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 Table of Contents  
ORIGINAL ARTICLE
Year : 2017  |  Volume : 45  |  Issue : 4  |  Page : 181-191

A randomized clinical trial to evaluate the efficacy of single versus multiple gastric lavage in the management of patients with acute organophosphorus poisoning


1 Department of Forensic Medicine and Clinical Toxicology, Faculty of Medicine, Tanta University, Tanta, Egypt
2 Department of Clinical Toxicology, Faculty of Medicine, Tanta University, Tanta, Egypt
3 Toxicologist and Forensic Chemistry Expert, Forensic Medicine Institute

Date of Submission27-Feb-2017
Date of Acceptance22-Aug-2017
Date of Web Publication12-Mar-2018

Correspondence Address:
Shaimaa A.M El-Gendy
Department of Forensic Medicine and Clinical Toxicology, Faculty of Medicine, Tanta University, Tanta
Egypt
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DOI: 10.4103/tmj.tmj_23_17

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  Abstract 


Background Despite lack of supporting evidence gastric lavage (GL) is one of the most commonly used decontamination method for organophosphorus (OP) ingestion in developing countries.
Aim This study was designed to evaluate the outcome of patients with OP pesticide poisoning treated with GL with regard to timing and frequency of the procedure.
Patients and methods In this study, GL was planned to be administered to patients with OP pesticide poisoning after initial stabilization irrespective of lavage given in peripheral hospitals. Therefore, some patients received one procedure (single GL) and some received more than one procedure (multiple GL). Early GL was defined as GL given within 2 h of poison exposure and late GL was referred to performing the procedure after 2 h.
Results During the study period, 40 patients with OP pesticide poisoning received GL comprising 11 who received early single, nine who received late single, 10 who received early multiple and 10 who received late multiple GL. Mortality, respiratory failure incidence, ICU admission and incidence of mechanical ventilation (MV) were not significantly different between patients receiving early single, late single, early multiple and late multiple GL. There was significant difference between patients who received early single, late single, early multiple and late multiple GL regarding the duration of MV, hospital stay duration, and atropine and oximes ampoules needed.
Conclusion Multiple GL created insignificant reduction in overall mortality from OP poisoning; yet early and multiple GL proved to be more effective than single GL in reducing the incidence of respiratory failure, ICU admission and MV and in decreasing hospital stay duration and atropine and oximes therapy amount significantly.

Keywords: gastric lavage, insecticides, organophosphorus, poisoning


How to cite this article:
El-Gendy SA, El-Mehallawi IH, Elwy AM, El-Ghrabawy IE. A randomized clinical trial to evaluate the efficacy of single versus multiple gastric lavage in the management of patients with acute organophosphorus poisoning. Tanta Med J 2017;45:181-91

How to cite this URL:
El-Gendy SA, El-Mehallawi IH, Elwy AM, El-Ghrabawy IE. A randomized clinical trial to evaluate the efficacy of single versus multiple gastric lavage in the management of patients with acute organophosphorus poisoning. Tanta Med J [serial online] 2017 [cited 2018 Jul 20];45:181-91. Available from: http://www.tdj.eg.net/text.asp?2017/45/4/181/227114




  Introduction Top


Organophosphorous (OP) compounds have been used as pesticides, petroleum additives, and as chemical warfare nerve agents. OP have been used as pesticides for more than 50 years and are still used in most developing countries [1]. OP pesticides poisoning can result from occupational, accidental or intentional exposure. Mortality is higher in the developing countries where OP pesticides are readily available and may be used to conduct suicide. They are estimated to cause 300 000 fatalities annually [1]. Absorption of cholinergic insecticide is rapid from the gut, but a Chinese clinical experience suggested that the poison may remain in the stomach for hours to days [2],[3]. Moreover, absorption of poison depends on its chemical nature and may be affected by the presence of other substances in the stomach [4]. There are few studies showing the beneficial impacts of multiple GL on the outcome of OP poisoning [5]. Nevertheless, due to some methodological weaknesses, those studies were not considered as high-quality evidence in systematic reviews. Therefore, it is necessary to assess the practice of multiple GL for the treatment of OP poisoning in randomized clinical trial (RCT) [5].


  Patients and methods Top


Study design

The RCT was conducted on 40 patients with acute OP poisoning admitted to the Poison-Control Center at Tanta University Hospitals in Egypt during the period of the study from July 2015 to January 2016.

