The relevance of hyponatraemia to perioperative care of surgical patients

Association of Pre-Operative Hyponatraemia with Morbidity and Mortality in Patients Undergoing Non-Urgent Degenerative Spine Surgery, a Retrospective Study

BACKGROUND AND OBJECTIVES

Hyponatraemia increases the morbidity and mortality risks of orthopaedic patients. When undergoing spine surgery, hyponatraemic patients have high risks of pneumonia and of staying in hospital for up to 1 day longer compared with non-hyponatraemic patients. This study aims to assess the occurrence of adverse events among patients with pre-operative hyponatraemia after undergoing lumbar surgery.

MATERIALS AND METHODS

A retrospective cohort study was conducted. Patients who underwent spinal surgery in 2011 to 2013 were identified from the American College of Surgeons National Surgical Quality Improvement Program database. Multivariate analysis was conducted to demonstrate the difference in post-operative complication rates between hyponatraemic patients and normonatraemic patients. Post-operative adverse events, need for blood transfusion and length of stay were considered as clinical outcome data.

RESULTS

A total of 58,049 patients were included; pre-operatively, 55,012 (94.8%) were normonatraemic and 3037 (5.2%) were hyponatraemic. Multivariate analysis showed that hyponatraemic patients had higher rates of adverse events, blood transfusions and urinary tract infections. Specifically, 632 (20.8%) hyponatraemic patients developed adverse events, compared with 6821 (12.4%) normonatraemic patients; the hyponatraemic patients received transfusions, compared with 6821 (7.4%) normonatraemic patients; and 97 (3.2%) hyponatraemic patients developed urinary tract infections, compared with 715 (1.3%) normonatraemic patients. Finally, an extended length of stay beyond 6 days occurred in 604 (19.9%) hyponatraemic patients, compared with 4676 (8.5%) normonatraemic patients.

CONCLUSIONS

Our study identified an association between pre-operative hyponatraemia and post-operative adverse events in spinal surgery patients. However, it is unclear whether hyponatraemia caused the higher adverse event rate.

Preoperative Laboratory Values Are Predictive of Adverse Postoperative Outcomes in Patients Older Than 65 Years Undergoing Brain Tumor Resection: A National Surgical Quality Improvement Program Study

OBJECTIVE

In this study, we used a large national database to assess the effect of preoperative laboratory value (PLV) derangements on postoperative outcomes in patients older than 65 years undergoing brain tumor resection.

METHODS

Data was collected for patients >65 years old undergoing brain tumor resection from 2015 to 2019 (N = 10,525). Univariate and multivariate analysis were performed for 11 PLVs and 6 postoperative outcomes.

RESULTS

Hypernatremia (odds ratio [OR], 4.707; 95% confidence interval [CI], 1.695-13.071; P < 0.01) and increased creatinine level (OR, 2.556; 95% CI, 1.291-5.060; P < 0.01) were the most significant predictors of 30-day mortality. The most significant predictor of Clavien-Dindo grade IV complications was increased creatinine level (OR, 1.667; 95% CI, 1.064-2.613; P < 0.05), whereas, significant predictors of major complications were hypoalbuminemia (OR, 1.426; 95% CI, 1.132-1.796; P < 0.05) and leukocytosis (OR, 1.347; 95% CI, 1.075-1.688; P < 0.05). Predictors of readmission were anemia (OR, 1.326; 95% CI, 1.047-1.680; P < 0.05) and thrombocytopenia (OR, 1.387; 95% CI, 1.037-1.856; P < 0.05), whereas, hypoalbuminemia (OR, 1.787; 95% CI, 1.280-2.495; P < 0.001) was predictive of reoperation. Increased partial thromboplastin time and hypoalbuminemia were predictors of extended length of stay (OR, 2.283, 95% CI, 1.360-3.834, P < 0.01 and OR, 1.553, 95% CI, 1.553-1.966, P < 0.001, respectively). Hypernatremia (OR, 2.115; 95% CI, 1.181-3.788; P < 0.05) and hypoalbuminemia (OR, 1.472; 95% CI, 1.239-1.748; P < 0.001) were the most significant predictors of NHD. Seven of 11 PLVs were associated with adverse postoperative outcomes.

