Pulmonary Dysfunction and Therapeutic Hypothermia in Asphyxiated Newborns: Whole Body versus Selective Head Cooling

Abstract

Compared with whole body cooling (WBC), selective head cooling (SHC) of asphyxiated newborns presumably allows effective brain cooling with less systemic hypothermia and potentially fewer systemic adverse effects. It is not known if pulmonary dysfunction, one of the potential adverse systemic effects of therapeutic hypothermic neuroprotection, differs with the method of cooling. We sought to investigate if pulmonary mechanics and gas exchange during therapeutic hypothermia differ between WBC and SHC. The severity of pulmonary dysfunction was determined in 59 asphyxiated newborns receiving therapeutic hypothermic neuroprotection by either SHC (n ¼ 31) or WBC (n ¼ 28). Ventilatory parameters and simultaneous alveolar-arterial oxygen gradient (A-a DO 2 ) and partial pressure of carbon dioxide, arterial (PaCO 2 ) were measured before the start of cooling (baseline), and at 4, 8, 12, 24, 48, and 72 hours of cooling. The diagnosis of persistent pulmonary hypertension of the newborn (PPHN) was established by echocardiography. Clinical monitoring and treatment during cooling, whether SHC or WBC, were similar. All (96%) but two infants (from the SHC group) required mechanical ventilation of varying duration during cooling, and nine infants (15%) developed PPHN. The baseline ventilator pressures requirement, and A-a DO 2 were similar among the 48 ventilated infants without PPHN (WBC 23, SHC 25) at the start of cooling. Ventilatory requirements remained modest and did not differ with the method of cooling. Similar numbers of infants without PPHN were able to be extubated after improvement in respiratory status while being cooled (WBC 42.8% versus SHC 37.9%, p ¼ 0.79, odds ratio [OR] 1.2, 95% confidence interval [CI] 0.4 to 3.5). Nine infants (WBC 5, SHC 4) developed PPHN. Six of the nine (WBC 4, SHC 2) required inhaled nitric oxide therapy, and one infant from the WBC group subsequently required extracorporeal membrane oxygenation. The incidence of PPHN was similar in both the WBC and SHC groups (17.8% versus 12.9%, p ¼ 0.72, OR 1.5, 95% CI 0.3 to 6.1). Pulmonary dysfunction is common but not severe in asphyxiated infants during therapeutic hypothermia. Pulmonary mechanics and gas exchange do not differ with the method of achieving hypothermia.

Effects of therapeutic hypothermia on multiorgan dysfunction in asphyxiated newborns: whole-body cooling versus selective head cooling

“…The demographic characteristics, acute intrapartum sentinel event (if known) and clinical and laboratory evidence of an intrapartum hypoxic-ischemic event (apgar scores at 5 and 10 min, clinical seizures before admission, pH and base deficit within 60 min of birth and stages of encephalopathy) at the initiation of cooling for the 28 WBC and 31 SHC infants have been reported and were similar between the two groups. 9 Of the 59 cooled infants (WBC-28, SHC-31), all but two infants from the SHC group required mechanical ventilation for varying duration and nine infants (WBC-5, SHC-4) developed PPHN during cooling ( Table 2). As reported earlier, 9 the incidence of PPHN was similar in both the WBC and SHC groups and equivalent numbers of infants from both groups were extubated after an improvement in respiratory status while still being cooled (Table 2).…”

“…Data collection for this present observation has been detailed elsewhere. 9 Cooling for the infants was started after written informed consent from a parent, and the study was approved by the Institutional Review Board.…”

“…The entry and exclusion criteria for recruitment of the infants have been reported earlier. 9 Clinical monitoring and treatment during cooling, whether SHC or WBC, were carried out according to the cool cap and NICHD WBC protocols. 6,7 The multiorgan dysfunction in infants during 72 h of therapeutic hypothermia, achieved by either SHC or WBC, was assessed by undertaking clinical monitoring, physiological recordings and laboratory tests at predefined time points, as originally described in the cool cap protocol.…”

Comparison of selective head cooling therapy and whole body cooling therapy in newborns with hypoxic ischemic encephalopathy: Short term results

“…Therefore, we think that seasonal conditions and environmental temperature should also be considered in babies who are transported by applying passive cooling. It may be questioned why active cooling was not performed during transportation in 31 Türk Ped Arş 2015; 50: [27][28][29][30][31][32][33][34][35][36] Atıcı et al Selective head cooling or whole body cooling the babies whose rectal temperatures were above 35° at the time of admission in our center in our study. The reason for this was concern about the possibility of development of deep hypothermia related with active cooling and active cooling during transportation is only recommended in cases where the rectal temperature can be monitorized continuously (30).…”

“…Necrotizing enterocolitis, hypoglycemia or hemoconcentration was not observed in any baby in the SHC and WBC groups. One of the babies who were applied SHC and one of the babies who were 29 Türk Ped Arş 2015; 50: [27][28][29][30][31][32][33][34][35][36] Atıcı et al Selective head cooling or whole body cooling applied WBC (8%) died in the hospital. There was no significant difference between the two groups in terms of in-hospital mortality (p=0.665).…”