Increased hospital mortality in patients with bedside hippus

Background

Hippus is a prominent, repetitive oscillation of the pupils. Although regarded by some as a normal variant of pupillary unrest, the clinical importance of hippus has not been investigated systematically in hospitalized patients.

Methods

We conducted a retrospective cohort study of 117 hospitalized patients demonstrating hippus. To mitigate observer bias, 486 control patients were selected using 2 adjacent admissions by the same attending physician before and after each index case. The primary outcomes were mortality during the admission and within 30 days of discharge.

Results

Patients with bedside hippus were more likely to die within 30 days of observation (P <.00005). Independent risk factors for death by 30 days were altered mental status (odds ratio [OR] 4.11; 95% confidence interval [CI], 2.05-8.25, P <.001), hippus (OR 2.99; 95% CI, 1.46-6.11, P = .003), cirrhosis (P = .029), and renal disease (P = .054); angiotensin-system inhibitors were protective (P = .012). Patients with hippus were more likely to have altered mental status (OR 11.23; 95% CI, 6.27-20.09, P <.001), a history of trauma (OR 3.76; 95% CI, 1.65-8.59, P = .002), cirrhosis (P = .038), renal disease (P = .051), and a history of using iron supplements (P = .016).

Conclusion

The recognition of hippus in hospitalized patients is a clinically important predictor of early mortality.