Study hypothesis

The main hypothesis was that multiple gastric lavages (GLs) may improve the outcome in OP poisoned patients. Since GL is a standard therapy in Egypt, it was impossible to perform an RCT of no GL neither versus a single GL nor versus multiple GLs. Instead, the first step in the assessment of the role of GL in OP poisoned patients was to compare patients receiving standard therapy plus either one lavage or three lavages. If three lavages do not offer benefit over a single lavage, it may be then appropriate to consider designing a placebo-controlled RCT of GL. If three GLs are shown to be beneficial, then such lavages should be encouraged worldwide for OP pesticide poisoning since the technique is cheap, widely available, and reasonably safe once the airway is protected.

Inclusion criteria

Adult patients (older than 18 years) and patients with a history of acute OP poisoning by oral ingestion within 24 h.

Exclusion criteria

Known pregnancy, age of patients less than 18 years, coingestion of another poison, patients with craniofacial abnormalities, concomitant head trauma, or any other bodily injuries that may not tolerate the lavage procedure. Patients who are at risk of hemorrhage or gastrointestinal tract (GIT) perforation. If a patient refuses to cooperate and resists, it should be considered at least as a relative contraindication for performing GL.

Methods

Patients were allocated randomly into two groups:

Group I: 20 OP poisoned patients received standard therapy plus single GL procedure.

Group II: 20 OP poisoned patients received standard therapy plus multiple GL procedures (at admission, 4 and 8 h after first lavage).

Forty slips of paper were used. Twenty were labeled as a single GL group and the others were labeled as multiple GL group. These slips were placed in an envelope and taken out for every patient before the start of procedure.

All patients were subjected to:
  1. Full history taking with emphasis on: age, sex, occupation, circumstances of poisoning whether intentional or accidental, time elapsed before hospital admission and history of medical diseases that induce oxidative stress such as liver, renal, cardiac, and/or active infections.
  2. Complete physical examination including: level of consciousness by Glasgow coma scale, regular monitoring of vital signs (pulse/blood pressure/respiratory rate/temperature), and general clinical examination.
  3. Investigations: arterial blood gases analysis and biochemical profile (serum sodium and potassium levels, kidney function tests and liver enzymes, complete blood count, and random blood sugar).
  4. Management of cases as follows:
    1. Emergency and supportive measures: maintain an open airway and assist ventilation if necessary, administer supplemental oxygen.
    2. Decontamination: dermal, ocular, and gastric decontamination by GL and by activated charcoal administration.
    3. Antidotal therapy:
      1. Atropine: used by bolus dose and then by maintenance infusion (10–20%) of bolus dose.
      2. Oximes: using obidoxime, the loading dose of 250 mg bolus then 750 mg every 24 h until at least 12 h after atropine is no longer required.


Gastric lavage

It was done as soon as a patient was stabilized and resuscitated. Patients received GL on admission, regardless of whether they have already received it at another health center. The procedure was performed in left lateral position for patients with insertion of nasogastric tube. In patients with depressed conscious level after securing the airway, once in the stomach, its position was confirmed by aspirating gastric content and auscultation over the stomach. The gastric content was aspirated first and then 300 ml of water at room temperature was pushed in, then aspirated completely and another 300 ml is administered. This procedure was repeated until the aspirated water was clear and without smell. The above procedure was repeated 4 and 8 h after the first GL in the group of patients receiving multiple lavages. A 10 ml sample of gastric aspirate was taken at the beginning of each GL for assessment of OP pesticides in the stomach using thin-layer chromatography (TLC).

Thin-layer chromatography

It is a technique for separation and identification of OP composition in GL aspirate. TLC can be regarded as the separation of substances on a planar surface coated with a stationary phase. The mobile phase moved across the planar surface from one edge to the other and substances separate out according to their distribution between the stationary phase and the mobile phase [6].

Outcome measures

  1. Primary outcome measures include: in-hospital mortality.
  2. Secondary outcome measures include: incidence of respiratory failure (RF), intermediate syndrome (IMS), need and duration of mechanical ventilation (MV) and the related complications, duration of hospital stay, and the needed amount of antidote therapy.


Statistical analysis

Data were analyzed using SPSS 16 (SPSS Inc., Chicago, Illinois, USA). Categorical variables are reported with frequency and percentage. Continuous variables with normal distribution were presented with mean and SD. The mean difference of normally distributed variables in two groups was analyzed with independent samples t-test. The difference of proportions in categorical variables was analyzed using χ2-test. P values of less than 0.05 were considered as statistically significant.


