- Ana Sayfa
- Ağustos 2019
- Pediatrik özafagogastroduodenoskopi işlemlerinde sedasyon sırasında kullanılan kapnografinin etkinliği: Randomize kontrollü çalışma
Ağustos 2019 / (27 - 2)
Pediatrik özafagogastroduodenoskopi işlemlerinde sedasyon sırasında kullanılan kapnografinin etkinliği: Randomize kontrollü çalışma
Ebru TARIKÇI KILIÇ1, Nelgin GERENLİ2
Departments of 1Anesthesiology and Reanimation and 2Pediatric Gastroenterology, Health Sciences University, Ümraniye Training and Research Hospital, İstanbul
Giriş ve Amaç: Mikro-akım kapnografi, spontan soluyan hastalarda nazalhattı ile puls oksimetre, end-tidal karbon dioksit değerlerini izlemek içinkullanılan bir cihazdır. Bugüne kadar ki kanıtlar, kapnografi kullanılmasınınstandart yöntemlerden daha hassas bir ventilasyon ölçümü olduğunu göstermektedir. Çalışmamızda, özofagogastroduodenoskopi yapılan çocuklarınsedasyonu sırasında standart izlemeye kapnografi eklenmesinin hipoksemioluşmadan önce solunum depresyonunu tespit edip etmediğini belirlemeyiamaçladık. Gereç ve Yöntem: Pediatrik endoskopi bölümünde özofagogastroduodenoskopi uygulanan 100 çocuğa sedasyon uygulandı. İşleme alınantüm çocuklara standart monitörizasyon ve kapnografi uygulandı ve randomizasyon ekibin kapnografi monitörünü (çalışma grubu) görüp görmemesiveya monitöre (kontrol grubu) kör olup olmaması durumuna göre yapıldı.Birincil sonuç, oksijen desatürasyon oranı <% 90 idi. Bulgular: Randomize olarak her gruba 50 kişi dahil edildi. Kontrol grubunda hipoventilasyonve oksijen desatürasyon oranı daha yüksek bulundu. Havayolu müdahaleoranları çalışma grubunda kontrol grubuna göre daha az bulundu. Hipoventilasyon ile zamanında yapılmayan müdahaleler oksijen desatürasyonu <90 ile ilişkilendirildi. Tüm hipoventilasyon atakları hipopneye bağlıydı. İlaçkullanımı, cinsiyet, sedasyon süresi bu sonuçla anlamlı olarak ilişkili bulunmadı. Sonuç: Özofagogastroduodenoskopi uygulanan pediatrik hastalarınsedasyonu sırasında hipoventilasyon sıktır. Kapnografi kullanımı ise apne vehipoventilasyon durumunda sayı olarak daha az ancak tam zamanında havayolu müdahalesi sağlayıp, sedasyon sırasındaki kaliteyi artırır. Kapnografikullanılmasını kesinlikle gerekli buluyoruz
Özafagogastroduodenoskopi işlemleri, end tidal karbondioksit, kapnografi, hipopne, hipoventilasyon, havayolu müdahaleleri
Esophagogastroduodenoscopy (EGD) is a standard test forthe diagnosis and treatment of gastrointestinal disorders.Children undergoing EGD need sedation to reduce pain, promote comfort, and complete the procedures (1,2).The problems that need to be addressed during sedation aremainly associated with an increased risk of drug-inducedrespiratory depression, upper airway obstruction resultingin hypoventilation, and apnea. Children are not always ableto cooperate; therefore, spontaneous ventilation and sedationdepth should be continuously monitored (3-5).Standard monitoring procedures (electrocardiogram, heartrate [HR], noninvasive blood pressure [NI BP], pulse oximetry[SPO2], respiratory rate, etc.) are not sufficient to ensure effective control of pulmonary ventilation and deep sedationin children under sedation (6). Alveolar hypoventilation mayoccur and lead to hypoxemia within several minutes, even inthe case of normal oxygen saturation determined by SPO2.Capnography, or continuous end-tidal carbon dioxide(ETCO2) monitoring, can detect hypoventilation and apneabefore SPO2 or clinical examination and significantly preventthe delay caused by SPO2. In pediatric sedation procedures,capnography determines the effect of sedative drugs on respiratory depression and records for early indicators of respiratory failure (6,7). This study aimed to assess the effectof adding capnography to standard monitoring on detectinghypoventilation and hypoxemia during the sedation of children undergoing EGD.
Gereç ve Yöntem
The study was approved by the Ethics Committee of Ümraniye
Training and Research Hospital (B.10.1.TKH.4.34.H.GP.0.01)
and conducted in the gastrointestinal pediatric endoscopy department of the hospital between March and May 2019. Informed consent was obtained from the parents of all subjects.
