Association of elevated preoperative blood pressure with preincision hypotension in pediatric surgical patients

[Intraoperative hypotension in children-Measurement and treatment]

Intraoperative hypotension is a common perioperative complication in pediatric anesthesia. Oscillometric blood pressure measurement is therefore an essential part of standard perioperative monitoring in pediatric anesthesia. The optimum measurement site is the upper arm. Attention must be paid to the correct cuff size. Blood pressure should be measured before induction. In children undergoing major surgery or in critically ill children, invasive blood pressure measurement is still the gold standard. Continuous noninvasive measurement methods could be an alternative in the future.Threshold values to define hypotension remain unknown, even in awake children. There are also little data on hypotension thresholds in the perioperative setting. The most reliable measurement parameter for estimating hypotension is the mean arterial pressure. The threshold values for intraoperative hypotension are 40 mm Hg in newborns, 45 mm Hg in infants, 50 mm Hg in young children and 65 mm Hg in adolescents. Treatment should be initiated at a deviation of 10% and intensified at a deviation of 20%.Bolus administration of isotonic balanced crystalloid solutions, vasopressors and/or catecholamines are used as treatment options. Consistent and rapid intervention in the event of hypotension appears to be crucial. So far there is no evidence as to whether this leads to an improvement in outcome parameters.

Elevated preoperative blood pressure and its relationship to intraoperative mean arterial pressure and blood loss in posterior spinal fusion for adolescent idiopathic scoliosis

PURPOSE

The relationship between preoperative blood pressure (BP) and intraoperative mean arterial pressure (MAP) and estimated blood loss (EBL) in pediatric spine surgery is currently unknown. The objectives of this study were to determine if elevated preoperative BP is associated with elevated intraoperative MAP, EBL, and percentage estimated blood volume (EBV) lost, and to determine if intraoperative MAP is associated with percentage of EBV lost during posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS).

METHODS

This is a retrospective cohort analysis of 209 patients undergoing PSF for AIS between 2016 and 2019 by a single surgeon. Data extracted included demographic characteristics, preoperative systolic and diastolic BP, continuous intraoperative MAP measured by arterial line, EBL, radiographic, and surgical characteristics. Time points of interest for MAP included incision and exposure. Elevated BP was defined as > 1 standard deviation above the mean BP of patients included in the study, and elevated MAP was defined as > 65 mmHg.

RESULTS

Elevated preoperative systolic BP was associated with elevated MAP at incision (p = 0.002). Patients with elevated preoperative diastolic BP had significantly higher MAP at exposure and throughout the procedure (p = 0.04). MAP > 65 at incision was associated with a 5% increase in EBV lost (p < 0.001).

CONCLUSIONS

Patients with elevated preoperative BP parameters have increased MAPs at incision, exposure, and throughout surgery. Elevated MAP at incision is associated with an increased percentage of EBV lost in a small number of patients undergoing PSF for AIS.

Factors predicting the recovery from acute kidney injury in children with primary nephrotic syndrome

BACKGROUND

The prognosis of acute kidney injury (AKI) varies in children with nephrotic syndrome (NS), data on factors predicting the recovery and recurrence of AKI in children with NS are limited. This study aimed to explore the possible factors predicting the recovery from and recurrence of AKI in children with primary NS.

METHODS

Children with primary NS complicated with AKI from 1993 to 2017 in a single centre were reviewed retrospectively. The clinical pictures and possible factors predicting the recovery from and recurrence of AKI in children with primary NS were investigated.

RESULTS

Sixty-eight episodes of AKI in 59 children with NS were analysed: 88.2% of AKI recovered within 3 months, and 2.9% of AKI did not recover after 3 months. Survival analysis revealed that leucocyturia is significantly related to the AKI recovery time (P = 0.001), and children with leucocyturia [22 (4, 79) days] recovered significantly slower than did children without leucocyturia [12.0 (2, 39) days]. Renal tubular and interstitial injury were prominent in children with leucocyturia, and 11.9% of children with index AKI experienced the recurrence of AKI.

CONCLUSIONS

Most episodes of AKI that occurred in children with NS recovered completely. Leucocyturia is a significant factor predicting the recovery time of AKI.