CONCLUSIONS

PLV derangements were significantly associated with adverse postoperative outcomes in patients older than 65 years undergoing brain tumor resection. The most significant predictors of adverse postoperative outcomes were hypoalbuminemia and leukocytosis.

Clinically predictive baseline labs for post-operative outcomes of brain tumors using NSQIP database

PURPOSE

This study was performed to assess the effect of baseline Preoperative Laboratory Values (PLV) on post-operative Brain Tumor Resection (BTR) outcomes in a large national registry.

METHODS

We extracted data from the National Surgical Quality Improvement Program (NSQIP) database for BTR patients 2015-2019 (n = 3 0,951). Uni- and multivariate analyses were performed for PLV and key surgical outcomes.

RESULTS

The most significant PLV predictors of 30-day mortality after BTR included hypernatremia (odds ratio, OR 4.184, 95% CI, 2.384-7.343, p < 0.001), high serum creatinine (OR 2.244, 95% CI 1.502-3.352, p < 0.001), thrombocytopenia (OR 1.997, 95% CI 1.438, 2.772, p < 0.001), and leukocytosis (OR 1.635, 95% CI 1.264, 2.116, p < 0.001). The most significant predictors of Clavien IV complications were increased INR (OR 2.653, 95% CI 1.444, 4.875, p < 0.01), thrombocytopenia (OR 1.514, 95% CI 1.280, 1.792, p < 0.001), hypoalbuminemia (OR 1.480, 95% CI 1.274, 1.719, p < 0.001), and leukocytosis (OR 1.467, 95% CI 1.306, 1.647, p < 0.001). The most robust predictors of eLOS were increased INR (OR 1.941, 95% CI 1.231, 3.060, p < 0.01) and hypoalbuminemia (OR 1.993, 95% CI 1.823, 2.179, p < 0.001), and those for non-routine discharge included increased INR (OR 1.897, 95% CI 1.196, 3.008, p < 0.01) and hypernatremia (OR 1.565, 95% CI 1.217, 2.012, p < 0.001).

CONCLUSIONS

Several PLV independently predicted worse outcomes in BTR patients. Baseline labs should be routinely used for the pre-operative risk stratification of these patients.

Association of preoperative hyponatremia with surgical outcomes: a systematic review and meta-analysis of 32 observational studies

BACKGROUND

Preoperative hyponatremia is prevalent in patients undergoing surgical procedures, but it is uncertain if hyponatremia will lead to increased risk of surgical mortality and morbidity.

METHODS

A systematic search of Medline (PubMed), Embase and Cochrane Library from inception till 2 July 2021 was performed. Full length articles that reported on the association between surgical outcomes among adults ≥18 years with documented preoperative hyponatremia were included.

FINDINGS

We identified 32 observational studies comprising 1,301,346 participants. All studies had low risk of bias. When adjusted for covariates, patients with hyponatremia had significantly higher odds of developing major complications (defined as a composite measure of 9 major complications) compared to patients with normal sodium concentrations (aOR =  1.37, 95%CI = 1.23-1.53, I2 = 78%. N = 10). Additionally, patients with preoperative hyponatremia also significantly higher hazards of early mortality (<90 days) compared to patients with normonatremia (aHR = 1.27, 95%CI = 1.13-1.43, I2 = 97%. N = 10) after adjustment for covariates. Preoperative hyponatremia also had significant associations with respiratory, renal and septic complications. In terms of prognostic performance, preoperative hyponatremia performed adequately in predicting major complications in surgical patients (AUC = 0.70, LR- 0.90) with a specificity of 88% and a sensitivity of 25%.

INTERPRETATION

Our meta-analysis suggests that preoperative hyponatremia is associated with poorer early mortality and major morbidity outcomes in surgical patients. Hyponatremia is also a specific prognosticator for major complications in surgical patients, reiterating its potential use as a clinical indicator of poor outcomes.

Preoperative risk factors for delirium in patients aged ≥75 years undergoing spinal surgery: a retrospective study

OBJECTIVE

The increasing number of spinal surgeries being performed in the elderly has increased the incidence of postoperative delirium. The prediction of delirium is complex, and few studies have been performed to examine the preoperative risk factors for delirium after spinal surgery in the elderly. This study was performed to clarify such risk factors in patients aged ≥75 years undergoing spinal surgery.

