Feasibility of Focused Cardiac Ultrasound Performed by Trainees During Cesarean Delivery.

BACKGROUND: Anesthesiology experts advocate for formal education in maternal critical care, including the use of focused cardiac ultrasound (FCU) in high-acuity obstetric units. While benefits and feasibility of FCU performed by experts have been well documented, little evidence exists on the feasibility of FCU acquired by examiners with limited experience. The primary aim of this study was to assess how often echocardiographic images of sufficient quality to guide clinical decision-making were attained by trainees with limited experience performing FCU in term parturients undergoing cesarean delivery (CD). METHODS: In this prospective cohort study, healthy term parturients (American Society of Anesthesiologists [ASA] ≤ 3, ≥37 weeks of gestation) with singleton pregnancy, body mass index (BMI) <40 kg/m2, and no history of congenital and acquired cardiac disease undergoing scheduled, elective CD were recruited by a trainee. After undergoing standardized training, including an 8-hour online E-learning module, a 1-day hands-on FCU course, and 20 to 30 supervised scans until the trainee was assessed competent in image acquisition, 8 trainees with limited FCU experience performed apical 4-chamber (A4CH), parasternal long-axis (PLAX), and short-axis (PSAX) view preoperatively after spinal anesthesia (SPA) and intraoperatively after neonatal delivery (ND). Obtained FCU images were graded 1 to 5 by 2 blinded instructors (1 = no image to 5 = perfect image obtainable; ≥3 defined as image quality sufficient for clinical decision-making). RESULTS: Following the screening of 95 women, 8 trainees with limited FCU experience each performed a median of 5 [3-8] FCUs in a total of 64 women. Images of sufficient quality were obtainable in 61 (95.3 %) and 57 (89.1 %) of women after SPA and ND, respectively. FCU images of perfect image quality were obtainable in 9 (14.1 %) and 7 (10.9 %) women preoperatively after SPA and intraoperatively after ND, respectively. A PLAX, PSAX, and A4CH view with grade ≥3 was obtained in 53 (82.8 %), 58 (90.6 %) and 40 (62.5 %) of women preoperatively after SPA and in 50 (78.1 %), 49 (76.6 %), and 29 (45.3 %) of women intraoperatively after ND. Left ventricular function could be assessed in 39 of 40 women (97.5 %) preoperatively after SPA and 39 of 40 (97.5%) intraoperatively after ND. Right ventricular function could be assessed in 31 of 40 (77.5 %) after SPA and in 23 of 40 (59%) after ND. We observed a difference in image grading between different trainees in the AP4CH-view (P = .0001). No difference in image grading was found between preoperative and intraoperative FCUs. CONCLUSIONS: FCU is feasible in the parturient undergoing CD and images of sufficient quality for clinical decision-making were obtained by trainees with limited experience in almost all parturients. Image acquisition and quality in the A4CH view may be impacted by the individual trainee performing the FCU.

Point-of-Care Lung Ultrasound Pattern in Healthy Parturients: Prevalence of Pulmonary Interstitial Syndrome Following Vaginal Delivery, Elective and Unplanned Intrapartum Cesarean Delivery.

