Effects of first and second division modes on euploidy acquisition in human embryo

The aim of this study was to non-invasively investigate euploid embryos using methods other than pre-implantation genetic testing for aneuploidy. The study focused on direct cleavage (DC) observed during early embryo development. We also investigated the relationship between the mode of early embryo division and embryo ploidy. Embryos were divided into the normal cleavage (NC) and DC groups, and the DC group was further subdivided into the DC-First (DC-F) and DC-Second (DC-S) groups, depending on whether DC was observed at the first or second cleavage, respectively. The acquisition rates of euploid embryos and embryos appropriate for transfer were compared between the groups. Our results revealed that the timing of the first division did not differ between blastocyst grades or in embryos with varying degrees of ploidy. Further, the timing of the first cleavage did not affect the acquisition rate of embryos appropriate for transfer and euploid embryo formation rate did not significantly differ between the DC and NC groups. We also noted that for embryos appropriate for transfer, euploidy acquisition rate did not differ significantly between the DC and NC groups. Further, the euploidy acquisition rate of embryos did not differ between the DC-F and DC-S groups. However, the acquisition rate of embryos appropriate for transfer, including those with low mosaicism, was significantly higher in the DC-S group than in the DC-F group. These findings indicated that the number of good-quality blastocysts formed was significantly higher in the NC group than in the DC group and the acquisition rate of embryos appropriate for transfer, including those with low mosaicism, was significantly higher in the DC-S group than in the DC-F group.

Original delayed-start ovarian stimulation protocol with a gonadotropin-releasing hormone antagonist, medroxyprogesterone acetate, and high-dose gonadotropin for poor responders and patients with poor-quality embryos

Introduction

The delayed-start gonadotropin-releasing hormone antagonist protocol seems effective for patients who are poor ovarian responders, but there are insufficient data on whether it is also effective for patients with poor-quality embryos and low rates of good blastocyst formation. Specifically, the effectiveness of delayed-start gonadotropin-releasing hormone antagonists with progesterone has not been adequately investigated. Therefore, we compared the efficacy of the original delayed-start gonadotropin-releasing hormone antagonist protocol using medroxyprogesterone acetate (MPA) and high-dose gonadotropin in patients with poor ovarian response.

Methods

Overall, 156 patients with recurrent assisted reproductive technology failure who underwent the original protocol were included. They received cetrorelix acetate (3 mg) and MPA (10 mg) on cycle day 3, and high-dose gonadotropin was initiated on day 11. When the leading follicle reached 14 mm, ganirelix acetate (0.25 mg) was administered until the trigger day. The number of oocytes retrieved, metaphase II (MII) oocytes, two pronuclear (2PN) zygotes, and good blastocysts and live birth rates were compared between the previous (Cycle A) and original (Cycle B) cycles in three groups (Group A, all patients; Group B, poor responders; and Group C, patients with poor-quality embryos).

Results

In Group A (n=156), the number of MII oocytes (3.6 ± 3.3 versus 4.5 ± 3.6), 2PN zygotes (2.8 ± 2.9 versus 3.8 ± 3.1), good blastocysts (0.5 ± 0.9 versus 1.2 ± 1.6), and live birth rates (0.6 versus 24.4) significantly increased in Cycle B. Similar results were obtained in Group B (n=83; 2PN zygotes [1.7 ± 1.7 versus 2.3 ± 1.8], good blastocysts [0.4 ± 0.7 versus 0.9 ± 1.3], live birth rates [0 versus 18.1]) and Group C (n=73; MII oocytes [5.1 ± 3.8 versus 6.6 ± 4.0], 2PN zygotes [4.0 ± 3.4 versus 5.4 ± 3.4], good blastocysts [0.7 ± 1.1 versus 1.6 ± 1.9], and live birth rates [1.4 versus 31.5]).

Conclusion

This original protocol increased the number of MII oocytes retrieved, 2PN zygotes, good blastocysts, and live birth rates in both poor responders and in patients with poor-quality embryos.

Smooth endoplasmic reticulum cluster presence does not affect embryo ploidy

PURPOSE

We examined the impacts of the smooth endoplasmic reticulum cluster (sERC) presence on embryonic development and blastocyst ploidy.

