الفهرس 
Introduction and aim of workOnly 14 pages are availabe for public view
 |  | from | 122 |  |  |
| | | from | 122 | | |
Abstract
Vomiting is the forceful expulsion of stomach contents through the mouth, caused by humoral stimulation of the chemoreceptor trigger zone (CRTZ) or neural stimulation of the emetic center. The CRTZ is activated and controlled by neurotransmitter manipulation at the receptor level. Gastritis, gastrointestinal ulceration, pancreatitis, motion sickness, uremia, chemotherapy and drug administration are common initiating causes of vomiting.
Ondansetron is ahighly specific and selective serotonin 5-HT3 receptor antagonist, with low affinity for dopamine receptors. The 5-HT3 receptors are present both peripherally on vagal nerve terminals and centrally in the chemoreceptor trigger zone of the area postrema in the medulla.Serotonin is released by the enterochromaffin cells of the small intestinein response to chemotherapeutic agents and may stimulate vagal afferents (via 5-ht3 receptors) to initiate the vomiting reflex. It is thought that ondansetron anti emetic action is mediated mostly via antagonism of vagal afferents with a minor contribution from antagonism of central receotors. The most important side effect of ondansetron is prolongation of Q t c interval.
The objective of this study is to determine the effect of ondansetron on Q T c interval.
Using a prospective observational study design, this study was conducted in our pediatric emergency unit on all children complained vomiting admitted in our unit aging from 1 month to 12 years of age from October 2019 to april 2020 with exclusion criteria in patients with congenital heart diseases and patients complaining of dysrrythmia.
Childerns whose complaining of vomiting admitted in sohag university hospital between 1 month to 12 years from october 2019 to april 2020 conducted in this study.
After patient stabilization medical history was collected through a specifically designed study questionnaire. These include demographic data; investigation done, previous treatment and previous illnesses, then complete clinical examination was conducted. Importantly, hemodynamic stability, vital signs.
12 leads E C G was done to to all patient complained vomiting before injection of ondansetron and after 15 min ,45 min from IV injection and after 30 min, 60 min from IM injection. There is significant change in Q T c interval but there is no cardiac problems to any patients.
E C G was done for 110 patients after injection of ondansetron 0.15 mg/ kg for vomiting. 60 Patients received ondansetron by intravenous injection and 50 patients received ondansetron by intramuscular injection. Age of studied patients ranged from 29 days to 12 years with mean age of 52.78 months. 68 (61.82%) males and 42 (38.18%) females were included.
Majority of children were males .
E C G s were done for 110 patients ,37 patients (33.64%) complained from gastroenteritis ,30 patients (27.30%) had pneumonia, 12 patients (10.90%) had metabolic causes of vomiting, 8 patients (7.27%) had CNS infection ,7 patients (6.36%) had acute tonsillitis ,6 patients (5.45%) had OM, 6 patients (5.45%) had UTI and 4 patients (3.64%) had obstructive uropathy.
Most causes of vomiting were infectious diseases.
CBC done for children with vomiting showed leukocytosis with mean leucocytic count of 13.62 cells per cmm and standard deviation of 6.99 , mean HB level was 10.16 (g/dL) with standard deviation of 2.43 , mean HCT level was 30.41% with standard deviation of 7.74 , mean MCV was 76.37 femtoliters with standard deviation of 12.88 , mean Platelet count was 371.3 per cmm with standard deviation of 164.54.
CBC showed leukocytosis because most of causes were infectious diseases and showed microcytic anemia.
mean Na level in the study patients was 132.38 with a standard deviation of 7.63 mmol/L , mean K level was 3.45 mmol/L with standard deviation of 0.62 mmol/L , mean Ca level was 1.07 mmol/L with standard deviation of 0.16 mmol/L .
Electrolyte were done to patients showed normal levels in most of cases .
Mean ALT level in the study patients was 38.71 IU/L with standard deviation of 118.47 IU/L , mean AST level was 39.79 IU/L with standard deviation of 111.17 IU/L, mean direct bilirubin level was 0.72 mg/dL with standard deviation of 2.99 mg/dL , mean total protein level was 7.14 gm/dL with standard deviation of 0.87 gm/dL , mean serum albumin level was 2.94 gm/dL with standard deviation of 0.43 gm/dL .
Liver functions were done showed normal levels in most of cases .
Mean serum creatinine level was 0.53 mg/dL with a standard deviation of 0.36 mg/dL , mean random blood sugar was 108.73 mg/dL with a standard deviation of 50.03 mg/dL .
Random blood suger and kidney function showed normal level in most of cases .
Sixty patients received IV ondansetron. EGCs were obtained and (QTcB) interval was measured before and 15, and 45 after a 0.15mg/kg IV dose of ondansetron given for children with vomiting. The mean baseline QTc was 418.67±20.59 milliseconds. Mean difference (15 min after-before) (95%CI) =5.34 (0.64:10.05), p= 0.03. Mean difference (45 min after-before) (95%CI) =7.59 (3.69:11.48), p= 0.0003, Mean difference (45 min after-15 min after) (95%CI) =2.24 (-1.38:5.87), p= 0.22. There was significant increase in QTc interval after 15 minutes and 45 minutes but there was no change at peak effect of 15 minutes or 45 minutes post peak clinically significant.