BACKGROUND: Pregnancy-related cardiovascular physiologic changes increase the likelihood of pulmonary edema, with the risk of fluid extravasating into the pulmonary interstitium being potentially at a maximum during the early postpartum period. Data on the impact of labor and peripartum hemodynamic strain on lung ultrasound (LUS) are limited, and the prevalence of subclinical pulmonary interstitial syndrome in peripartum women is poorly described. The primary aim of this exploratory study was to estimate the prevalence of pulmonary interstitial syndrome in healthy term parturients undergoing vaginal (VD), elective (eCD), and unplanned intrapartum cesarean deliveries (uCD). Secondary aims were to estimate the prevalence of positive lung regions (≥3 B-lines on LUS per region) and to assess the associations between positive lung regions and possible contributing factors. METHODS: In this prospective observational cohort study, healthy women at term undergoing VD, eCD, or uCD were enrolled. Following international consensus recommendations, a LUS examination was performed within 4 hours after delivery applying an 8-region technique. Pulmonary interstitial syndrome was defined by the presence of 2 or more positive lung regions per hemithorax. Ultrasound studies were reviewed by 2 blinded reviewers and assessed for interobserver reliability. RESULTS: Seventy-five women were assessed (n = 25 per group). No pulmonary interstitial syndrome was found in the VD and eCD groups (each 0 of 25; 0%, 95% confidence interval [CI], 0-13.7). Pulmonary interstitial syndrome was found in 2 of 25 (8%, 95% CI, 1-26) women undergoing an uCD (P = .490 for VD versus uCD and P = .490 for eCD versus uCD). In 1 woman, this correlated clinically with the development of pulmonary edema. One or more positive lung regions were present in 5 of 25 (20%), 6 of 25 (24%), and 11 of 25 (44%) parturients following VD, eCD, and uCD, respectively (P = .136). Positive lung regions were predominantly found in lateral lung regions. The number of positive lung regions showed a weak correlation with patient age (r = 0.25, 95% CI, 0.05-0.47; P = .033). No significant association was found between LUS pattern and parity, duration of labor, labor augmentation, labor induction, estimated total intravenous fluid intake, or net intravenous fluid intake. CONCLUSIONS: Although many focal areas of increased extravascular lung water (20%-44% prevalence) can be identified on LUS, the overall prevalence of pulmonary interstitial syndrome was 2.7% (2 of 75; 95% CI, 0.3-9.3) among healthy term parturients soon after delivery. Focal areas of positive lung water regions were weakly correlated with maternal age.

Point-of-Care Ultrasound Abnormalities in Late-Onset Severe Preeclampsia: Prevalence and Association With Serum Albumin and Brain Natriuretic Peptide.

BACKGROUND: Pilot studies applying point-of-care ultrasound (POCUS) in preeclampsia indicate the presence of pulmonary interstitial edema, cerebral edema, and cardiac dysfunction. Laboratory markers of oncotic pressure (albumin) and cardiac dysfunction (brain natriuretic peptide [BNP]) may be abnormal, but the clinical application remains unclear. We investigated the prevalence of pulmonary interstitial syndrome (PIS), cardiac dysfunction, and increased optic nerve sheath diameter (ONSD) in late-onset preeclampsia with severe features. The primary aim was to examine the association between PIS or ONSD and maternal serum albumin level. The secondary aims were to explore the association between cardiac dysfunction and PIS, ONSD, BNP, and serum albumin level and between POCUS-derived parameters and a suspicious or pathological cardiotocograph. METHODS: Ninety-five women were enrolled in this prospective observational cohort study. A POCUS examination of lungs, heart, and ONSD was performed. PIS was defined as a bilateral B-line pattern on lung ultrasound and diastolic dysfunction according to an algorithm of the American Society of Echocardiography. ONSD >5.8 mm was interpreted as compatible with raised intracranial pressure (>20 mm Hg). Serum BNP and albumin levels were also measured. RESULTS: PIS, diastolic dysfunction, systolic dysfunction, and raised left ventricular end-diastolic pressure (LVEDP) were present in 23 (24%), 31 (33%), 9 (10%), and 20 (25%) women, respectively. ONSD was increased in 27 (28%) women. Concerning the primary outcome, there was no association between albumin level and PIS (P = .4) or ONSD (P = .63). With respect to secondary outcomes, there was no association between albumin level and systolic dysfunction (P = .21) or raised LVEDP (P = .44). PIS was associated with diastolic dysfunction (P = .02) and raised LVEDP (P = .009; negative predictive value, 85%). BNP level was associated with systolic (P < .001) and diastolic dysfunction (P = .003) and LVEDP (P = .007). No association was found between POCUS abnormalities and a suspicious/pathological cardiotocograph (P = .07). CONCLUSIONS: PIS, diastolic dysfunction, and increased ONSD were common in preeclampsia with severe features. Cardiac ultrasound abnormalities may be more useful than albumin levels in predicting PIS. The absence of PIS may exclude raised LVEDP. The further clinical relevance of PIS and raised ONSD remains to be established. BNP level was associated with cardiac ultrasound abnormalities. Although this study was not designed to directly influence clinical management, the findings suggest that POCUS may serve as a useful adjunct to clinical examination for the obstetric anesthesiologist managing these complex patients.

Hormonal and Clinical Predictors for Post-egg Retrieval Pain in Women Undergoing Assisted Reproductive Technology Procedures.

