Adult toxicology in critical care: Part II: specific poisonings

Simultaneous, Multi-Channel, Near-Infrared Fluorescence Visualization of Mesenteric Lymph Nodes Using Indocyanine Green and Methylene Blue: A Demonstration in a Porcine Model

Near-infrared fluorescence (NIRF) image-guided surgery is a useful tool that can help reduce perioperative complications and improve tissue recognition. Indocyanine green (ICG) dye is the most frequently used in clinical studies. ICG NIRF imaging has been used for lymph node identification. However, there are still many challenges in lymph node identification by ICG. There is increasing evidence that methylene blue (MB), another clinically applicable fluorescent dye, can also be useful in the intraoperative fluorescence-guided identification of structures and tissues. We hypothesized that MB NIRF imaging could be used for lymph node identification. The aim of this study was to evaluate the feasibility of intraoperative lymph node fluorescence detection using intravenously (IV) administered MB and compare it to ICG via a camera that has two dedicated near-infrared (NIR) channels. Three pigs were used in this study. ICG (0.2 mg/kg) was administered via a peripheral venous catheter followed by immediate administration of MB (0.25 mg/kg). NIRF images were acquired as video recordings at different time points (every 10 min) over an hour using the QUEST SPECTRUM^® 3 system (Quest Medical Imaging, Middenmeer, The Netherlands), which has two dedicated NIR channels for simultaneous intraoperative fluorescence guidance. The 800 nm channel was used to capture ICG fluorescence and the 700 nm channel was used for MB. The target (lymph nodes and small bowel) and the background (vessels-free field of the mesentery) were highlighted as the regions of interest (ROIs), and corresponding fluorescence intensities (FI) from these ROIs were measured. The target-to-background ratio (TBR) was then computed as the mean FI of the target minus the mean FI of the background divided by the mean FI of the background. In all included animals, a clear identification of lymph nodes was achieved at all time points. The mean TBR of ICG in lymph nodes and small bowel was 4.57 ± 1.00 and 4.37 ± 1.70, respectively for the overall experimental time. Regarding MB, the mean TBR in lymph nodes and small bowel was 4.60 ± 0.92 and 3.27 ± 0.62, respectively. The Mann-Whitney U test of the lymph node TBR/small bowel TBR showed that the TBR ratio of MB was statistically significantly higher than ICG. The fluorescence optical imaging technology used allows for double-wavelength assessment. This feasibility study proves that lymph nodes can be discriminated using two different fluorophores (MB and ICG) with different wavelengths. The results suggest that MB has a promising potential to be used to detect lymphatic tissue during image-guided surgery. Further preclinical trials are needed before clinical translation.

Toxicological Emergencies

Poisoning, drug overdose, and adverse drug effects continue to be a common encounter, especially in the intensive care unit (ICU). Patients are often critically ill or have a potential to rapidly deteriorate and warrant ICU admission. Adults suffering from overdoses rarely give a complete and accurate description of the quantity or type of medications ingested. In most adult cases, multiple substances are involved. A tentative diagnosis in most overdose and poisoning cases can be made by physical examination and simple laboratory tests (electrolyte panel, creatinine, serum osmolarity, urinalysis, etc). Supportive care, with particular attention to airway management, oxygenation, and circulation, is the mainstay of treatment. Basic treatment principles include limiting the amount of toxin absorbed, enhancing the elimination of ingested toxin, and preventing the conversion of non-toxic compounds to toxic metabolites. Drugs or poisons, where specific antidotes or effective therapies exist (especially acetaminophen, salicylates, methanol, ethylene glycol, and digitalis), should be aggressively sought and treated after initial stabilization has been accomplished. For those drugs or poisons where specific quantitative tests are available, levels should be obtained before treatment and may be repeated as clinically indicated.

Synthesis, photocatalytic and antidiabetic properties of ZnO/PVA nanoparticles

A series of ZnO and ZnO/poly(vinyl alcohol) (PVA) catalysts were prepared using sol–gel method. An X-ray diffraction analysis confirmed the existence of the wurtzite ZnO phase, and scanning electron microscopy (SEM) observation revealed the formation of spherical ZnO and ZnO/PVA nanoparticles. The decomposition of methylene blue (MB) and methyl orange (MO) induced by the synthesized pure ZnO and ZnO/PVA nanoparticles was studied under ultraviolet–visible irradiation. Among the catalysts evaluated, ZnO/5PVA was the most active in the decomposition of MB, whereas ZnO/7PVA was the most active catalyst in the decomposition of MO. Moreover, an investigation of the biological activity of pure ZnO and ZnO/PVA indicated that ZnO/5PVA exhibited the best performance in lowering the glucose level in diabetic rats.