  Results Top


Patients’ demographic data

[Table 1] shows no significant difference between studied groups as regards demographic characteristics (age, sex, residence, and employment status).
Table 1 Demographic characteristics (age, sex, residence, and employment status) of the studied groups (I and II) of patients with acute organophosphate poisoning

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Exposure characteristics

[Table 2] and [Table 3] show that there was no significant difference between both groups as regards the mode of poisoning, distribution of types of poisons, and delay time before treatment.
Table 2 Mode of poisoning, referral from other hospitals and types of organophosphorus in the studied groups I and II of patients with acute organophosphate poisoning

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Table 3 Delay time in hours before treatment in the studied groups (I and II) of patients with acute organophosphate poisoning

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Clinical characteristics

As regards muscarinic manifestations, colic and miosis were the most common signs in all cases (100%) followed by vomiting (75%), then crepitation and wheezy chest (70%), then bradycardia (42.5%), then diarrhea (37.5%), followed by hypotension (35%) and lastly sweating (32.5%). As regards muscarinic manifestations in each group, no significant difference was found. Regarding nicotinic manifestations, muscle weakness was the most common sign (67.5%), followed by fasciculation (65%), then hypertension (62.5%), and lastly tachycardia (57.5%); no significant difference was found between both studied groups. Regarding the conscious level of patients, 17 (42.5%) patients were fully conscious; 10 (25%) patients were drowsy; and 13 (32.5%) patients were comatose. There was insignificant difference between both groups.

Severity of organophosphorus poisoning

The patients included in the present study were classified based on the severity of clinical manifestations according to Minton and Murray [7] into mild to moderate group and severe group. [Table 4] shows that there was no significant difference between both groups as regards distribution of mild to moderate and severely poisoned patients.
Table 4 Distribution of patients in the studied groups I and II according to the severity of poisoning (mild to moderate and severe) [7]

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Results of thin-layer chromatography of gastric lavage (aspirate) samples

[Table 5] show the incidence of detection of OP in TLC-analyzed GL samples with the following results: in group I, OP was detected in two (18.2%) patients with mild to moderate poisoning and was detected in four (44.4%) patients with severe poisoning, while in group II with multiple GL procedure. OP was detected in first GL in six (50%) patients with mild to moderate poisoning and in six (75%) patients with severe poisoning while OP was detected in second GL in two (16.7%) patients with mild to moderate poisoning and in three (37.5%) patients with severe poisoning, and lastly OP was detected in third GL in one (8.3%) patient with mild to moderate poisoning and in six (75%) patients with severe poisoning.
Table 5 Incidence of organophosphorus detection in thin-layer chromatography-analyzed gastric lavage sample in organophosphorus poisoned patients

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Assessment of gastric lavage safety

No complications were recorded due to GL procedure in both groups of study I and II.

Assessment of outcomes of organophosphorus poisoned patients after treatment

As regards the frequency of gastric lavage: [group I (single gastric lavage) or group II (multiple gastric lavage)]

Mortality: two patients died with a percentage of 10% in group I, while one patient died in group II with a percentage of 5%. There was no significant difference between both studied groups as regards the incidence of mortality.

RF: occurred in nine (45%) patients in group I, while in group II, RF occurred in eight (40%) patients. There was no significant difference between both groups regarding the incidence of RF.

Need for ICU admission: nine (45%) patients needed ICU admission in group I while eight (40%) patients needed ICU admission in group II. No significant difference was found between both groups regarding the need for ICU admission.

Need for endotracheal intubation (ETT): in group I, nine patients needed endotracheal intubation (45%) while eight patients needed ETT in group II (40%). No significant difference was found between both groups regarding the need for ETT.

Need for MV: in group I, nine (45%) patients needed MV while eight (40%) patients in group II. No significant difference was found between both groups as regards the need for MV.

Duration of MV: the mean duration of MV was 6.67±4.61 in group I (ranged between 1 and 15 days) and 3.13±0.99 in group II (ranged between 1 and 4 days). There was no significant difference between both groups regarding the duration of MV.

Duration of hospital stay: the mean duration of hospital stay in group I was 9.35±3.83 (6–20 days) while in group II, it was 3.30±2.27 (1–10 days). There was significant difference between the two groups as regards the duration of hospital stay.

