Using Pupillary Pain Index to Assess Nociception in Sedated Critically Ill Patients.

BACKGROUND: Pupillary reflex dilation is a reliable indicator of response to noxious stimulation. In a proof of concept study, we investigated the performance of pupillary pain index, a new score derived from pupillary reflex dilation measurements, to predict nociceptive response to endotracheal suctioning in sedated critically ill patients. METHODS: Twenty brain-injured and 20 non-brain-injured patients were studied within 48 hours of admission (T1) in the intensive care unit and at 48-72 hours later (T2). Video-based pupillometer was used to determine pupillary reflex dilation during tetanic stimulation. The tetanic stimulation (100 Hz) was applied to the skin area innervated by the ulnar nerve and was stepwise increased from 10 to 60 mA until pupil size had increased by 13% compared to baseline. The maximum intensity value allowed the determination of a pupillary pain index score ranging from 1 (no nociception) to 9 (high nociception). The Behavioral Pain Scale response to endotracheal suctioning was measured thereafter. RESULTS: Behavioral Pain Scale responses to endotracheal suctioning and pupillary pain index scores were positively correlated at T1 and T2 (both P < .01). After adjustments for repeated measurements and group of patients, the area under the receiver operating characteristic curve of pupillary pain index to predict Behavioral Pain Scale response to endotracheal suctioning was of 0.862 (95% CI, 0.714-0.954). In the combined set of patients, a pupillary pain index score of ≤4 could predict no nociceptive response to endotracheal suctioning with a sensitivity of 88% (95% CI, 68%-97%) and a specificity of 79% (95% CI, 66%-88%). By contrast with endotracheal suctioning, tetanic stimulation had no effect on intracranial pressure in the brain-injured group. CONCLUSIONS: These results are a proof of concept. The nociceptive response to endotracheal suctioning could be accurately predicted using the determination of pupillary pain index score in sedated critically ill patients whether they have brain injury or not.

Pupillometry to detect pain response during general anaesthesia following unilateral popliteal sciatic nerve block: a prospective, observational study.

CONTEXT: Pupillary reflex dilation appears to be a reliable indicator of response to noxious stimulation even under general anaesthesia. The ability of pupillometry to detect the effects of extremity blocks during continuous infusion of opioids remains unknown. OBJECTIVE: To explore the performance of pupillometry to detect differences in pupillary reflex dilation response to a standardised noxious stimulus applied to each leg following unilateral popliteal sciatic nerve block during continuous infusion of remifentanil. DESIGN: Prospective, observational study. SETTING: University hospital anaesthesia department, between June 2010 and December 2010. PATIENTS: Twenty-four adult patients undergoing elective foot or ankle surgery under general anaesthesia who requested a peripheral nerve block. Unilateral popliteal sciatic nerve block with 0.75% ropivacaine and 1% lidocaine was performed awake. General anaesthesia was maintained with steady-state infusions of propofol and remifentanil. MAIN OUTCOME MEASURE: Video-based pupillometer was used to determine pupillary reflex dilation during tetanic stimulation (60 m, 100 Hz) applied to the skin area innervated by the sciatic nerve for 5 s after the onset of general anaesthesia. RESULTS: Sensory nerve block led to a blunted maximal pupillary reflex dilation response to noxious stimulation compared with the non-blocked leg: median (interquartile range) change from baseline 2% (1 to 4%) versus 17% (13 to 24%), respectively (P < 0.01). The differences in the response persisted throughout the 5-s stimulus and the recovery phase. CONCLUSION: These results are a proof of concept. The effects of peripheral nerve block can be detected via the measurement of pupillary reflex dilation response to noxious stimulation of the skin in patients receiving remifentanil.

Corticosteroid after etomidate in critically ill patients: a randomized controlled trial.

OBJECTIVE: To investigate the effects of moderate-dose hydrocortisone on hemodynamic status in critically ill patients throughout the period of etomidate-related adrenal insufficiency. DESIGN: : Randomized, controlled, double-blind trial (NCT00862381). SETTING: University hospital emergency department and three intensive care units. INTERVENTIONS: After single-dose etomidate (H0) for facilitating endotracheal intubation, patients without septic shock were randomly allocated at H6 to receive a 42-hr continuous infusion of either hydrocortisone at 200 mg/day (HC group; n = 49) or saline serum (control group; n = 50). MEASUREMENTS AND MAIN RESULTS: After completion of a corticotrophin stimulation test, serum cortisol and 11ß-deoxycortisol concentrations were subsequently assayed at H6, H12, H24, and H48. Forty-eight patients were analyzed in the HC group and 49 patients in the control group. Before treatment, the diagnostic criteria for etomidate-related adrenal insufficiency were fulfilled in 41 of 45 (91%) and 38 of 45 (84%) patients in the HC and control groups, respectively. The proportion of patients with a cardiovascular Sequential Organ Failure Assessment score of 3 or 4 declined comparably over time in both HC and control groups: 65% vs. 67% at H6, 65% vs. 69% at H12, 44% vs. 54% at H24, and 34% vs. 45% at H48, respectively. Required doses of norepinephrine decreased at a significantly higher rate in the HC group compared with the control group in patients treated with norepinephrine at H6. No intergroup differences were found regarding the duration of mechanical ventilation, intensive care unit length of stay, or 28-day mortality. CONCLUSION: These findings suggest that critically ill patients without septic shock do not benefit from moderate-dose hydrocortisone administered to overcome etomidate-related adrenal insufficiency.