Kendu (Diospyros melanoxylon Roxb) fruit peel activated carbon-an efficient bioadsorbent for methylene blue dye: equilibrium, kinetic, and thermodynamic study

In this work, activated carbon was synthesized by the carbonization of kendu fruit peel followed by chemical activation using ammonium carbonate as an activating agent to get modified kendu fruit peel (MKFP). The SEM and FESEM images of the biomaterial illustrated a highly porous honeycomb-like structure, further supported by the N₂ sorption isotherm analysis. The FTIR spectra specified the presence of oxygen-containing functional groups such as carboxyl, carbonyl, and hydroxyl on the adsorbent surface. Batch experiments were performed for the optimization of methylene blue (MB) dye removal. The adsorption process followed pseudo-second-order kinetic model and Langmuir isotherm model with a maximum adsorption capacity of 144.9 mg g^-1. No desorption was found because the adsorbent surface was bonded with the chromophoric group of the MB dye by means of strong chemical interaction evident from the high adsorption energy (E = 10.42 kJ mol^-1) and enthalpy change (∆H = 42.7 kJ mol^-1). Hence, the MKFP has the potential to act as an efficient bioadsorbent for MB dye removal. Graphical abstract.

Epidemiology of Self-poisoning with Drug in the Central Anatolian Region in Turkey

Aim: Deliberate self-poisoning (DSP) is a common cause of intensive care hospitalization among young adults and a serious health problem worldwide. Demographic data vary according to geographical and sociocultural characteristics of the regions. In recent years, studies investigating epidemiological features and prognosis of these patients have increased. In our study, we retrospectively examined patients who committed suicide with drugs and were treated in the ICU of our hospital.

Materials and Methods: The files of 148 patients who took drugs or substances for committing suicide and who were hospitalized in the ICU of Aksaray Training and Research Hospital between 2015 and 2019 were examined. Demographic data of the patients, type of the agent used in the suicide, time to reach hospital, treatment methods applied, length of hospital stay, vital signs, complications, need for intubation, and mortality rates were recorded.

Results: Mean age of the 148 patients who took drugs for suicide was 26.7. Female rate was 73%. The most frequently used drug for suicide was paracetamol (34.4%). Antidepressants took the second place and were followed by drugs in the NSAID group. The duration of admission in the hospital after taking the medicine ranged from 1 to 6 h, while it was less than 3 h in 68.2% of the patients. In most suicide patients, the treatment method was in the form of intravenous fluid and supportive therapy (95%). N-acetyl cysteine (paracetamol intoxication) was used in 7% of the patients, an intubation requirement developed in 2.7%, and three patients taking organophosphate died.

Conclusion: In studies conducted in developing countries such as Turkey, female sex (63%-71%) and 25 years of age have been found to be the proportion of the patients (56%-63%), whereas our study found even higher ratios compared to those (73%-66%). In studies conducted in developed countries, most commonly used agents for suicide were benzodiazepines and tricyclic antidepressants, while the most common suicide agent was paracetamol in our study. We believe that the reason for this could be the possibility of accessing the agent without a prescription.

Pharmacist involvement on a rapid response team

PURPOSE

The effect of a pharmacist on a rapid response team (RRT) was investigated.

METHODS

This study evaluated 234 patients before and 157 patients after pharmacist involvement on an RRT. The primary outcome was time to medication administration, with a goal turnaround time of less than 30 minutes. Secondary outcomes included most frequently used medications, readmissions to the intensive care unit (ICU) within 48 hours, number of rapid responses that resulted in ICU admission, length of hospital stay, and survival to hospital discharge. Additionally, pharmacist interventions were tracked in the postinterventional group.

RESULTS

The preinterventional group screened 326 rapid response events, of which 234 were included for analysis; during the postinterventional phase, 256 rapid response events were evaluated, of which 157 were included. The primary outcome, median time to medication administration from central pharmacy, was lower in the postinterventional group compared with the preinterventional group (32.0 minutes versus 64.5 minutes, p = 0.004). ICU admission rates following rapid response were not significantly different between the two groups. Additionally, there were no significant differences between rates of medical emergency and survival to hospital discharge. The most common medications administered were metoprolol and naloxone. Pharmacists provided documentation for 90 of 157 (57%) patient cases. In the 90 cases with documentation, 18 (20% of patients) had documented pharmacist interventions, including dosing assistance for 8 cases (44% of interventions).

