[Ultrasound assessment of gastric content in cesarean delivery patients: an observational study]

BACKGROUND

The aim of this observational study is to examine the benefit of ultrasound assessment of gastric content in cesarean delivery (CD) patients.

METHODS

Thirty-nine patients scheduled for CD were assigned to a scheduled CD group and to an emergency group. Before CD, gastric ultrasonography examinations to calculate CSA (cross sectional area) of gastric antrum were performed to determine if gastric content was residual, and patients in the emergency group were asked what and when they had eaten. They were classified as full stomach when CSA was 2.5 cm2 or more and the sonographic characteristics of the antrum showed mixture with high echogenic particles.

RESULTS

Eight patients were assigned to a scheduled CD group and thirty-one patients to an emergency group, respectively. None of the scheduled CD group should be CSA of 2.5 cm2 or more and eight of the emergency group should be 2.5 cm2 or more, including 3 patients with or without labor showing residual gastric contents after more than 10 hours of ingestion.

CONCLUSIONS

There are some CD patients with the high risk of aspiration with or without labor even 10 hours after the last ingestion.

[Effects of magnesium on the onset time of rocuronium in patients for cesarean delivery]

BACKGROUND

Although magnesium can potentially shorten onset time of a muscle relaxant, it is unclear whether it does shorten the onset time of rocuronium for patients in cesarean delivery (CD). Thus the purpose of this study is to compare the onset time of rocuronium in patients with or without preoperative magnesium treatment.

METHODS

In 9 CD patients without magnesium (CD group) and 8 CD patients with magnesium (CD-Mg group), neuromuscular function was continuously assessed with acceleromyography immediately after induction of general anesthesia with intravenous injection of thiopental (4-5 mg x kg(-1)) and rocuronium (0.6 mg x kg(-1)). Onset time of muscle relaxation, defined by the time from rocuronium bolus injection until complete absence of twitch height, was measured.

RESULTS

The onset time of both groups did not significantly differ (50 +/- 10 seconds vs. 51 +/- 11 seconds; P = 0.93, unpaired t-test). Median magnesium concentration, 5.2 mg x dl(-1) (3.8-6.3), and the onset time of CD-Mg group did not correlate magnesium concentrations (P = 0.23, Pearson's correlation coefficient test).

CONCLUSIONS

Magnesium did not shorten the onset time of rocuronium 0.6 mg x kg(-1) in CD patients.

[Reversal of rocuronium-induced neuromuscular blockade with sugammadex in patients for cesarean delivery treated with magnesium sulfate]

BACKGROUND

We investigated whether sugammadex could reverse neuromuscular blockade induced by rocuronium in patients for cesarean delivery treated with magnesium sulfate preoperatively.

METHODS

Twenty-three pregnant women received general anesthesia induced with thiopental and rocuronium. They were maintained by nitrous oxide, oxygen and sevoflurane (GOS) before delivery and after delivery by GOS, midazolam, and propofol. After the surgery, the patients with two or more counts of train-of-four (TOF), the moderate block group were classified into Mg (-) M and Mg (+) M, depending whether magnesium sulfate had been injected or not, and sugammadex 2 mg x kg(-1) was administered to both groups. Patients with PTC 2 or more, the profound block group, were classified into Mg (-) P or Mg (+) P and sugammadex 4 mg x kg(-1) was administered to both groups. Recovery time was defined as the time required to reach TOFR 0.9 or more after the injection of sugammadex.

RESULTS

Median recovery times of the Mg (-) M, the Mg (-) P, the Mg (+) M and the Mg (+) P were 63 seconds (range: 26-130, N = 7), 127 seconds (range: 63-228, N = 7), 104 seconds (range: 67-133, N = 5), and 142 seconds (range: 57-209, N = 4), respectively.

CONCLUSIONS

Sugammadex could reverse rocuronium-induced neuromuscular blockade in a dose-response manner even in the patients treated with magnesium sulfate.

[Effects of pregnancy on the onset time of rocuronium]

BACKGROUND

Rapid onset of a muscle relaxant is required for general anesthesia with rapid sequence induction technique. Although a high dose of rocuronium was demonstrated to achieve the rapid onset in non-pregnant persons, it is still unknown whether this is true in women during late pregnancy. The purpose of this study is to compare the onset time of high dose rocuronium between pregnant and non-pregnant women.

METHODS

Ten pregnant women undergoing cesarean delivery and 10 age, height, and body weight-matched non-pregnant women were enrolled in the study. Neuromuscular function was continuously assessed by twitch response with acceleromyography immediately after induction of general anesthesia with intravenous injection of thiopental (4-5 mg x kg(-1)) and rocuronium (0.9 mg x kg(-1)). Onset time of muscle relaxation, defined by the time from rocuronium bolus injection to complete absence of twitch height, was measured.

