Prolonged neuromuscular blockade as a result of malnutrition-induced pseudocholinesterase deficiency

Detection of cocaine 24 h after administration before nasotracheal intubation

BACKGROUND

Cocaine may be applied to decongest the nasal mucosa before nasotracheal intubation, but patients risk a criminal offence if cocaine is detected when patients drive a car shortly after surgery. We aimed to evaluate whether benzoylecgonine levels in saliva exceeded the cut-off point 24 h after administration in patients undergoing nasotracheal intubation and whether cocaine would be detectable above the Danish legal fixed limit in blood samples 1 and 24 h after surgery.

METHODS

We conducted a prospective study following approval from the local research ethics committee and the national medicine agency. Written informed consent was obtained from all patients. We included patients scheduled for surgery under general anaesthesia with nasotracheal intubation. They received 80 mg cocaine as a nasal spray 5 min before induction and nasotracheal intubation. The primary outcome was a dichotomous assessment of benzoylecgonine levels in saliva samples measured 24 h after administration of nasal cocaine with a cut-off limit of 200 ng/mL. Secondary outcomes were dichotomous assessments of cocaine in whole blood samples measured 1 and 24 h after administration of nasal cocaine with a cut-off limit of 0.01 mg/kg.

RESULTS

Overall, 70 patients had valid saliva samples and 75 had valid blood samples 24 h after cocaine administration. Benzoylecgonine in saliva was traceable above the cut-off in 9/70 patients (13%; CI95%: 6% to 23%), and cocaine in blood was detected above the cut-off in 2/75 patients (3%; CI95%: 0.3% to 9%).

CONCLUSION

We found benzoylecgonine traceable in saliva in 13% of patients and cocaine traceable in blood in 3% of patients 24 h after administration of 80 mg nasal cocaine. Patients should be informed when receiving cocaine and advised not to drive for at least 24 h.

A Case of Pseudocholinesterase Deficiency Resulting From Malnutrition

Pseudocholinesterase deficiencies occur because of both genetic and acquired factors. We present the case of a patient with a history of bariatric surgery and severe malnutrition who subsequently developed prolonged neuromuscular blockade after succinylcholine administration. She had markedly decreased pseudocholinesterase levels at the time of the incident, but her motor function returned to normal with supportive care. After aggressive nutritional support over multiple weeks, her pseudocholinesterase levels drastically improved. For those patients in a poor nutritional state who experience an unexpected episode of apnea or prolonged neuromuscular blockade, practitioners must always consider malnutrition-induced pseudocholinesterase deficiency as a possible etiology.

Pseudocholinesterase Enzyme Deficiency in Adıyaman City Area

OBJECTIVE

Pseudocholinesterase (PChE) is an enzyme responsible for the hydrolysis of succinylcholine. In case of its deficiency, the effect of succinylcholine that is approximately 5-10 min is prolonged up to few hours. The use of succinylcholine has been declined recently. However, it is still actively used in some special conditions and in developing countries. In this study, incidence of PChE enzyme deficiency around Adiyaman city was investigated and presented with the literature review.

METHODS

After obtaining an approval from the investigational board of our hospital (Adiyaman University Medical School, Biomedical Research Ethics Board, 30.12.2012, Nr: B.30.2.ADY.0.20.00-600/51), patients undergoing any elective operation under general anaesthesia in the Adiyaman University Medical School Hospital between March and December 2013 were recruited for the study. After obtaining the patients' written consents, blood PChE, alanine aminotransferase (ALT), aspartate aminotransferase (AST), urea, creatinine, international normalisation ratio (INR) and activated partial thromboplastin time (aPTT) values of the patients were analysed. Possible association of the PChE deficiency with other values was also investigated. The normal value of PChE was taken as 4260-11250 for females aged 16-40 years and 5320-12920 U L(-1) for other patients.

RESULTS

The study was completed with 964 patients, 702 (72.8%) of whom were females. PChE enzyme levels were under the normal in 7.2% of the patients. There were no correlation between patient group, ALT, INR, aPTT and creatinine elevation with PChE deficiency (p>0.05), whereas AST and urea level elevation was significantly associated with PChE deficiency (p<0.05). The risk of PChE deficiency was 4.5 and 9 times higher in the patients with the elevation of AST and urea levels, respectively.

CONCLUSION

Pathological elevations of AST and urea that are a part of normal pre-operative biochemical analysis of blood will indicate the possible deficiency of PChE enzyme.

