Generalizability of nociception level as a measure of intraoperative nociceptive stimulation: A retrospective analysis.

BACKGROUND: Nociception-guided intraoperative opioid administration might help reduce postoperative pain. A commonly used and validated nociception monitor system is nociception level (NOL), which provides the nociception index, ranging from 0 to 100, with 0 representing no nociception and 100 representing extreme nociception. We tested the hypothesis that NOL responses are similar in men and women given remifentanil and fentanyl, across various types of anesthesia, as a function of American Society of Anesthesiologists physical status designations, and over a range of ages and body morphologies. METHODS: We conducted a retrospective cohort analysis of trial data from eight prospective NOL validation studies. Among 522 noncardiac surgical patients enrolled in these studies, 447 were included in our analysis. We assessed NOL responses to various noxious and non-noxious stimuli. RESULTS: The average NOL in response to 315 noxious stimuli was 47 ± 15 (95% CI = 45-49). The average NOL in response to 361 non-noxious stimuli was 10 ± 12 (95% CI = 9-11). NOL responses were similar in men and women, in patients given remifentanil and fentanyl, across various types of anesthesia, as a function of American Society of Anesthesiologists physical status designations, and over a range of ages and body morphologies. CONCLUSION: Nociception level appears to provide accurate estimates of intraoperative nociception over a broad range of patients and anesthetic conditions.

Preoperative clear fluid fasting and endoscopy-measured gastric fluid volume in children.

BACKGROUND: In light of new recommendations to shorten clear fluid fasting time before anesthesia, our study aimed at exploring residual fluid volume in the stomach after different fasting times. We intended to perform direct endoscopic aspiration of stomach contents under vision, as part of routine gastroscopy assessment. Hereby we would be able to quantify true residual gastric fluid volume and acidity in children and measure their correlation with fasting times. METHODS: The study was performed as a single-center, prospective study in pediatric perioperative day care at a university-affiliated tertiary care center. Aspiration of gastric fluid contents was performed in anesthetized children aged 1-18 years undergoing an elective gastroscopy. Recorded data included patient fast time, last meal content, last clear fluid content, and aspirated gastric volume and pH, as well as patient characteristics. RESULTS: We included 253 gastroscopies, performed in 245 children. Mean fasting time for clear fluids was 6.9 h (range 1 h 40 min - 18 h 35 min) (SD 4.5). Mean age was 9.8 years (SD 5.1) and mean body weight was 33.2 kg (SD 18.7). Mean residual gastric volume was 12 mL (0-90) (SD 13.5) or 0.34 mL/kg (SD 0.37) and mean pH was 1.5 (SD 0.9). No significant correlation was observed between clear fluid fasting time and the child's residual gastric fluid volume per kg body weight (r = -.103, p = .1), nor between clear fluid fasting time and the pH of the residual gastric fluid (r = -.07, p = .3). In more than half of the patients the residual gastric volume was less than 10 mL, unrelated to fasting time. CONCLUSIONS: In children undergoing gastroscopy, we could not demonstrate any association between clear fluid fasting time and the child's residual gastric fluid volume per kg body weight. Since we did not see a clinically relevant association between clear fluids fasting time and gastric residual volume, this study may support the recommendation to shorten clear fluids fasting time.

Reduced postoperative pain in patients receiving nociception monitor guided analgesia during elective major abdominal surgery: a randomized, controlled trial.

The Nociception Level index (NOL™) is a multiparameter index, based on artificial intelligence for the monitoring of nociception during anesthesia. We studied the influence of NOL-guided analgesia on postoperative pain scores in patients undergoing major abdominal surgery during sevoflurane/fentanyl anesthesia. This study was designed as a single-center, prospective randomized, controlled study. After Institutional Review Board approval and written informed consent, 75 ASA 1-3 adult patients undergoing major abdominal surgery, were randomized to NOL-guided fentanyl dosing (NOL) or standard care (SOC) and completed the study. The sevoflurane target MAC range was 0.8-1.2. In the NOL-guided group (N = 36), when NOL values were > 25 for at least 1 min, a weight adjusted fentanyl bolus was administered. In the control group (N = 39) fentanyl administration was based on hemodynamic indices and clinician judgement. After surgery, pain, was evaluated using the Numerical Rating Scale (NRS) pain scale, ranging from 0 to 10, at 15 min intervals for 180 min or until patient discharge from the PACU. Median postoperative pain scores reported were 3.0 [interquartile range 0.0-5.0] and 5.0 [3.0-6.0] at 90 min in NOL-guided and control groups respectively (Bootstrap corrected actual difference 1.5, 95% confidence interval 0.4-2.6). There was no difference in postoperative morphine consumption or intraoperative fentanyl consumption. Postoperative pain scores were significantly improved in nociception level index-guided patients. We attribute this to more objective fentanyl dosing when timed to actual nociceptive stimuli during anesthesia, contributing to lower levels of sympathetic activation and surgical stress. Clinicaltrials.gov identifier: NCT03970291 date of registration May 31, 2019.

Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) in the Multidisciplinary Management of Morbidly Adherent Placenta.

BACKGROUND: Morbidly adherent placentation (MAP) increases the risk for obstetric hemorrhage. Cesarean hysterectomy is the prevalent perioperative approach. Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a minimally invasive and relatively simple endovascular procedure to temporarily occlude the aorta and control below diaphragm bleeding in trauma. It has been effectively used to reduce obstetric hemorrhage. OBJECTIVES: To evaluate whether REBOA during cesarean delivery (CD) in women with morbidly adherent placentation is a safe and effective treatment modality. METHODS: We introduced REBOA for CD with antepartum diagnosis of MAP in 2019 and compared these patients (RG) to a standard approach group (SAG) treated in our center over the preceding year, as a control. All relevant data were collected from patient electronic files. RESULTS: Estimated blood loss and transfusion rates were significantly higher in SAG; 54.5% of SAG patients received four RBC units or more vs. one administered in RG. No fresh frozen plasma, cryoprecipitate, or platelets were administered in RG vs. mean 3.63, 6, and 3.62 units, respectively in SAG. Ten SAG patients (90.9%) underwent hysterectomy vs. 3 RG patients (30%). Five SAG patients (45%) required post-surgical intensive care unit (ICU) admission vs. no RG patients. Bladder injury occurred in five SAG cases (45%) vs. 2 RG (20%). One RG patient had a thromboembolic event. Perioperative lactate levels were significantly higher in SAG patients. CONCLUSIONS: Use of REBOA during CD in women with MAP is safe and effective in preventing massive bleeding, reducing the rate of hysterectomy, and improving patient outcome.

Chronic pain in parturients with an accidental dural puncture: A case-controlled prospective observational study.

BACKGROUND: We set out to examine incidence of chronic headache and back pain in women with PDPH after accidental dural puncture during labor. METHODS: Chronic headache, backache, and disability were assessed 18-24 months postpartum. Women with PDPH treated with epidural blood patch (PDPH-EBP) were identified and matched with women who had a PDPH without epidural blood patch (PDPH-no EBP), with women with uncomplicated epidural analgesia and with women without epidural analgesia. Our primary outcome was incidence of chronic headache and backache. Secondary outcome was the effect of epidural blood patch on chronic pain development. We used Chi-square or Fisher's exact test to calculate odds ratios. RESULTS: There was no statistically significant difference in demographic characteristics between groups. In the no epidural group, no women reported chronic headache and 2/116 (1.7%) reported chronic backache. In the uncomplicated epidural group, no women reported chronic headache and 7/116 (6.0%) reported chronic backache. In the PDPH-no EBP group, 9/56 (16.1%) women reported chronic headache and 10/56 (17.9%) reported chronic backache. In the PDPH-EBP group, 12/59 (20.3%) had chronic headache and 14/59 (23.7%) had chronic backache. No women in the no epidural or uncomplicated epidural group reported disability (chronic pain score of 3 or 4). High disability was reported by 8.9% of women in the PDPH-no EBP group and by 8.4% in the PDPH-EBP group. CONCLUSION: Women with PDPH had a high incidence of chronic headache, back pain, and disability. We did not find a statistically significant difference in chronic pain development between conservatively treated and EBP-treated patients.

Anesthetic considerations for repeat cesarean section.

