The “weekend effect” (WE) is a term used to describe poorer patient outcomes associated with treatment out-of-hours. There has been debate in the human literature if this effect is “real” or not. Specific focus has been aimed at mortality or morbidity associated with the WE. A recent study in England, looked at the WE in relation to decompressive hemilaminectomy surgery in a cohort study (comparing a poputation of dogs having surgery afterhours to those operated during business hours) and, I found it informative. (Low D, et al. Veterinary Surgery. 2024;1–10.)
You may be aware that the timing of spinal cord decompression has been hotly debated over the past…oh..100 years or so. Recently, some studies have suggested that surgical decompression for an acutely non-ambulatory dog is not an emergency and therefore can occur during normal business hours. This has been suggested for dogs with and without deep pain sensation. Additional studies have supported that in fact it DOES matter and those studies advocate for decompression of dogs with a loss of deep pain within 24 hours of documented loss of deep pain. I tend to favor the “don’t wait, cut ASAP” approach but the choice is controversial. The study by Low and colleagues from England did not address the pros or cons of timing of surgery but instead looked at outcome (did they walk, or not) and adverse events (urinary tract infections, gastric ulcers, skin infections/ulcers, post operative neurologic deterioration, etc.) for dogs undergoing back surgery within or outside of business hours.
The findings of this study were interesting. They identified a significant difference in postoperative morbidity and the recovery of ambulation in a group of dogs undergoing surgery afterhours vs those undergoing surgery during business hours. They stated that 1 in 8 dogs would not recovery ambulation when exposed to weekend surgery compared to if they were exposed to weekday surgery. Furthermore 1 in 7 dogs would experience an additional post operative morbidity when exposed to weekend surgery, compared to weekday surgery.
What contributed to the results? The variables for a patient undergoing, and recovering from, surgery are numerous regardless of the timing of the surgery. For example, there are pre-hospital variables (such as the timing and treatment provided by the referring vet), hospital variables (staff tiredness, case load, surgeon experience) and post-hospital factors (availability of aftercare support in the patient’s home, the hospital discharge process). Many of the hospital variables were evaluated in the study and not statistically associated with outcome or morbidity. The pre- and post-hospital factors are more difficult to study due to the inherently heterogenous state.
What do I do with this information? I included this study as at TidBit Tuesday to increase awareness of the possible WE in both veterinary medicine at large (yet to be fully determined) and specifically within neurosurgery. The data does not suggest that you shouldn’t make a referral if you have a nonambulatory patient, especially if they’ve lost deep pain! It also shouldn’t be used to deter a client from pursuing surgery on a weekend or afterhours. I’m not sure there is an actionable outcome by gaining this knowledge, except for the simple purpose of increasing your (and my) knowledge of the existence of a WE. By being aware, we can sometimes change our actions in subtle ways that may improve the outcome for our patients. Have you ever managed an especially difficult seizure patient? What if you had a dog develop liver disease while taking zonisamide or phenobarbital? Those cases increase our awareness of the “bad” outcomes and increase our sensitivity to treating the next seizure case, or next dog on zonisamide or phenobarbital. In fact, population statistics would suggest that a low number of dogs have resistant epilepsy but when it is 1 of your 10 or so cases that you’ve managed it feels like a high risk and may change how you discuss seizures with the next client that walks in the door with a pet with seizures. Awareness of the WE may change how we, as neurologists, operate and intern may affect the WE. Time shall tell!
Thanks for reading through this long TidBit. I hope you enjoyed the lovely weekend weather (it was in the 70s for us!) and have a wonderful week.