Transnasal Humidified Rapid-Insufflation Ventilatory Exchange (THRIVE) as unique technique for airway management during operative hysteroscopy under general anesthesia: a registered feasibility pilot cohort study.

OBJECTIVE: The term THRIVE refers to the delivery of 100% heated and humidified oxygen via a nasal cannula to maintain viable gas exchange during prolonged apnea. There are no reports of its application for Operative Hysteroscopy (OH) under general anesthesia (GA). The aim of the study is to investigate the success rate of THRIVE as unique airway management technique in this setting. The results will support the development of a randomized controlled trial (RCT) to demonstrate the non-inferiority of THRIVE compared to traditional techniques. PATIENTS AND METHODS: Twenty consecutive ASA I-II women presenting for OH were enrolled. Standard anesthesia, as well as transcutaneous carbon dioxide (tcCO2) monitoring, was performed. After preoxygenation with 30 L∙min-1, GA was induced with propofol and fentanyl, then oxygen flow was increased to 70 L∙min-1 and anesthesia maintained with propofol infusion. The primary outcome was success rate of THRIVE defined as SpO2 > 94%, tcCO2 < 60 mmHg and no need for rescue airway intervention. RESULTS: Mean age was 47 ± 12 years. Mean duration of the procedure was 25 ± 9 minutes, and the success rate of the technique was 100%. Median SpO2 during the procedure was 100 (IQR 99-100) %. Mean maximum tcCO2 level was 51 ± 7 mmHg while mean tcCO2 level during the procedure was 45 ± 7 mmHg. At the end of the procedure, mean tcCO2 was 44 ± 5 mmHg. CONCLUSIONS: THRIVE allowed adequate gas exchange during OH under GA, without additional rescue airway interventions. The application of THRIVE in this setting may allow minimal airway manipulation and optimal comfort for the patient with low failure rate. We calculated the sample size for the planned non-inferiority RCT investigating the effectiveness of THRIVE versus laryngeal mask ventilation in OH: 82 is the minimal number of patients per group to test a non-inferiority limit of 10%.

Erector spinae plane block for postoperative analgesia after total laparoscopic hysterectomy: case series and review of the literature.

OBJECTIVE: Total laparoscopic hysterectomy (TLH) is associated with significant postoperative pain that worsens outcomes and prolongs hospital stay. Ultrasound guided erector spinae plane block (ESPB) is a new technique for thoracic analgesia. Few cases have been described for postoperative analgesia in laparoscopy. We describe the use of preoperatory bilateral ESPB at level T10 to provide postoperative analgesia following THL. PATIENTS AND METHODS: We enrolled 10 ASA 1-2 patients scheduled for TLH. After written informed consent we performed bilateral ESPB at T10 level in sitting position, with a linear probe and in plane cranio-caudal approach and ropivacaine 0.5% 20 for each side. The sensitive block was tested by pinprick. Standard general anesthesia was administered. Patient controlled analgesia (PCA) with morphine 1 mg/ml was delivered. We measured postoperative pain by visual analogue scale (VAS). RESULTS: Five patients (50%) underwent simple TLH, 5 women (50%) had TLH plus salpingo-oophorectomy. VAS scores was <4 in all cases but one, and PCA morphine consumption was 4.1 ± 3.5 mg (mean ± SD). Pinprick was positive bilaterally in 3 patients (30%). CONCLUSIONS: ESPB was an effective and safe procedure for postoperative pain control after TLH. Future research should compare ESPB to other techniques to assess its role on perioperative management of THL.

Bladder function after spinal anesthesia for cesarean section: an urodynamic evaluation.