PURPOSE OF REVIEW: The prevalence of cesarean delivery is increasing worldwide despite the advance of Trial of Labor After Cesarean section. In many countries, a history of previous cesarean section is an almost absolute indication for a repeat cesarean section. The purpose of this review was to examine if the perioperative anesthetic management of patients with repeat cesarean section is different from the anesthetic management of patients with primary cesarean section. RECENT FINDINGS: This review discusses important topics, such as early diagnosis of cases with a potentially high risk for complications; the need for assessment of patients diagnosed with abnormal placentation; the importance of a multidisciplinary approach that includes interaction of the anesthesiologist, gynaecologist, and invasive radiologist; emphasizing the need for reinforcement of new methods of invasive procedures; management of massive bleeding, use of new technologies, and development of an institutional protocol for management of patients with abnormal placentation. SUMMARY: According to this review, we show that the management of patients with repeat cesarean section without abnormal placentation is almost the same as the management of patients for primary cesarean section. Timely diagnosis of patient with abnormal placentation and multidisciplinary approach is crucial for prevention of morbidity or even mortality.

Anesthetic approach to postdural puncture headache in the peripartum period: An Israeli national survey.

BACKGROUND: Accidental dural puncture frequency among pregnant women is about 1.5%, while approximately 60% of these women will suffer from post-dural puncture headache (PDPH) that may be debilitating. METHODS: Following IRB approval, we conducted a national survey of the lead anesthesiologist in 23 labor and delivery rooms in Israel. Each survey inquired about medical center annual delivery volume, training program for residents, accidental dural puncture management, processing of information, and PDPH management strategies. RESULTS: Data were collected from all 23 surveyed hospitals. As for methods for PDPH prevention, in most hospitals (87%) a prophylactic epidural blood patch (EBP) is not considered. Injection of epidural normal saline after delivery as a preventive measure is never considered in most (78.3%) hospitals, while four (17.4%) hospitals reported of constitutive use of this technique and one hospital only occasionally. Duration of conservative treatment was 24-48 hours in 95.7% of PDPH cases. CONCLUSION: In this survey, different aspects of treatment and PDPH management were examined. EBP is considered the gold standard in treating PDPH, although prophylactic blood patch is ineffective. We observed a tendency of very low performance of both prophylactic EBP and epidural normal saline administration after delivery in most centers. Most hospitals perform EBP after 24-48 hours of conservative treatment, along with published recommendations that show increased EBP efficiency with this timeframe. In light of the survey information, we aim to reach a uniform literature-based management strategy across Israeli hospitals.

Five years' experience in an anesthesiology antenatal clinic for high-risk patients.

INTRODUCTION: The aim, of this study is to describe our approach and outcomes in an outpatient anesthesia/analgesia antepartum clinic among ambulatory high-risk obstetric patients. METHODS: This was a retrospective evaluation of the activity of the anesthesiology antenatal clinic from its inception in 2010 until 2016 (a 5-year period). The clinic works in collaboration with the Department of Obstetrics and Gynecology. The catchment area of the study University Affiliated Hospital attends a multiethnic population characterized by high parity. RESULTS: There were 241 referrals over the 5 years, each of whom was discharged with a consult and a delivery management plan and 228 (95%) of which were performed as planned. Mean gestational age at consultation was 34.4 weeks (range: 20-37). There were no preconceptional consultation. No limitations regarding mode of anesthesia/analgesia was considered for 47% of the referrals. Nulliparous women accounted for 50% of the referrals and 17% were in their second pregnancy. The greatest number of referrals (30%) was for musculoskeletal conditions. No maternal death encountered. The mode of delivery was vaginal in 139 (65%) women; elective cesarean section in 44 (21%) women; and emergent cesarean section in 30 (14%) women. The neonatal outcomes were unremarkable; 210 (87%) in hospital births, 97.1% had an a 5' Apgar score of 9. CONCLUSION: Our findings reveal the need for high-risk obstetric patients consult with a dedicated obstetric anesthesiologist to devise a management plan for labor and delivery that is tailored to their comorbidity and obstetric status, to ensure an optimum outcome for mother and child.

Activation of Adenosine Triphosphate-regulated Potassium Channels during Reperfusion Restores Isoflurane Postconditioning-induced Cardiac Protection in Acutely Hyperglycemic Rabbits.