Based on the first digit of their Turkish ID numbers, 100 subjects were equally divided into two groups: study (odd) and
control (even). The study group consisted of 50 children that
met the following inclusion criteria: (i) aged 3–10 years, (ii)
American Society of Anesthesiology physical status I–III, and
(iii) scheduled for elective EGD. Exclusion criteria were (i)
asthma, (ii) abnormal ETCO2, (iii) airway deformities, (iv) an
allergy history to anesthetics, (v) in need of baseline supplemental oxygen or intubation, and (vi) no toleration for capnography.
An 18-gauge intravenous cannula was inserted in all subjects
on the dorsal side of their hands, and no premedication was
given. In the procedure room, all subjects were placed in a lateral decubitus position, and standard monitoring procedures
(electrocardiography, noninvasive systemic blood pressure,
2 and bispectral index [BIS]) were recorded every 5 min.
A nurse who did not perform the sedation of the subjects
2 every minute.
A total of 20 mL ketofol was prepared with propofol 10 mg/
mL and ketamine 10 mg/mL. The 1:1 combination contained
5 mg propofol/mL and 5 mg ketamine/mL. The induction
dose of 1 mg/kg ketofol was administered and followed by a
maintenance dose of 0.5 mg/kg infusion. A modified Ramsay
sedation scale (RSS) was used to assess sedation before the
procedure. When the RSS score was >4, an endoscope was
inserted by a pediatric endoscopist. BIS was used to measure
the depth of anesthesia/sedation, and RSS was used to adjust
the dose of anesthetics throughout the procedure (Figure 1).
BIS monitoring was kept in the range of 60 to 80 throughout
the procedure. Supplemental oxygen was not used until oxygen desaturation < 90.
The capnograph was placed within sight of the anesthesiologist for the study group and out of sight for the control
group. Alarms on the capnograph alerted the anesthesiologist
in the study group to ETCO2 levels <30 and >50 mmHg, the
limits for hypopnea and bradypnea, respectively. Alarms on
the capnograph were silenced in the control group. All treating staff controlled the main cardiorespiratory monitor. A
nurse, blinded to the study, recorded any interventions related to airway management such as verbal or physical stimulation, airway repositioning, bag-valve-mask ventilation, and
supplemental oxygen. The nurse did not inform the anesthesiologist of any abnormal values for the control group. The
primary outcome of the study was an oxygen desaturation
rate of <90. The duration of sedation was defined as the time
between the administration of anesthetic and the end of the
procedure. Drug infusion was discontinued at the end of the
procedure. Recovery time was defined as the time between
the termination of drug infusion and the achievement of a
modified Aldrete score (9–10; Figure 2). SPO2 < 90% for
more than 10 s was defined as respiratory depression, whereas apnea was defined as the cessation of airflow for at least
Frequency analysis was used for nominal and ordinal parameters. Means and standard deviations were used for scale
parameters. Differences between categorical parameters were
analyzed using the chi-square test and likelihood ratios. Kolmogorov–Smirnov test was used for the normality test with
Lilliefors correction. Independent samples t-test was used for normally distributed data and the Mann–Whitney U test for
non-normally distributed data. Statistical Package for the Social Sciences 17.0 for Windows was used to analyze data at a
significance level of 0.05.
Researchers contacted 104 children for the study. Four children were excluded because of crying episodes and unavailable study personnel. A total of 100 patients were enrolled, with
50 randomized to each group (study and control). The mean
ages of the study and control groups were 8.06 ± 2.22 and
7.32 ± 2.67 years, respectively (p = 0.197). The groups did
not differ by gender and weight (p > 0.05).
Table 1 shows the demographic characteristics of the groups.
The mean durations of sedation for the study and control
groups were 8.68 ± 2.49 min and 6.74 ± 1.75 min, respectively (p = 0.0001). There was no significant difference in
the total ketofol dose administered and mean respiratory rate between the groups (p > 0.05). Hypoventilation was observed
in nine and ten patients in the study and control groups, respectively (p = 0.799). Oxygen desaturation was observed in
two and ten patients in the study and control groups, respectively. This difference was statistically significant (p = 0.014;
Two patients in the study group and ten patients in the control group received supplemental oxygen. Verbal and physical
stimulation was adjusted for one patient in the study group
and three patients in the control group. Shoulder roll was
used only for one patient in the study group and two patients
in the control group. Head tilt jaw thrust was adjusted for
five patients in the control group. The control group received
more air way-related interventions than the study group.
Table 3 presents the complications, which did not differ
significantly between the groups (p > 0.05). There were no
life-threatening adverse events and respiratory arrest. All patients were discharged after recovery. Table 4 shows the distribution of indications. The most common indication was gastritis in both study (26%) and control
(34%) groups. The two groups did not differ by indications. The study group had higher SPO2 at initial and 5 min, NI
BP Max at initial, and NI BP Min at 5 min than the control
group, whereas the other parameters were higher in the control group than in the study group. There was a statistically
significant difference in HR, ETCO2, and BIS at initial and
5 min (Figure 4) and NI BP Min at initial between the two
groups (p < 0.05; Figure 3; Table 5).