BACKGROUND: This study evaluates the effects of spinal anesthesia with hyperbaric bupivacaine plus sufentanil on bladder function in women undergoing cesarean section. SUBJECTS AND METHODS: Thirty caucasian healthy pregnants scheduled for elective Cesarean section under spinal anesthesia performed with hyperbaric bupivacaine plus sufentanil were enrolled. Filling cystometry, proprioceptive bladder sensation during cystometry, rate of spontaneous voiding, post void residual volume, anocutaneous and bulbocavernosus reflex were analyzed at 4, 6 and 8 hours after spinal anesthesia. RESULTS: The proportion of women experiencing first sensation, first desire and strong desire at 4 hours was significantly different from that reported at 6 and 8 hours (p < 0.05 for first sensation and p < 0.01 for first and strong desire). Significant differences were also observed between volumes at which first sensation arose at first measurement (4 hours) and at second and third measurements (p < 0.01). There was a significant difference in rate of spontaneous micturition, with 80% of patients at 8 hours able to spontaneously void versus 40% at 6 hours, (p < 0.01). Moreover, a lower percentage of women had absent and/or light reflexes at 4 hour than at 6 and 8 hours (p < 0.01). CONCLUSIONS: Spinal anesthesia with bupivacaine plus sufentanil causes a clinically significant disturbance on bladder function in women undergoing cesarean section. Even thought recovery of proprioceptive bladder sensation is fast, a full recovery of spontaneous voiding requires a much longer time. A close monitoring of urinary function and of bladder distension is, therefore, advisable.

General anesthesia for caesarean delivery in a pregnant woman affected by acute myocardial infarction.

Acute myocardial infarction rarely occurs in women during childbearing age (1:20,000), but maternal mortality rate is high (11%). Management of pregnant woman affected by myocardial infarction could be a challenge for obstetricians, cardiologists and anesthetists. In this report, we present the management of a 36 years-old nulliparous woman affected from hypertension and dyslipidemia, who experienced acute myocardial infarction at 25th gestational week and was scheduled for caesarean delivery at 35th week. General anesthesia for cesarean section was conducted using sevoflurane and remifentanil target controlled infusion (TCI); the patient was monitored with ECG, pulse oximetry, invasive blood pressure, haemodynamic measurement by lithium dilution cardiac output (LiDCO plus) and bispectral index. The titrated use of remifentanil and the close control of hemodynamic parameters by LiDCO plus monitoring may contribute to improve maternal outcome and newborn well-being in the management of general anesthesia for caesarean section.

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.

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 µg) 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 µg/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 section.

Remifentanil for cesarean section under general anesthesia: effects on maternal stress hormone secretion and neonatal well-being: a randomized trial.

BACKGROUND: Remifentanil may attenuate maternal hemodynamic response during cesarean section under general anesthesia, but could cause transient but significant neonatal depression. We investigated the effect of low-dose remifentanil on maternal neuroendocrine response and fetal wellbeing. METHODS: Forty-two ASA I-II parturients undergoing cesarean section at term under general anesthesia were randomized to receive either fentanyl after delivery (n=21, group C) or remifentanil bolus 0.5 microg/kg before induction followed by a continuous infusion at 0.15 microg x kg(-1)min(-1) until peritoneal incision, then restarted after delivery (n=21, group R). Maternal heart rate and blood pressure, and epinephrine, norepinephrine, adrenocorticotropic hormone (ACTH), and growth hormone levels were measured at baseline, uterine incision, and the end of surgery. Remifentanil was measured in maternal and umbilical arterial and venous blood. One- and 5-minute Apgar scores and umbilical arterial and venous pH were recorded. RESULTS: ACTH was significantly higher in group C at uterine incision (P<0.01). No significant differences were observed in hemodynamics, catecholamines or growth hormone. Apgar scores at 1 (P<0.05) and 5 min (P<0.01) were significantly higher in group C. Mean umbilical pH values were within normal range but significantly higher in group C. Three neonates in group R required intubation but recovered at 5 min without naloxone. Mean+/-SD maternal remifentanil concentration was 1.67+/-1.04 ng/mL. CONCLUSIONS: Remifentanil administration before peritoneal incision partially reduced the hormonal stress response. Maternal benefits must be weighed against transitory but significant neonatal respiratory depression. Neonatal resuscitation facilities are mandatory when remifentanil is used.