RESULTS

The onset time of rocuronium in pregnant women was significantly shorter than that in non-pregnant women (42 +/- 9 seconds vs. 56 +/- 10 seconds; P = 0.0039. unpaired t-test).

CONCLUSIONS

The onset time of high dose of rocuronium in pregnant women was significantly shorter than that of non-pregnant women.

[Efficacy of ultrasound imaging of lumbar epidural anesthesia in patients for cesarean delivery: A comparative study between longitudinal and transverse plane imaging]

BACKGROUND

It has been demonstrated that preparatory ultrasound scanning can facilitate lumbar epidural anesthesia. We compared longitudinal with transverse approach of ultrasound imaging to test the precision and the quality of acquired images in cesar ean delivery patients.

METHODS

We enrolled 34 cesarean delivery patients. Measured distances from the skin to dura on each ultrasound view was compared with the actual needle depth. Additionally we measured ultrasound visibility score.

RESULTS

The both distances measured in ultrasound strongly correlated with the actual depth (R2= 0.87 and 95% limits of agreement of -3.07 to 6.45 mm on longitudinal view, R2=0.82 and 95% limits of agreement of -3.50 to 7.74 mm on longitudinal view). The visibility score of the longitudinal view was significantly higher than that of transverse view (P<0.01).

CONCLUSIONS

Both planes provided accurate information about the epidural space and depth, and the longitudinal plane was superior in the imaging quality. It was suggested that both approaches may help identify epidural spaces.

[Case of emergent caesarean delivery in a patient with aplastic anemia complicated with pregnant induced hypertension]

A 32-year-old pregnant woman diagnosed with aplastic anemia was admitted for emergent caesarean delivery of 26th week of the gestation due to PIH (pregnancy-induced hypertension) and NRFS (non-reassuring fetal status). After compensating platelets counts to 5.3x10(4) microl-1, general anesthesia was induced with propofol and rocuronium. Anesthesia was maintained with O2 and sevoflurane until delivery and with modified-NLA after delivery. She was additionally monitored with Vigileo/FloTrac system (Edwards Lifesciences, USA) and TOF-WATCH SX (Nihon Kohden, Tokyo). After 8 minutes of operation her baby was born with the 5-minute Apgar score of 5 and the UA-pH of 7.387. It was only 2 hours and 12 minutes that the baby was born after she was admitted. The baby was tracheally intubated and transferred to NICU. Blood loss during operation was 835 g and two units of RCC was transfused. Circulatory values were kept acceptable and neuromuscular blocking was completely reversed by sugammadex and extubated in the operating room. Bleeding tendency and atonic bleeding were not observed. She survived perioperative period and was to be treated for aplastic anemia. Her baby was discharged neurologically free. We should be ready to respond to anesthetic requirement for urgent cases of aplastic anemia.

[Safe practice of oral rehydration therapy by oral rehydration solution and carbohydrate loading--evaluation by non-invasive gastric echo examination]

Many anesthesiologists are reluctant to depart from their traditional long fasting periods, even though many guidelines recommend that oral intake of clear fluids administered up to 2-3 hours prior to general anesthesia does not adversely affect the gastric contents. It also indicates that the application of these guidelines does not affect the incidence of pulmonary aspiration. One of the reasons why they have not changed their practices is that they wonder whether it is safe to administer clear fluids as recommended in the guidelines. In this review, we emphasize that oral rehydration therapy using clear fluids (such as OS-1, water and carbohydrate-rich beverage) is safe based on the non-invasive gastric echo examinations as many guidelines have already indicated. Oral rehydration therapy should be considered not only as an alternative to intravenous therapy for preoperative fluid and electrolyte management but also as one of the important modalities which can enhance the recovery of surgical patients.

[Safety of preoperative oral rehydration therapy]

BACKGROUND

OS-1 is an oral rehydration solution that conforms with the principles of oral rehydration therapy. It may be useful for preoperative fluid management of surgical patients. While intake of clear fluids 2 hours before surgery is considered safe, it is not known if the same applies to OS-1. We therefore investigated the safety of OS-1 for preoperative patients as compared with clear fluids.

METHODS

First, eight healthy adult volunteers were studied in a crossover manner. Volunteers ingested 500 ml of OS-1 or water (clear fluid). Gastric emptying time was measured using gastric ultrasonography. Gastric antral area as measured by ultrasonography correlates well with gastric volume in a close-to-linear manner. Next, we measured gastric volume of elective surgical patients who had drunk OS-1 until two hours before the induction of anesthesia.

RESULTS

Gastric emptying time did not differ between OS-1 and water. The stomach was emptied 30 minutes after ingestion of both OS-1 and water. The fasting stomach was identified in all patients who had drunk OS-1 before surgery.

CONCLUSIONS

We concluded that allowing elective surgical patients to drink OS-1 until two hours before anesthesia did not affect the volume of gastric contents.

