Prediction rule of supratherapeutic peak serum salicylate level in poisoning patients attending emergency departments

Background:

Analgesic poisoning is common in Hong Kong. Analgesics containing salicylate are easily available. Salicylate poisoning may be encountered in the daily practice of the accident and emergency department. The issue of routine salicylate screening was discussed in a number of articles, and the viewpoints of most authors were that routine salicylate screening was unnecessary.

Objectives:

The primary outcome is to explore the predictive factors of supratherapeutic peak serum salicylate level (>2.17 mmol/L) and delineate the role of routine screening serum salicylate level in poisoned patients attending the accident and emergency department.

Methods:

This is a retrospective cohort study. Poisoning cases presented to Hong Kong Poison Information Centre between 1 July 2008 and 31 October 2020 with serum salicylate level checked were included. The demographics, laboratory parameters and clinical outcomes were reviewed.

Results:

There were 8673 cases included with serum salicylate level checked, accounting for 17% of all poisoning cases. Sixty-six (0.76%) cases had supratherapeutic peak serum salicylate level and 11 (0.13%) of them were undeclared salicylate ingestion. Worse clinical outcomes were observed in cases with supratherapeutic peak serum salicylate level. Univariate analysis showed that tinnitus, hyperthermia, alkalaemia, metabolic acidosis, respiratory alkalosis and therapeutic use of aspirin were significantly associated with supratherapeutic peak serum salicylate level. Variables with p < 0.3 were entered into the backward stepwise logistic regression by likelihood ratio. A clinical prediction rule with three attributes (tinnitus, therapeutic use of aspirin and partial pressure of CO2 <5 kPa) was derived. It showed 100% sensitivity in internal validation.

Conclusion:

Serum salicylate level should be checked in poisoned patients with (1) tinnitus, (2) the therapeutic use of aspirin or (3) partial pressure of CO2 <5 kPa in arterial or venous blood gas. Routine salicylate screening remained a tool for clinicians not experienced in toxicology.

Electrochemical Pretreatment for Sludge Sulfide Control without Chemical Dosing: A Mechanistic Study

Sulfide is a toxic and corrosive odorant generated in various sludge treatment and disposal systems. We developed an electrochemical pretreatment (EPT) approach to eliminate sludge sulfide production without adding chemicals. Biochemical sulfide potential (BSP) test was used to evaluate the effectiveness of EPT on sludge sulfide production. The sulfide control was effective with EPT, and we determined the underlying mechanism of EPT. EPT which was operated at 12 V for 720 s eliminated 99% of dissolved sulfide and 100% of gaseous H₂S_(g). In comparison, the dissolved sulfide reached 104 ± 1 mg S/L in the control BSP test. A sulfur mass balance analysis in the BSP test showed that 90% of the produced sulfide was removed via metal precipitation. Metal distribution results confirmed that metals (i.e., Fe, Mn, and Ni) in the sludge became soluble after EPT and were released from their residual and organically bound fractions. EPT which was operated at 15 V solubilized around 73, 92, and 72% of Fe, Mn, and Ni, and these metals precipitated the sulfide that was produced from biological sulfate reduction. Sludge analysis revealed that EPT disintegrated sludge flocs and disrupted metal-binding functional groups. Specifically, reduction of 17% C═O functional groups in the sludge was found, which could be associated with metal release. The impact of oxidants (e.g., chlorine) generated from EPT on sulfide oxidation was minimal. The findings of this study broadened up our understanding of the electrochemical process for sulfide control during saline sludge digestion.

Hong Kong Poison Information Centre: Annual Report 2013

Objective

To report and analyse the poisoning data of Hong Kong Poison Information Centre (HKPIC) in 2013.

Methods

In 2013, all poisoning cases received by HKPIC were retrieved from its database [Poison Information and Clinical Management System (PICMS)] for analysis.

Results

A total of 3,783 poisoned cases were analysed. There were 1,595 male patients (42.2%), 2,185 female patients (57.8%) and 3 sex unspecified patients (0.1%). Middle aged group (30-39 years) composed about one-fifth (20.8%) of the poisoning cases while about two-third (66.8%) of them were between 20 and 59 years old. Common causes for poisoning were suspected self-harm/suicidal attempt (43%), unintentional exposure (15.3%) and abusive substances use (14.5%). Five commonest types of poison exposed were paracetamol, benzodiazepine, zopiclone, household products and Chinese herbal medicine. Majority of the patients were managed with supportive measures, and 13.2% and 10.8% of them were treated by decontamination and antidotes respectively. Most cases had uneventful recovery; 0.9% of the poisoning resulted in death and 4.3% had major outcomes.

Conclusions

This 8th annual report provided updated epidemiological information on poisoning pattern in Hong Kong and highlighted important changes in comparing with our previous reports. (Hong Kong j. emerg.med. 2014;21:249-259)