BACKGROUND: Hyperglycemia is known to inhibit myocardial anesthetic postconditioning. The authors tested whether activation of adenosine triphosphate-regulated potassium (KATP) channels would restore anesthetic postconditioning during acute hyperglycemia. METHODS: Rabbits subjected to 40-min myocardial ischemia and 3-h reperfusion (ischemia-reperfusion [I/R]) were assigned to groups (n = 10 in each group) with or without isoflurane postconditioning (2.1% for 5 min) in the presence or absence of hyperglycemia and/or the KATP channel agonist diazoxide. Creatine kinase MB fraction and infarct size were measured. Phosphorylated protein kinase B (Akt) and endothelial nitric oxide synthase (eNOS) were assessed. Oxidative stress was evaluated by measuring malondialdehyde, and apoptosis was assessed by dUTP nick-end labeling and activated caspase-3. RESULTS: Postconditioning significantly reduced myocardial infarct size (26 ± 4% in the isoflurane [ISO] group vs. 53 ± 2% in the I/R group; P = 0.007); whereas, hyperglycemia inhibited this effect (infarct size: 47 ± 2%, P = 0.02 vs. the ISO group). Phosphorylated and eNOS levels increased, whereas malondialdehyde and myocardial apoptosis were significantly lower after isoflurane postconditioning compared with I/R. These effects were inhibited by acute hyperglycemia. Diazoxide restored the protective effect of isoflurane in the hyperglycemic animals (infarct size: 29 ± 2%; P = 0.01 vs. the I/R group), reduced malondialdehyde levels and myocardial apoptosis, but did not affect the expression of phosphorylated Akt or eNOS. CONCLUSIONS: KATP channel activation restored anesthetic postconditioning-induced myocardial protection under acute hyperglycemia. This effect occurred without increasing Akt or eNOS phosphorylation, suggesting that KATP channels are located downstream to Akt and eNOS in the pathway of isoflurane-induced myocardial postconditioning.

Anesthetic management of prophylactic cervical cerclage: a retrospective multicenter cohort study.

OBJECTIVES: Cervical incompetence complicates approximately 1 in 500 pregnancies and is the most common cause of second-trimester spontaneous abortion and preterm labor. No prospective or large retrospective studies have compared regional and general anesthesia for cervical cerclage. STUDY DESIGN: Following IRB approval, we performed a retrospective study in the two main medical centers over an 8-year period to assess the association of anesthesia choice with anesthetic and obstetric outcomes. Anesthetic and perioperative details were retrospectively collected from fails of all patients undergoing cervical cerclage from 01/01/2005 until 31/12/2012. Details included demographic data, anesthetic technique, PACU data and perioperative complications. RESULTS: We identified 487 cases of cervical cerclage in 327 women during the study period. The most commonly used anesthetic technique was general anesthesia (GA) (402/487; 82.5%) compared with regional anesthesia (RA) (85/487; 17.5%). When GA was performed, facemask was the most commonly used technique (275/402; 68.4%), followed by intravenous deep sedation (61/402; 15.2%); LMA (51/402; 12.7%) and tracheal intubation (13/402; 3.2%). There were no significant differences in demographic characteristics between women receiving general and regional anesthesia. Average duration of suturing the cervix among the GA group was 9.8 ± 1.6 and 10.6 ± 2.1 min in the RA group (p < 0.001). Average length of stay in the operating room in the GA group was 20.5 ± 3.9 and 23 ± 4.6 min in the RA group (p < 0.001). Patients receiving GA received in the PACU more opioids (6.2 versus 1.2%; p < 0.05) and more non-opioids analgesics (36.8 versus 9.4%; p < 0.001). Duration of PACU stay was shorter after GA (49.5 ± 18 min) than after RA (62.4 ± 28 min; p < 0.001). There were no other differences in anesthetic or perioperative outcome between groups. This study was not designed to provide evidence that RA reduces the risk of pulmonary aspiration, airway complications or adverse fetal neurological effects from maternal anesthetic exposure. CONCLUSIONS: Both regional and general anesthesia were safely used for the performance of cerclage. Patients after general anesthesia had a shorter recovery time but a higher demand for opioids and non-opioids analgesia.

Anesthetic considerations for high order cesarean sections: a prospective cohort study.