Which Protocol for Milrinone to Treat Cerebral Vasospasm Associated With Subarachnoid Hemorrhage?

BACKGROUND: Milrinone has emerged as an option to treat delayed cerebral ischemia after subarachnoid hemorrhage. However, substantial variation exists in the administration of this drug. We retrospectively assessed the effectiveness of 2 protocols in patients with angiographically proven cerebral vasospasm. METHODS: During 2 successive periods, milrinone was administered using either a combination of intra-arterial milrinone infusion followed by intravenous administration until day 14 after initial bleeding (IA+IV protocol), or a continuous intravenous milrinone infusion for at least 7 days (IV protocol). The primary endpoint was the reversion rate of vasospastic arterial segments following the first IA infusion of milrinone (IA+IV protocol) compared with the reversion rate during the first week of IV infusion (IV protocol). RESULTS: There were 24 and 77 consecutive patients in IA+IV and IV protocols, respectively. The reversion rate was comparable between the 2 protocols: 71% (95% confidence interval [CI], 59%-83%) in the IA+IV protocol versus 64% (95% CI, 58%-71%) in the IV protocol (P=0.36). Rescue procedures for persistence or recurrence of vasospasm, that is, mechanical angioplasty and/or IA milrinone infusion, were similar between the 2 protocols. Patients with a good neurological outcome at 1 year, that is, modified Rankin Scale scores 0-2, were comparable between the 2 protocols. Side effects of milrinone were uncommon and equally distributed within the 2 protocols. CONCLUSIONS: These findings indicate that a continuous IV infusion of milrinone was as efficient as combined IA+IV infusion and suggest that this modality could be considered as a first easy-to-use option to treat patients with CVS.

Duration of adrenal inhibition following a single dose of etomidate in critically ill patients.

OBJECTIVE: To determine the incidence and duration of adrenal inhibition induced by a single dose of etomidate in critically ill patients. DESIGN: Prospective, observational cohort study. SETTING: Three intensive care units in a university hospital. PATIENTS: Forty critically ill patients without sepsis who received a single dose of etomidate for facilitating endotracheal intubation. MEASUREMENTS AND MAIN RESULTS: Serial serum cortisol and 11beta-deoxycortisol samples were taken at baseline and 60 min after corticotropin stimulation test (250 microg 1-24 ACTH) at 12, 24, 48, and 72 h after etomidate administration. Etomidate-related adrenal inhibition was defined by the combination of a rise in cortisol less than 250 nmol/l (9 microg/dl) after ACTH stimulation and an excessive accumulation of serum 11beta-deoxycortisol concentrations at baseline. At 12 h after etomidate administration, 32/40 (80%) patients fulfilled the diagnosis criteria for etomidate-related adrenal insufficiency. This incidence was significantly lower at 48 h (9%) and 72 h (7%). The cortisol to 11beta-deoxycortisol ratio (F/S ratio), reflecting the intensity of the 11beta-hydroxylase enzyme blockade, improved significantly over time. CONCLUSIONS: A single bolus infusion of etomidate resulted in wide adrenal inhibition in critically ill patients. However, this alteration was reversible by 48 h following the drug administration. The empirical use of steroid supplementation for 48 h following a single dose of etomidate in ICU patients without septic shock should thus be considered. Concomitant serum cortisol and 11beta-deoxycortisol dosages are needed to provide evidence for adrenal insufficiency induced by etomidate in critically ill patients.

Capillary lactate concentration on admission of normotensive trauma patients: a prospective study.

BACKGROUND: Elevated serum blood lactate is an indicator of on-going bleeding in severe trauma patients. Point-of-care (POC) capillary lactate measurement devices may be useful to rapidly assess lactate concentration at the bedside. The aim of this study was to test the diagnostic performance of capillary lactate to predict significant transfusion in normotensive trauma patients. METHODS: We conducted a prospective observational study in one level-I trauma centre. From August 2011 to February 2013, 120 consecutive adult patients with systolic blood pressure (SBP) higher than 90 mmHg were included. Capillary lactate was measured on admission in the trauma bay. The primary outcome was defined as a significant transfusion within the first 48 h. Diagnostic performance was determined using receiver operating characteristic (ROC) curve analysis. We also tested the agreement between capillary lactate and blood lactate concentrations using Bland and Altman analysis. RESULTS: Of the 120 normotensive trauma patients, 30 (25 %) required at least one unit of packed red blood cells (RBC) and 12 (10 %) patients received at least four RBC within the first 48 h. All patients with significant RBC transfusion had capillary lactate higher than 3.5 mmol/l. The area under the ROC curve of capillary lactate on admission to predict transfusion of at least 4 RBC units was 0.68 [95 % CI 0.58 - 0.78]. The average bias between capillary and blood lactate measurements was 2.4 mmol/l with a standard deviation of 3.0 mmol/l (n = 60 patients). CONCLUSIONS: Although a significant association was found between POC lactate concentration and transfusion requirements, the diagnostic performance of capillary lactate measurements was poor. Due to large disagreement between capillary lactate and blood lactate, capillary lactate cannot be considered in the clinical setting. TRIAL REGISTRATION: ClinicalTrials.gov, No. NCT01793428 .