Spinal morphine is the mainstay of postcesarean analgesia. Quadratus lumborum block has recently been proposed as an adjunct or alternative to spinal morphine. The authors evaluated the analgesic effectiveness of quadratus lumborum block in cesarean delivery with and without spinal morphine.
Randomized trials evaluating quadratus lumborum block benefits in elective cesarean delivery under spinal anesthesia were sought. Three comparisons were considered: spinal morphine versus spinal morphine and quadratus lumborum block; spinal morphine versus quadratus lumborum block; and no block or spinal morphine versus quadratus lumborum block. The two coprimary outcomes were postoperative (1) 24-h cumulative oral morphine equivalent consumption and (2) pain at 4 to 6 h. Secondary outcomes included area under the curve pain, time to analgesic request, block complications, and opioid-related side effects.
Twelve trials (924 patients) were analyzed. The mean differences (95% CIs) in 24-h morphine consumption and pain at 4 to 6 h for spinal morphine versus spinal morphine and quadratus lumborum block comparison were 0 mg (−2 to 1) and −0.1 cm (−0.7 to 0.4), respectively, indicating no benefit. For spinal morphine versus quadratus lumborum block, these differences were 7 mg (−2 to 15) and 0.6 cm (−0.7 to 1.8), respectively, also indicating no benefit. In contrast, for no block or spinal morphine versus quadratus lumborum block, improvements of −18 mg (−28 to −7) and −1.5 cm (−2.4 to −0.6) were observed, respectively, with quadratus lumborum block. Finally, for no block or spinal morphine versus quadratus lumborum block, quadratus lumborum block improved area under the 48-h pain curve by −4.4 cm · h (−5.0 to −3.8), exceeding the clinically important threshold (3.96 cm · h), but no differences were observed in the other comparisons.
Moderate quality evidence suggests that quadratus lumborum block does not enhance analgesic outcomes when combined with or compared with spinal morphine. However, the block improves postcesarean analgesia in the absence of spinal morphine. The clinical utility of this block seems limited to situations in which spinal morphine is not used.
26 Major Short-term Complications of Arterial Cannulation for Monitoring in Children
Perioperative arterial cannulation in children is routinely performed. Based on clinical observation of several complications related to femoral arterial lines, the authors performed a larger study to further examine complications. The authors aimed to (1) describe the use patterns and incidence of major short-term complications associated with arterial cannulation for perioperative monitoring in children, and (2) describe the rates of major complications by anatomical site and age category of the patient.
The authors examined a retrospective cohort of pediatric patients (age less than 18 yr) undergoing surgical procedures at a single academic medical center from January 1, 2006 to August 15, 2016. Institutional databases containing anesthetic care, arterial cannulation, and postoperative complications information were queried to identify vascular, neurologic, and infectious short term complications within 30 days of arterial cannulation.
There were 5,142 arterial cannulations performed in 4,178 patients. The most common sites for arterial cannulation were the radial (N = 3,395 [66.0%]) and femoral arteries (N = 1,528 [29.7%]). There were 11 major complications: 8 vascular and 3 infections (overall incidence, 0.2%; rate, 2 per 1,000 lines; 95% CI, 1 to 4) and all of these complications were associated with femoral arterial lines in children younger than 5 yr old (0.7%; rate, 7 per 1,000 lines; 95% CI, 4 to 13). The majority of femoral lines were placed for cardiac procedures (91%). Infants and neonates had the greatest complication rates (16 and 11 per 1,000 lines, respectively; 95% CI, 7 to 34 and 3 to 39, respectively).
The overall major complication rate of arterial cannulation for monitoring purposes in children is low (0.2%). All complications occurred in femoral arterial lines in children younger than 5 yr of age, with the greatest complication rates in infants and neonates. There were no complications in distal arterial cannulation sites, including more than 3,000 radial cannulations.
52 Association between Neuraxial Labor Analgesia and Neonatal Morbidity after Operative Vaginal Delivery: A Retrospective Cross-sectional Study
Up to 84% of women who undergo operative vaginal delivery receive neuraxial analgesia. However, little is known about the association between neuraxial analgesia and neonatal morbidity in women who undergo operative vaginal delivery. The authors hypothesized that neuraxial analgesia is associated with a reduced risk of neonatal morbidity among women undergoing operative vaginal delivery.
Using United States birth certificate data, the study identified women with singleton pregnancies who underwent operative vaginal (forceps- or vacuum-assisted delivery) in 2017. The authors examined the relationships between neuraxial labor analgesia and neonatal morbidity, the latter defined by any of the following: 5-min Apgar score less than 7, immediate assisted ventilation, assisted ventilation greater than 6 h, neonatal intensive care unit admission, neonatal transfer to a different facility within 24 h of delivery, and neonatal seizure or serious neurologic dysfunction. The authors accounted for sociodemographic and obstetric factors as potential confounders in their analysis.
The study cohort comprised 106,845 women who underwent operative vaginal delivery, of whom 92,518 (86.6%) received neuraxial analgesia. The proportion of neonates with morbidity was higher in the neuraxial analgesia group than the nonneuraxial group (10,409 of 92,518 [11.3%] vs. 1,271 of 14,327 [8.9%], respectively; P < 0.001). The unadjusted relative risk was 1.27 (95% CI, 1.20 to 1.34; P < 0.001); after accounting for confounders using a multivariable model, the adjusted relative risk was 1.19 (95% CI, 1.12 to 1.26; P < 0.001). In a post hoc analysis, after excluding neonatal intensive care unit admission and neonatal transfer from the composite outcome, the effect of neuraxial analgesia on neonatal morbidity was not statistically significant (adjusted relative risk, 1.07; 95% CI, 1.00 to 1.16; P = 0.054).
In this population-based cross-sectional study, a neonatal benefit of neuraxial analgesia for operative vaginal delivery was not observed. Confounding by indication may explain the observed association between neuraxial analgesia and neonatal morbidity, however this dataset was not designed to evaluate such considerations.