IMS: All patients involved in this study were cured after treatment without the development of IMS.

Total dose of atropine and oximes: regarding atropine dose, the mean number of ampoules (1 ampoule=1 mg) administered to cases in group I was 26.50±15.32 (ranging from 11 to 70 ampoules), while in group II the mean number of atropine ampoules was 14.45±8.63 (ranging between 5 and 29 ampoules). There was significant difference between both groups as regards total atropine dose (P=0.001). Oximes dose: the mean number of oximes (toxogonin) ampoules (1 ampoule=250 mg) was 12.95±8.52 (ranged from 4 to 36 ampoules) in group I, while it was 8.80±5.52 (ranged from 3 to 19 ampoules) in group II. There was significant difference between both groups as regards oximes dose (P=0.018) ([Table 6] and [Table 7]).
Table 6 Incidence of mortality, respiratory failure, needs for ICU admission, endotracheal intubation, and mechanical ventilation in organophosphorus poisoned patients as regards the frequency of gastric lavage (single gastric lavage: group I vs. multiple gastric lavage: group II)

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Table 7 Mean duration of mechanical ventilation (days), hospital stay duration (days), and atropine and oximes ampoules numbers in organophosphorus poisoned patients as regards the frequency of gastric lavage (single gastric lavage: group I vs. multiple gastric lavage: group II)

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As regards both frequency and timing of gastric lavage: (early single, late single, early multiple, and late multiple gastric lavage groups) (early gastric lavage within 2 h and late gastric lavage after 2 h)

Mortality: it was not recorded in mild to moderate OP poisoned patients. However, in severe OP poisoned patients, mortality was recorded in two (22.2%) patients of late single GL group, and in one (10%) patient of late multiple GL group. Mortality was not recorded in early GL groups either single or multiple GL groups with no significant difference between the four studied groups as regards incidence of mortality.

RF: it did not occur in mild to moderate OP poisoned patients, while in severe OP poisoning, RF was observed in three (27.3%) patients with early GL of group I, while in patients with late GL of group I, RF occurred in six (66.7%) patients, in patients with early GL of group II, RF occurred in five (50%) patients and lastly, in patients with late GL of group II, RF occurred in three (30%) patients. There was no significant difference between the studied groups.

Need for ICU admission: No need for ICU admission was recorded in mild to moderate OP poisoned patients. However, in severe OP poisoned patients, the number of patients who needed ICU admission in early single GL group was three (27.3%) patients, while in late single GL group it was six (66.7%) patients in early multiple GL group it was five (50%) patients and lastly, in late multiple GL group it was three (30%) patients with no significant difference between the four groups (early single, late single, early multiple, and late multiple GL).

Need for ETT: The study revealed that mild to moderate poisoned patients did not need ETT. In severe OP poisoning, the number of patients who needed ETT admission in early single GL group was three (27.3%), while in late single GL group, it was six (66.7%) patients. On the other hand, five (50%) patients who received early multiple GL group needed ETT while three (30%) patients with late multiple GL group needed ETT with no significant difference between the four groups (early single, late single, early multiple, and late multiple GL).

Need for MV: it was not required in mild to moderate OP poisoned patients. However, in severe OP poisoning, there were three (27.3%) patients and six (66.7%) patients who needed MV in early single and late single GL groups respectively, while in early multiple GL and late multiple GL groups; there were five (50%) patients and three (30%) patients who needed MV. No significant difference was found between the four studied groups as regards timing and frequency of GL.

Duration of MV: in severe OP poisoning, in early single GL group, the mean duration of MV was 10.33±4.04 (ranged between 8 and 15 days) while in late single GL group, the mean duration of MV was 4.83±3.92 (ranged between 1 and 9 days) but in early multiple GL group, the mean duration of MV was 3.60±0.55 (ranged between 3 and 4 days) and lastly, in late multiple GL group, the mean duration of MV was 2.33±1.15 (ranged between 1 and 3). There was significant difference between four groups.