CONCLUSION

The addition of a pharmacist to an RRT reduced time to medication administration, helped improve medication accessibility, and helped optimize medication selection and dosing.

Enhancement of ultrasound-assisted degradation of Eosin B in the presence of nanoparticles of ZnO as sonocatalyst

In this research, ZnO nanoparticles, as a sonocatalyst for degradation of Eosin B dye under ultrasonic irradiation, were synthesized. Various experimental conditions (ultrasound irradiation power: 50-250 W, ultrasound irradiation time: 10-70 min, catalyst dosage: 1-3 g/L and initial dye concentration: 5-25 mg/L), using ZnO nanoparticles were investigated in order to find the optimal condition for the degradation of Eosin B. The crystalline and grain size of samples were obtained using X-Ray Diffraction (XRD) and Transmission Electron Microscopy (TEM), 15 and 30 nm, respectively. The nanoparticles structure was observed in the form of hexagonal. The band-gap of the prepared nanoparticles was measured as 2.9 eV which is appropriate for sonodegradation process under ultrasonic irradiation. Results demonstrated that Eosin B degradation efficiency was enhanced considerably in sonicated samples compared to non-sonicated ones. The experiments were analyzed via response surface methodology (RSM) based on central composite design (CCD). Analysis of variance (ANOVA) confirmed a good reliability of quadratic response surface model for predicting the sonocatalytic efficiency at various operational parameters (R² = 0.9918 and Adjusted R² = 0.9841). Results indicated that increasing the ultrasound power and time led to enhancement of Eosin B removal efficiency, while increasing the dye concentration caused to its decreasing. The degradation of dye, increased by enhancement of the catalyst dosage, where in the specified value (2.17 g/L) it began to decrease. The optimization of the process showed the maximum sonocatalyst degradation of 93.46% at irradiation power, irradiation time, catalyst dosage and dye concentration of 250 W, 70 min, 2.17 g/L and 5.08 mg/L, respectively. Kinetic studies showed that the sonodegradation of Eosin B corresponds well to first-order reaction.

A Mitochondria-Specific Fluorescent Probe for Visualizing Endogenous Hydrogen Cyanide Fluctuations in Neurons

An ability to visualize HCN in mitochondria in real time may permit additional insights into the critical toxicological and physiological roles this classic toxin plays in living organisms. Herein, we report a mitochondria-specific coumarin pyrrolidinium-derived fluorescence probe (MRP1) that permits the real-time ratiometric imaging of HCN in living cells. The response is specific, sensitive (detection limit is ca. 65.6 nM), rapid (within 1 s), and reversible. Probe MRP1 contains a benzyl chloride subunit designed to enhance retention within the mitochondria under conditions where the mitochondria membrane potential is eliminated. It has proved effective in visualizing different concentrations of exogenous HCN in the mitochondria of HepG2 cells, as well as the imaging of endogenous HCN in the mitochondria of PC12 cells and within neurons. Fluctuations in HCN levels arising from the intracellular generation of HCN could be readily detected.

Polyol asserted hydrothermal synthesis of SnO2 nanoparticles for the fast adsorption and photocatalytic degradation of methylene blue cationic dye

Schematic representation of the photocatalytic degradation of MB dye using the SnO₂ nanocatalyst.

The effect of ultrasonic irradiation on the structure, morphology and photocatalytic performance of ZnO nanoparticles by sol-gel method

In this research, the effect of ultrasonic irradiation power (0, 75, 150 and 200W) and time (0, 5, 15 and 20min) on the structure, morphology and photocatalytic activity of zinc oxide nanoparticles synthesized by sol-gel method was investigated. Crystallographic structures and the morphologies of the resultant powders were determined by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The XRD patterns showed that ZnO samples were crystallized in their pure phase. The purity of samples was increased by increasing the ultrasonic irradiation power and time. Not only did ultrasonic irradiation unify both the structure and the morphology, but also it reduced the size and prohibited particles from aggregation. The optical behavior of the samples was studied by UV-vis spectroscopy. Photocatalytic activity of particles was measured by degradation of methyl orange under radiation of ultraviolet light. Ultrasound nanoparticles represented higher degradation compared to non-ultrasound ones.