There was a significant increase in QTc interval by 5.34 milliseconds after 15 minutes from injection of ondansetron and by 7.59 milliseconds from 45 minutes from injection.
In this study fifty patients received IM ondansetron. EGCs were obtained and (QTcB) interval was measured before and 30 and 60 after a 0.15mg/kg IM dose of ondansetron given for children with vomiting. The mean baseline QTc before ondansetron injection was 416.48±24.18 milliseconds. The mean difference (30 min after-before) (95%CI) was 3.21 (0.21 to6.22) milliseconds (p= 0.04). The mean difference (60 min after-before) (95%CI) was 6.60 (3.56 to9.62) milliseconds (p =0.0001), the mean difference (60 min after-30 min after) (95%CI) was 3.38 (1.04 to5.73) milliseconds (p =0.006).
There was significant increase in QTc interval after 30 minutes and 60 minutes and there was a change at peak effect of 30 minutes or 60 minutes post peak that was clinically significant.
There was increase in QTc interval by 3.21milliseconds from 30 minutes after ondansetron injection and by 6.60 milliseconds after 60 minutes from injection.
Sixty patients received IV ondansetron. The mean baseline PR was 121.03±20.92 milliseconds. Mean difference (15 min after-before) (95%CI) = -7.12 (-13.21: -1.03), p= 0.02. Mean difference (45 min after-before) (95%CI) =-5.24 (-12.13:1.64), p= 0.13 and mean difference (45 min after-15 min after) (95%CI) =1.88 (-4.53:8.29), p= 0.56.
There was significant decrease in PR interval after 15 minutes but there is no change at peak effect or 15 min or 45 min post peak was clinically significant.
Fifty patients received IM ondansetron. The mean baseline PR was 127.31±15.83 milliseconds. Mean difference (30 min after-before) (95%CI) =-25.40 (-30.98: -19.83), p<0.0001. Mean difference (60 min after-before) (95%CI) =-5.44 (-10.72:131.71), p= 0.04, Mean difference (60 min after-30 min after) (95%CI) =19.96 (13.31:26.61), p<0.0001.
There was significant decrease in PR interval after 30 minutes and 60 minutes and a change between 30 minutes and 60 minutes post peak that was clinically significant.
Sixty patients received IV ondansetron. The mean baseline QRS duration was 75.53±12.50 milliseconds. Mean difference (15 min after-before) (95%CI) =-4.05 (-7.54: -0.57), p= 0.02. Mean difference (45 min after-before) (95%CI) =-1.98 (-5.81:1.85), p= 0.30, Mean difference (45 min after-15 min after) (95%CI) =2.07 (-1.08:5.21), p= 0.19. There was a significant decrease in QRS duration at 15 minutes after injection of ondansetron but there was no significant change at post peak effect of 45 minutes or between 15 minutes and 45 minutes post peak.
Fifty patients were included. The mean baseline QRS duration was 78.44±11.85 milliseconds. Mean difference (30 min after-before) (95%CI) =-9.5 (-12.84: -6.16), p= <0.0001. Mean difference (60 min after-before) (95%CI) =-2.87 (-6.81:1.09), p= 0.15, Mean difference (60 min after-30 min after) (95%CI) =6.63 (3.41:9.86), p<0.0001. there was a statistically significant decrease between QRS duration before and after 30 minutes of ondansetron injection and between 30 minutes and 60 minutes post peak but there was no significant change between QRS duration before and after 60 minutes post peak.
Conclusions
1-110 children’s complaining of vomiting due to different causes received ondansetron and ECG done before and after injection to show the effect of ondansetron on QTc interval.
2- Intravenous ondansetron is a commonly used as antiemetic in the emergency unit for the treatment of nausea and vomiting.
3-In late 2011, the U.S. Food and Drug Administration (FDA) issued a boxed warning for ondansetron due to the possibility of QT interval prolongation and urged caution with its use for certain patient populations
4-Majority of cases was males by 61.82 %.
5-Most of causes of vomiting were infectious causes.
6-CBC showed leukocytosis due to most cases complaining of infectious diseases and showed microcytic anemia.
7-Electrolytes were done to cases were within normal levels
8-Liver functions, random blood sugar and kidney functions were within normal levels.
9-There was significant increase in QTc interval after 15 minutes and 45 minutes from IV route of injection but there was no change at peak effect of 15 minutes or 45 minutes post peak clinically significant.
10- There was significant increase in QTc interval after 30 minutes and 60minutes from IM route of injection but there was no change at peak effect of 30 minutes or 60 minutes post peak clinically significant.
11- There was significant decrease in PR interval after 15 minutes and 45minutes from IV route of injection but there was no change at peak effect of 15 minutes or 45 minutes post peak clinically significant.
12-There was significant decrease in PR interval after 30 minutes and 60minutes from IM route of injection but there was no change at peak effect of 30 minutes or 60 minutes post peak clinically significant.
13-There was significant decrease in QRS duration after 15 minutes and 45minutes from Iv route of injection but there was no change at peak effect of 15minutes or 45 minutes post peak clinically significant.
14- There was significant decrease in QRS duration after 30 minutes and 60minutes from IM route of injection but there was no change at peak effect of 30minutes or 60 minutes post peak clinically significant.
Recommendations
1- The effect of repeated dose of ondansetron on QTC interval must be done in further studies.
2- ECG should be done before ondansetron to exclude children with long QT interval (congenital or acquired).