BACKGROUND: In a previous retrospective study we demonstrated that perioperative complications occurred in a minority of high order repeat cesarean sections (HOR-C/S). In this prospective study we compared the incidence of complications in patients who have had four or more cesarean sections to those that had three or less. METHODS: This was a prospective, observational cohort study of parturients undergoing C/S at a single tertiary care hospital over a 1 year period. We compared the incidence of conversion from regional to general anesthesia, duration of surgery and incidence of major blood loss in HOR-C/S to control. RESULTS: We studied a total of 831 parturients, 129 underwent HOR-C/S. The incidence of conversion from regional to general anesthesia was similar in both groups (RR = 0.97, 95% CI 0.2, 4.3). The median duration of surgery was 40 min (range 10-145 min) in the HOR-C/S group and 30 min (range 10-150 min) in the control group (p < 0.001). The incidence of prolonged surgery was increased in the HOR-C/S group (RR = 3.6, 95% CI 2.4, 5.4). The incidence of intraoperative blood transfusion was higher in the HOR-C/S group (RR = 3.4, 95% CI 1.1, 10.2). CONCLUSIONS: Patients who have HOR-C/S are more likely to have prolonged surgery and require blood transfusion than controls. However, in our population, this was not associated with an increased incidence of conversion from regional to general anesthesia. Provided causes of severe hemorrhage such as abnormal placentation have been ruled out, HOR-C/S is not an absolute contraindication to regional block.

Patterns of use of perioperative angiotensin-converting enzyme inhibitors in coronary artery bypass graft surgery with cardiopulmonary bypass: effects on in-hospital morbidity and mortality.

BACKGROUND: Despite proven benefit in ambulatory patients with ischemic heart disease, the pattern of use of angiotensin-converting enzyme inhibitors (ACEIs) in coronary artery bypass graft surgery has been erratic and controversial. METHODS AND RESULTS: This is a prospective observational study of 4224 patients undergoing coronary artery bypass graft surgery. The cohort included 1838 patients receiving ACEI therapy before surgery and 2386 (56.5%) without ACEI exposure. Postoperatively, the pattern of ACEI use yielded 4 groups: continuation, 915 (21.7%); withdrawal, 923 (21.8%); addition, 343 (8.1%); and no ACEI, 2043 (48.4%). Continuous treatment with ACEI versus no ACEI was associated with substantive reductions of risk of nonfatal events (adjusted odds ratio for the composite outcome, 0.69; 95% confidence interval, 0.52-0.91; P=0.009) and a cardiovascular event (odds ratio, 0.64; 95% confidence interval, 0.46-0.88; P=0.006). Addition of ACEI de novo postoperatively compared with no ACEI therapy was also associated with a significant reduction of risk of composite outcome (odds ratio, 0.56; 95% confidence interval, 0.38-0.84; P=0.004) and a cardiovascular event (odds ratio, 0.63; 95% confidence interval, 0.40-0.97; P=0.04). On the other hand, continuous treatment of ACEI versus withdrawal of ACEI was associated with decreased risk of the composite outcome (odds ratio, 0.50; 95% confidence interval, 0.38-0.66; P<0.001), as well as a decrease in cardiac and renal events (P<0.001 and P=0.005, respectively). No differences in in-hospital mortality and cerebral events were noted. CONCLUSIONS: Our study suggests that withdrawal of ACEI treatment after coronary artery bypass graft surgery is associated with nonfatal in-hospital ischemic events. Furthermore, continuation of ACEI or de novo ACEI therapy early after cardiac surgery is associated with improved in-hospital outcomes.

Is Ultrasound-Guided Single-Shot Quadratus Lumborum Block a Viable Alternative to a Caudal Block in Pediatric Urological Surgery?

OBJECTIVE: To review our experience with quadratus lumborum block (QLB) in pediatric urology. MATERIALS AND METHODS: This mixed prospective-retrospective study included 41 patients who received QLB following induction of general anesthesia. Data collected included: the duration of block induction, surgery, hospitalization, postoperative pain score, and the use of rescue analgesia. The results were compared with a matched cohort of patients who received caudal block (CB) during similar surgeries from our retrospectively acquired data registry. RESULTS: There was no difference between the type and length of surgery, weight, sex, and age of the patients between the two groups. The duration of block induction was significantly shorter in the CB group compared with the QLB group (35.6 ± 14.6 vs. 239 ± 33.4 seconds [p < 0.0001]). There was no difference between the groups in pain scores at 1, 4, and 24 hours postoperatively, in the time to first rescue analgesia, or in the postoperative opioid requirements. However, the QLB group required more rescue analgesia compared with CB group (p = 0.016). Finally, no differences were found in the use of rescue analgesics at home, pain record behavior, and overall satisfaction. CONCLUSION: Our data show that QLB might serve as a viable alternative to CB in pediatric urological surgery.