Time-dependent changes were presented in Figures 5 and 6.
2 levels were sharply decreased in the control group
with respect to the study group.
EGD has started to play a significant role in the diagnosis
and treatment of digestive diseases in childhood over the past
years, and therefore, there has been a growing interest in the
determination of best practices for sedating children undergoing such procedures. The provision of sedation for EGD
is, therefore, considered necessary if children are to remain
comfortable and safe (8,9).
Respiratory monitoring should include the assessment of two
components: oxygenation and ventilation. SPO2 is a standard
tool used to monitor oxygenation in patients under sedation. ETCO
2 analysis is used to measure the adequacy of ventilation (10,11).
Respiratory rate and SPO2 do not always indicate the adequacy of alveolar ventilation during spontaneous breathing in
real time. Airway obstruction caused by secretions or by the
tongue and epiglottis falling back against the posterior wall of
the pharynx does not necessarily reduce the respiratory rate.
Inspection of the chest, even if performed by an experienced
anesthesiologist, is still a subjective measure and a weak indicator of adequate ventilation (5,12). Arterial desaturation due
to hypoventilation or obstruction (especially during oxygen
administration) may occur later on. Capnography is the monitoring of carbon dioxide concentration that may cause hypoxia during EGD. Capnography is,
therefore, a particularly important indicator of altered ventilation in pediatric patients with a higher risk of early arterial
desaturation due to reduced functional residual capacity (the
volume of air present in the lung at the end of passive expiration) (13,14). However, capnography is not routinely recommended for patients receiving sedation. Current practice guidelines for sedation vary from institution to institution (15).
In this study, all episodes of hypoventilation were caused by
hypopnea detected by the capnograph (ETCO2 values < 30
mmHg without hyperventilation). Patients had hypoventilation episodes while sedated and increased over time in both
groups, but the change in rate was significantly greater in the
control group than in the study group (16,17). Capnography was shown to be superior in detecting all types of hypoventilation. An increased volume of dead space leads to low
2 values in hypopnea. Although apnea can be detected
through physical examination or monitoring, hypopnea cannot. Burton et al. (2006) and Lightdale et al. (2006) reported
that capnography detected apnea in 25% patients, whereas
staff detected none as in our study (3,8).
Sedation leads to hypoxemia from hypoventilation over time.
Langhan et al. (5) reported that 50% of children had hypopnea and were 6.6 times more likely to have oxygen desaturations during sedation. Oxygen desaturation was observed also
in 25% of our subjects during sedation.
Capnography led to a decrease in the number of airway-related interventions in the study group, which might be due
to its increased sensitivity for hypoventilation. Langhan et al.
(5) reported that capnography decreased the number of staff
interventions, which were simple and noninvasive like in our
study. Furthermore, the staff was more attentive to the capnography data of the study group and performed interventions timely before reaching cut-off values related to abnormal
capnography. The control group received more but delayed
interventions because of oxygen desaturation as the anesthesiologist was blind to capnography, which also accounts for
the difficulties of detecting hypoventilation. No serious or less frequent adverse events were recorded. Ketofol was used in all subjects for all EGD procedures in this
Ketofol, which consists of two pharmaceutical drugs, is considered safe when mixed in the same syringe. It provides
analgesia, sedation, rapid recovery with hemodynamic stability, and fewer postprocedural complications with minimal
respiratory depression (18–20). It also prevents hypopneic
hypoventilation, resulting in low postoperative vomiting incidence and earlier discharge (21,22). Various sedative agents
can cause different results.
This is one of the first randomized trials to assess the effect of
adding capnography to standard monitoring during sedation
in upper endoscopies in children. The results showed that
capnography reduced hypoventilation episodes and oxygen
Furthermore, endoscopy units are positioned in an environment where frequent distractions threaten patients’ safety. In
terms of patients’ safety, its ease of use and interpretation we
recommend its routine utilization.
There are several limitations to our present study. Patient
morbidity associated with oxygen desaturations is not known.
Also, ketofol was used in all patients as it is considered to be
safe for sedation and hypopneic hypoventilation. Various sedative agents or combinations can lead to different adverse
Hypopneic hypoventilation is common among children and
only detectable by capnography. The staff who had access to
capnography monitoring performed fewer timely airway-related interventions during sedation, which was due to fewer
episodes of hypoventilation and oxygen desaturation. It is
recommended that future studies assess the effect of adding
capnography to standard monitoring on more serious adverse
Acknowledgment: We would like to thank all investigators
and staff who contributed to this study.
Footnotes: No potential conflict of interest was reported by
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