METHOD

This retrospective observational study included 299 patients aged ≥75 years. Comorbidities, medication history, preoperative examination findings, surgery-related characteristics, and health scale assessments, including the 36-Item Short-Form Survey (SF-36) score and prognostic nutritional index (PNI), were examined as potential risk factors for delirium.

RESULTS

Delirium occurred in 53 patients (17.7%). The preoperative risk factors for delirium were a history of stroke and mental disorders, hypnotic drug use, malnutrition, hyponatremia, anemia, respiratory dysfunction, and cervical surgery. Logistic regression analysis demonstrated that the independent predictors of delirium were a history of stroke, non-benzodiazepine hypnotic drug use, preoperative hyponatremia, the PNI, and the SF-36 physical component summary (PCS) score.

CONCLUSIONS

Independent preoperative predictors of delirium in elderly patients undergoing spinal surgery included a history of stroke, non-benzodiazepine hypnotic drug use, preoperative hyponatremia, the PNI, and the SF-36 PCS score.

Chronicity of Uncorrected Hyponatremia and Clinical Outcomes in Older Patients Undergoing Hip Fracture Repair

Background: Chronic hyponatremia is a risk factor for hip fracture but remains uncorrected in most patients. This study evaluated if preoperative chronicity of uncorrected hyponatremia influences outcomes after hip fracture repair.

Materials and Methods: Evaluated were older patients hospitalized for hip fracture repair between 2007 and 2012 with plasma sodium measured at admission and ≥1 preadmission outpatient measurement. Patients were classified as being normonatremic (NN; plasma sodium 135–145 mmol/L), chronic prolonged hyponatremia (CPH; ≥2 consecutive plasma sodium values <135 mmol/L over >90 days), or recent hyponatremia (one plasma sodium <135 mmol/L within 30 days before admission with previously normal plasma sodium). Length of hospital stay, in-hospital death, post-operative complications, 30-day readmission, and long-term mortality were the evaluated outcomes. Multivariable Cox regression was used to evaluate the association of hyponatremia status with outcomes.

Results: Among 1,571 eligible patients, 76.7% were NN, 14% had CPH, and 9.1% had RH. Compared with NN patients, CHN patients were older and had more prior heart failure, alcoholism, and anticonvulsant drug use. In multivariable analyses, neither CPH or RH was associated with hospital length of stay, in-hospital or 30-day death, or 30-day readmission, while RH was associated with post-operative sepsis [adjusted odds ratio (aOR) 1.84, 95% CI: 1.01–3.35). Only CPH was independently associated with long-term all-cause death (OR 1.53, 95% CI: 1.12–2.09).

Conclusions: Hyponatremia affects nearly 25% of patients undergoing hip fracture repair. Preoperative chronic untreated hyponatremia is associated with increased post-operative mortality following surgical repair of a hip fracture in older patients. Future studies should evaluate if correction of hyponatremia could decrease long-term mortality after hip fracture repair.

Risks and complications of thyroglossal duct cyst removal

OBJECTIVES/HYPOTHESIS

Thyroglossal duct cysts (TGDCs) are the most common congenital neck cyst and typically present in childhood or adolescence, although a subset remains asymptomatic until adulthood. Although treatment involves surgical excision, few large-scale studies exist regarding the risks of surgical treatment of TGDCs in adults. This study aims to describe the characteristics of adult patients undergoing TGDC excision and to analyze risk factors associated with reoperation or other postoperative complications.

STUDY DESIGN

Retrospective cohort study utilizing the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database.

METHODS

Patients age ≥ 18 years in the NSQIP database who underwent TGDC removal from 2005 to 2014 were included. Covariates included patient demographics, comorbidities, preoperative variables, and intraoperative variables. Outcomes included reoperation, complications, and length of hospital stay.

RESULTS

A total of 793 cases met inclusion criteria. Patients were predominantly female (57.0%) and white (64.3%), with a mean age of 44.3 years. Thirty-day mortality did not occur in this cohort, but 3.0% of patients experienced at least one complication. Forty-eight patients (6.1%) underwent reoperation. Wound infection rates were higher in revision operations compared with primary operations (8.3% and 0.9%, respectively; P = .003). Low preoperative sodium was associated with reoperation (P = .047). Additionally, length of hospital stay was associated with increased total operative time (P = .02).

