Whether DSP status is a cause or a marker, the question that clinicians must answer as a part of perioperative risk stratification is whether drug screening results identify a population for whom general anesthesia is unsafe. The literature shows little evidence that a positive drug screen increases anesthetic risk.[8161718] However, because of the harm of chronic drug abuse, the presence of illegal drugs on a screening test has raised concerns for perioperative cardiac risk.[919] A survey study showed that 30% of providers believe that cocaine-positive patients should wait 7 days after a positive drug screen before undergoing an elective surgical procedure.[10]

Time to procedure is one of the few predictor variables that is potentially modifiable in the acute setting. Theoretically, by delaying procedures, one could operate at a time when the patient is less vulnerable to drug-related cardiac complications as the drugs are metabolized and eliminated. We can look at the rate of complications versus time to surgery to see if waiting longer is associated with lower risk.

The early increased risk is not surprising because procedures done within the first few hours typically address life-threatening conditions. However, when a procedure is classified as urgent rather than emergent, surgeons have more control over the timing. Surgery can often be delayed for a matter of days. There are some cases when polytraumatized patients may benefit from the delay of major surgical procedures. A model for deciding when cases should be delayed is damage control orthopedics.

There is evidence of better outcomes delaying orthopedic procedures for unstable patients. Early surgery may increase the systemic inflammatory response and lead to a “second hit”, whereas an initial period of recovery may make surgery safer. Predictors of morbidity include physiologic variables such as temperature, base deficit, and lactate.[20212223]

If the patient is stable, early appropriate care leads to better outcomes.[24] There is even evidence that delay may increase cardiac complications. In a study of geriatric hip fracture patients, Smeets et al. found that preoperative cardiac evaluation in excess of ACC/AHA guidelines (overscreening) increased delay to surgery by 9.9 h. Delay to surgery of more than 48 h was associated with more postoperative cardiovascular complications and mortality.

While there is evidence of benefit from delaying cases according to the principles of damage control, there is little evidence that delaying cases due to drug screening results improve risk. Ryb and Cooper showed that among trauma patients undergoing surgery the 1^st posttrauma day, cocaine status did not increase complications.[25] Our results are consistent with this study.

If it were beneficial to delay surgery until drugs of abuse are eliminated, we would expect an initial higher risk with DSP patients which would converge with DSN patients over time. Instead, our results show that the perioperative cardiac risk for DSP patients is lower than that for DSN patients for every time interval until first procedure. The multivariate analysis of time until procedure as a continuous variable shows that DSP patients experience greater cardiac risk with increasing time of delay.