb–tHb difference was defined as “very accurate” if <0.5 g/dL and “inaccurate” if >2.0 g/dL. Perfusion index (PI) values at the time of each SpHb–tHb measurement were compared.

Results

There were 57 and 78 data points in this and our previous study, respectively. The presence of a DNB resulted in 37 % of measurements having SpHb values in the “very accurate group” versus 12 % in patients without a DNB. When the PI value was >2.0, only 1 of 57 DNB values was in the “inaccurate” group. The PI values were both higher and less variable in the patients who received a DNB.

Conclusions

A DNB significantly increased the number of “very accurate” SpHb values and decreased the number of “inaccurate” values. We conclude that a DNB may facilitate the use of SpHb as a guide to transfusion decisions, particularly when the PI is >2.0.     

Does ultrasound guidance improve the efficacy of dorsal penile nerve block in children?

Background: Penile nerve block (PNB) is a well‐established technique used for circumcision; it requires the injection of local anesthetics close to the dorsal nerve of the penis. The goal of this study was to compare the efficacy of ultrasound‐guided PNB versus the classical landmark‐based technique (LBT) in children undergoing circumcision. Methods: Forty boys, aged 1–14 years old that were scheduled for circumcision were randomly assigned to ultrasound‐guided and landmark‐based groups. All patients were placed under standard anesthesia with sevoflurane. In each group, patients received the penile block with ropivacaine, 0.75 mg·kg^?1 per side, and 0.05 mg·kg^?1 at the penis base. Groups were compared for intraoperative failure rate of the block, anesthesia time, postoperative pain scale, time of first required dose of paracetamol, time to first micturition, and average duration of stay in the postanesthesia care unit. Results: The failure rate of dorsal PNB was not statistically different between groups (P = 0.5). Ultrasound guidance improved the efficacy of the PNB compared to the LBT in terms of postoperative pain scores on arrival in the PACU (P < 0.01) and after 30 min (P < 0.01). The ultrasound‐guided technique also delayed the time to the first paracetamol dose administration (P < 0.0001), but the duration of the procedure, defined as the time between anesthesia induction and the end of surgery, was increased by 10 min in the US‐guided group (P = 0.001). Conclusion: Ultrasound‐guided PNB improved the efficacy of the block compared with the LBT in terms of the postoperative pain during the first postoperative hour and the time to the first requirement for postoperative analgesia.     

Follicular lesions of the thyroid. Does frozen section evaluation alter operative management?

OBJECTIVE: The authors determined the usefulness of frozen section (FS) evaluation in the operative management of follicular lesions of the thyroid. SUMMARY BACKGROUND DATA: Fine-needle aspiration (FNA) cannot reliably discriminate between benign and malignant follicular lesions of the thyroid. Accordingly, FS evaluation is used routinely to guide intraoperative management. METHODS: One hundred twenty-five consecutive patients with follicular thyroid lesions who underwent surgical exploration at the Johns Hopkins Hospital were reviewed. RESULTS: Frozen sections were categorized in 104 of 120 patients (87%) as "follicular lesion, defer to permanent section," rendering no useful clinical information. In only 4 of 120 patients (3.3%) did FS evaluation correctly modify the operative procedure. Notably, in six cases (5.0%), an incorrect FS evaluation misled the surgeon, resulting in four misguided operations. CONCLUSION: Frozen section evaluation is of minimal diagnostic value for follicular thyroid lesions, rendering no additional information 87% of the time; it prolongs the operation, increases costs, and leads to misguided interventions. Until a more definitive diagnostic tool exists for follicular thyroid lesions, FS evaluation could be omitted, resection of the lobe with the nodule could be performed, and the definitive operative management could be based on the final permanent histology.     

General anesthetic-induced neurotoxicity: an emerging problem for the young and old?

