A study of low-dose S-ketamine infusion as "preventive" pain treatment for cesarean section with spinal anesthesia: benefits and side effects

BACKGROUND: Attenuation of central sensitization with NMDA-active drugs such as S-Ketamine may play a role in postoperative analgesia and prevention of neuropathic pain. However, during cesarean section with neuraxial block, S-Ketamine might have adverse effects on the interaction between mothers and infants, including breastfeeding. METHODS: Women undergoing elective repeat cesarean section with subarachnoid anesthesia (0.5% hyperbaric bupivacaine 8-10 mg and sufentanil 5 \u3bcg) were enrolled in a double-blind, randomized study. Patients in the S-Ketamine group (N.=28) received i.v. midazolam 0.02 mg/kg and S-Ketamine 0.5 mg/kg i.m. bolus 10 minutes after birth followed by a 2 \u3bcg/kg/min i.v. continuous infusion for 12 h. The control group (N.=28) received placebo. Paracetamol and patient controlled analgesia with intravenous morphine were given postoperatively. Von Frey filaments were used to assess pain threshold on the inner forearm and T10-T11 dermatomes (supposed hyperalgesic area). RESULTS: S-Ketamine reduced morphine consumption at 4-8, 8-12, and 12-24 hours after surgery (total 31%), even after its effect has ceased, suggesting an anti-hyperalgesic action. Mild side effects were observed in the S-Ketamine group one hour after delivery. All side effects were rated as light and there were no serious adverse events. Pain threshold was not significantly different between groups. S-Ketamine patients showed a trend towards reduced pain sensitivity at the T10 dermatome, which is involved by surgical damage. After three years, patients reported no differences in residual pain, dysesthetic symptoms, or duration of breast-feeding. CONCLUSION: Preventive administration of S-Ketamine via 12-hour infusion was safe and may have anti-hyperalgesic action after cesarean sectio

Pregnancy-induced analgesia:a combined psychophysical and neurophysiological study

BACKGROUND: To investigate changes in heat pain threshold and modifications in heat pain processing during pregnancy and labour, seventy-six nulliparous pregnant women were enrolled in two studies. METHODS: In the first study (psychophysical), 60 pregnant women underwent a quantitative sensory testing (QST) investigating heat perception in two body areas (right forearm and T10 dermatome) according to these groups: 32-33 gestational weeks (GW), 39-40 GW, early stage of active labour and 24 h after the delivery. In the other study (neurophysiological), contact heat-evoked potentials (CHEPs) were recorded in other 16 women at the 32nd GW and in 11 of these also at the 40th GW. RESULTS: The psychophysical study showed that heat pain threshold was significantly increased at the forearm at 32-33 GW (median ± IQR: 39.6 ± 0.7 °C), at 39-40 GW (40.6 ± 1.1 °C) and at early stage of active labour (40.8 ± 1.5 °C) as compared to 20 non-pregnant controls (p < 0.001). Heat pain threshold tested at T10 level was significantly increased at 32-33 GW (41.0 ± 1.6 °C), at 39-40 GW (42.1 ± 1.8 °C), and at early stage of active labour (42.3 ± 1.3 °C) as compared to the non-pregnant women (p < 0.001). The N2-P2 CHEP amplitude (main negative N2 and positive P2 components of the vertex biphasic potential) recorded from the pregnant women was significantly lower at the 40th than at the 32nd GW, after stimulation of both the forearm (p < 0.001) and the abdomen (p < 0.001). CONCLUSIONS: In pregnant women, there is a progressive increase of heat pain threshold and a reduction of the CHEP amplitude, suggesting that a general inhibitory mechanism may be involved

Ultrasound-guided genitofemoral nerve block for inguinal hernia repair in the male adult: A randomized controlled pilot study