OBJECTIVES: The intensity of post-egg retrieval pain is underestimated, with few studies examining postprocedural pain and predictors to identify women at risk for severe pain. We evaluated the influence of preprocedural hormonal levels, ovarian factors, and mechanical temporal summation (mTS) as predictors for post-egg retrieval pain in women undergoing in vitro fertilization. METHODS: Eighteen women scheduled for ultrasound-guided egg retrieval under standardized anesthesia and postprocedural analgesia were enrolled. Preprocedural mTS, questionnaires, clinical data related to anesthesia and the procedure itself, postprocedural pain scores, and pain medication for breakthrough pain were recorded. Statistical analysis included Pearson product-moment correlations, Mann-Whitney U tests, and multiple linear regressions. RESULTS: Average peak post-egg retrieval pain during the first 24 hours was 5.0±1.6 on a numerical response scale (0=no pain, 10=worst pain imaginable). Peak post-egg retrieval pain was correlated with basal antimullerian hormone (AMH) (r=0.549, P=0.018), preprocedural peak estradiol (r=0.582, P=0.011), total number of follicles (r=0.517, P=0.028), and number of retrieved eggs (r=0.510, P=0.031). Ovarian hyperstimulation syndrome (n=4) was associated with higher basal AMH (P=0.004), higher peak pain scores (P=0.049), but not with peak estradiol (P=0.13). The mTS did not correlate with peak postprocedural pain (r=0.266, P=0.286), or peak estradiol level (r=0.090, P=0.899). DISCUSSION: Peak post-egg retrieval pain intensity was higher than anticipated. Our results suggest that post-egg retrieval pain can be predicted by baseline AMH, high peak estradiol, and ovarian hyperstimulation syndrome. Further studies to evaluate intraprocedural and postprocedural pain in this population are needed, as well as clinical trials to assess postprocedural analgesia in women presenting with high hormonal levels.

The effects of low-dose ketamine on the analgesia nociception index (ANI) measured with the novel PhysioDoloris™ analgesia monitor: a pilot study.

The PhysioDoloris™ analgesia monitor assesses nociception effects on the autonomic nervous system by analyzing changes in heart rate variability (HRV). This non-invasive device analyses ECG signals and determines the analgesia nociception index (ANI), allowing for quantitative assessment of the analgesia/nociception balance in anesthetized patients. Ketamine, an analgesic adjuvant with sympathomimetic properties, has been shown to improve perioperative pain management. The purpose of this pilot study was to evaluate whether low-dose ketamine, due to its intrinsic effect on the sino-atrial node, affects HRV and, therefore, interferes with ANI measurements. This pilot study included 20 women undergoing abdominal hysterectomies. Anesthesia and analgesia were maintained with sevoflurane and fentanyl respectively, in a standardized manner. Five minutes after intubation, 0.5 µg kg(-1) of intravenous (i.v.) ketamine was administered. ANI, bispectral index (BIS), heart rate and blood pressure were recorded from the induction of anesthesia until 5 min after skin incision. There was not any significant decrease in mean (±SD) ANI values after intubation (2.11±20.11, p=0.35) or i.v. ketamine administration (1.31±15.26, p=0.28). The mean (±SD) reduction in ANI values after skin incision was statistically significant (13.65±15.44, p=0.01), which is consistent with increased nociception. A single i.v. bolus of 0.5 µg kg(-1) ketamine did not influence the ANI values of 20 women under standardized general anesthesia conditions and absent noxious stimulation. These results suggest that the ANI derived from the PhysioDoloris™ analgesia monitor is feasible under such clinical conditions.

The Short-Form McGill Pain Questionnaire-Revised to evaluate persistent pain and surgery-related symptoms in healthy women undergoing a planned cesarean delivery.