METHODS

Patients who underwent oocyte retrieval from January 2019 to November 2021 were included in the study. We classified the oocytes into three groups: normal oocytes in the sERC ( -) cycle, normal oocytes in the sERC ( +) cycle, and sERC ( +) oocytes. Next, the levels of serum estradiol, progesterone, anti-Mullerian hormone, follicle-stimulating hormone, and human menopausal gonadotropin were compared between the groups. Moreover, fertilization, degeneration, and abnormal fertilization rates were compared between groups. To investigate developmental outcomes, the blastocyst and good-quality blastocyst rates after intracytoplasmic sperm injection were compared. The quality of the transferred blastocysts was evaluated at follow-up. Additionally, embryos were submitted for next-generation sequencing analysis to examine the effect of sERC presence on ploidy.

RESULTS

The sERC ( +) group had significantly higher serum estradiol, serum progesterone, and serum anti-Mullerian hormone concentrations compared to those in the sERC ( -) group (P < 0.01). The abnormal fertilization rate was higher in the sERC ( +) cycle-sERC ( +) oocyte group (16.1%; 37/230) than in the sERC ( +) cycle-normal oocyte (6.2%; 63/971) and sERC ( -) cycle-normal oocyte groups (7.1%; 174/2467) (P < 0.01). After embryo transfer, nine women gave birth, and no confirmed congenital anomalies were observed. There was no significant difference in ploidy between the sERC ( +) and sERC ( -) groups.

CONCLUSION

The occurrence rates of embryos with euploidy were similar between the sERC ( +) and sERC ( -) groups.

P-175 Relationship Between oocytes with sERC and Ploidy

Study question

We investigated the effects of the presence or absence of sERC on subsequent embryonic development and the ploidy of embryos.

Summary answer

The acquisition rates for euploidy embryos were similar to those for the embryos derived from oocytes without smooth endoplasmic reticulum cluster (sERC).

What is known already

The effects of the presence of sERC have been reported on embryonic development processes and pregnancy rate after embryo transfer (ET). In this study, we investigated the effects of the presence of sERC not only on embryonic development and pregnancy rate, but also on the ploidy of embryos from the oocytes with sERC.

Study design, size, duration

The subjects comprised women from whom oocytes were collected from January 2019 to November 2021. The group with the oocytes with sERC was designated as sERC(+), and the other group without sERC as sERC(-).

Participants/materials, setting, methods

Retrospective analysis was performed using a time-lapse system (EmbryoScope+). They were divided into two groups according to the presence of sERC. The groups were compared for fertilization rate, degeneration rate, abnormal fertilization rate (1PN, 3PN, 2.1PN), blastocyst rate, and good-quality-blastocyst rate after ICSI. The prognosis of the transferred embryos was followed up on. In addition, the embryos that were subjected to NGS analysis were investigated for effects of the presence of sERC on their ploidies.

Main results and the role of chance

The sERC(+) group exhibited a significantly lower fertilization rate (74.8%) compared to that of the sERC(-) group (82.4%, P &lt; 0.01). The sERC(+) group exhibited a significantly higher abnormal fertilization rate (14.8%) compared to that of the sERC(-) group (6.6%, P &lt; 0.01). The sERC(+) group showed a significantly higher blastocyst formation rate (57.4%) compared to the sERC(-) group (45.2%, P &lt; 0.01). With respect to after ET prognosis, eight women gave birth with no confirmed congenital anomality. At the very least, the presence of sERC has been shown to have no effect on childbirth. The investigation on ploidy showed that the oocytes in the sERC(+) group included 24.2% euploidy (8/33), 9.1% mosaic (3/33), and 66.7% aneuploidy (22/33) embryos, while the oocytes in the sERC(-) group included 30.4% euploidy (137/451), 12.4% mosaic (56/451), and 57.2% aneuploidy (258/451) embryos. Thus, there was no difference due to the presence of sERC. Three out of the eight euploidy blastocysts in the sERC (+) group had been transferred, one of which reached childbirth.

Limitations, reasons for caution

PGT-A is still under clinical research in Japan.