Recurrent episodes of life-threatening vasodilatory shock following unintentional intoxication with amlodipine

Calcium channel blockers (CCBs) have a narrow therapeutic index, and their intake in excess is associated with a critical clinical presentation of sustained hypotension and non-cardiogenic pulmonary edema, which are difficult to treat. Unfortunately, the available treatments fail to resuscitate a significant number of patients poisoned by CCBs, rendering them the main cardiovascular drugs involved in death due to overdose. Importantly, in all cases reported until now in the literature, CCB intoxication was known at the time of patients' presentation and the medical challenge solely consisted of the therapeutic approach. In this case report, we describe our experience in treating a 72-year-old patient with recurrent episodes of sustained hypotension refractory to crystalloid and vasoconstrictor infusions. Prolonged pharmacologic support and intermittent sessions of hemofiltration induced stabilization and recovery. The results of an extensive diagnostic workup to elucidate the cause were unfruitful. The recurrent and paroxysmal nature of the clinical presentation along with its incidence after the patient left the protected setting of the hospital led the diagnostic approach to search for a possible external factor, which was shown to be, after toxicological investigation, unintentional amlodipine intoxication.

Probing the Effects of Templating on the UV and Visible Light Photocatalytic Activity of Porous Nitrogen-Modified Titania Monoliths for Dye Removal

Porous nitrogen-modified titania (N-titania) monoliths with tailored morphologies were prepared using phase separation and agarose gel templating techniques. The doping and templating process were simultaneously carried out in a one-pot step using alcohol amine-assisted sol-gel chemistry. The amount of polymer used in the monoliths that were prepared using phase separation was shown to affect both the physical and optical properties: higher poly(ethylene glycol) content increased the specific surface area, porosity, and visible light absorption of the final materials. For the agarose-templated monoliths, the infiltration conditions affected the monolith morphology. A porous monolith with high surface area and the least shrinkage was obtained when the N containing alkoxide precursor was infiltrated into the agarose scaffolds at 60 °C. The effect of the diverse porous morphologies on the photocatalytic activity of N-titania was studied for the decomposition of methylene blue (MB) under visible and UV light irradiation. The highest visible light activity was achieved by the agarose-templated N-titania monolith, in part due to higher N incorporation. This sample also showed better UV activity, partly because of the higher specific surface area (up to 112 m(2) g(-1)) compared to the phase separation-induced monoliths (up to 103 m(2) g(-1)). Overall, agarose-templated, porous N-titania monoliths provided better features for effectively removing the MB contaminant.

A retrospective analysis of antidepressant poisonings in the emergency department: 11-year experience

Between 1993 and 2004, patients with antidepressant poisoning admitted to an emergency department (ED) were analysed retrospectively with regard to demographics, clinical findings and treatment attempts. Age, gender, suicide attempts, classification of antidepressants, Glasgow Coma Scale (GCS) score, ECG findings, need for endotracheal intubation, follow-up period and Antidepressant Overdose Risk Assessment (ADORA) criteria were analysed by SPSS software. A total of 356 antidepressant poisoning cases were evaluated. Tricyclic antidepressants (TCA), especially opipramol and amitriptyline, were the most common agents (58.4%). The most frequent ECG finding was sinus tachycardia (40.7%, n=145). Endotracheal intubation was required in 9.6% of cases. Patients with TCA ingestion had a longer observation time in the ED, abnormal ECG findings, abnormal physical examination findings and more ADORA criteria, than patients who ingested selective serotonin re-uptake inhibitors (SSRI) (P=0.008, P=0.008, P<0.001, P<0.001). It was found that the patients who ingested TCA (P=0.001), poisoned with amitriptyline (P=0.001), patients with GCS scores of 8 and less (P=0.001), patients with two or more ADORA criteria (P=0.001), with seizures (P=0.001), with abnormal ECG (P=0.012), and patients with a history of two or more suicide attempts were intubated more frequently. Suicide attempts, classification of the antidepressant, ECG findings, seizure, GCS score and number of detected ADORA criteria affect the need for intubation in patients with antidepressant poisoning.

Engineered biomimetic nanoabsorbent for cellular detoxification of chemotherapeutics

An approach to reduce the nonspecific cytotoxicity of chemotherapeutics has been put-forth using a biomimetic nanoabsorbent (NAb) as a detoxifying agent.

Demographic and Clinical Characteristics of Theophylline Exposures between 1993 and 2011

BACKGROUND

Acute and chronic exposure to theophylline can cause serious signs and symptoms of poisoning. Additionally, with a narrow therapeutic range, toxicity could be observed even with therapeutic doses of theophylline. Epidemiological data on theophylline exposures in our country are extremely limited. The results of our study may improve the clinical management of theophylline poisoning in our country and elsewhere.