BACKGROUND: Ultrasound-guided (USG) ilioinguinal/iliohypogastric nerve (II/IHN) block is a widely validated anesthetic technique for inguinal herniorrhaphy. As the spermatic cord, scrotum, and adjacent thigh receive sensory innervation from the genital branch of genitofemoral nerve (GFN), the addition of GFN block has been suggested to improve the quality of perioperative anesthesia and analgesia. The aim of this study is to compare GFN block plus II/IHN block with II/IHN block alone for intraoperative anesthesia and post-operative pain management. METHODS: We enrolled 80, ASA I-III, male adults scheduled for elective open herniorrhaphy. Patients were randomized to receive either USG II/IHN plus GFN block (Case Group) or USG II/IHN block alone (Control Group). The outcome measures were the assessment of postoperative VAS scores on coughing and the adequacy of anesthesia, measured with intraoperative requirement for extra local anesthetic (LA) infiltration and number of patients needing systemic sedation. RESULTS: The requirement of intraoperative additional doses of LA was significantly lower in the Case Group (median LA volume administered by the surgeon: 13.8\ub15.6 mL vs. 20.7\ub19.1 mL, P<0.05). Two patients in the Control Group needed systemic sedation. VAS scores at 15 minutes, 30 minutes, 1 hour, 2 hours, pre-discharge, and 24 hours were significantly lower in the Case Group (P<0.005). Four cases of femoral nerve block were reported, three in the Control Group, one in the Case Group (2.2% vs. 7.7%, P>0.05). CONCLUSIONS: The combination of GFN block and II/IHN block is associated with lower postoperative VAS scores and lower doses of intraoperative additional LA

Hypotension Prediction Index with non-invasive continuous arterial pressure waveforms (ClearSight): clinical performance in Gynaecologic Oncologic Surgery

Intraoperative hypotension (IOH) is common during major surgery and is associated with a poor postoperative outcome. Hypotension Prediction Index (HPI) is an algorithm derived from machine learning that uses the arterial waveform to predict IOH. The aim of this study was to assess the diagnostic ability of HPI working with non-invasive ClearSight system in predicting impending hypotension in patients undergoing major gynaecologic oncologic surgery (GOS). In this retrospective analysis hemodynamic data were downloaded from an Edwards Lifesciences HemoSphere platform and analysed. Receiver operating characteristic curves were constructed to evaluate the performance of HPI working on the ClearSight pressure waveform in predicting hypotensive events, defined as mean arterial pressure < 65 mmHg for > 1 min. Sensitivity, specificity, positive predictive value and negative predictive value were computed at a cutpoint (the value which minimizes the difference between sensitivity and specificity). Thirty-one patients undergoing GOS were included in the analysis, 28 of which had complete data set. The HPI predicted hypotensive events with a sensitivity of 0.85 [95% confidence interval (CI) 0.73–0.94] and specificity of 0.85 (95% CI 0.74–0.95) 15 min before the event [area under the curve (AUC) 0.95 (95% CI 0.89–0.99)]; with a sensitivity of 0.82 (95% CI 0.71–0.92) and specificity of 0.83 (95% CI 0.71–0.93) 10 min before the event [AUC 0.9 (95% CI 0.83–0.97)]; and with a sensitivity of 0.86 (95% CI 0.78–0.93) and specificity 0.86 (95% CI 0.77–0.94) 5 min before the event [AUC 0.93 (95% CI 0.89–0.97)]. HPI provides accurate and continuous prediction of impending IOH before its occurrence in patients undergoing GOS in general anesthesia

Lung ultrasonography for early management of patients with respiratory symptoms during COVID-19 pandemic

COVID-19 pandemic is representing a serious challenge to worldwide public health. Lung Ultrasonography (LUS) has been signaled as a potential useful tool in this pandemic contest either to intercept viral pneumonia or to foster alternative paths. LUS could be useful in determining early lung involvement suggestive or not of COVID-19 pneumonia and potentially plays a role in managing decisions for hospitalization in isolation or admission in general ward. In order to face pandemic, in a period in which a large number of emergency room accesses with suspicious symptoms are expected, physicians need a standardized ultrasonographic approach, fast educational processes in order to be able to recognize both suggestive and not suggestive echographic signs and shared algorithms for LUS role in early management of patients