Intraoperative use of the machine learning-derived nociception level monitor results in less pain in the first 90†min after surgery.

In this pooled analysis of two randomized clinical trials, intraoperative opioid dosing based on the nociception level-index produced less pain compared to standard care with a difference in pain scores in the post-anesthesia care unit of 1.5 (95% CI 0.8-2.2) points on an 11-point scale. The proportion of patients with severe pain was lower by 70%. Severe postoperative pain remains a significant problem and associates with several adverse outcomes. Here, we determined whether the application of a monitor that detects intraoperative nociceptive events, based on machine learning technology, and treatment of such events reduces pain scores in the post-anesthesia care unit (PACU). To that end, we performed a pooled analysis of two trials in adult patients, undergoing elective major abdominal surgery, on the effect of intraoperative nociception level monitor (NOL)-guided fentanyl dosing on PACU pain was performed. Patients received NOL-guided fentanyl dosing or standard care (fentanyl dosing based on hemodynamic parameters). Goal of the intervention was to keep NOL at values that indicated absence of nociception. The primary endpoint of the study was the median pain score obtained in the first 90 min in the PACU. Pain scores were collected at 15 min intervals on an 11-point Likert scale. Data from 125 patients (55 men, 70 women, age range 21-86 years) were analyzed. Sixty-one patients received NOL-guided fentanyl dosing and 64 standard care. Median PACU pain score was 1.5 points (0.8-2.2) lower in the NOL group compared to the standard care; the proportion of patients with severe pain was 70% lower in the NOL group (p = 0.045). The only significant factor associated with increased odds for severe pain was the standard of care compared to NOL treatment (OR 6.0, 95% CI 1.4 -25.9, p = 0.017). The use of a machine learning-based technology to guide opioid dosing during major abdominal surgery resulted in reduced PACU pain scores with less patients in severe pain.

Hyperglycemia inhibits anesthetic-induced postconditioning in the rabbit heart via modulation of phosphatidylinositol-3-kinase/Akt and endothelial nitric oxide synthase signaling.

Hyperglycemia is known to inhibit ischemic and anesthetic preconditioning. We tested whether hyperglycemia inhibits anesthetic postconditioning with isoflurane and whether this effect is mediated via phosphatidylinositol-3-kinase/Akt and nitric oxide signaling. New Zealand white rabbits subjected to 40 minutes of myocardial ischemia, followed by 3 hours of reperfusion were assigned to the following groups: ischemia and reperfusion (I/R), isoflurane (1 minimal alveolar concentration) postconditioning, and isoflurane postconditioning with hyperglycemia (15% dextrose in water infusion). A control group of hyperglycemia + I/R was also included. Levels of MB fraction of creatine kinase (CK-MB) were assessed as an indicator of myocardial damage, and infarct size was evaluated. Akt, iNOS, and endothelial nitric oxide synthase (eNOS) expression was assessed by immunoblotting. Determination of nitrite and nitrate levels in the myocardium was also performed. Isoflurane postconditioning reduced infarct size compared with the I/R group: 25% +/- 4% versus 49% +/- 5% (P < 0.01). CK-MB concentrations in the postconditioned animals (124% +/- 14% above baseline levels) were lower than those in the I/R group (236% +/- 9% above baseline levels; P < 0.01). Hyperglycemia inhibited the cardioprotective effect of isoflurane: myocardial infarction size was 46% +/- 4% and CK-MB increased to 241% +/- 11% above baseline. Phosphorylated Akt and eNOS protein expression increased after isoflurane postconditioning compared with the I/R group. These effects were also inhibited by hyperglycemia. iNOS expression, however, did not change significantly within the various experimental groups. There were increased tissue levels of nitrite and nitrate (NO(x)) in the postconditioning group. This was also blocked by hyperglycemia. Our results suggest that hyperglycemia inhibits cardioprotection provided by isoflurane postconditioning. This effect seems to be mediated via modulation Akt and eNOS.

