Comparative study of the effectiveness of a mobile destruction unit (Unit DU2100-M2 from MedClair™) of nitrous oxide (N2O) for low-pain delivery in the delivery room
- Conditions
- T41.0Inhaled anaesthetics
- Registration Number
- DRKS00027493
- Brief Summary
During the physical examination before the start of the study, none of the pregnant women had any contraindications to participating in the study. The demographic data (age, height, weight, BMI) of the patients and midwives did not differ statistically significantly between the two groups. In eight patients, more than one midwife was involved in the birth process (e.g. due to shift changes, training). There were no statistically significant differences between the two groups with regard to gender, height, weight, Apgar scores at one, five and ten minutes, umbilical arterial pH values, base excess, the proportion of newborns with a pH < 7.1, the need for assisted ventilation, tactile stimulation or admission to a neonatal intensive care unit. No statistically significant differences were observed between the two groups with regard to parity, previous caesarean deliveries or previous nitrous oxide experience. Overall, three pregnant women had a history of previous caesarean deliveries and three pregnant women had experience of nitrous oxide during previous deliveries. The patients were at a median of 40.4 (39.8 - 41.3) weeks gestation, the median time between rupture of membranes and delivery was 3 h (1.2 h - 12.2 h), statistically significant differences between the groups were not observed. 67% (n = 8) of patients in group I and 42% (n = 5) of patients in group II used only the nitrous oxide-oxygen mixture to relieve labour pain during delivery. In 25% (n = 3) of the patients in group I and 58% (n = 7) of the patients in group II, an Peridural anesthesia was applied during labor and the application of nitrous oxide was terminated. One patient from group I received an intravenous opioid in addition to the nitrous oxide-oxygen mixture. In 25% (n = 3) and 42% (n = 5) of patients in groups I and II, respectively, a secondary caesarean section was indicated during the course of labour. There were also no statistically significant differences between the two groups with regard to these obstetric parameters. An episiotomy was performed in a total of 38% (n = 9) of the study participants in both groups; 58% (n = 7) received the nitrous oxide-oxygen mixture for suturing the episiotomy. The nitrous oxide-oxygen mixture was also used for the surgical treatment of other injuries to the birth canal; 25% (n = 6) of all patients received it. During the study, the median duration of N2O application was 3.9 h (2.3 h - 5.5 h). The median consumption of N2O in grams and bar was 1360 g (380 g - 1960 g) and 42.5 bar (15 bar - 78 bar) in group I, and 790 g (570 g - 1220 g) and 25 bar (18 bar - 50 bar) in group II. Although N2O consumption tended to be lower in group II, no statistically significant differences in N2O consumption were found between the two groups. Evaluation of the three N2O detectors: When measuring the N2O concentration, it was noticed during the evaluation that three measurements (n = 1 group I, n = 2 group II) were not recorded due to a defect. Detector 1: Detector 1 was the detector stationed 150 cm away from the head of the delivery bed on a shelf at a height of 165 cm. The mean TWA 8 (ppm) value was 90.9 ± 103 ppm (maximum: 267.8 ppm) in group I and 24.4 ± 23.4 ppm (maximum: 64.9 ppm) in group II. The p-value for a group difference was not significant, but showed a trend (p = 0.0609). The adjustment for nitrous oxide consumption showed a similar result (p = 0.0670). In group I, the TWA 8 value (average nitrous oxide exposure per hour) remained < 100 ppm in 64% (n = 7 of 11) of patients, in group II in 100% (n = 10 of 10) patients < 100 ppm. In group I at least one measured value > 500 ppm was observed in 18% (n = 2), in group II in 20% (n = 2) of the patients. Births exclusively with measured values < 150 ppm were observed in group I in 45% (n = 5), in group II in 70% (n = 7). Births exclusively with measured values < 100 ppm were observed in group I in 27% (n = 3), in group II in 60% (n = 6) (p = 0.1301). Detector 2: Detector 2 was the detector stationed 80 cm above the head of the delivery bed. The mean TWA 8 (ppm) value in group I was 84.5 ± 105.9 ppm (maximum: 297.4 ppm), in group II 31.5 ± 37.7 ppm (maximum: 100.9 ppm). The p-value for a group difference was not significant (p = 0.1246). The adjustment for nitrous oxide consumption showed a similar result (p = 0.1528). In group I, the TWA 8 value remained < 100 ppm in 67% (n = 8 of 12), in group II in 92% (n = 11 of 12) of the patients. In group I, at least one measured value > 500 ppm was observed in 33% (n = 4), in group II in 17% (n = 2) of the patients. Births exclusively with measured values < 150 ppm were observed in group I in 42% (n = 5), in group II in 50% (n = 6). Births exclusively with measured values < 100 ppm were observed in group I in 33% (n = 4), in group II in 42% (n = 5) (p = 0.6733). Detektor 3: Detector 3: Detector 3 was the detector worn on the midwife. The mean TWA 8 (ppm) value in group I was 68.1 ± 85.2 ppm (maximum: 270.4 ppm), in group II 25.5 ± 27.6 ppm (maximum: 66.9 ppm). The p-value for a group