Wider implications of the findings

Many reports suggested that oocytes with sERC can be used as embryos appropriate for transfer when they develop into blastocysts. The investigation into the ploidy of sERC(+)-derived blastocysts in this study confirmed that the presence of sERC did not affect the ploidy of embryos and that these embryos were transferable.

Trial registration number

not applicable

P-163 Effects of Early Modes of Cell Division on Blastocyst Ploidy

Study question

Abnormal cleavage (AC) has been confirmed at early development. We performed an NGS analysis on AC-derived blastocysts to investigate ploidy of the resulting embryos.

Summary answer

Group in which AC occurred during second division showed significantly higher rates for embryos appropriate for transfer than group where AC occurred during first division.

What is known already

Early division is important in embryogenesis and serves as an indicator of subsequent embryonic development. The occurrence of AC during early development can be identified with the advent of the time-lapse incubator, which in turn has led to difficulties in determining whether such AC-derived blastocysts can be used embryo transfer. In this study, we performed NGS analysis on AC-derived blastocysts to investigate the ploidy of the resulting embryos.

Study design, size, duration

The subjects comprised women from whom oocytes were collected for NGS analysis from January 2019 to November 2021. Retrospective analysis was performed using a time-lapse system (EmbryoScope+). Embryos were categorized into two groups: those with abnormal divisions observed during the first and second divisions and those in which normal divisions were observed in the same cycle.

Participants/materials, setting, methods

The group with AC observed was designated the AC group and the other with normal divisions as the Normal Cleavage (NC) group. Within the AC group, the subgroup with AC observed during first division was designated as the First (AC-F) group and the subgroup with AC observed during second division as the Second (AC-S) group for comparing the acquisition rates for euploidy embryos and embryos appropriate for transfer.

Main results and the role of chance

The AC group (17.3%) showed a significantly lower rate of good blastocyst formation than did the NC group (53.4%) (P &lt; 0.01). The cutoff point for mosaicism was defined as &gt; 20% of abnormal cells. Percentage &lt;20 were classified as normal (euploid); &gt;80, abnormal (aneuploidy); and 20-80, mosaic. Using a cutoff of 50% to differentiate ‘‘low’’ mosaics from ‘‘high’’ mosaics. There was no difference between the two groups in the acquisition rates for euploidy embryos (30.8-35.1%) and the embryos appropriate for transfer, including low-mosaic ones (44.3-46.1%). There also was no difference in the acquisition rates for euploidy embryos (24.0-37.0%) between the AC-F and AC-S groups. However, the AC-S group (59.3%) showed significantly higher acquisition rates than the AC-F group (32.0%) for the embryos appropriate for transfer, including low-mosaic ones (P &lt; 0.05).

Limitations, reasons for caution

PGT-A is still under clinical research in Japan.

Wider implications of the findings

The group in which AC occurred during second division showed significantly higher acquisition rates for the embryos appropriate for transfer than the group in which AC occurred during first division. This indicates that the most important factor for identifying euploidy embryos is going through the two-cell phase during first division.

Trial registration number

not applicable

The effects of differences in trophectoderm biopsy techniques and the number of cells collected for biopsy on next‐generation sequencing results

Purpose

To examine how differences in trophectoderm biopsy techniques affect the frequency of mosaic embryos and sequencing results.

Methods

We examined differences in next‐generation sequencing (NGS) analysis results among operators or according to biopsy technique. Additionally, we determined the cut‐off for the number of collected cells to predict the occurrence of mosaicism. We collected cells according to the cut‐off value and examined whether there was a difference in the NGS analysis results between the pulling and flicking methods.

Results

There was no difference in the NGS analysis results among the operators. Regarding re‐biopsy, changes in the mosaic were observed in all specimens. The cut‐off value for the number of collected cells was five, and when more than five cells were collected, there was no difference in the NGS analysis results between the two methods.

Conclusions

We demonstrated that if trophectoderm biopsy techniques and NGS are stable, the cell collection location has a greater effect on NGS results than the biopsy technique.