PURPOSE OF REVIEW: A growing body of evidence from cells, rodents, and sub-human primates suggests that general anesthetics can be neurotoxic to the developing and senescent brain. We review this evidence and put the studies into perspective for the practicing clinician. RECENT FINDINGS: Studies indicate that a variety of general anesthetics, which act primarily as gamma-amino-butyric acid receptor modulators and N-methyl-D-aspartic acid glutamate receptor antagonists, produce apoptotic neurodegeneration in the developing rodent and nonhuman primate brain. Vulnerability to this neurotoxicity is greatest during the period of synaptogenesis and presumably reflects disruption of the normal balance between excitation and inhibition during a critical period of brain development. Moreover, in the rodent, the neurodegeneration is associated with cognitive impairment into adulthood. Recent data also reveal that general anesthesia produces enduring cognitive impairment in aged but not young rodents and that halothane and isoflurane increase the generation and toxicity of amyloid beta, a protein strongly implicated in the pathogenesis of Alzheimer's disease. The meaning of these experimental results for human surgical patients is unclear, however, because human studies are lacking. SUMMARY: General anesthetics produce neurotoxicity and enduring cognitive impairment in young and aged animals but it is premature to change clinical practice because the issue has not been adequately studied in humans.     

Does the timing of shoulder manipulation under ultrasound-guided cervical nerve root block for frozen shoulder affect the clinical outcome?

BackgroundAlthough the clinical outcomes of manipulation under ultrasound-guided fifth and sixth cervical nerve root block for frozen shoulder have been reported, few studies have focused on the timing of manipulation. This study aimed to determine whether the timing of manipulation impacts the clinical outcomes.MethodsWe retrospectively reviewed the outcomes of 103 frozen shoulder patients (mean age 51.5 years) who underwent manipulation in one shoulder (n = 103 shoulders) between January 2012 and April 2019. Stiff shoulder was defined as limited range of motion in at least three directions, i.e., passive forward flexion of ≤100°, passive external rotation at the side of ≤10°, and internal rotation of ≤L5. The patients were categorized into two groups: those mobilized within 6 months after symptom onset (early group, 44 shoulders) and those mobilized >6 months after symptom onset (late group, 59 shoulders). The range of motion (forward flexion, external rotation, and internal rotation), Japanese Orthopaedic Association shoulder scores, Constant Shoulder Score, and University of California, Los Angeles scores before and 3, 6, and 12 months after manipulation were compared between groups.ResultsThe late group exhibited significant improvement in forward flexion, external rotation, internal rotation, Japanese Orthopaedic Association scores, Constant Shoulder Score, and University of California, Los Angeles scores at 3 months; forward flexion at 6 months; and forward flexion and University of California, Los Angeles scores at 12 months after manipulation compared to the early group.ConclusionsOur results indicate that timing has a significant influence on the outcome of manipulation for frozen shoulders. The optimal time for manipulation may be >6 months after symptom onset. These findings can be applied in counselling for frozen shoulder patients and for improved outcomes after manipulation.     

Does a mid-lumbar block level provide adequate anaesthesia for transurethral prostatectomy?

In this prospective, randomized study, 23 patients having spinal anaesthesia for transurethral prostatectomy (TURP) were evaluated for the adequacy of their block using a visual analog pain score (V4 PS). Each patient with a “standard”(≥T₁₀) block level (n = 5) or “intermediate” (L₁ or T₁₂) block level (n = 5) found the block adequate. Sixty-two percent (8/13) of patients with a “low”-L₃) block level found their block adequate. The VAPS was assessed every five minutes or whenever pain abruptly increased during TURP; an “inadequate block” was defined as a V4 PS ≥ 5 /10 during prostatic resection. Intravesical pressure was monitored and kept <15 mmHg to distinguish between pain from bladder distension and from prostatic resection. “Low” block patients (LBP) who found their block inadequate (n = 5) received supplemental intrathecal local anaesthetic given through a spinal catheter. The subsequent L₁ block level was adequate for TURP. In LBP, who found their block adequate (n = 8), a higher (P < 0.01) VAPS was observed than in patients with a “standard” block level. However, a smaller (P < 0.05) maximum percent decrease in diastolic blood pressure was found in LBPs, than in “intermediate” or “standard” block patients. It is concluded that a spinal block ≥L₁) is adequate during TURP when bladder pressure is monitored and kept low. Mid-lumbar block levels should be reserved for patients in whom the benefit of minimizing haemodynamic changes outweighs the risk of a “less complete” anaesthetic.