All the data everyone keeps asking about will come. As many have eluded to previously, all the current outcomes research attempts to look at anesthesitc realated morbidity and mortality which is rare and hard to tease out. But even in those situations evidence is present that supports decreased morbidity and mortality with anesthesiologist involvment. The classic study often pushed by my CRNA colleagues really should be thrown out but I want to dive into the article:
Outcomes looked at:
To measure possible anesthesia complications, we identified seven relevant patient safety indicators developed by the Agency for Healthcare Research and Quality:
15 complications of anesthesia (patient safety indicator 1); death in low-mortality diagnoses (indicator 2); failure to rescue from a complication of an underlying illness or medical care (indicator 4); iatrogenic pneumothorax, or collapsed lung (indicator 6); postoperative physiologic and metabolic derangements, or physical or chemical imbalances in the body (indicator 10); postoperative respiratory failure (indicator 11); and transfusion reaction (indicator 16).
Numbers:
This left us with 481,440 hospitalizations for analysis, of which 412,696 were in non-opt-out states and 68,744 were in opt-out states. Of the latter, 41,868 hospitalizations occurred before the state had opted out.
(so a total of 26,876 cases perfromed with a solo CRNA without a physician supervising.)
Hospitalizations without a Part B anesthesia claim were excluded unless a surgical procedure took place in a Medicare “pass-through” hospital. In these hospitals, claims for services by nurse anesthetists are rolled into (“passed through”) the Part A hospital claims. Therefore, observations from these hospitals were assigned to the certified registered nurse anesthetist solo category.
(Most independent CRNAs cases occur in these hospitals, so of the 26, 876 total "solo CRNA" cases some of them likely did not even involve a CRNA...flex sigs, cardiac caths, lumps and bumps etc..and just had RN sedation)
Statistical games:
We did find that case-mix complexity was different for the two types of providers. Anesthesia base units for procedures in which anesthesiologists practiced solo were a full point higher than for procedures in which certified registered nurse anesthetists worked alone.
Although base units might not completely describe the complexity of either surgical or anesthetic procedures, base units were associated with a statistically greater mortality risk in our multivariate model. We estimate that each one-point increase in procedure base units is associated with a 7 percent higher mortality risk.
Anesthesiologists practicing alone were involved in more complex surgical procedures than certified registered nurse anesthetists practicing alone. Therefore, we adjusted anesthesiologist solo mortality rates by applying to the anesthesiologist solo group the nurse anesthetist case-mix for surgeries that the two providers had in common
So they looked at a very small number of basic surgical cases perfromed by "solo CRNAs" and found no difference in anesthetic related morbidity and mortality between solo CRNA and anesthesiologist involvement...real shocker. Not sure 26, 876 cases perfromed by "Solo CRNAs" over a 7 yr period even comes close to having enough power to suggest the following conclusion made by the article:
Policy Recommendations
Our analysis of seven years of Medicare inpatient anesthesia claims suggests that the change in CMS policy allowing states to opt out of the physician supervision requirement for certified registered nurse anesthetist reimbursement was not associated with increased risks to patients. In particular, the absolute increase in the provision of anesthesia by unsupervised nurse anesthetists in opt-out states was virtually identical to the increase in non-opt-out states, and the proportional increase was smaller in opt-out states.
This lends no support to the belief that a meaningful shift in provider shares occurred as a consequence of the policy change. Similarly, our analysis found no evidence to suggest that there is an increase in patient risk associated with anesthesia provided by unsupervised certified registered nurse anesthetists.
Both a change in the proportion of anesthesia provided by the different groups—nurse anesthetists alone, anesthesiologists alone, and nurse anesthetists and anesthesiologists working in teams—and a difference in the outcomes of the different groups are necessary to conclude that the change in CMS policy led to changes in patient safety. Because our data provide no evidence to support either of these conditions, we conclude that patient safety was not compromised by the opt-out policy.
We recommend that CMS return to its original intention of allowing nurse anesthetists to work independently of surgeon or anesthesiologist supervision without requiring state governments to formally petition for an exemption. This would free surgeons from the legal responsibility for anesthesia services provided by other professionals. It would also lead to more-cost-effective care as the solo practice of certified registered nurse anesthetists increases.