[Hemodynamic changes during pregnancy and cesarean delivery in three cases of triplet pregnancy]

Polypregnancy is one of the major problems to both mothers and fetuses leading to poor prognosis. Even though hemodynamic parameters change greatly during pregnancy and cesarean delivery, it is unclear how blood volume (BV) and cardiac output (CO) increase during triplet pregnancy and how CO goes up and down during cesarean delivery in the cases of triplet pregnancy. We measured BV and CO by dye-densitogram analyzer (DDG-analyzer: Nihon Kohden, Tokyo, Japan) and CO by FlowTrac (Edwards Lifesciences, Irvine, USA) on three cases of triplet pregnancy. BV increased up to about 50% above that of singleton after 20 weeks of gestational age. However, there was no such tendency in CO. When they underwent cesarean delivery under combined spinal-epidural anesthesia (CSEA) or sequential-CSE (S-CSE) receiving a 10 or 12 mg intrathecal isobaric bupivacaine with 20 microg fentanyl, CO decreased in parallel with blood pressure from ten minutes after spinal anesthesia, to the start of operation and just after the birth of third fetus.

[Simulation of obstetrical disseminated intravascular coagulation (DIC) by scoring algorithm criteria established by the Japanese Association for Acute Medicine, the revised Japanese Ministry of Health and Welfare criteria and the International Society on Thrombosis and Haemostasis criteria]

BACKGROUND

Although obstetric disease is one of the major causes of disseminated intravascular coagulation (DIC), no gold standard exists. Three current criteria, the Japanese Association for Acute Medicine (JAAM) -DIC criteria, the revised Japanese Ministry of Health and Welfare (JMHW) criteria and the International Society on Thrombosis and Haemostasis (ISTH) criteria, do not clarify the usefulness in obstetric DIC. We therefore conducted a retrospective study by simulation.

METHODS

We enrolled 89 cases of emergent caesarean section when platelet count decreased to below 150,000 x 10(9) x mm(-3) during 7 days from 3 days before operation to 3 days after operation from April 2004 to March 2007. We applied them and compared diagnostic rates and investigated characteristics of obstetric DIC.

RESULTS

After excluding 21 cases, 68 cases were examined. The number of patients diagnosed with DIC by JAAM-DIC criteria, JMHW criteria and ISTH criteria were 15 (22.1%), 5 (7.4%) and 3 (4.4%), respectively. Fifteen patients who fulfilled JAAM-DIC criteria included all 5 patients for whom DIC was diagnosed by JMHW criteria, and those 5 patients included all 3 patients for whom DIC was diagnosed by ISTH criteria.

CONCLUSIONS

The current study indicates that JAAM-DIC criteria can be useful but may overdiagnose the DIC.

Prone position increases collapsibility of the passive pharynx in infants and small children

On the basis of two observations that avoiding prone sleeping decreased incidence of sudden infant death syndrome and that obstructive sleep apnea is closely linked with the syndrome, we hypothesized that the prone position may increase upper airway collapsibility in infants and small children. Passive pharyngeal collapsibility of 19 infants and small children (10-101 weeks old) was examined in three postures: supine with face straight up, supine with neck rotated, and prone with neck rotated. The collapsibility was evaluated with the maximal distension of the most collapsible region, pharyngeal stiffness, and pharyngeal closing pressure, estimated from static pressure-area relationship of the passive pharynx. No significant changes in pharyngeal stiffness were detected; however, maximal distension was reduced in the prone position (mean +/- SD, 0.56 +/- 0.26 versus 0.44 +/- 0.20 cm(2); supine with face straight up versus prone position, p < 0.05). Pharyngeal closing pressure increased at neck rotation in the supine position (-4.5 +/- 2.4 versus -2.8 +/- 2.3 cm H(2)O; supine with face straight up versus supine with neck rotated, p < 0.05), and a further increase was observed in the prone position (-0.3 +/- 2.9 cm H(2)O, p < 0.05 versus supine with neck rotation). Pharyngeal closing pressure in the prone position was above atmospheric pressure in half of our subjects, whereas all subjects had negative pharyngeal pressure in the supine position. We conclude that the prone position increases upper airway collapsibility, although the mechanism is yet unclear.

[Extracardiac fontan procedure in adult: report of a case]

We report a case of a 28-year-old female who underwent an extracardiac Fontan procedure. The subject was diagnosed as an atrioventricular septal defect (Rastelli classification: type C), a double outlet right ventricle, pulmonary artery stenosis, a hypoplasty of left ventricle, total anomalous venous return (Darling: Ib + IIb), and atrial flutter. She underwent a Blalock shunt and an aorto-pulmonary shunt at the ages of 3 and 9 years, respectively. Under a total CPB, an extracardiac total cavo-pulmonary connection (TCPC), using a 26 mm Hemashield graft, was completed. The postoperative course was uneventful. The complicated atrial anatomy and atrial arrhythmia indicated TCPC in this adult patient.