Hormonal Blood Pressure Regulationduring General Anesthesia Usinga Standardized Propofol Dosagein Children and Adolescents SeemsNot to Be Affected by Body Weight

Obesity in pediatric surgical patients is a challenge for the anesthesiologist. Despite potentially beneficial properties, propofol might also induce hypotension. This study examined whether a dose adjustment in overweight children could avoid hypotension and if there would be differences regarding hormonal regulation in children under anesthesia. Fifty-nine children undergoing surgery under general anesthesia were enrolled in this prospective observational trial. Participants were allocated into two groups according to their BMI. The induction of anesthesia was conducted using propofol (“overweight”: 2 mg/kgBW, “regular”: 3.2 mg/kgBW). The maintenance of anesthesia was conducted as total intravenous anesthesia. Hormone levels of renin, angiotensin II, aldosterone, copeptin, norepinephrine and epinephrine were assessed at different timepoints. Blood pressure dropped after the administration of propofol in both groups, with a nadir 2 min after administration—but without a significant difference in the strength of reduction between the two groups. As a reaction, an increase in the plasma levels of renin, angiotensin and aldosterone was observed, while levels of epinephrine, norepinephrine and copeptin dropped. By adjusting the propofol dosage in overweight children, the rate of preincision hypotension could be reduced to the level of normal-weight patients with a non-modified propofol dose. The hormonal counter regulation was comparable in both groups. The release of catecholamines and copeptin as an indicator of arginine vasopressin seemed to be inhibited by propofol.

Risk factors for post-induction hypotension in children presenting for surgery

BACKGROUND

Preoperative factors have been correlated with pre-incision hypotension (PIH) in children undergoing surgery, suggesting that PIH can be predicted through preoperative screening. We studied blood pressure (BP) changes in the 12 min following the induction of anesthesia to study the incidence of post-induction hypotension and to assess the feasibility of predicting PIH in low-risk children without preoperative hypotension or comorbid features.

METHODS

We retrospectively evaluated 200 patients ranging in age from 2 to 8 years with American Society of Anesthesiologists' (ASA) physical status I or II, undergoing non-cardiac surgery. Patients were excluded if they had preoperative (baseline) hypotension (systolic blood pressure (SBP) < 5th percentile for age). BP and heart rate (HR) were recorded at 3 min intervals for 12 min after the induction of anesthesia. Pre-incision hypotension (PIH) was initially defined as SBP < 5th percentile for age: (1) at any timepoint within 12 min of induction; (2) for the median SBP obtained during the 12 min study period; or (3) at 2 or more timepoints including the final point at 12 min after the induction of anesthesia (sustained hypotension). In addition, we examined PIH defined as > 20% decrease in SBP from baseline: (4) at any timepoint within 12 min of the induction of anesthesia; (5) for the median SBP obtained during the 12 min study period; or (6) at two or more timepoints including the final point at 12 min after the induction of anesthesia. Agreement among the six definitions was analyzed, in addition to the effects of age, gender, type of anesthetic induction, use of premedication, preoperative BP, preoperative HR, and body mass index on the incidence of PIH according to each definition.

RESULTS

Five patients were excluded due to baseline hypotension and six were excluded for missing data. In the remaining cohort, estimated PIH prevalence ranged from 4% [definition (Stewart et al., in Paediatr Anaesth 26:844-851, 2016), sustained PIH according to SBP percentile-for-age] to 57% [definition (Task Force on Blood Pressure Control in Children, in Pediatrics 79:1-25, 1987), at least one timepoint where SBP was > 20% lower than baseline]. Pairwise agreement among the six definitions ranged from 49 to 91% agreement. No sequelae of PIH were noted during subsequent anesthetic or postoperative care. On multivariable analysis, no covariates were consistently associated with PIH risk across all six definitions of PIH.

CONCLUSION

The present study describes the incidence and prediction of PIH in a cohort of relatively healthy children. In this setting, accurate prediction of PIH appears to be hampered by lack of agreement between definitions of PIH. Overall, there was a low PIH incidence when the threshold of SBP < 5th percentile for age was used.

LEVEL OF EVIDENCE

II.