AIMS

To present aetiological and demographic features, clinical findings and treatment attempts with regard to theophylline exposures reported to Dokuz Eylül University Drug and Poison Information Center (DPIC), between 1993 and 2011.

STUDY DESIGN

Descriptive study.

METHODS

The data regarding demographics, date, time, type of exposure, route of and reason for exposure, signs and symptoms upon admission, clinical management and outcome were retrospectively evaluated.

RESULTS

The DPIC recorded 88,562 poisoning calls between 1993 and 2011; 354 (0.4%) of them were due to theophylline exposure. The mean age of all cases was 24.1±15.4 (range between 1 month and 90 years). Females dominated all age groups (72.6%, 257 females). Intentional exposure was significantly higher in women than in men (88.2% vs. 68.2% for all age groups; p<0.001 for children; p<0.001 for adults; p<0.001 for all age groups). While 60.5% of the cases had no symptoms, severe signs of toxicity were present in 1.9% of theophylline exposure cases during the telephone inquiry. Signs and symptoms were found to be significantly more prevalent in adults than in children (p<0.01). The serum theophylline level was regarded as toxic in 74% (65 toxic levels) of theophylline measured cases. Clinical signs and symptoms were found to be significantly prevalent in cases with toxic theophylline levels (p<0.001). The rate of gastrointestinal decontamination procedures was higher than that of recommended gastrointestinal decontamination procedures by DPIC (83% and 66%, respectively). There were two fatalities (4.6%) associated with chronic theophylline toxicity and theophylline overdose in an acute setting for suicide (a 90 year-old and 25 year-old, respectively).

CONCLUSION

Although most of the theophylline exposure cases had no symptoms, some reported serious signs and symptoms of poisoning such as hypokalaemia, tachycardia and hyperglycaemia. DPICs have an important role in the management of theophylline exposure without unnecessary gastrointestinal decontamination procedures.

Management of calcium channel blocker overdoses

Calcium channel blockers (CCBs) are some of the most commonly used medications in clinical practice to treat hypertension, angina, cardiac arrhythmias, and some cases of heart failure. Recent data show that CCBs are the most common of the cardiovascular medications noted in intentional or unintentional overdoses.(1) Novel treatment approaches in the form of glucagon, high-dose insulin therapy, and intravenous lipid emulsion therapies have been tried and have been successful. However, the evidence for these are limited to case reports and case series. We take this opportunity to review the various treatment options in the management of CCB overdoses with a special focus on high-dose insulin therapy as the emerging choice for initial therapy in severe overdoses.

Successful use of sustained low efficiency dialysis in a case of severe phenobarbital poisoning

A 30-year-old female presented with coma and subsequent cardiac arrest caused by phenobarbital overdosage, requiring ventilatory and vasopressor support. She had also developed severe hypoxia following gastric aspiration. Initial therapy, including activated charcoal and forced alkaline diuresis, failed to significantly lower her drug levels and there was minimal neurological improvement. As she was hemodynamically unstable, and unsuitable for conventional dialysis, she was put on sustained low efficiency dialysis (SLED) to facilitate drug removal. SLED resulted in marked reduction in plasma level of phenobarbital, which eventually led to early extubation, improved cognition and aided full recovery. Thus, we concluded that SLED can be an effective alternative in cases of severe phenobarbital poisoning, where conventional hemodialysis or hemoperfusion cannot be initiated, to hasten drug elimination and facilitate early recovery.

Enhanced Photocatalytic Degradation of Methylene Blue Using ZnFe2O4/MWCNT Composite Synthesized by Hydrothermal Method

Multiwalled carbon nanotubes (MWCNTs) were synthesized using arc discharge method at a magnetic field of 430 G and purified using HNO3/H2O2. Transmission electron micrographs revealed that MWCNTs had inner and outer diameter of ~2 nm and ~4 nm, respectively. Raman spectroscopy confirmed formation of MWCNTs showing G-band at 1577 cm−1. ZnFe2O4 and ZnFe2O4/MWCNT were produced using one step hydrothermal method. Powder X-ray diffraction (XRD) confirmed the formation of cubic spinel ZnFe2O4 as well as incorporation of MWCNT into ZnFe2O4. Visible light photocatalytic degradation of methylene blue (MB) was studied using pure ZnFe2O4 and ZnFe2O4/MWCNT. The results showed that ZnFe2O4/MWCNT composite had higher photocatalytic activity as compared to pure ZnFe2O4. After irradiation for 5 hours in the visible light, MB was almost 84% degraded in the presence of ZnFe2O4 photocatalyst, while 99% degradation was observed in case of ZnFe2O4/MWCNT composite. This enhancement in the photocatalytic activity of composite may be attributed to the inhibition of recombination of photogenerated charge carriers.

