Orthostatic intolerance after fast‐track knee arthroplasty: Incidence and hemodynamic pathophysiology

Abstract

Background Early postoperative mobilization can be hindered by orthostatic intolerance (OI) due to failed orthostatic cardiovascular regulation. The underlying mechanisms are not fully understood and specific data after total knee arthroplasty (TKA) are lacking. Therefore, we evaluated the incidence of OI and the cardiovascular response to mobilization in fast‐track TKA. Methods This prospective observational cohort study included 45 patients scheduled for primary TKA in spinal anesthesia with a multimodal opioid‐sparing analgesic regime. OI and the cardiovascular response to sitting and standing were evaluated with a standardized mobilization procedure preoperatively, and at 6 and 24 h postoperatively. Hemodynamic variables were measured non‐invasively (LiDCO™ Rapid). Perioperative bleeding, fluid balance, surgery duration, postoperative hemoglobin, opioid use, and pain during mobilization were recorded. Results Eighteen (44%) and 8 (22%) patients demonstrated OI at 6 and 24 h after surgery, respectively. Four (10%) and 2 (5%) patients experienced severe OI and terminated the mobilization procedure prematurely. Dizziness was the most common OI symptom during mobilization at 6 h. OI was associated with decreased orthostatic responses in systolic, diastolic, mean arterial pressures, and heart rate (all p < .05), while severe OI patients demonstrated impaired diastolic, mean arterial pressures, heart rate, and cardiac output responses (all p < .05). No statistically significant differences in perioperative bleeding, fluid balance, surgery duration, postoperative hemoglobin, pain, or opioid use were observed between orthostatic tolerant and intolerant patients. Conclusion Early postoperative OI is common following fast‐track TKA. Pathophysiologic mechanisms include impaired orthostatic cardiovascular responses. The progression to severe OI symptoms appears to be primarily due to inadequate heart rate response.

Postoperative orthostatic intolerance following fast-track unicompartmental knee arthroplasty: incidence and hemodynamics—a prospective observational cohort study

“…This single-center prospective observational cohort study’s key finding is the low incidence of early OI after UKA of ~ 15%, compared to previously described incidence of ~ 40% after the more extensive TKA procedure [ 8 ]. No patients experienced severe OI preventing mobilization, hence all patients completed the mobilization procedure.…”

“…Previous observations on OI in TKA patients in our department showed an incidence of ~ 40% [ 8 ]. We assumed a lower OI incidence in UKA patients due to limited blood loss and assumed minor surgical trauma.…”

“…A single prospective observational study reported an OI incidence of 4% after superficial breast cancer surgery [ 9 ], while a recent retrospective study examining OI incidence and risk factors after knee arthroplasty only included eight UKA patients and reported OI in a single patient [ 17 ]. In contrast, numerous studies have described OI incidence of 40–60% after major surgical procedures, such as total knee arthroplasty [ 8 ], total hip arthroplasty [ 7 , 24 , 25 ], laparoscopic colorectal resection [ 5 ], radical prostatectomy [ 6 , 26 ], gastrectomies [ 27 ], laparoscopic gynecologic surgery [ 28 ] and various cardiothoracic procedures [ 28 , 29 ]. Hence, the findings in the current study further contribute to the notion that the severity of the surgical stress response plays a significant role in the development of OI.…”

“…A recent study investigating OI after TKA reported a high OI incidence of 44% and 22% at 6 and 24 h, respectively, whilst only 12% of patients were discharged at 24 h [ 8 ]. In addition to the lower incidence found in the current UKA study, our data also show that 75% of UKA patients were already discharged 24 h after surgery.…”

“…Postoperative OI is a complex condition with multifactorial pathogenesis that might include surgical stress response, residual anaesthesia effects, postoperative autonomic nervous system dysfunction, hypovolemia, pain and opioid use [ 4 ]. The incidence of early OI is reported to be 40–60% across several major procedures [ 5 , 6 ], including total hip [ 7 ] and total knee arthroplasty (TKA) [ 8 ]. On the contrary, minor surgical procedures such as superficial breast cancer surgery, have minimal OI sequelae [ 9 ], suggesting that the severity of the inflammatory response to surgery might play an important role in the development of OI.…”