Duration of hospital stay: in mild to moderate OP poisoning; the mean hospital stay duration in early single GL group was 6.625±0.477 (ranged between 6 and 8 days) while in late single GL group it was 7.33±1.154 (6–8 days) and in early multiple GL group it was 2.2±0.836 (ranged between 1 and 3 days). Lastly in late multiple GL group, the mean hospital stay duration was 1.57±0.786 (1–3 days). Significant difference was found between the four studied groups (P<0.001). In severe OP poisoning; the mean hospital stay duration in early single GL group was 12.66±4.618 (ranged between 10 and 18 days) while in late single GL group it was 12.33±3.77 (10–20 days) and in early multiple GL group it was 5.0±0.70 (ranged between 4 and 6 days). Lastly in late multiple GL group, the mean hospital stay duration was 6.33±3.214 (4–10 days). Significant difference was found between the four studied groups (P=0.001).

IMS: All patients involved in this study were cured after treatment without the development of IMS.

Total dose of atropine and oximes: regarding atropine dose in mild to moderate OP poisoning, the mean number of atropine ampoules (1 ampoule=1 mg) in patients of group I with early GL was 13.37±2.263 (ranged between 11 and 16) while in patients of group I with late GL it was 21.67±9.29 (ranged between 14 and 32) but in group II with early GL it was 6.6±1.82 (ranged between 5 and 9) and in group II with late GL it was 8.71±1.603 (ranged between 6 and 10). Significant difference was found between the studied groups (P<0.001). In severe OP poisoning, the mean number of atropine ampoules (1 ampoule=1 mg) in patients of group I with early GL was 33.66±5.85 (ranged between 27 and 38), while in patients of group I with late GL it was 42.34±14.01 (ranged between 34 and 70); in group II with early GL, the mean number of atropine ampoules was 23.4±2.88 (ranged between 20 and 28) and in group II with late GL, it was 26.0±2.65 (ranged between 24 and 29). Significant difference was found between the studied groups (P=0.001). Oximes: in mild to moderate OP poisoning, the mean number of oxime ampoules (1 ampoule=250 mg) in group I with early GL was 6.0±1.195 (ranged between 4 and 8) while in group I with late GL it was 7.0±1.0 (ranged between 6 and 8); in group II with early GL it was 4.8±1.095 (ranged between 4 and 6) and in group II with late GL it was 4.428±0.975 (ranged between 3 and 6). There was significant difference between the four studied groups (P=0.003). In severe OP poisoning, the mean number of oxime ampoules (1 ampoule=250 mg) in group I with early GL was 19.33±0.577 (ranged between 19 and 20) while in group I with late GL it was 22.0±7.21 (ranged between 15 and 36) but in group II with early GL it was 15.0±1.58 (ranged between 13 and 17) and in group II with late GL it was 15.33±3.512 (ranged between 12 and 19). There was significant difference between the four studied groups (P=0.003) ([Table 8],[Table 9],[Table 10]).
Table 8 Incidence of mortality, respiratory failure, needs for ICU admission, endotracheal intubation, and mechanical ventilation in organophosphorus poisoned patients as regards timing of gastric lavage (early and late gastric lavage) in studied groups I and II

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Table 9 Duration of mechanical ventilation (days), hospital stay duration (days), and atropine and oximes ampoules numbers in mild to moderate organophosphorus poisoned patients as regards timing of gastric lavage (early and late gastric lavage) in studied groups I and II

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Table 10 Duration of mechanical ventilation (days), hospital stay duration (days), and atropine and oximes ampoules numbers in severe organophosphorus poisoned patients as regards timing of gastric lavage (early and late gastric lavage) in studied groups I and II

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  Discussion Top


Acute OP poisoning represents a major health problem. According to the WHO, one million serious accidental and two million suicidal poisonings with OP occur worldwide every year, and of these, ∼200 000 died, mostly in developing countries [8].

The aim of this work was to evaluate the outcome of patients with acute OP poisoning treated with GL with regard to timing and frequency of the procedure.

Since GL is currently the standard therapy in Egypt, it was impossible and unethical to perform an RCT of no GL neither versus a single GL nor versus multiple GL. Instead a first step in reassessment of the role of GL in OP poisoned patients was to compare patients receiving standard therapy plus either one lavage or three lavages. If three lavages do not offer benefit over a single lavage, it may then be appropriate to consider designing a placebo-controlled RCT of GL in future studies. If three GLs are shown to be beneficial, then such lavages should be encouraged worldwide for OP pesticide poisoning.