Toxicology today: what you need to know now

Clinicians are frequently confronted with toxicological emergencies and challenged with the task of correctly identifying the possible agents involved and providing appropriate treatments. In this review article, we describe the epidemiology of overdoses, provide a practical approach to the recognition and diagnosis of classic toxidromes, and discuss the initial management strategies that should be considered in all overdoses. In addition, we evaluate some of the most common agents involved in poisonings and present their respective treatments. Recognition of toxidromes with knowledge of indications for antidotes and their limitations for treating overdoses is crucial for the acute care of poisoned patients.

[Anesthesia in drug addiction]

The growing social problem of drug abuse has increased the likelihood that anesthesiologists will find acute or chronic drug users among patients requiring anesthesia for elective or emergency surgery. We must therefore be aware of the effects drugs have on the organism and their possible pharmacokinetic and pharmacodynamic interactions with anesthetic agents in order to prevent complications during surgery and postoperative recovery. Such knowledge is required for the management of abstinence syndrome or overdose, which pose the greatest potential dangers for the hospitalized drug addict.

Barbicidal overdose

Acute severe methemoglobinaemia is an uncommon but life-threatening condition caused by a variety of oxidizing agents commonly used in both health care and industrial settings. Thus, recognition is important as it is readily treatable. The oxygen transport is compromised as a result of abnormal levels of oxidized haemoglobin, and this leads to skin discolouration and a variety of symptoms. Diagnostic confusion occurs as the oxygen saturations (SpO2) on the pulse oximeter are unreliable (Sharma V, Haber A. Acquired methaemoglobinaemia: a case report of benzocaine-induced methaemoglobinaemia and a review of the literature. Clin Pul Med. 2002;9(1):53–8). A case of severe methaemoglobinaemia due to self poisoning with barbicide is presented with a brief discussion of the patho-physiology and an overview of the treatment. A barbicidal overdose has never been reported before.

Seizures as a cause of altered mental status

The differential diagnosis and empiric management of altered mental status and seizures often overlap. Altered mental status may accompany seizures or simply be the manifestation of a postictal state. This article provides an overview of the numerous causes of altered mental status and seizures: metabolic, toxic, malignant, infectious, and endocrine causes. The article focuses on those agents that should prompt the emergency physician to initiate unique therapy to abate the seizure and correct the underlying cause.

Pulmonary complications related to heroin overdose and some changes in immune reactivity

To examine the clinical spectrum of complications in pulmonary system and changes of some parameters of humoral and cell mediated immunity related to heroin overdose. The study includes 16 patients who are long-term heroin abusers with acute heroin and mixed with other psychoactive drugs intoxications with an average age of 21,5 ± 5.04 years (12 men and 4 woman). All patients were hospitalized in the Clinic of Toxicology, MHATEM “N.I.Pirogov”, Sofia. We have used clinical, clinico-laboratory, immunological, chimicotoxicological, instrumental methods. In severe intoxications with heroin and other psychoactive drugs, we observed pulmonary system complications, i.e. pneumonia, aspiration of gastric contents, noncardiogenic pulmonary edema (NCPE) and acute respiratory distress syndrome (ARDS.). Of the 16 patients in our study, 3 patients died due to complications. Some changes in the immune reactivity observed in the study were (1) statistically significant lower mean levels of IgG and (2) tendency to lower mean levels of IgA, IgM and complement components — C3 in the studied patients in comparison with the values in healthy people. The changes were more demonstrative in the group with pulmonary complications compared to the group without pulmonary complications. We observed that the CD4 lymphocytes were significantly less in the studied patients; in addition, a lower level of CD56-bearing lymphocytes (natural killer /NK/ cells) was observed in comparison to healthy controls. The results show that the mixture of acute heroin with other psychoactive drugs leads to complications in the pulmonary system and changes of some parameters of cell-mediated and humoral immunity.