BACKGROUND AND OBJECTIVES: The incidence of chronic pain after cesarean delivery (CD) has been estimated to range between 0.3% and 18%. This wide range may be explained by differing study methodologies. Furthermore, a comprehensive characterization of pain quality is lacking. The aim of this study was to evaluate persistent pain in a healthy obstetric population undergoing planned CD and to provide a comprehensive description of pain quality. METHODS: Three hundred eighty-one women with no pain history undergoing CD were included in this prospective, observational cohort study. Spinal anesthesia was standardized, and postoperative pain was recorded at 24 hours. In each woman, pain was assessed at 8 weeks, and 6 and 12 months using questionnaires of pain intensity and interference. Pain quality was assessed using the Short-Form McGill Pain Questionnaire-Revised. RESULTS: The incidence of persistent pain at 8 weeks was 11% (95% confidence interval, 8%-14%), with pain reported as being mild and interfering with common daily activities by 32% of women. At 6 and 12 months, the incidence was 3% (95% confidence interval, 2%-6%) and 0.6% (95% confidence interval, 0%-2%) respectively, with pain rarely interfering with daily activities. However, 22% of women described other surgery-related symptoms at 12 months. CONCLUSIONS: The incidence of chronic pain at 12 months after planned CD is low (0.6%) and if present symptoms are mostly mild and not interfering with common daily activities. Using Short-Form McGill Pain Questionnaire-Revised, this study provides a comprehensive evaluation of pain quality that can be used as a basis in future post-CD pain trials.

Effect of transversus abdominis plane block with and without clonidine on post-cesarean delivery wound hyperalgesia and pain.

BACKGROUND AND OBJECTIVES: The transversus abdominis plane (TAP) block is an established technique to manage post-cesarean delivery pain. Transversus abdominis plane blocks with a local anesthetic only offer no analgesic benefits compared with intrathecal morphine. Adjuvants to extend TAP block duration and possibly reduce wound hyperalgesia, known to be a risk factor for chronic pain, have not been studied. We hypothesized that a TAP block with clonidine will affect postsurgical wound hyperalgesia and improve pain outcomes. METHODS: Ninety women were randomly assigned to receive 1 of 3 TAP blocks after cesarean delivery: saline (placebo), bupivacaine (BupTAP), or bupivacaine + clonidine (CloTAP). The primary outcome was wound hyperalgesia index at 48 hours. Secondary outcomes included pain scores, analgesic consumption, and pain descriptors up to 12 months. RESULTS: Wound hyperalgesia index at 48 hours (median [25th-75th percentiles]) was 1.07 (0.48-3.26) in the placebo group, 1.27 (0.59-2.95) in the BupTAP group, and 0.74 (0.09-2.25) in the CloTAP group (P = 0.48). Morphine request in the postanesthesia care unit was significantly higher in the placebo group compared with the other TAP groups (P = 0.01). Postoperative pain scores and requests for breakthrough medication at 48 hours (30% in the placebo group, 24% in the BupTAP group, and 12% in the CloTAP group, P = 0.25) or chronic pain descriptors reported up to 12 months did not differ significantly among groups. CONCLUSIONS: Adding clonidine to a TAP block with bupivacaine did not affect wound hyperalgesia index and it did not improve short-term or long-term pain scores in women undergoing elective cesarean delivery. Further studies are warranted to determine the benefits of antihyperalgesic adjuvants in TAP solutions for specific individuals at risk for chronic pain.

Evaluation of performance of two different chest tubes with either a sharp or a blunt tip for thoracostomy in 100 human cadavers.

BACKGROUND: Emergent placement of a chest tube is a potentially life-saving procedure, but rate of misplacement and organ injury is up to 30%. In principle, chest tube insertion can be performed by using Trocar or Non-trocar techniques. If using trocar technique, two different chest tubes (equipped with sharp or blunt tip) are currently commercially available. This study was performed to detect any difference with respect to time until tube insertion, to success and to misplacement rate. METHODS: Twenty emergency physicians performed five tube thoracostomies using both blunt and sharp tipped tube kits in 100 fresh human cadavers (100 thoracostomies with each kit). Time until tube insertion served as primary outcome. Complications and success rate were examined by pathological dissection and served as further outcomes parameters. RESULTS: Difference in mean time until tube insertion (63 s vs. 59 s) was statistically not significant. In both groups, time for insertion decreased from the 1st to the 5th attempt and showed dependency on the cadaver's BMI and on the individual physician. Success rate differed between both groups (92% using blunt vs. 86% using sharp tipped kits) and injuries and misplacements occurred significantly more frequently using chest tubes with sharp tips (p = 0.04). CONCLUSION: Data suggest that chest drain insertion with trocars is associated with a 6-14% operator-related complication rate. No difference in average time could be found. However, misplacements and organ injuries occurred more frequently using sharp tips. Consequently, if using a trocar technique, the use of blunt tipped kits is recommended.