gms | German Medical Science

Objective: Posterior fossa (PF) operations are considered high risk procedures and postoperative intensive care unit (ICU) admission is mandatory at many centers. In times of limited ICU beds and focus on financial aspects of health care such apodictive rules should be validated to achieve patient-oriented and sustainable ICU resource allocation. Aim of this study was to analyze ICU utilization and identify risk factors after scheduled PF surgery.

Methods: We retrospectively analyzed 466 ICU admissions after scheduled PF surgery between 2013 and 2017. Variables were extracted from electronic patient notes. Descriptive statistical analyses were performed.

Results: A cohort of 48% female and 52% male patients with a mean age of 58 years (range 6–83) was analyzed. Mean body mass index was 26 (range 15–42) and Karnofsky performance score was 90 (60–100). 24% were smokers. 52% had arterial hypertension. Concerning signs of heart failure, 32% were classified as New York Heart Association (NYHA) grade I, 12% as grade II and 12% grade III. 10% had diabetes or chronic obstructive pulmonary disease and 4% had history of myocardial infarction or peripheral arterial occlusion, respectively. According to the American Society of Anesthesiologists (ASA) classification, physical status was graded ASA I in 12%, ASA II in 52%, ASA III in 24% and ASA IV in 4%. Mean duration of surgery was 4 hours (range 2–9), comprising 52% extraaxial (mainly meningioma and acoustic neuroma) and 48% intraaxial (mainly metastasis) pathologies. Mean duration of postoperative ICU admission was 19 hours (range 4–91). According to the Landriel Classification System, 4% of patients suffered a grade Ia complication (unexpected neurological deficit), 8% a grade Ib complication (arterial hypertension) and 8% a grade IIb complication (impaired consciousness, arterial hyper- or hypotension and respiratory insufficiency). 80% of complications were encountered after surgery for intraaxial lesions. There was no significant correlation with preoperative patient variables.

Conclusion: ICU resources were utilized in 20% of cases in this cohort, with the only probable risk factor being surgery for an intraaxial pathology. Events requiring ICU management therefore appear to be relatively rare after posterior fossa surgery and optimization of ICU resource allocation appears feasible in this subgroup. Larger cohorts and possibly prospective studies are required to further establish risk factors and guide decision-making.