Unexpected hyperkalemia following succinylcholine administration in prolonged immobilized parturients treated with magnesium and ritodrine

Suxamethonium-Induced Hyperkalemia: A Short Review of Causes and Recommendations for Clinical Applications

After the introduction of suxamethonium in 1953, cases of cardiac arrest during induction of anesthesia were recorded. In the following years, hyperkalemia was identified as the cause, and the connection to acetylcholine receptor modulation as the underlying molecular mechanism was made. Activation of the acetylcholine receptor with suxamethonium, acetylcholine, or choline causes an efflux of potassium to the extracellular space. However, certain pathological conditions cause acetylcholine receptor proliferation and the emergence of immature receptors capable of a larger potassium efflux to the bloodstream. These pathologic conditions include upper and lower neuron injuries, major burns, trauma, immobility, muscle tumors, muscular dystrophy, and prolonged critical illness. The latter is more important and relevant than ever due to the increasing number of COVID-19 patients requiring prolonged respiratory support and consequent immobilization. Suxamethonium can be used safely in the vast majority of patients. Still, reports of lethal hyperkalemic responses to suxamethonium continue to emerge. This review serves as a reminder of the pathophysiology behind extensive potassium release. Proficiency in the use of suxamethonium includes identification of patients at risk, and selection of an alternative neuromuscular blocking agent is imperative.

Hypermagnesemia disturbances in rats, NO-related: pentadecapeptide BPC 157 abrogates, L-NAME and L-arginine worsen

AIM

Stable gastric pentadecapeptide BPC 157, administered before a high-dose magnesium injection in rats, might be a useful peptide therapy against magnesium toxicity and the magnesium-induced effect on cell depolarization. Moreover, this might be an NO-system-related effect. Previously, BPC 157 counteracts paralysis, arrhythmias and hyperkalaemia, extreme muscle weakness; parasympathetic and neuromuscular blockade; injured muscle healing and interacts with the NOS-blocker and NOS-substrate effects.

MAIN METHODS

Assessment included magnesium sulfate (560 mg/kg intraperitoneally)-induced muscle weakness, muscle and brain lesions, hypermagnesemia, hyperkalaemia, increased serum enzyme values assessed in rats during and at the end of a 30-min period and medication (given intraperitoneally/kg at 15 min before magnesium) [BPC 157 (10 µg, 10 ng), L-NAME (5 mg), L-arginine (100 mg), alone and/or together]. In HEK293 cells, the increasing magnesium concentration from 1 to 5 mM could depolarize the cells at 1.75 ± 0.44 mV.

KEY FINDINGS

L-NAME + magnesium-rats and L-arginine + magnesium-rats exhibited worsened severe muscle weakness and lesions, brain lesions, hypermagnesemia and serum enzymes values, with emerging hyperkalaemia. However, L-NAME + L-arginine + magnesium-rats exhibited all control values and normokalaemia. BPC 157 abrogated hypermagnesemia and counteracted all of the magnesium-induced disturbances (including those aggravated by L-NAME or L-arginine). Thus, cell depolarization due to increasing magnesium concentration was inhibited in the presence of BPC 157 (1 µM) in vitro.

SIGNIFICANCE

BPC 157 likely counteracts the initial event leading to hypermagnesemia and the life-threatening actions after a magnesium overdose. In contrast, a worsened clinical course, higher hypermagnesemia, and emerging hyperkalaemia might cause both L-NAME and L-arginine to affect the same events adversely. These events were also opposed by BPC 157.

Rebound hyperkalemia after cessation of ritodrine in a parturient undergoing cesarean section

A 36-year-old parturient with a suspicion of placenta accreta under tocolytic therapy with ritodrine infusion underwent emergency cesarean section under general anesthesia with propofol, ketamine, and remifentanil because massive bleeding was anticipated. The ritodrine infusion was discontinued 1 h before cesarean section. The baby was delivered 6 min after induction of anesthesia. However, after the manual removal of the placenta from the uterus, the bleeding was massive and uncontrollable. We rapidly transfused crystalloid, colloid, and red blood cells through potassium removal filter. Hyperkalemia (5.8 mmol/L) was detected just before blood transfusion. One hour later, hemostasis was still difficult, and hyperkalemia was promoted (6.1 mmol/L). Thus, glucose insulin therapy started with intravenous furosemide to treat hyperkalemia. Gynecologists decided to induce the Bakri balloon tamponade for the treatment of postpartum hemorrhage. At the end of surgery, plasma potassium level also reduced to 5.5 mmol/L. In the ICU, the bleeding still continued, and then radiologists performed bilateral internal iliac artery embolization for full hemostasis. Postoperative plasma potassium level was stable and 3.3 mmol/L in the next morning. Although one of the common adverse reactions of ritodrine is hypokalemia, we should also beware of a rebound hyperkalemia after its cessation.

Controversies in Pediatric Perioperative Airways

Pediatric airway management is a challenge in routine anesthesia practice. Any airway-related complication due to improper procedure can have catastrophic consequences in pediatric patients. The authors reviewed the current relevant literature using the following data bases: Google Scholar, PubMed, Medline (OVID SP), and Dynamed, and the following keywords: Airway/s, Children, Pediatric, Difficult Airways, and Controversies. From a summary of the data, we identified several controversies: difficult airway prediction, difficult airway management, cuffed versus uncuffed endotracheal tubes for securing pediatric airways, rapid sequence induction (RSI), laryngeal mask versus endotracheal tube, and extubation timing. The data show that pediatric anesthesia practice in perioperative airway management is currently lacking the strong evidence-based medicine (EBM) data that is available for adult subpopulations. A number of procedural steps in airway management are derived only from adult populations. However, the objective is the same irrespective of patient age: proper securing of the airway and oxygenation of the patient.

Serum creatine phosphokinase elevation in patients treated with intravenous magnesium sulfate

OBJECTIVE

During the treatment of pre-term labor with magnesium sulfate, we noted an abnormal elevation of maternal serum creatine phosphokinase. This study was aimed at evaluating the relationship between tocolysis with MgSO4 and maternal serum CPK elevation, which represents the possible damage of muscles by magnesium sulfate.

METHODS

Clinical records of 45 women treated with magnesium sulfate and beta-sympathomimetics for the treatment of pre-term labor were retrospectively examined.

RESULTS

Serum CPK was abnormally elevated in 32 out of 45 cases (71.1%), but in only one out of 21 in the control group. In three cases, the decrease of serum creatine phosphokinase after cessation of magnesium sulfate was demonstrated, despite the continuous infusion of beta-sympathomimetics.

CONCLUSION

Magnesium sulfate may cause muscular damage and abnormal elevation of maternal serum creatine phosphokinase. Special attention must be paid to patients when drugs acting on muscle cells, for example succinyl choline, are going to be used.

Pharmacological considerations during pregnancy

We present a brief overview of recent literature concerning some of the drugs used in pregnancy, labour and delivery. Obstetric anaesthesia continues to evolve through the reuse of old drugs such as magnesium sulphate or the manipulation of current drugs (e.g. propofol for emesis) in order to improve patient outcome. Pregnant women have traditionally been therapeutic orphans. The use of new agents such as levobupivacaine and ropivacaine in obstetric patients lags behind that of their non-pregnant counterparts. However, this gap is decreasing and these new drugs offer benefits to the parturient woman.