HCPLive Network

Hyponatremia Associated with Worse Outcomes Following Cardiac Surgery

 
To study the association between postoperative hyponatremia and mortality, length of hospital stay (LOS), and complications, the authors of “Postoperative Hyponatremia Predicts an Increase in Mortality and In-Hospital Complications after Cardiac Surgery,” published in Journal of the American College of Surgeons, studied outcomes from 4,850 patients who underwent cardiac surgery.
 
They found that 59% of patients experienced postoperative hyponatremia. These patients tended to have lower left ventricle ejection fraction, higher mean pulmonary artery pressures, lower glomerular filtration rate, higher EuroSCORE, and were more likely to be New York Heart Association class IV.
 
Hyponatremic patients in the study also had a higher prevalence of COPD, and peripheral vascular disease.
 
Patients with hyponatremia experienced increased overall and late mortality rates, with mortality rates increasing with the severity of the hyponatremia.
 
They also spent more time in the hospital (average length of stay of 11 days vs. 7 days for non-hyponatremic patients).
 
The authors reported that, after adjusting for baseline and procedure variables, “postoperative hyponatremia was associated with increase in mortality (hazard ratio 1.22, 95% CI 1.06–1.4, p = 0.004), LOS (multiplier 1.34, 95% CI 1.22–1.49, p < 0.001), infectious (odds ratio [OR] 2.32, 95% CI 1.48–3.62, p < 0.001), pulmonary (OR 1.82, 95% CI 1.49–2.21, p < 0.001), and renal failure complications (OR 2.46, 95% CI 1.58–3.81, p < 0.001) and need for dialysis (OR 3.66, 95% CI 1.72–7.79, p = 0.001).
 
Based on these results, the author concluded that “hyponatremia is common after cardiac surgery and is an independent predictor of increased mortality, length of hospital stay, and postoperative complications.”



Further Reading
Results from a small retrospective study indicate that treatment with tolvaptan increases sodium concentrations and excretion rhythm without significantly affecting kidney function in patients with refractory hyponatremia and dcompensated heart failure.
Recent studies show preoperative hyponatremia is associated with increased rate of postoperative complications, longer hospital stays, and other poor outcomes in patients who undergo cardiac surgery.
Patients with end-stage renal disease who live in the Midwest begin dialysis at an earlier stage than patients who live in other regions of the US.
Study results show hyponatremia is closely associated with all-cause mortality in patients with chronic kidney disease (CKD), but few previous studies have examined this relationship.
Early diagnosis by primary care physicians and aggressive treatment are essential to slowing the epidemic of kidney and cardiovascular disease.
Findings from a new study show that patients with moderate and severe kidney impairment need reduced doses of warfarin.
For patients with treatment-resistant hypertension and chronic kidney disease, renal denervation reduces blood pressure and can slow renal function decline, according to a study presented at the American Heart Association's 2013 Scientific Sessions, held from Nov. 16 to 19 in Dallas.
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