CONCLUSIONS

TGDC excision is a safe and well-tolerated procedure in the adult population, with low complication rates. However, the risk of reoperation, surgical-site infections, and medical complications should be taken into consideration during preoperative planning.

LEVEL OF EVIDENCE

NA Laryngoscope, 130:381-384, 2020.

Intraoperative Use of Desmopressin for Treatment of Profound Hyponatremia in the Setting of Emergency Surgery: A Case Report

Correction of profound hyponatremia requires careful planning and close monitoring to reduce the risks of neurologic injury. Although there are various suggested treatment strategies in the setting of a medical ward or intensive care unit, reports of intraoperative management to prevent rapid increases in serum sodium are lacking. We present a case of profound hyponatremia of 102 mmol/L in a patient who required emergent operative repair for bowel obstruction. This is the first case to our knowledge that demonstrates a perioperative fluid and desmopressin treatment strategy to prevent overly rapid changes of sodium concentration in a patient with severe hyponatremia.

Analyzing the efficacy of frequent sodium checks during hypertonic saline infusion after elective brain tumor surgery

OBJECTIVE

To assess the utility of frequent sodium checks (every 6h) in patients receiving hypertonic saline (HS) after elective brain tumor surgeries.

PATIENTS AND METHODS

A single-institution retrospective review of patients having undergone elective craniotomies for brain tumors and treated with postoperative continuous intravenous infusions of 3% HS was performed. Changes in serum sodium values were analyzed at different time points. The rates of <12.5, 25, and 50cc/h infusions were also examined. Healthcare cost analysis was performed by extrapolating our cohort to the total number of craniotomies performed in the United States.

RESULTS

No significant differences among sodium values checked between 0 to 4, 4-6, 6-8, 8-10, and >10h were observed (P=.64). In addition, no differences in serum sodium values among the rates of <12.5, 25, and 50cc/h were found (P=.30). No patients developed symptoms of acute hypernatremia.

CONCLUSIONS

Serum sodium values did not significantly change more than 10h after infusion of HS. Further studies are needed to determine the optimal frequency of routine sodium checks to increase the quality of care and decrease healthcare costs.

Diagnosis and treatment of hyponatraemia in neurosurgical patients

Hyponatraemia is the most common electrolyte imbalance in neurosurgical patients. Acute hyponatraemia is particularly common in neurosurgical patients after any type of brain insult, including brain tumours and their treatment, pituitary surgery, subarachnoid haemorrhage or traumatic brain injury. Acute hyponatraemia is an emergency condition, as it leads to cerebral oedema due to passive osmotic movement of water from the hypotonic plasma to the relatively hypertonic brain which ultimately is the cause of the symptoms associated with hyponatraemia. These include decreased level of consciousness, seizures, non-cardiogenic pulmonary oedema or transtentorial brain herniation. Prompt treatment is mandatory to prevent such complications, minimize permanent brain damage and therefore permit rapid recovery after brain insult. The infusion of 3% hypertonic saline is the treatment of choice with different rates of administration based on the severity of symptoms and the rate of drop in plasma sodium concentration. The pathophysiology of hyponatraemia in neurotrauma is multifactorial; although the syndrome of inappropriate antidiuresis (SIADH) and central adrenal insufficiency are the commonest causes encountered. Fluid restriction has historically been the classical treatment for SIADH, although it is relatively contraindicated in some neurosurgical patients such as those with subarachnoid haemorrhage. Furthermore, many cases admitted have acute onset hyponatraemia, who require hypertonic saline infusion. The recently developed vasopressin receptor 2 antagonist class of drug is a promising and effective tool but more evidence is needed in neurosurgical patients. Central adrenal insufficiency may also cause acute hyponatraemia in neurosurgical patients; this responds clinically and biochemically to hydrocortisone. The rare cerebral salt wasting syndrome is treated with large volume normal saline infusion. In this review, we summarize the current evidence based on the clinical presentation, causes and treatment of different types of hyponatraemia in neurosurgical patients.