Delayed Onset of Central Diabetes Insipidus With Ketamine Sedation: A Report of 2 Cases

Ketamine Use in Adult and Pediatric Patients Receiving Extracorporeal Membrane Oxygenation (ECMO): A Systematic Review

Background: Analgesia and sedation are often critical elements of therapy for patients undergoing extracorporeal membrane oxygenation (ECMO). Aside from potential drug-drug interactions, the PK changes associated with ECMO make appropriate analgosedative selection challenging. Ketamine is less lipophilic and has lower protein binding than alternative agents, and may be less impacted by the PK changes during ECMO. Objective: To systematically identify all instances of ketamine use during ECMO support in the literature to elucidate associated efficacy and safety outcomes and prevalence of use, as well as commonly used dosing strategies and pharmacokinetic data. Methods: Web of Science, Cochrane Library, Scopus, Ovid MEDLINE, PubMed, and OVID Embase were searched through 02/2023 using keywords ketamine and ECMO or extracorporal life support (ECLS). Case reports, case series, and studies were included that had (1) original data, (2) included patients that were on ECMO and continuous infusion ketamine, and (3) reported pertinent ketamine related clinical endpoints or prevalence of use. Results: Of the 307 articles screened, 25 were identified as relevant and 11 met our inclusion criteria. Heterogeneity of patient population, ketamine indication, reported outcomes, and reported safety endpoints were identified in the included articles. Commonly reported information includes indications, pharmacokinetics, dosing, adverse effects and use in pediatrics for ketamine, and suspected opioid sparing effect. Conclusion: Our review has found a lack of consistency in reporting and results in adult and pediatric patients. Increased consistency in reporting and larger studies are required to increase our knowledge of ketamine use in both the adult and pediatric patient population.

Polyuria in COVID-19 Patients Undergoing Extracorporeal Membrane Oxygenation

Background: The COVID-19 pandemic caused an unprecedented number of patients requiring veno-venous extracorporeal membrane oxygenation (VV ECMO) therapy. Clinical polyuria was observed at our ECMO center during the pandemic. This study aims to investigate the incidence, potential causes, and implications of polyuria in COVID-19 patients undergoing VV ECMO therapy. Methods: Here, 68 SARS-CoV-2 positive patients receiving VV ECMO were stratified into the following two groups: polyuria (PU), characterized by an average urine output of ≥3000 mL/day within seven days following initiation, and non-polyuria (NPU), defined by <3000 mL/day. Polyuria in ECMO patients occurred in 51.5% (n = 35) within seven days after ECMO initiation. No significant difference in mortality was observed between PU and NPU groups (60.0% vs. 60.6%). Differences were found in the fluid intake (p < 0.01) and balance within 24 h (p = 0.01), creatinine (p < 0.01), plasma osmolality (p = < 0.01), lactate (p < 0.01), urea (p < 0.01), and sodium levels (p < 0.01) between the groups. Plasma osmolality increased (p < 0.01) after ECMO initiation during the observation period. Results: Diuresis and plasma osmolality increased during VV ECMO treatment, while mortality was not affected by polyuria. Conclusions: Polyuria does not appear to impact mortality. Further investigations are warranted to elucidate its underlying mechanisms and clinical implications in the context of VV ECMO therapy and COVID-19 management.

Establishment and validation of a predictive nomogram for polyuria during general anesthesia in thoracic surgery

BACKGROUND

To develop and evaluate a predictive nomogram for polyuria during general anesthesia in thoracic surgery.

METHODS

A retrospective study was designed and performed. The whole dataset was used to develop the predictive nomogram and used a stepwise algorithm to screen variables. The stepwise algorithm was based on Akaike's information criterion (AIC). Multivariable logistic regression analysis was used to develop the nomogram. The receiver operating characteristic (ROC) curve was used to evaluate the model's discrimination ability. The Hosmer-Lemeshow (HL) test was performed to check if the model was well calibrated. Decision curve analysis (DCA) was performed to measure the nomogram's clinical usefulness and net benefits. P < 0.05 was considered to indicate statistical significance.

RESULTS

The sample included 529 subjects who had undergone thoracic surgery. Fentanyl use, gender, the difference between mean arterial pressure at admission and before the operation, operation type, total amount of fluids and blood products transfused, blood loss, vasopressor, and cisatracurium use were identified as predictors and incorporated into the nomogram. The nomogram showed good discrimination ability on the receiver operating characteristic curve (0.6937) and is well calibrated using the Hosmer-Lemeshow test. Decision curve analysis demonstrated that the nomogram was clinically useful.

CONCLUSIONS

Individualized and precise prediction of intraoperative polyuria allows for better anesthesia management and early prevention optimization.

Transient diabetes insipidus in critically ill COVID19 patients

PURPOSE

Vasopressin has become an important vasopressor drug while treating a critically ill patient to maintain adequate mean arterial pressure. Diabetes insipidus (DI) is a rare syndrome characterized by the excretion of a large volume of diluted urine, inappropriate for water homeostasis. We noticed that several COVID19 patients developed excessive polyuria suggestive of DI, with a concomitant plasma sodium-level increase and/or low urine osmolality. We noticed a temporal relationship between vasopressin treatment cessation and polyuria periods. We reviewed those cases to better describe this phenomenon.

METHODS

We retrospectively collected COVID19 ECMO patients' (from July 6, 2020, to November 30, 2021) data from the electronic medical records. By examining urine output, urine osmolality (if applicable), plasma sodium level, and plasma osmolality, we set DI diagnosis. We described the clinical course of DI episodes and compared baseline characteristics between patients who developed DI and those who did not.

RESULTS

Out of 37 patients, 12 had 18 episodes of DI. These patients were 7 years younger and had lower severity scores (APACHE-II and SOFA). Mortality difference was not seen between groups. 17 episodes occurred after vasopressin discontinuation; 14 episodes were treated with vasopressin reinstitution. DI lasted for a median of 21 h, with a median increase of 14 mEq/L of sodium.

CONCLUSIONS

Temporary DI prevalence after vasopressin discontinuation in COVID19 ECMO patients might be higher than previously described for vasopressin-treated patients.

Intra-operative diabetes insipidus associated with cervical spine traction during staged scoliosis surgery

A 15-year-old boy with cerebral palsy and epilepsy presented for a posterior spinal fusion as part of staged repair of thoracolumbar scoliosis. Total intravenous anaesthesia was induced and maintained with propofol, remifentanil and ketamine. Following prone positioning, cervical traction was applied. Polyuria developed intra-operatively, from 4 to 18 ml.kg^-1.h^-1. There was a corresponding rise in plasma sodium concentration from 132 to 145 mmol.l^-1. Haemodynamic stability was maintained with boluses of Hartmann's solution and a noradrenaline infusion. Given the possibility of diabetes insipidus due to reduced cerebral perfusion pressure, the cervical traction was removed. This initially showed a good response with a transient reduction in polyuria to 3 ml.kg^-1.h^-1 before rising to 8 ml.kg^-1.h^-1. Subsequently, a vasopressin infusion was started with normalisation of diuresis and plasma sodium concentration by the end of surgery. Diabetes insipidus is an endocrine disorder related to lack of production or insensitivity to vasopressin. In the peri-operative period, it is mainly associated with pituitary surgery and rarely with spinal surgery. To the authors' knowledge, this is only the second report of diabetes insipidus associated with staged scoliosis surgery. Cervical traction should be considered as a potential cause of intra-operative diabetes insipidus.