Outcome of Peripartum Anesthesia in Women with Valvular Disease.

OBJECTIVE: Maternal heart disease is one of the major causes for mortality among parturients. In our study, we surveyed 220 patients with different valvular disorders who gave birth in our medical center in the years 2012-2018. The aim of this study was to characterize various valvular pathologies and compare the results of different anesthetic approaches. METHODS: In this retrospective study, the computerized system and file archive were searched for maternal valvular pathologies according to the International Classification of Diseases, Ninth Revision (ICD-9). The women included in the study were defined as American Society of Anesthesiology (ASA)-II or more, who suffer from valvular heart disease. RESULTS: The most common pathology was mitral valve regurgitation (57.73% of all cardiac patients). Most women were defined as having mild insufficiency, and 82.68% had normal vaginal delivery. In 17.3% of patients who had cesarean section, the main type of anesthesia was neuraxial anesthesia (95.45%). The second most common pathology was tricuspid valve regurgitation (22.73%). Most patients (78%) had normal vaginal delivery, and epidural analgesia was used in 64.1%. A minority of cardiac patients in our study were patients with stenotic heart diseases, such as aortic stenosis, mitral stenosis and pulmonic stenosis (8.18%, 4.55%, and 1.36%, respectively). No complications were observed in the peripartum period. CONCLUSION: The use of regional anesthesia is recommended for all valvular pathologies without exception, as we observed no cases in which the severity of cardiac condition had not allowed the use of various types of regional anesthesia, for surgery or vaginal delivery.

Isoflurane preconditioning decreases myocardial infarction in rabbits via up-regulation of hypoxia inducible factor 1 that is mediated by mammalian target of rapamycin.

BACKGROUND: Volatile anesthetics are known to protect the heart against ischemia-reperfusion injury. The authors tested whether anesthetic preconditioning with isoflurane is mediated via activation of the transcription factor hypoxia inducible factor 1 (HIF-1) and evaluated the role of mammalian target of rapamycin signaling in this process. METHODS: New Zealand White rabbits subjected to 40 min of regional myocardial ischemia, followed by 180 min of reperfusion, were assigned to the following groups: ischemia and reperfusion (I/R) only, isoflurane (1 minimal alveolar concentration) preconditioning, and isoflurane preconditioning in the presence of the mammalian target of rapamycin inhibitor rapamycin (0.25 mg/kg). Sham-operated, isoflurane + sham, rapamycin + sham, rapamycin + I/R, and dimethyl sulfoxide + I/R groups were also included. Creatine kinase-MB levels were assessed as an indicator of myocardial damage, and infarct size was evaluated by triphenyl tetrazolium chloride staining. HIF-1alpha expression and DNA binding were assessed by Western blotting and electrophoretic mobility shift analysis, respectively. RESULTS: Isoflurane preconditioning reduced infarct size compared with the I/R group: 26 +/- 4% versus 44 +/- 6% (P < 0.05). Creatine kinase-MB concentrations in the preconditioned animals (103 +/- 8% above baseline) were lower than in the I/R group (243 +/- 12% above baseline; P < 0.05). Rapamycin inhibited the cardioprotective effect of isoflurane: myocardial infarction increased to 44 +/- 4% and creatine kinase-MB level increased to 254 +/- 9% above baseline. HIF-1alpha protein expression and DNA binding activity increased after isoflurane preconditioning compared with the ischemia group. These effects were also inhibited by rapamycin. CONCLUSIONS: The current results indicate that isoflurane-induced myocardial protection involves activation of the HIF-1 pathway that is mediated by the mammalian target of rapamycin.

Myocardial metabolism altered by ischemic preconditioning and enflurane in off-pump coronary artery surgery.