A novel trophectoderm biopsy technique for all blastocyst stages

Purpose

This study was conducted to assess the effectiveness of a new trophectoderm (TE) biopsy method that does not require prior opening of the zona pellucida at the blastocyst stage.

Methods

TE biopsy was conducted using a modified extrusion method for embryos during the cleavage stage. In this method, culture medium was injected into the perivitelline space to help extrude TE cells from the zona pellucida before TE biopsy.

Results

Our extrusion method preserves the embryo culture environment until immediately before biopsy because it does not require opening of the zona pellucida prior to TE biopsy. Furthermore, this method does not require a waiting time for blastocyst hatching after laser irradiation, thereby minimizing damage to the embryos and maintaining the time schedule of culture operations.

Conclusions

TE biopsy using this novel extrusion method may be useful in various applications, including the collection of TE cells for next‐generation sequencing analysis.

The effect of repeated cryopreservation and thawing using cryotip on the clinical outcomes of embryos

PURPOSE

To compare the clinical outcomes of embryo transfers that were cryopreserved and thawed two or three times with those cryopreserved and thawed once by CryoTip.

METHODS

Data for 388 single cryopreserved-thawed blastocyst transfer cycles, performed from April 2012 to March 2014, were assessed. The blastocysts were classified into three groups: blastocysts (A) cryopreserved once, (B) cryopreserved twice, and (C) cryopreserved three times.

RESULTS

The pregnancy rate was 43.8% (134/306) in group A and 46.3% (38/82) in group B, while the miscarriage rate was 29.1% (39/134) in group A and 23.7% (9/38) in group B. The rate of improvement/maintenance of blastocyst grade was 84.0% (257/306) in group A and 80.5% (66/82) in group B. The pregnancy and miscarriage rates of the blastocysts that showed improvement/maintenance in the grade were 45.9% (118/257) and 29.7% (35/118) in group A and 48.5% (32/66) and 21.9% (7/32) in group B, respectively. The pregnancy rate was 33.3% (2/6), while the miscarriage rate was 0.0% (0/2) in group C.

CONCLUSIONS

Pregnancy rates achieved with re-cryopreserved and rethawed blastocyst transfer were comparable to those achieved with single cryopreserved-thawed blastocyst transfer.

Pleomorphic type of malignant fibrous histiocytoma with myxoid stroma of the vulva in a young woman

Malignant fibrous histiocytoma (MFH) of the vulva is extremely rare; to date, there have been nine case reports. Almost all of these cases involved middle-aged women. We encountered a 21-year-old woman with a 4.5 × 2.6 cm superficial, localized, exophytic tumor of the right vulva. Microscopic findings on punch biopsy of the tumor initially suggested a vulvar sarcoma. The patient underwent wide local excision of the vulva. The extirpated specimen demonstrated the pleomorphic type of MFH with myxoid stroma of the vulva. The clinical stage was found to be IIB, based on the American Joint Committee on Cancer staging system. Chromosomal analysis of the tumor using the conventional G-band method was normal (46XX). This seems to be a very rare case of MFH of the vulva in a young woman. Physicians should therefore include MFH in the differential diagnosis of vulvar tumors, even though it is a rare disease.

Daily changes of the area of density in the dependent lung region - evaluation using transesophageal echocardiography

OBJECTIVE

To evaluate the daily changes of the area of density using transesophageal echocardiography (TEE) in acute respiratory distress syndrome (ARDS) and acute lung injury (ALI) patients.

DESIGN

Retrospective observational study.

SETTING

General ICU in a university hospital.

PATIENTS

Fifteen patients with ARDS or ALI who underwent TEE examination for more than 5 days.

MEASUREMENTS

Densities in the lower left lung region were observed through the descending aorta by TEE. Daily changes of the area of density were evaluated. The areas of density estimated by TEE were compared with those obtained by computed tomography (CT). The relation between the area of density and PaO(2)/FIO(2)was calculated.

RESULTS

The area of density in the dependent lung region measured by TEE was 11.1+/-5.7 cm(2) (mean +/- SD) at the mid-esophageal position. The area of density in ARDS patients changed daily from 12.0+/-2.8 cm(2) to 8.5+/-6.7 cm(2). The areas of density evaluated using TEE in the left lung correlated significantly with those estimated using CT ( r=0.72, p<0.01). In addition, we found a significant correlation between PaO(2)/FIO(2) and the area of density estimated by TEE ( r=-0.53, p<0.05).