Pharmacologically-induced metabolic acidosis: a review

Metabolic acidosis may occasionally develop in the course of treatment with drugs used in everyday clinical practice, as well as with the exposure to certain chemicals. Drug-induced metabolic acidosis, although usually mild, may well be life-threatening, as in cases of lactic acidosis complicating antiretroviral therapy or treatment with biguanides. Therefore, a detailed medical history, with special attention to the recent use of culprit medications, is essential in patients with acid-base derangements. Effective clinical management can be handled through awareness of the adverse effect of certain pharmaceutical compounds on the acid-base status. In this review, we evaluate relevant literature with regard to metabolic acidosis associated with specific drug treatment, and discuss the clinical setting and underlying pathophysiological mechanisms. These mechanisms involve renal inability to excrete the dietary H+ load (including types I and IV renal tubular acidoses), metabolic acidosis owing to increased H+ load (including lactic acidosis, ketoacidosis, ingestion of various substances, administration of hyperalimentation solutions and massive rhabdomyolysis) and metabolic acidosis due to HCO3- loss (including gastrointestinal loss and type II renal tubular acidosis). Determinations of arterial blood gases, the serum anion gap and, in some circumstances, the serum osmolar gap are helpful in delineating the pathogenesis of the acid-base disorder. In all cases of drug-related metabolic acidosis, discontinuation of the culprit medications and avoidance of readministration is advised.

Over 8 years experience on severe acute poisoning requiring intensive care in Hong Kong, China

In order to obtain up-to-date information on the pattern of severe acute poisoning and the characteristics and outcomes of these patients, 265 consecutive patients admitted to an intensive care unit in Hong Kong for acute poisoning from January 2000 to May 2008 were studied retrospectively. Benzodiazepine (25.3%), alcohol (23%), tricyclic antidepressant (17.4%), and carbon monoxide (15.1%) were the four commonest poisons encountered. Impaired consciousness was common and intubation was required in 67.9% of admissions, with a median duration of mechanical ventilation of less than 1 day. The overall mortality was 3.0%. Among the 257 survivors, the median lengths of stay in the intensive care unit and acute hospital (excluding days spent in psychiatric ward and convalescent hospital) were less than 1 day and 3 days, respectively. Factors associated with a longer length of stay included age of 65 or older, presence of comorbidity, Acute Physiology and Chronic Health Evaluation II score of 25 or greater, and development of shock, rhabdomyolysis, and aspiration pneumonia, while alcohol intoxication was associated with a shorter stay. This is the largest study of its kind in the Chinese population and provided information on the pattern of severe acute poisoning requiring intensive care admission and the outcomes of the patients concerned.

Real-time, near-infrared, fluorescence-guided identification of the ureters using methylene blue

BACKGROUND

The aim of this study was to determine whether the invisible near-infrared (NIR) fluorescence properties of methylene blue (MB), a dye already approved by the U.S. Food and Drug Administration for other indications, could be exploited for real-time, intra-operative identification of the ureters.

METHODS

The optical properties of MB were quantified in vitro. Open surgery and laparoscopic NIR fluorescence imaging systems were employed. Yorkshire pigs were injected intravenously with 0.1-mg/kg MB (n = 8), 10-mg furosemide followed by 0.1-mg/kg MB (n = 6), or 0.5-mg/kg MB (n = 6). The contrast-to-background ratio (CBR) of the kidney and ureters, and the MB concentration in the urine, were quantified.

RESULTS

Peak MB absorbance, emission, and intensity in urine occurred at 668 nm, 688 nm, and 20 mumol/L, respectively. After intravenous injection, doses as low as 0.1-mg/kg MB provided prolonged imaging of the ureters, and a dose of 0.5 mg/kg provided statistically significant improvement of CBR. The preinjection of furosemide increased urine volume but did not improve CBR. Laparoscopic identification of the ureter using MB NIR fluorescence was demonstrated.

CONCLUSION

Ureteral imaging using MB NIR fluorescence provides sensitive, real-time, intra-operative identification of the ureters during open and laparoscopic surgeries.

Cocaine-related admissions to an intensive care unit: a five-year study of incidence and outcomes

Cocaine misuse is increasing and it is evidently considered a relatively safe drug of abuse in Ireland. To address this perception, we reviewed the database of an 18-bed Dublin intensive care unit, covering all admissions from 2003 to 2007. We identified cocaine-related cases, measuring hospital mortality and long-term survival in early 2009. Cocaine-related admissions increased from around one annually in 2003-05 to 10 in 2007. Their median (IQR [range]) age was 25 (21-35 [17-47]) years and 78% were male. The median (IQR [range]) APACHE II score was 16 (11-27 [5-36]) and length of intensive care stay was 5 (3-9 [1-16]) days. Ten patients died during their hospital stay. A further five had died by the time of follow-up, a median of 24 months later. One was untraceable. Cocaine toxicity necessitating intensive care is increasingly common in Dublin. Hospital mortality in this series was 52%. These findings may help to inform public attitudes to cocaine.