difference was not significant (p = 0.1228). The adjustment for nitrous oxide consumption showed a similar result (p = 0.1482). In group I, the TWA 8 value remained < 100 ppm in 75% (n = 9 of 12), in group II in 100% (n = 12 of 12) of the patients. In group I at least one measured value > 500 ppm was observed in 33% (n = 4), in group II in 25% (n = 3) of the patients. Births exclusively with measured values < 150 ppm were observed in group I in 33% (n = 4), in group II in 67% (n = 8). Births exclusively with measured values < 100 ppm were observed in group I in 33% (n = 4), in group II in 67% (n = 8) (p = 0.1025). Following the delivery, the patients answered 14 questions (yes/no; complete disagreement = 1, neutral = 3, complete agreement = 5 on a scale of 1 - 5, combined agreement 4 and 5) about the procedure. 96% (n = 23) of the patients felt well informed about the study. 92% (n = 22) of the patients found it easy to fit the demand valve and mask. 88% (n = 21) of the patients did not feel restricted in their movements by the demand valve and the mask. 100% (n = 24) of the patients felt comfortable during the application of the nitrous oxide-oxygen mixture in the delivery room (noise level, space, etc.). 79% (n = 19) of the patients would use the nitrous oxide-oxygen mixture again in a future delivery to relieve labor pain, 8% (n = 2) completely refused to use N2O again to relieve labor pain. 26% (n = 6) patients had less than 10 pain events during delivery, 65% (n = 15) had between 10 and less than 20 pain events and 9% (n = 2) had more than 20 pain events during delivery. 43% (n = 10) had received additional pain medication during the delivery, 57% (n = 13) had not, one answer was missing. When asked whether they would choose nitrous oxide for pain therapy again in the event of another delivery, 83% (n = 20) of the patients answered yes, 17% (n = 4) no. Nausea was reported by 29% (n = 7) of patients, vomiting by 13% (n = 3) and dizziness by 25% (n = 6). The effect of nitrous oxide met expectations for pain relief during childbirth in 79% (n = 19) of patients, but not in 21% (n = 5). No statistically significant differences were observed between the two groups with regard to the answers to the patient's questionnaire. At the end of the examination, the midwives answered nine questions about the examination procedure. 74% (n = 17) of the midwives felt well instructed and informed about the administration of the nitrous oxide-oxygen mixture, 13% (n = 3) completely denied this. 91% (n = 22) of the midwives found it easy to explain the demand valve and face mask, two midwives did not answer this question. In group II, the group using the mobile nitrous oxide destruction unit, 91% (n = 11) of the midwives found it easy to use the mobile destruction unit, one (9%) completely denied this.73% (n = 8) of the midwives felt sufficiently familiarised with the function of the mobile nitrous oxide destruction unit, 18% (n = 2) denied this completely, one answer was missing. 87% (n = 20) of the midwives felt that the atmosphere in the delivery room during the examination was pleasant, 8% (n = 2) denied this (1 and 2), one answer was missing. 77% (n = 17) of the midwives rated the analgesia provided by the nitrous oxide as sufficient for the patient, 14% (n = 3) remained neutral in their assessment (3 out of 5), 9% (n = 2) denied this completely. The only statistically significant difference between the groups in the entire study was found in response to the question "During the birth, the wish for additional analgesia was expressed". In group II (with two missing answers) 70% (n = 7) of the midwives answered "yes", 30% (n = 3) of the midwives answered "no". In group I, 25% (n = 3) of the midwives answered "yes", 75% (n = 9) of the midwives answered "no", p = 0.0348. 92% of the midwives (n = 21) stated that the inhalation and exhalation of the nitrous oxide-oxygen mixture was carried out by the patient with a tight-fitting mask as instructed during the induction, 8% (n = 2) denied this, one answer was missing. 65% of the midwives (n = 15) stated that they were familiar with the use of the nitrous oxide-oxygen mixture during delivery and the method, 17% (n = 4) denied this, one answer was missing.
- Detailed Description
Not available
Recruitment & Eligibility
- Status
- Complete
- Sex
- Female
- Target Recruitment
- 25
Willingness and ability to give consent present
- Age: at least 18 years
- Good understanding of German
- No contraindications for nitrous oxide
- Pregnancy without complications
- singleton pregnancy
- Expected vaginal delivery
- Time: opening or expulsion phase of labor with painful, regular contractions
- Lack of informed consent
- Multiple pregnancy
- Planned cesarean delivery
- Contraindications for nitrous oxide
- Peridural analgesia catheter (PDA) already in situ
Study & Design
- Study Type
- interventional
- Study Design
- Not specified
- Primary Outcome Measures
Name Time Method Effectiveness of the mobile nitrous oxide (N2O) destruction unit (results of nitrous oxide (N2O) measurements in the delivery room and time-weighted 8-hour exposure mean for delivery room staff (midwives).
- Secondary Outcome Measures
Name Time Method Questionnaires (midwives, patients) about their experiences with the mobile nitrous oxide (N2O) destruction unit.