The age of the patients in the study here ranged between 18 and 75 years. The majority of patients were between 20 and 40 years representing 40%. Men were more frequently exposed to OP than women (57.5 and 42.5%, respectively). A study by Kumar et al. [9] in India reported that the majority of patients were men (71.25%) than women. The majority of patients in Kumar et al. [9] study were in the age group between 15 and 29 years (53.75%) and 30 and 44 years (30%). This indicates that there is an increased incidence of OP compounds poisoning among the young people. This age group is the most active one, physically, mentally, and socially and so, it is more prone to stress during life. In this study, the majority of patients were students (37.5%). This is against the study by Somasundaram et al. [10] in India, who reported that the majority of the victims of OP poisoning (95%) were farmers and agricultural laborers. In this study, the majority of patients were from rural origin in both groups I and II (60%), which could be justified by the wide availability and use of OP compounds in the rural agricultural society in the Delta region due to its low price. El-Sarnagawy et al. [11] reported similar findings in their works in the Delta region.

Regarding the circumstances of acute OP poisoning, this study has shown that the majority of patients in both groups (77.5%) were exposed by attempts of suicides and this result coincides with the young age and the students who were the majority of cases in this study and more prone to stress during life with suicidal attempts. This result is in contrast to those obtained by Elgazzar et al. [12] who reported that 65.5% of their studied patients were accidentally exposed to OP compounds. Generally, suicidal attempts are always linked to the stressful atmosphere whatever the kind and source of the stress be: marital, financial, employment, or unemployment stresses.

In the present study, the mean delay time in acute OP poisoned patient was less than 5 h; (4.55±4.86 h) with no significant difference between both groups (group I and group II). A similar result was obtained by Amanvermez et al. [13]. The rapid patient transfer to Tanta Emergency Hospital that resulted in short delay time in this study is due to its close vicinity to the surrounding rural areas being in the Middle Delta region. Such result could provide an explanation for the high incidence of mild to moderate cases of acute OP poisoning in this study (55% in group I and 60% in group II). In this study; patients referred from other hospitals represented 20% with no significant difference between both studied groups (group I and II) and this may be due to the fact that Tanta Toxicology Center is the only specialized center in the Middle Delta region.

The most common type of OP ingested was phosacetim (rodenticides) (50%), followed by malathion (35%), then max killer, and purefox (5%) and lastly octakrof and octaphose (2.5%). However, Somasundaram et al. [10] reported that dimethoate was the commonest compound of OP consumed in 50% of the patients in his study in India.

As regards patients’ presentation with muscarinic manifestations in this study, colic and miosis were the most common signs in both groups. There was significant difference between both groups as regards muscarinic manifestations. The same result was reported by Soni et al. [14] in his study in India. Regarding the nicotinic manifestations at admission, the patients mainly showed muscle weakness and fasciculations. This coincided with the results of Thunga et al. [15] who found that fasciculations were more prominent and they were seen in 50% of his patients in India. Concerning the vital signs; hypotension was recorded in 35% of patients, while hypertension was recorded in 62.5%. Regarding pulse, bradycardia was recorded in 42.5%, while tachycardia was recorded in 57.5%. Hypertension and tachycardia seen in OP poisoned patients of this study were nicotinic effects, whereas hypotension and bradycardia were muscarinic manifestations. Similar findings were observed by Karki et al. [16] who reported sinus tachycardia as a more frequent finding (40.5%) than bradycardia (18.9%) and stated that tachycardia could be considered a sign of severe OP poisoning. In contrast, Akdur et al. [17] reported that bradycardia was more frequent than tachycardia in their studied cases (11.1 and 5.6%, respectively).

The cases of this study were classified based on the severity of clinical manifestations according to Minton and Murray [7] into mild to moderate and severe. Consequently, group I was divided into two subgroups; group IA including 11 patients showing mild to moderate manifestations and group IB including nine severely poisoned patients. Group II was divided into two subgroups: group IIA including 12 patients with mild to moderate manifestations of toxicity and group IIB including eight patients with severe manifestations of OP poisoning.

Regarding the safety of GL, no complications were encountered in both groups of the present study. This finding was in contrast to that of Andrews et al. [18] who reported that aspiration pneumonia is one of the common complications attributed to GL. Additionally, 25.6% of his patients developed pneumonia (both ventilator associated and aspiration related). However, over half of them were recovered with antibiotics. Moreover, the frequency of lavage was not associated with the likelihood of pneumonia. In the present study, chance of aspiration was nil. This may be due to using smaller quantities of lavage fluid and protecting the airway using prophylactic endotracheal intubation especially in patients with GCS less than 10 [19]. Moreover, one of the complications of GL is pushing down poison distal into the stomach as reported by Eddleston et al. [20]. This was prevented in the present study by giving activated charcoal to all patients after GL and magnesium sulfate to ensure gut motility and passage of stool.