Psycho-pharmacotherapy for anxiety and obsessive-compulsive disorder: the issue of prolonged barbiturate retention

The authors report the case of a 32-year-old man who had been treated for anxiety and obsessive-compulsive disorder and had received 800 mg methylphenobarbital (MPB). After switching to a barbiturate-free schedule, his condition continued to be unstable for more than 21 MPB half-lives (approx. 30 days) and did not stabilize until MPB-metabolites dropped below their urinary detection limit. Considering that this article provides findings from a single patient, the authors use this experience to discuss and emphasize the importance of clinical control of barbiturates in psychiatry.

Toxicology in the critical care unit

Toxicologic conditions are encountered in critically ill patients due to intentional or unintentional misuse of or exposure to therapeutic or illicit drugs. Additionally, toxicities related to medical interventions may develop in hospitalized patients. This review focuses on recent developments in the field of critical care toxicology. Early interventions to decrease absorption or enhance elimination of toxins have limited value. Specific interventions to manage toxicities due to analgesics, sedative-hypnotics, antidepressants, antipsychotics, cardiovascular agents, alcohols, carbon monoxide, and cholinergic agents are reviewed. Hospital-acquired toxicities due to methemoglobinemia, propylene glycol, and propofol should be recognized and treated. The clinician is continually required to incorporate clinical judgment along with available scientific data and clinical evidence to determine the best therapy for toxicologic conditions.

[Hemoptysis in a young man]

INTRODUCTION

We describe the development of severe and recurrent alveolar hemorrhage in a 30 year old man. The patient had presented with frank hemoptysis, that recurred after an interval of 4 weeks, associated with dyspnea and severe anemia requiring transfusion. The chest x-ray and CT scan showed bilateral diffuse ground glass shadows. Fibreoptic bronchoscopy confirmed bilateral diffuse bleeding. Investigations for the common causes of diffuse alveolar hemorrhage (immunological, infective) proved to be negative on two occasions. Toxicological examination of the urine during the relapse revealed a significant level of cannabis and a trace of cocaine. The patient repeatedly denied the use of illicit drugs.

CASE REPORT

Because of the general condition of this young patient a lung biopsy was performed by video-thoracoscopy. This showed evidence of diffuse alveolar damage compatible with inhalation of cocaine. Faced with these results the patient admitted that he regularly smoked "improved joints".

CONCLUSION

This clinical observation emphasises that the inhalation of cocaine is a cause of diffuse alveolar hemorrhage particularly in young adults.

Approaches to the development of medications for the treatment of methamphetamine dependence

BACKGROUND

Methamphetamine abuse has become an increasing problem in both the United States and globally with concomitant increases in adverse medical, social and environmental sequelae. Behavioral therapies have been used with some success to treat methamphetamine abusers and dependent individuals, but are not universally efficacious. Methamphetamine has a rich pharmacology that theoretically provides many opportunities for potential pharmacotherapeutic intervention. Nevertheless, there are no approved medications with an indication for treating methamphetamine abusers or addicts at this time.

AIM

To describe briefly how methamphetamine functions and affects function in brain and report how basic researchers and clinicians are attempting to exploit and exploiting this knowledge to discover and develop effective pharmacotherapies.

RESULTS

Scientifically based approaches to medications development by evaluating medications that limit brain exposure to methamphetamine; modulate methamphetamine effects at vesicular monoamine transporter-2 (VMAT-2); or affect dopaminergic, serotonergic, GABAergic, and/or glutamatergic brain pathways that participate in methamphetamine's reinforcing effects are presented.

CONCLUSION

The evidence supports the rationale that pharmacotherapies to decrease methamphetamine use, or reduce craving during abstinence may be developed from altering the pharmacokinetics and pharmacodynamics of methamphetamine or its effects on appetitive systems in the brain.

Toxins

Exposures to toxins are prevalent, frequently complicate surgical emergencies, and impact critical care. A fundamental understanding of pathophysiologic principles and management strategies is essential for the anesthesiologist frequently responsible for the acute care of patients who have toxicologic exposures. Given their pervasiveness and ability to confound the clinical presentations in the perioperative or intensive care setting, substances of abuse and asphyxiants warrant particular attention and a high degree of vigilance.