# Role of Central Venous Pressure and Mean Arterial Pressure to Central Venous Pressure Ratio in Assessing Poisoning Severity and Poor Outcomes in Intensive Care Unit-Admitted Acute Aluminum Phosphide-Poisoned Patients

## TL;DR

This study shows that higher central venous pressure and lower MAP/CVP ratios in ICU patients poisoned with aluminum phosphide are linked to higher mortality and need for mechanical ventilation.

## Contribution

The study introduces the MAP/CVP ratio as a novel prognostic tool for predicting outcomes in acute aluminum phosphide poisoning.

## Key findings

- Higher CVP levels (≥25 mmHg) and lower MAP/CVP ratios (≤2.48) are strongly associated with increased in-hospital mortality.
- MAP/CVP ratio demonstrated better predictive power than CVP alone for mechanical ventilation and mortality.
- Non-survivors showed increased CVP after vasopressor administration, while survivors showed a decrease.

## Abstract

Aluminum phosphide (ALP) is a highly toxic pesticide endangering the healthcare system. Higher central venous pressure (CVP) values may be linked to poorer outcomes in various medical conditions. This study evaluated the role of CVP and mean arterial pressure (MAP)/CVP ratio as prognostic factors for intensive care unit (ICU) admitted acute ALP-poisoned patients. This retrospective study included 145 acutely ALP-poisoned patients who were referred to the ICU during two years. Data regarding history, clinical manifestations, laboratory investigations, and outcome were collected and stratified by quartiles (Q1-Q4) of the measured CVP during the first 6 h after admission. In-hospital mortality and need for mechanical ventilation (MV) were significantly predominant in Q3 and Q4 groups of CVP levels (89.4% and 92% & 91.5% and 96%, respectively) (p-values < 0.001). After vasopressors administration, survivors demonstrated a significant mean reduction in CVP measurements (–4.5 mmHg), whereas non-survivors had a mean increase (+ 0.6 mmHg) (p = 0.011). MAP/CVP ratio has good discriminatory power (the areas under the curve (AUCs) = 0.836 and 0.846) for predicting the need for MV and in-hospital mortality, respectively. The CVP measurement (AUCs = 0.812 and 0.782, respectively) comes in second, followed by the poisoning severity score (AUCs = 0.778 and 0.768, respectively). There was a significant decrease in survival probability in patients with CVP ≥ 25 mmHg, and MAP/CVP ratio ≤ 2.48 (p-values < 0.001). Lower MAP/CVP ratios and higher CVP measurements are alarming signs, warranting a higher risk of the need for MV and in-hospital mortality in acute ALP poisoning.

The online version contains supplementary material available at 10.1007/s12012-026-10103-0.