The study revealed that only 30% of group I showed OP in their analyzed GL samples. This may be explained by the presence of vomiting in 75% of the cases in addition to being referred from other health facilities with trials of GIT decontamination. Moreover, OP was detected in 40% in second and third GL samples in group II. Substantially, Chinese studies have found the concentration of OP in GL samples to be still high several hours or even days after ingestion and GL. This contrasts with previous studies from Hanoi, Vietnam, which found little OP to be present after first GL [4],[21]. On the other hand, in a study performed by Mohanty et al. [22] after autopsy of OP poisoned patients where kerosene smell of OP was shown to be persistent in the stomach up to 3 days postingestion for which chemical analysis was positive for the poison in 70% of the cases. This suggests that lavage was ineffective in removing poison from the stomach similar to a previous observation of Saetta and Quinton [23] which showed that multiple GL could not completely remove toxic agents and drugs from the stomach.

The observed persistence of OP in TLC analysis of multiple gastric aspirates in the present study may help to define the toxic kinetics of OP and effects of GL on it aiming to improve the care and outcomes of OP poisoned patients.

As regards the outcome of patient after treatment, depending on the frequency of GL, multiple GL had insignificant impact on mortality rate (10% in group I and 5% in group II). These findings are similar to previous observations by Andrew et al. [18] and Indira et al. [24]. Additionally, You et al. [25] showed that repeated lavages every 2 h for 24–48 h reduced mortality from 20.94 to 4.65%. Luo et al. [26] looked at lavages every 4–6 h for up to 24 h and demonstrated a reduction in mortality from 47.5 to 14.6%. On the other hand, the present study showed that early GL may have an insignificant impact on reducing mortality incidence (no mortality in early single and early multiple GL subgroups and 22.2 and 10% mortality incidence in late single and late multiple subgroups, respectively). Similar observations were reported by Andrew et al. [18] and Li et al. [27].

Regarding the incidence of RF, the present study showed that it decreased insignificantly in multiple GL group compared with single GL group. Also, the timing of GL had an insignificant impact reducing the incidence of RF in early GL compared with late GL. Substantially, Bhardwaj et al. [19] reported that early RF occurred in single GL (20.5%) more than multiple GL (16.2%); also late RF occurred in single GL (20.5%) more than multiple GL (9%). According to the timing of GL, early RF occurred in late GL (21.4%) more than early GL (14%) and late RF occurred also in late GL (18.6%) more than early GL (9.7%). This might be attributed to reduction of continued absorption of poison from the gut by extensive decontamination and consequently decrease in late-onset complications. Available data show that early RF is mainly due to the direct effect of poison on the central nervous system and may be related to the type of compound and rapidness of absorption, whereas the cause of late RF is peripheral, attributed to persistent depolarization of neuromuscular junction by activity of acetylcholine [28],[29]. Prolonged absorption and potential deposition of the poison in fat with late release can also be the reason for persistent activity of acetylcholine [30]. Therefore, the removal of poison may not be fully effective with a rapidly absorbing poison that induces immediate central RF, but may be effective in the cessation of further absorption-storage-slow release process and thereby decreasing late-onset complications.

The present study showed that multiple GL reduced the incidence of ICU admission insignificantly in group II with multiple GL (30%) compared with group I with single GL (45%). On the other hand, early GL affected the incidence of ICU admission (27 and 50% in single and multiple GL, respectively) compared with late GL (66.7 and 30% in single and multiple GL, respectively). These findings are comparable to those by Andrews et al. [18].

As regards the need for endotracheal intubation; 45 and 40% needed EET in group I with single GL and group II with multiple GL, respectively. However, 50% of patients with early multiple GL needed ETT compared with 30% of patients with late multiple GL. These findings are comparable to those of Andrews et al. [18].

Regarding the need for MV in the current study, 45% of patients needed MV in group I with single GL and 40% in group II with multiple GL with insignificant difference between both groups. Considering both timing and frequency of GL, no need for MV was recorded in mild to moderate OP poisoned patients, while, in severe OP poisoning, there were 27.3 and 66.7% of patients who needed MV in early single and late single GL groups, respectively. In early multiple GL and late multiple GL groups, there were 50 and 30% of patients who needed MV. These findings are comparable to those reported by Andrews et al. [18].

