11: Use of the Intensive Care Unit

INTRODUCTION

The practice of critical care medicine has its roots in the resuscitation of dying patients, and it focuses on the restoration of normal physiology without necessarily involving a complete understanding of a patient’s chronic conditions. Over the past several decades, critical care has led to improved patient survival from many serious conditions. This is the direct result of noninvasive and invasive tools used to describe and correct pathophysiology.²⁹

Like many critically ill patients, the history of poisoned patients is often partial or incomplete, thereby confounding their care. The history is often unreliable regarding the xenobiotic ingested, time of ingestion, and amount ingested, even further complicating care. Additionally, the xenobiotic may have unknown or unpredictable effects at the exposure dose. Finally, the therapies, antidotes, and complications of acute poisoning may be unfamiliar to the intensive care unit (ICU) staff. These uncertainties challenge health care providers and influence decisions about admitting poisoned patients to the ICU.

In 2011, the American Association of Poison Control Centers (AAPCC) National Poison Database System (NPDS) reported 2,334,004 human exposures, of which 615,869 required health care facility management. Most patients did not require critical care, with only 7% of the total human exposures reporting moderate/major clinical outcomes or death and only 101,175 of the admitted patients admitted to critical care units; this represented only 4.3% of all human exposures reported that year.⁷ Most critically ill poisoned patients have acutely reversible conditions that will clearly benefit from an ICU intervention,⁶⁹ with a total attributable mortality of only 0.06%.

Unlike many patients with diseases managed in the ICU, poisoned patients are often admitted to the ICU for observation and monitoring, not for intervention.⁹³ Fewer than 25% of those hospitalized required specific treatments or antidotes other than gastrointestinal (GI) decontamination.^6,93 Many physicians elect to observe poisoned patients in an ICU in anticipation of possible delayed, unrecognized life-threatening toxicity. The ICU provides necessary monitoring and individual nursing care that can help in the early recognition of developing toxicity. ICUs give health care providers the best opportunity to minimize morbidity and decrease mortality. However, ICU care is very expensive and has contributed significantly to the escalation of health care costs. In addition, critical care units struggle with overcrowding, requiring a justifiable decision-making process for each and every patient before committing these valuable resource.

The decision to admit a patient to a critical care unit is multifactorial. Patient characteristics, the need for acute reversal of physiologic abnormalities, and the characteristics of the exposure are all potential reasons for admission. Beyond managing the obvious end-organ toxicity requiring intervention, the ICU is especially useful for observing patients for the progression of end-organ effects that may require intervention. Because the natural course of a toxicologic emergency is often unpredictable, consideration must be given to patients at risk of deteriorating to the point that critical care interventions are required. ...