ICU Staffing in the United States

Abstract

Background: The last national estimates of US ICU physician staffing are 25 years old and lack information about interprofessional teams.

Research question: How are US adult ICUs currently staffed?

Study design and methods: We conducted a cross-sectional survey (May 4, 2022-February 2, 2023) of adult ICU clinicians (targeting nurse/physician leadership) contacted using 2020 American Hospital Association (AHA) database information and, secondarily, through professional organizations. The survey included questions about interprofessional ICU staffing availability and roles at steady state (pre-COVID-19). We linked survey data to hospital data in the AHA database to create weighted national estimates by extrapolating ICU staffing data to nonrespondent hospitals based on hospital characteristics.

Results: The cohort consisted of 596 adult ICUs (response rates: AHA contacts: 2.1%; professional organizations: unknown) with geographic diversity and size variability (median, 20 beds; interquartile range, 12-25); most cared for mixed populations (414 [69.5%]), yet medical (55 [9.2%]), surgical (70 [11.7%]), and specialty (57 [9.6%]) ICUs were well represented. A total of 554 (93.0%) had intensivists available, with intensivists covering all patients in 75.6% of these and onsite 24 h/d in one-half (53.3% weekdays; 51.8% weekends). Of all ICUs, 69.8% had physicians-in-training and 77.7% had nurse practitioners/physician assistants. For patients on mechanical ventilation, nurse to patient ratios were 1:2 in 89.6% of ICUs. Clinical pharmacists were available in 92.6%, and respiratory therapists were available in 98.8%. We estimated 85.1% (95% CI, 85.7%-84.5%) of hospitals nationally had ICUs with intensivists, 51.6% (95% CI, 50.6%-52.5%) had physicians-in-training, 72.1% (95% CI, 71.3%-72.9%) had nurse practitioners/physician assistants, 98.5% (95% CI, 98.4%-98.7%) had respiratory therapists, and 86.9% (95% CI, 86.4%-87.4%) had clinical pharmacists. For patients on mechanical ventilation, 86.4% (95% CI, 85.8%-87.0%) used 1:2 nurses/patients.

Interpretation: We found that intensivist presence in adult US ICUs has greatly increased over 25 years. Intensivists, respiratory therapists, and clinical pharmacists are commonly available, and each nurse usually provides care for two patients on mechanical ventilation. However, team composition and workload vary.

Keywords: ICUs; nurse practitioners; nurses; pharmacists; physician assistants; physicians.

Graphical abstract

Figure 1

A, B, Overview of staffing across US ICUs. A, Intensivist coverage. B, Additional physician coverage. IMV = invasive mechanical ventilation; pts = patients.

Figure 2

Intensivist staffing models stratified by time of week among 596 cohort ICUs. Data from 554 ICUs reporting intensivist involvement.

Figure 3

Differences in staff responsibilities and support throughout the week among 596 cohort ICUs. The remainder of ICUs reported never having these responsibilities and/or supports throughout the week. †Out of 543 ICUs with an intensivist (n = 554) for which other responsibilities were not unknown (n = 11). ‡Out of 589 ICUs with RTs available to provide patient care. §Out of 552 ICUs with clinical pharmacists available to provide patient care. RT = respiratory therapist.

Figure 4

Nurse-to-patient ratios by patient type among 596 cohort ICUs. CRRT = continuous renal replacement therapy; ECMO = extracorporeal membrane oxygenation; EVD = extraventricular drain; IABP = intraaortic balloon pump; IMV = invasive mechanical ventilation; NIPPV = noninvasive positive pressure ventilation; pt = patient.