The mean duration of mechanical ventilation in this study was significantly longer in single GL group compared with multiple GL group. Considering the timing of GL, the study showed that mean duration of MV was significantly the longest in early single GL patients, while the shortest duration was observed in late multiple GL group showing that the impact of frequency of GL is more prominent on the duration of MV than timing. Bhardwaj et al. [19] reported that the mean duration of MV was longer in single GL than multiple GL while the mean duration of MV was longer in late GL than early GL.

In this study, the mean duration of hospital stay was significantly longer in patients with single GL compared with multiple GL group. Considering both timing and frequency of GL, hospital stay duration was significantly longer in mild to moderate OP poisoned patients with early single GL compared with late single GL, then early multiple GL, and lastly late multiple GL. The longer duration of hospital stay in severe OP poisoning compared with mild to moderate poisoning is expected and can be explained on the basis of occurrence of RF and the consequent need for ETT, ICU, and MV. Hospital stay was significantly longer in single GL group compared with multiple GL group providing evidence to the possible role of multiple GL in eliminating OP from GIT and protecting from grievous outcomes like RF. Additionally, the shortest duration of hospital stay was encountered in early multiple GL subgroups highlighting the impact of both early and multiple GL in reducing the outcomes of poisoning necessitating longer hospital stay.

As regards IMS, all patients involved in this study were cured after treatment without the development of IMS. It is against the results of Andrews et al. [18] who reported that IMS occurred in 23.6% of single GL patients and in 9.9% of multiple GL patients and IMS occurred in 11.8% of early GL patients and in 20.7% of late GL patients.

Regarding atropine therapy in patients of the present study, the mean number of atropine ampoules in group I with single GL was significantly higher than that of group II with multiple GL. Moreover, the mean number of atropine ampoules was found to be the least in patients who received early and multiple GL, while it was the highest in patients who received late GL once regardless of the severity of OP poisoning. Regarding oximes therapy in patients of the present study, the mean number of oximes ampoules was significantly lower in multiple GL group compared with single GL group. On the other hand, the mean number of oximes ampoules was found to be the least in early multiple GL group and it was the highest in late single GL group regardless of the severity of OP poisoning. The results of this study as regards atropine and oximes therapy are similar to the results of Li et al. [31], who reported that atropine and oximes therapy was more extensive in single GL than multiple GL.

The observed decrease in the duration of hospital stay, need, and duration of MV and atropine and oximes therapy associated with early and multiple GL should be considered in OP poisoned patients regardless of the severity of poisoning reflecting the impact of early multiple GL on improving the outcomes of OP poisoned patients, saving the efforts of healthcare personnel and reducing costs of management especially in resource-limited medical settings in Egypt and other developing countries.

It has been suggested that the multiple lavage technique may work by removing the pesticide left in the stomach after the first lavage, pesticide re-entering the stomach from the small bowel in the supine patient, and/or pesticide secreted by the gastric mucosa into the stomach (enterovascular circulation) [21].

The American Academy of Clinical Toxicology and European Association of poisons centers limited the performance of GL to patients presenting after 1 h of poison ingestion and with substantial amount of poison [32]. These guidelines are based largely on overdose of relatively safe pharmaceutical agents in western countries [33]. The present study provided evidence for the clinical effectiveness of early multiple GL technique which is cheap, widely available, and effective and reasonably safe once the airway is protected in aspirating liquid pesticides.


  Conclusion Top


This study suggests that early multiple GL for OP poisoning has several advantages over late single one. Early and multiple lavage proved to be more effective than late single one in reducing the incidence of RF, ICU admission, and mechanical ventilation and in decreasing hospital stay duration and atropine and oximes therapy amount significantly.

The study has had some limitations

In the present study, neither the ingested amounts of poison nor the retrieved poison in lavage fluid could be quantified. Moreover, the chemical identity of the poisons could not be confirmed by toxicological analysis. The concentration of poison in the blood before and after GL was not assessed. The overall risk or benefit of GL could not be commented in the study as it was impossible to do GL on nonreceiving OP patients, which is completely unethical.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
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    Tables

  [Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6], [Table 7], [Table 8], [Table 9], [Table 10]



 

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