Comparison between pulse waveform analysis and thermodilution cardiac output determination in patients with severe pre-eclampsia.

BACKGROUND: This study compared cardiac output (CO) measurements derived from pulse waveform analysis with values obtained by thermodilution (TD), in patients with post-partum complications of severe pre-eclampsia. METHODS: Eighteen patients were recruited, 24-96 h post-delivery. After central venous calibration of the pulse waveform analysis monitor (LiDCOplus), CO readings were compared with those obtained by the TD method and repeated twice at 15 min intervals. The comparison was repeated after peripheral venous calibration. Further comparisons were made in eight patients at 120 and 240 min after peripheral venous calibration. RESULTS: Data were pooled for measurements at 0, 15, and 30 min after calibration. For the comparison between TD and LiDCOplus using central venous calibration, TD exhibited a significant positive bias of 0.58 litre min⁻¹ [95% confidence interval (CI): 0.77 to 0.39]. After peripheral venous calibration, there was no significant bias [0.16 litre min⁻¹ (95% CI: -0.37 to 0.06)]. The estimated limits of agreement for central and peripheral venous calibrations were -2.12 to 0.96 and -1.50 to 1.20 litre min⁻¹, respectively. When comparing LiDCOplus and TD, there was no time-based effect at 120 or 240 min post-peripheral calibration. CONCLUSIONS: Central and peripheral venous calibrations of the LiDCOplus monitor were associated with clinically insignificant bias when compared with TD. Limits of agreement were within the recommendation of 30% for acceptance of a new CO technique when compared with current reference methods. This form of minimally invasive CO monitoring may have a valuable role in obstetric critical care.

The organisational response of a hospital critical care service to the COVID-19 pandemic: The Groote Schuur Hospital experience.

Background: There are limited data about the coronavirus disease-19 (COVID-19)-related organisational responses and the challenges of expanding a critical care service in a resource-limited setting. Objectives: To describe the ICU organisational response to the pandemic and the main outcomes of the intensive care service of a large state teaching hospital in South Africa. Methods: Data were extracted from administrative records and a prospective patient database with ethical approval. An ICU expansion plan was developed, and resource constraints identified. A triage tool was distributed to referring wards and hospitals. Intensive care was reserved for patients who required invasive mechanical ventilation (IMV). The total number of ICU beds was increased from 25 to 54 at peak periods, with additional non-COVID ICU capacity required during the second wave. The availability of nursing staff was the main factor limiting expansion. A ward-based high flow nasal oxygen (HFNO) service reduced the need for ICU admission of patients who failed conventional oxygen therapy. A team was established to intubate and transfer patients requiring ICU admission but was only available for the first wave. Results: We admitted 461 COVID-19 patients to the ICU over a 13-month period from 5 April 2020 to 5 May 2021 spanning two waves of admissions. The median age was 50 years and duration of ICU stay was 9 days. More than a third of the patients (35%; n=161) survived to hospital discharge. Conclusion: Pre-planning, leadership, teamwork, flexibility and good communication were essential elements for an effective response. A shortage of nurses was the main constraint on ICU expansion. HFNO may have reduced the requirement for ICU admission, but patients intubated after failing HFNO had a poor prognosis. Contributions of the study: We describe the organisational requirements to successfully expand critical care facilities and strategies to reduce the need for invasive mechanical ventilation in COVID-19 pneumonia. We also present the intensive care outcomes of these patients in a resource-constrained environment.