CONCLUSION

Using TEE, we could evaluate daily changes of the area of density in the dependent lung region in the intensive care situation. The areas of density in ARDS patients changed from day to day following the changes of oxygenation.

A new galloylglucoside from Cleyera ochnacea DC

A new galloylglucoside, 3-hydroxy-5-methylphenol 1-O-beta-D-(6'-galloyl)glucopyranoside (1) was isolated from Cleyera ochnacea DC. (Theaceae). Its structure was elucidated on the basis of chemical and spectral analysis. Compound 1 showed inhibitory activity against rat cerebellar nitric oxide synthase (NOS).

Reaction of 3-acetonyl-5-cyano-1,2,4-thiadiazole with phenylhydrazine hydrochlorides: indolization and phenylpyrazolation

Treatment of 3-acetonyl-5-cyano-1,2,4-thiadiazole (1) with 4-methyl or 4-methoxyphenylhydrazine hydrochloride provided 5-cyano-3-(2,5-dimethylindol-3-yl)-1,2,4-thiadiazole (2) or 5-cyano-3-(5-methoxy-2-methylindol-3-yl)-1,2,4-thiadiazole (3) as the sole product, respectively. In contrast, treatment of 1 with phenylhydrazine hydrochloride resulted in the formation of 5-cyano-3-(2-methylindol-3-yl)-1,2,4-thiadiazole (4) and the unexpected 5-cyano-3-(3,5-dimethyl-1-phenylpyrazol-4-yl)-1,2,4-thiadiazole (5). In a similar manner, when 1 was treated with 4-chlorophenylhydrazine hydrochloride, indolization was suppressed by phenylpyrazolation giving rise to 5-cyano-3-(5-chloro-2-methylindol-3-yl)-1,2,4-thiadiazole (6) and 5-cyano-3-[1-(4-chlorophenyl)-3,5-dimethylpyrazol-4-yl]-1,2,4-thia diazole (7). The reaction mechanism is discussed. Compounds 4, 5 and 6 exhibited weak antimicrobial activity against Helicobacter pylori.

Does indocyanine green accurately measure plasma volume independently of its disappearance rate from plasma in critically ill patients?

OBJECTIVE

To determine whether plasma volume determined by the indocyanine green (ICG) dilution method (PV-ICG) is equally accurate independently of its disappearance rate from plasma in the critically ill.

DESIGN

Retrospective clinical investigation.

SETTING

Intensive care unit of a university teaching hospital.

PATIENTS AND METHODS

192 adult patients were initially enrolled. The PV-ICG and the initial distribution volume of glucose (IDVG) were calculated utilizing a one-compartment model by simultaneous administration of ICG 25 mg and glucose 5 g on the first day of measurement in each patient. Twenty-one patients were excluded from the study because of a higher PV-ICG/IDVG ratio (> 0.45) indicating apparent overestimation of the PV-ICG associated with the generalized protein capillary leakage. The remaining 171 patients were divided into four groups according to the magnitude of their disappearance rate of ICG from plasma (Ke-ICG).

RESULTS

Convergence was assumed consistently in each ICG or glucose decay curve, even in the lower Ke-ICG less than 0.10/min. The relationship between the two volumes was not statistically different among groups.

CONCLUSIONS

The results suggest that the measurement of the PV-ICG can be equally accurate independently of its disappearance rate from plasma unless there is generalized protein capillary leakage.

