Early diagnosis of paroxysmal sympathetic hyperactivity in the ICU

Background: Paroxysmal sympathetic hyperactivity (PSH) is a complication of acquired brain injury manifesting with episodic tachycardia, tachypnea, hypertension, diaphoresis, hypertonia, and posturing. No universally accepted diagnostic criteria exist and diagnosis is often delayed until the rehabilitation phase. Methods: Electronic records were screened to identify consecutive cases of PSH diagnosed in an intensive care unit (ICU) between 1/2006 and 8/2012 and assess the validity of early clinical diagnosis against formal diagnostic criteria. Data collected included patient demographics, brain injury etiology, symptoms noted by the clinician to support the diagnosis of PSH, PSH manifestations, therapeutic interventions, relevant brain imaging, and investigations to exclude alternative diagnoses. An operational set of diagnostic criteria based on previous literature was used for comparison. Results: Fifty-three consecutive patients with PSH were identified. Mean age was 33.6 ± 14.5 years (range 16-67). Traumatic brain injury was the most common etiology (30 patients, 56.6 %) but causes were diverse. Mean time to diagnosis was 8.3 ± 11.0 days; 31 patients (59 %) were diagnosed within 7 days and 20 patients (38 %) within 3 days of admission. Tachycardia was almost uniformly present, and diaphoresis, fever, hypertension, and tachypnea were also present in most cases. Dystonia and posturing were present in less than half of patients. 89 % of clinically diagnosed cases met formal diagnostic criteria. Conclusions: Paroxysmal sympathetic hyperactivity can be diagnosed early in the ICU. Strict diagnostic criteria supported the clinician's diagnosis in the majority of cases. Diagnosis should not be rejected because of any particular sign's absence, especially dystonia and posturing.