Prevalence and Risk Factors for Intraoperative Hypotension During Craniotomy for Traumatic Brain Injury

Abstract

Background Hypotension after traumatic brain injury (TBI) is associated with poor outcomes. However, data on intraoperative hypotension (IH) are scarce and the effect of anesthetic agents on IH is unknown. We examined the prevalence and risk factors for IH, including the effect of anesthetic agents during emergent craniotomy for isolated TBI. Methods A retrospective cohort study of patients ≥ 18 years who underwent emergent craniotomy for TBI at Harborview Medical Center (level-1 trauma center) between October 2007 and January 2010. Demographic, clinical and radiographic characteristics, hemodynamic and anesthetic data were abstracted from medical and electronic anesthesia records. Hypotension was defined as systolic blood pressure (SBP) < 90 mmHg. Univariate analyses were performed to compare the clinical characteristics of patients with and without IH and multiple logistic regression analysis was used to determine independent risk factors for IH. Results Data abstracted from 113 eligible patients aged 48±19 years was analyzed. Intraoperative hypotension was common (n=73, 65%) but not affected by the choice of anesthetic agent. Independent risk factors for IH were multiple Computed Tomographic (CT) lesions (AOR 19.1 [95% CI: 2.08–175.99]; p=0.009), SDH (AOR 17.9 [95% CI: 2.97–108.10]; p=0.002), maximum CT lesion thickness (AOR 1.1 [95% CI: 1.01–1.13]; p=0.016), and anesthesia duration (AOR 1.1 [95% CI: 1.01–1.30]; p=0.009). Conclusion Intraoperative hypotension was common in adult patients with isolated TBI undergoing emergent craniotomy. The presence of multiple CT lesions, subdural hematoma, maximum thickness of CT lesion and longer duration of anesthesia increase the risk for IH.

Intraoperative Secondary Insults During Orthopedic Surgery in Traumatic Brain Injury

“…Unlike Townsend et al 11 who recommended delaying surgery to prevent secondary insults including hypotension, similar to our results, Velhamos et al 12 and Kalb et al 14 reported no difference in intraoperative hypotension based on timing of orthopedic surgery. Interestingly, the prevalence of intraoperative hypotension in this series is similar to the 65% prevalence we recently reported during craniotomy for TBI 9 indicating that hypotension is a common problem, irrespective of the type of surgery in TBI patients. Avoidance of hypotension may be crucial even in patients undergoing surgery days after TBI because cerebral autoregulation may be impaired up to 2 weeks after moderate-severe TBI, 33 predisposing them to the risk of cerebral ischemia.…”

“…25,26 In addition, surgical intervention leads to fluid shifts and blood loss. Secondary insults during craniotomy for TBI have been reported, 9,10,27–32 and as evidenced by our data here, secondary insults are also common during orthopedic surgery in patients with TBI and may contribute to worse outcomes. Therefore, anesthesiologists can potentially contribute to improving TBI outcomes by reducing the burden of secondary insults during craniotomy as well as extracranial surgery.…”

“…3–8 Although previous studies have examined secondary insults in the pre-hospital period, during transportation to a tertiary care center, in the emergency department and in the intensive care setting, 3–8 data on intraoperative secondary insults are limited. 9,10 Moreover, patients with TBI frequently have associated orthopedic injuries requiring surgical intervention and data on secondary insults during orthopedic surgery in TBI and their impact on neurological outcomes are sparse and old. 11–14 …”

“…Given the advances in anesthetic and intraoperative management in general, and the modification of clinical care guidelines for TBI management (such as change in the recommended cerebral perfusion pressure {CPP} goal to 50–70 mmHg), 17 it is important to quantify the current burden of intraoperative secondary insults and examine their impact. We have previously reported on intraoperative secondary insults during craniotomy for TBI 9,10 but secondary insults in other surgical settings were not examined. The primary aim of this retrospective study was to examine the prevalence of intraoperative secondary insults during orthopedic surgery within 2 weeks of moderate-severe TBI.…”

Perioperative Management of Adult Traumatic Brain Injury

“…45 Moreover, the presence of multiple CT lesions, subdural hematoma, maximum thickness of CT lesion and longer duration of anesthesia increase the risk for intraoperative hypotension, and anesthesiologists can use the presence of these factors to anticipate and expediently address these complications. 46 Perioperative hypotension should be treated promptly. Warm, non-glucose containing isotonic crystalloid solution is preferable for intravenous administration in TBI patients.…”