Ratio of indocyanine green and glucose dilutions detects capillary protein leakage following endotoxin injection in dogs

This study was designed to determine whether endotoxin-induced generalized capillary protein leakage can be detected using the ratio of indocyanine green (ICG) and glucose dilutions. Plasma volume determined by the ICG dilution method (Vd-ICG) and the initial distribution volume of glucose (IDVG) were assessed simultaneously before and after either the administration of lipopolysaccharide (LPS) 0.3 mg kg-1 or equal amounts of isotonic saline in two groups of eight dogs, using a one-compartment model after simultaneous infusions of both ICG 0.5 mg kg-1 and glucose 100 mg kg-1. The IDVG has been shown to indicate the extracellular fluid volume of highly perfused organs including plasma. All post-treatment values decreased compared with the pre-treatment values (P < 0.05), except Vd-ICG in the LPS group, even though the post-treatment total plasma protein concentration of the LPS group decreased significantly compared with the pre-treatment value (P < 0.05). The post-treatment Vd-ICG/IDVG ratio of the saline group remained unchanged compared with that of the pre-treatment, and the post-treatment ratio of the LPS group increased significantly (P < 0.01). It can be concluded that overestimation of the Vd-ICG can occur after endotoxin injection, which can be detected by simultaneous measurements of the Vd-ICG and the IDVG.

Measurements of extracellular fluid volume in highly perfused organs and lung water in hypo- and hypervolaemic dogs

The purpose of this study was to identify whether the central extracellular fluid volume status following hypo- and hypervolaemia can be measured by the initial distribution volume of glucose or by the extravascular lung water. These two estimates were compared with the initial distribution volume of sucrose which has been used as an indicator for the measurement of the extracellular fluid volume. The above three estimates were determined by the administration of glucose, chilled saline and sucrose solutions, before and after haemorrhage (30 mL kg-1), and subsequent fluid load (lactated Ringer's solution 90 mL kg-1). The distribution volumes of glucose and sucrose decreased after haemorrhage and increased after fluid load compared with normovolaemic values, and a linear correlation was obtained between these two distribution volumes (r = 0.93, P < 0.001, n = 36). However, the extravascular lung water remained statistically unchanged throughout the procedure, despite a weak linear correlation with the sucrose distribution volume (r = 0.38, n = 33, P < 0.05). These results indicate that the initial distribution volume of glucose is more useful as an indicator of the central extracellular fluid volume status than the extravascular lung water.

Elimination of FK-506 by continuous hemodiafiltration in a liver transplant patient

A liver transplant patient who developed renal failure postoperatively was treated using continuous hemodiafiltration (CHDF). Doses ranging from 0.01 to 0.06 mg/kg/day of FK-506 had been administered intravenously. FK-506 concentrations before and after the filter, and in the ultradiafiltrate were 45.3 +/- 2.9, 56.0 +/- 5.3, and 9.1 +/- 3.1 ng/ml (mean, +/- S.D.), respectively. The filtration rate was 23.6 +/- 6.4%, and extracted FK-506 amounted to 522.0 micrograms (11.3% of administered dose). A part of the FK-506 administered was eliminated through the filter during CHDF.

Possible Overestimation of Plasma Volume Determined by the Indocyanine Green Dilution Method in the Presence of Protein Leak From Capillary Beds – A Discussion of Two Clinical Cases

Indocyanine green (ICG) has been demonstrated to be a reliable indicator for the estimation of plasma volume in man. Since this dye is bound to plasma protein when administered intravenously, overestimation of the plasma volume would occur during the presence of protein leak from plasma. However, to our knowledge, up to now no report has described whether or not plasma volume determined by the indocyanine green dilution method (PV_ICG) is clinically significantly overestimated under such conditions. We report two burned patients who temporally had an unusual large PV_ICG even though other clinical variables did not support the presence of hypervolemia. From the case described it can be concluded that a possible overestimation of PV_ICG occurs when the vascular permeability for proteins is increased.

[Changes in rectal temperature during tympanoplasty under general anesthesia]

We measured rectal temperature of 35 patients who underwent tympanoplasty under various types of general anesthesia. They were allocated at random to three groups according to the types of general anesthesia; 10 patients of enflurane-N2O (enflurane group); 10 patients of neuroleptic anesthesia with droperidol, pentazocine-N2O (NLA group); 15 patients of total intravenous anesthesia with droperidol, fentanyl and ketamine (DFK group). After the induction of anesthesia, their rectal temperature was continuously monitored with an electric thermometer of NEC San-ei throughout the surgical procedure. Increase in rectal temperature was observed in all three groups, and increase in DFK group was significant compared with other two groups. It is possible that the significant increase in rectal temperature in DFK group is supposedly due to normally maintained hypothalamic thermoregulatory function as well as direct surgical stimulation to central nervous system.