Reversal of succinylcholine induced apnea with an organophosphate scavenging recombinant butyrylcholinesterase

BACKGROUND

Concerns about the safety of paralytics such as succinylcholine to facilitate endotracheal intubation limit their use in prehospital and emergency department settings. The ability to rapidly reverse paralysis and restore respiratory drive would increase the safety margin of an agent, thus permitting the pursuit of alternative intubation strategies. In particular, patients who carry genetic or acquired deficiency of butyrylcholinesterase, the serum enzyme responsible for succinylcholine hydrolysis, are susceptible to succinylcholine-induced apnea, which manifests as paralysis, lasting hours beyond the normally brief half-life of succinylcholine. We hypothesized that intravenous administration of plant-derived recombinant BChE, which also prevents mortality in nerve agent poisoning, would rapidly reverse the effects of succinylcholine.

METHODS

Recombinant butyrylcholinesterase was produced in transgenic plants and purified. Further analysis involved murine and guinea pig models of succinylcholine toxicity. Animals were treated with lethal and sublethal doses of succinylcholine followed by administration of butyrylcholinesterase or vehicle. In both animal models vital signs and overall survival at specified intervals post succinylcholine administration were assessed.

RESULTS

Purified plant-derived recombinant human butyrylcholinesterase can hydrolyze succinylcholine in vitro. Challenge of mice with an LD100 of succinylcholine followed by BChE administration resulted in complete prevention of respiratory inhibition and concomitant mortality. Furthermore, experiments in symptomatic guinea pigs demonstrated extremely rapid succinylcholine detoxification with complete amelioration of symptoms and no apparent complications.

CONCLUSIONS

Recombinant plant-derived butyrylcholinesterase was capable of counteracting and reversing apnea in two complementary models of lethal succinylcholine toxicity, completely preventing mortality. This study of a protein antidote validates the feasibility of protection and treatment of overdose from succinylcholine as well as other biologically active butyrylcholinesterase substrates.

Neuromuscular pharmacodynamics of mivacurium in adults with major burns

BACKGROUND

Mivacurium is metabolized by plasma pseudocholinesterase (PChE) enzyme, which is decreased in burns. We tested whether the decreased metabolism of mivacurium due to decreased PChE activity can overcome the pharmacodynamic resistance to non-depolarizing relaxants previously seen in major burns.

METHODS

Thirty adults with 35 (13)% [mean (sd)] burn were studied at 5-91 post-burn days and 31 non-burns matched controls. Mivacurium 0.2 mg kg(-1) was administered as a single bolus. Neuromuscular block was monitored with single-twitch response using TOF-Watch™. Onset time (drug administration to maximal twitch suppression) and spontaneous recovery were measured.

RESULTS

Onset time was significantly prolonged in burns when compared with non-burns (115 vs 90 s; P<0.001). The PChE levels were lower in burns [1432 (916) vs 2866 (731) IU litre(-1); P<0.001] and the neuromuscular recovery to 50% of baseline twitch height was prolonged in burns (41 vs 26 min; P<0.001). There was a significant correlation between PChE and time to 50% recovery for the whole group together (r=-0.6; P<0.001). The dibucaine numbers were not different.

CONCLUSIONS

The prolonged onset time suggests resistance to neuromuscular effects, whereas the prolonged recovery suggests increased sensitivity. This divergent response can be explained by qualitative and quantitative changes in acetylcholine receptor expression causing resistance and decreased PChE activity causing sensitivity. Despite using a relatively large dose of mivacurium (0.2 mg kg(-1)) in the presence of decreased PChE levels, this did not overcome the resistance resulting from up-regulated receptors.

Prolonged paralysis and apnea after receiving a neuromuscular blocking agent: what nurses should know

After receiving mivacurium, a short-acting neuromuscular blocking agent used for intubation before surgery, a patient experienced prolonged paralysis and prolonged apnea that required ventilator support. Although this complication is rare, all critical care nurses should be aware of it so they can be competent in managing and providing holistic and comprehensive nursing care to the patient and the patient's family. Although this complication has been documented in the anesthesia literature, it has received little mention in critical care nursing journals.

A case of pseudocholinesterase deficiency in the PACU

A 39-year-old patient with unrecognized atypical pseudocholinesterase was given succinylcholine during the rapid-sequence induction process and subsequently had a prolonged neuromuscular blockade. The patient was reassured, sedated, and ventilated in the postanesthesia care unit (PACU). The primary nursing interventions included airway clearance, communication, comfort, and patient education. Several important learning experiences occurred for the nurses in the PACU related to identifying possible causes, ordering the pseudocholinesterase and dibucaine inhibition test, interpreting the results, and developing and delivering patient education. This article will provide the perianesthesia nurse with the fundamental understanding of the physiology, laboratory diagnostic interpretation, and nursing interventions needed to deliver evidence-based, high-quality care to patients diagnosed with pseudocholinesterase deficiency.

Prehospital Airway Management Complicated by Reported Pseudocholinesterase Deficiency

Patients with pseudocholinesterase deficiency can experience prolonged neuromuscular blockade if given succinylcholine or certain other drugs. We describe the case of a patient with a reported pseudocholinesterase deficiency requiring emergent prehospital airway management. Knowledge of the reported condition influenced airway management decisions.