Geographic disparities in performance of pediatric polysomnography to diagnose obstructive sleep apnea in a universal access health care system

BACKGROUND

Diagnostic polysomnography (PSG) is recommended prior to adenotonsillectomy (AT) for children with obstructive sleep apnea (OSA) and certain high-risk characteristics, but resource limitations often prevent this practice.

OBJECTIVE

We performed a population-based assessment of children across Ontario, Canada to describe and quantify disparities in PSG.

METHODS AND MATERIALS

This retrospective cohort study was performed using provincial health administrative data held at ICES. We identified children 0-10 years old who underwent PSG and AT between 2009 and 2018, and those with a PSG within 18 months prior to and/or 12 months following AT. We calculated the odds of PSG prior to/following AT after adjustment for demographics, medical comorbidities, geographic and socioeconomic characteristics. Our main predictor was driving time/distance to the nearest pediatric sleep centre ascertained using spatial analysis and geographic information systems.

RESULTS

We identified 27,837 children <10 years old who underwent AT for OSA in Ontario. Only 12.8% had a PSG within 18 months prior and 5.7% had a PSG within 12 months following AT. Shorter driving time/distance, older age, male sex and certain comorbidities were associated with increased odds of PSG.

CONCLUSION

Only a small proportion of children in our cohort underwent PSG prior to or following AT surgery despite universal access to healthcare. This study suggests a need to increase overall PSG access, particularly for those living distant from existing pediatric sleep centres. Future studies could determine if increased PSG testing in 'underserviced areas' would reduce overall surgery rates and/or improve health outcomes.

A randomized trial of tranexamic acid to reduce blood transfusion for scoliosis surgery

Pediatric patients who undergo posterior spinal fusion surgery to correct scoliosis often require multiple blood transfusions. Tranexamic acid is a synthetic antifibrinolytic drug that reduces transfusion requirements in cardiac surgery and total knee arthroplasty. We evaluated the efficacy of prophylactic tranexamic acid to reduce perioperative blood transfusion requirements in a prospective, double-blinded, placebo control study. Forty patients, 9-18 yr of age, were randomized to either tranexamic acid (initial dose of 10 mg/kg and infusion of 1 mg. kg(-1). h(-1)) or placebo (isotonic saline). Perioperative management was standardized. A uniform transfusion threshold for noncell saved red blood cells was 7.0 g/dL. The total amount of blood transfused in the perioperative period was significantly reduced in the Tranexamic group (P = 0.045). No thrombotic complications were detected in either group. The administration of prophylactic tranexamic acid in patients with scoliosis undergoing posterior spinal fusion surgery has the potential to reduce perioperative blood transfusion requirements.

IMPLICATIONS

The administration of prophylactic tranexamic acid in patients with scoliosis who are undergoing posterior spinal fusion surgery has the potential to reduce perioperative blood transfusion requirements.

Cerebral microembolization during pediatric scoliosis surgery: a transcranial doppler study

SUMMARY

The goal of this study was to identify cerebral microemboli during scoliosis surgery and their potential relationship with visual alterations. Transcranial Doppler identified high-intensity transient signals (HITS) during surgery in both middle cerebral arteries, and ophthalmologic examination assessed their potential effects on the visual system. Thirteen children (age 13-17 years) undergoing surgery for scoliosis or kyphosis with spine curvature >45 degrees were studied. HITS were identified in 92%. Eleven patients had a total count of <15 HITS, but in the remaining two the count was unexpectedly high (63 and 265 HITS). Echocardiography in these two patients indicated the presence of an atrial right-to-left shunt. Uneventful preoperative and postoperative visual function was found in 11 patients. One patient had preoperative blindness and in another ophthalmologic complications developed not related to microembolization. Scoliosis surgery is frequently associated with low counts of cerebral microemboli. It appears that such low embolic counts have no effects on postoperative visual function as determined clinically. Some patients may show high rates of microemboli, which may be related to the presence of right-to-left cardiac shunts. The impact of these signals on brain function remains to be investigated.

Adding low dose meperidine to spinal lidocaine prolongs postoperative analgesia

PURPOSE

To investigate the effects of the addition of low dose meperidine to spinal lidocaine on the sensory and motor blockade profile, and the quality and duration of postoperative analgesia.

METHODS

In a randomized double blind prospective dose finding study 40 patients undergoing transurethral prostatectomy with spinal anesthetic were allocated to receive 75 mg lidocaine 5% intrathecally as the sole agent (group A), or co-administered with 0.15 mg x kg(-1) meperidine (group B) or 0.30 mg x kg(-1) meperidine (group C). Sensory and motor blockade profiles were documented. Postoperatively, the amount of analgesics required, time to first analgesic, visual analogue scores and adverse events were recorded.

RESULTS

Sensory blocks at or above T10 was maintained for 128, 156 and 145 minutes in groups A, B and C respectively. There was no difference in the latency or duration of the motor block among the three groups. Patients in group C had lower visual analogue pain scores (VAPS) over time than did those in groups A and B (P < 0.05). Time to first analgesia was longer (429 +/- 197 minutes) in group C than in group A (254 +/- 157 minutes) (P < 0.05). Fewer patients in group C required parenteral opioid postoperatively than in group A (P < 0.05). The incidence of bradycardia was higher in the groups receiving meperidine. No symptoms of transient radicular irritation (TRI) were reported in the groups receiving meperidine.

CONCLUSION

The addition of 0.3 mg x kg(-1) of meperidine to spinal lidocaine prolongs postoperative analgesia without delaying discharge from post anesthetic care unit (Table II) and reduces the requirement for parenteral analgesics (Table III).

Cerebral blood flow velocity during occlusive manipulation of patent ductus arteriosus in children

Patent ductus arteriosus (PDA) with left-to-right shunting modifies the Doppler flow pattern of the intracranial circulation. The ability of increases in cerebral blood flow velocity (CBFV) to predict shunt resolution during PDA occlusion was evaluated. A 2 MHz transcranial Doppler (TCD) monitored diastolic and mean CBFV, plus the systolic/mean CBFV ratio in the middle cerebral artery from before (baseline) to immediately after PDA occlusion. Shunt resolution was verified by echocardiography and/or angiography. A minimum of 40% increase in diastolic-CBFV from baseline was considered successful resolution. Patients were age-stratified into group I (< 15 months; n = 23) and group II (> 15 months; n = 10). Thirty-three children were studied (age, 0.1 to 109 months) during surgical (n = 22) or coil occlusions (n = 11). Transcranial Doppler successfully identified shunt resolution in 78% of cases in group I, as compared to 0% in group II (p < 0.01). Identification rate decreased from 79% in cases of minimum ductal diameter of 3 mm (n = 19) to 21% in smaller ductuses (n = 14) (p < 0.01). Body weight and left-atrium size (p = 0.004) in group I and PDA diameter in group II (p = 0.02), were the only preoperative ductal parameters associated with diastolic-CBFV changes after ductus occlusion. Transcranial Doppler detects shunt resolution in infants with moderate to large PDAs.