OBJECTIVE: During off-pump coronary artery bypass (OPCAB) surgery, the heart is subjected to ischemia and reperfusion. The authors hypothesized that the volatile anesthetics are as effective as ischemic preconditioning (IPC) in preserving myocardial function during off-pump cardiac surgery, and this effect is because of multiple mechanisms of action. Therefore, the effects of enflurane with its calcium inhibition and antioxidative properties were compared with mechanical IPC in preserving myocardial cellular markers. DESIGN: A prospective, randomized, controlled, and partly blinded study. SETTING: A tertiary care university hospital. PARTICIPANTS: Twenty-five patients undergoing elective single-graft OPCAB surgery. INTERVENTIONS: Patients were randomized into 3 groups: (1) control (n = 8), (2) a single 5-minute ischemia/reperfusion interval of IPC before coronary occlusion (n = 9), and (3) 1.6% enflurane anesthesia 15 minutes before and during graft attachment (n = 8). Arterial and coronary sinus venous blood were analyzed for biochemical indices of ischemia and hydroxyl radical generation. MEASUREMENTS AND MAIN RESULTS: Although the hemodynamic changes were small, myocardial lactate production in the control group increased by 120%, whereas in the enflurane group it decreased significantly (p < 0.01) compared with the control and IPC groups. Oxygen utilization in the control group was 44% higher (p < 0.03), and there was also a larger release of the hydroxyl radical-dependent adduct 2,3-dihydroxybenzoic acid (225% increase, p < 0.05) compared with both study groups. During reperfusion, initial anterior wall hypokinesis by TEE was observed, with slow recovery during reperfusion compared with early recovery in both study groups. CONCLUSIONS: Coronary occlusion during OPCAB surgery results in increased production of ischemia-related metabolic products. The application of methods such as IPC or volatile anesthesia appears to reduce the metabolic deficit, free-radical production, and physiologic changes.

Pediatric sedation/anesthesia outside the operating room.

PURPOSE OF REVIEW: The demand of procedures performed on children outside the operating room setting often exceeds the capacity of anesthesia services. The number of children requiring sedation outside the traditional operating room is rapidly approaching the number of children requiring anesthesia in the operating room. We address some of the major issues and controversies in this continuously evolving field. RECENT FINDINGS: Pediatric sedation continues to be a challenging field. Recently, the Society of Pediatric Sedation has been created. In the last year, important issues have been raised among pediatric sedation providers, keeping on feeding the debate within all the recognized experts. Why worry about nihil per os status? Is bispectral index useful as a sedation monitor? Should there be standards for simulation-based training of nonanesthesiologists for delivery of sedation? Is propofol well tolerated? Is dexmedetomidine a good choice for painful procedures? What is the role of etomidate? SUMMARY: A standard approach (adequate preparation, clinical assessment of the child, fasting as required and right sedation plan) is mandatory to provide safety and efficiency. Sedation is a continuum, and it can be easy to advance from one level to the next and even reach a state of general anesthesia. Newer modalities such as end-tidal CO2 and, maybe, bispectral index monitoring are indeed enhancing the safety of procedural sedation and analgesia.

Platelet-derived microparticles induce angiogenesis and stimulate post-ischemic revascularization.

OBJECTIVE: Platelet activation is accompanied by the release of microparticles. However, little is known about the role of platelet-derived microparticles (PMP) in the regulation of angiogenesis and related clinical situations. The aim of our study was to evaluate the effect of PMP on angiogenesis and to analyze its mechanisms. METHODS: Both in vitro (rat aortic ring model, cell invasion test) and in vivo (agarose bead transplantation, artificial cardiac ischemia in Sabra rats) approaches were used in the study. RESULTS: A dose-dependent pro-angiogenic effect of PMP was observed in the rat aortic ring model. This effect could be eliminated by inhibition of VEGF, bFGF, and PDGF, but not heparanase. PMP exerted their effect via PI 3-kinase, Src kinase, and ERK, whereas protein kinase C and p38 were not involved. Moreover, PMP induced invasion of endothelial cells through a layer of matrigel. This effect was mediated by VEGF, heparanase, and PDGF, but not bFGF. Furthermore, PMP induced angiogenesis in an in vivo model in which agarose beads containing PMP were transplanted subcutaneously into mice. In addition, the effect of PMP on angiogenesis was evaluated in the model of in vivo chronic myocardial ischemia in rats. Ischemia induced a decrease in the number of functioning capillaries (34+/-21.5 vs. 157+/-42.0 per view field), but their amount increased after injection of PMP into the myocarium (97+/-27.3; p<0.001 vs. ischemia without PMP). CONCLUSIONS: PMP induce angiogenesis both in vitro and in vivo. Injection of PMP into the ischemic myocardium might improve the process of revascularization after chronic ischemia.