Continuous controlled-infusion of hypertonic saline solution in traumatic brain-injured patients: a 9-year retrospective study

Abstract

Introduction: Description of a continuous hypertonic saline solution (HSS) infusion using a dose-adaptation of natremia in traumatic brain injured (TBI) patients with refractory intracranial hypertension (ICH).

Methods: We performed a single-center retrospective study in a surgical intensive care unit of a tertiary hospital. Fifty consecutive TBI patients with refractory ICH treated with continuous HSS infusion adapted to a target of natremia. In brief, a physician set a target of natremia adapted to the evolution of intracranial pressure (ICP). Flow of NaCl 20% was a priori calculated according to natriuresis, and the current and target natremia that were assessed every 4 hours.

Results: The HSS infusion was initiated for a duration of 7 (5 to 10) (8 ± 4) days. ICP decreased from 29 (26 to 34) (31 ± 9) mm Hg at H0 to 20 (15 to 26) (21 ± 8) mm Hg at H1 (P < 0.05). Cerebral perfusion pressure increased from 61 (50 to 70) (61 ± 13) mm Hg at H0 up to 67 (60 to 79) (69 ± 12) mm Hg at H1 (P < 0.05). No rebound of ICH was reported after stopping continuous HSS infusion. Natremia increased from 140 (138 to 143) (140 ± 4) at H0 up to 144 (141 to 148) (144 ± 4) mmol/L at H4 (P < 0.05). Plasma osmolarity increased from 275 (268 to 281) (279 ± 17) mmol/L at H0 up to 290 (284 to 307) (297 ± 17) mmol/L at H24 (P < 0.05). The main side effect observed was an increase in chloremia from 111 (107 to 119) (113 ± 8) mmol/L at H0 up to 121 (117 to 124) (121 ± 6) mmol/L at H24 (P < 0.05). Neither acute kidney injury nor pontine myelinolysis was recorded.

Conclusions: Continuous HSS infusion adapted to close biologic monitoring enables long-lasting control of natremia in TBI patients along with a decreased ICP without any rebound on infusion discontinuation.

Figure 1

Dose-adaptation of continuous hypertonic saline solution infusion. The attending physician set the targets of natremia according to the intracranial pressure (ICP). The target could be modified by a step of 5 mmol/L from 145 to 155 mmol/L. Natremia and natriuresis were assessed every 4 hours. Target was considered achieved if -2 mmol/L < Delta < +2 mmol/L; otherwise, the flow of NaCl infusion was adapted. On infusion initiation or when natremia was below the target (left side), a 1-hour bolus was performed. When the target of natremia was reached (middle), the flow of a continuous infusion of HSS (NaCl 20%) was adapted to the urinary excretion of sodium, and the extraurinary sodium loss was neglected. If natremia was above the target (right side), the infusion of NaCl (20%) was discontinued for 1 hour. ‡Except in case of intracranial pressure > 20 mm Hg. Natriuresis, urinary sodium concentration (mmol/L); kaliuresis, urinary potassium concentration (mmol/L); dieresis, urinary output (ml/h); Delta, natremia - target).

Figure 2

Flow chart. ICHT, intracranial hypertension; ICP, intracranial pressure; TBI, traumatic brain injury.

Figure 3

Time evolution of (a) intracranial pressure and (b) cerebral perfusion pressure during and after the continuous HSS infusion. Cerebral perfusion pressure was calculated as follows: Mean arterial pressure - Intracranial pressure. Results were provided for the first 96 hours of HSS infusion (from H0 to H96; white boxes) and 2 days after the stop of infusion (from day 1 to day 2; gray boxes). *P < 0.05.

Figure 4

Time evolution of (a) natremia, (b) blood osmolarity, and (c) delta of natremia during and after the continuous HSS infusion. (a) Natremia was assessed every 4 hours. (b) Osmolarity was assessed once per day. Results are given for the first 96 hours of HSS infusion (white boxes) and 2 days after the stop of infusion (gray boxes). (c) Delta between assessed natremia and target of natremia was calculated every 4 hours. Target was considered as achieved if -2 mmol/L < Delta ≤ 2 mmol/L. Results are given for the first 96 hours of HSS infusion (white boxes). *P < 0.05.

Figure 5

Time evolution of (a) chloremia, (b) kaliemia, (c) creatininemia, and (d) pH during the continuous HSS infusion. Results of (a) chloremia, (b) kaliemia, (c) creatininemia, and (d) pH were collected every 24 hours. Results were provided for the first 96 hours of HSS infusion (unchanged for longer duration). *P < 0.05.