[Effect of pirenzepine on gastric secretion during anesthesia and surgery]

Effect of pirenzepine on gastric secretion during anesthesia and surgery was evaluated in 46 surgical patients ranged in age from 18 to 68 years. The patients underwent orthopedic, ophthalmic, ENT, plastic or non-abdominal general surgery under neuroleptanesthesia except two patients who had enflurane or isoflurane anesthesia. They received either pirenzepine 10 mg, 20 mg or the combination of pirenzepine 10 mg and famotidine 20 mg intravenously just before the induction of anesthesia. Volume and acidity of gastric juice were measured for 3 hours after the administration of these agents. Decrease in volume and acidity of gastric juice after pirenzepine 10 mg as well as after pirenzepine 20 mg continued for more than 3 hrs after the administration of the agents. Efficacy of the combination of pirenzepine and famotidine on gastric secretion was more prominent than that of pirenzepine alone in a double dose.

[Clinical study on intraoperative hyperketonemia in non-diabetic surgical patients under general anesthesia]

We measured plasma 3-hydroxybutyrate (3-OHBA) concentrations in 925 non-diabetic surgical patients who underwent various surgical procedures under various types of general anesthesia. Lactated Ringer's solution only was used as an intraoperative fluid. Among them, 46 patients (4.9%) developed high 3-OHBA levels of over 500 microM.l-1 during surgery. The causes of observed hyperketonemia would be surgical stress and preoperative fasting irrespective of 8 types of general anesthesia. Blood glucose, lactic acid, base excess and pH were not influenced by hyperketonemia. Prolonged recovery from anesthesia was not observed in any patients with hyperketonemia. Without any specific treatments, plasma 3-OHBA levels were unchanged or rather decreased in 70% of the patients whose 3-OHBA levels were over 500 microM. The results suggest that hyperketonemia below 500 microM.l-1 is not always disadvantageous in nondiabetic patients under general anesthesia.

[Clinical study on total intravenous anesthesia with droperidol, fentanyl, and ketamine--18. Effect on peripheral circulation as judged by core-peripheral temperature gradient]

Effect of total intravenous anesthesia with droperidol, fentanyl and ketamine (DFK) on peripheral circulation was studied by examining core-peripheral temperature gradient in twenty five patients who underwent abdominal surgery. A core temperature probe was attached on the forehead and peripheral probe on the palm of the hand of the side on which the blood pressure cuff was not applied. The temperature gradient was less than three degrees centigrade in 60% of the patients and the gradient was significantly less as compared with that of isoflurane anesthesia even at 300 minutes after the start of surgical operation. This advantage would have been caused by such factors as circulatory stimulating effect of ketamine, sympathetic blocking effect by droperidol and adequate postoperative analgesia by fentanyl and norketamine, a metabolite of ketamine. The results suggest that DFK would exert a beneficial effect on peripheral circulation, particularly during prolonged surgical procedures.

[Excessive nitrous oxide exhalation by postoperative patients in the recovery room]

Expired nitrous oxide from patients in the recovery room is considered to be the major source of air pollution. We measured expired concentrations of nitrous oxide in three patients and three volunteers. After only 5 minute inhalation of 50% nitrous oxide, it took over 2 hours for exhaled N2O concentration to decrease to 25 ppm in volunteers and after 30 minute inhalation, it took over 4 hours. The patients inhaled 50% nitrous oxide for 60, 165, 150 minutes, respectively and all patients expired nitrous oxide, the concentrations of which exceed 100 ppm over 3 hours. As to the patient who inhaled nitrous oxide for 150 minutes, expired nitrous oxide over 25 ppm was detected 10 hours after the end of anesthesia, and it was 4 ppm even after 20 hours. Any personnel including anesthesiologists and nurses working in the operating room can be exposed to high concentrations of nitrous oxide exceeding the permissible limit of 25 ppm, whenever they take care closely of their patients. We do not have any effective measures to protect us from this kind of air pollution except employing total intravenous anesthesia.