Noise generated in the intensive care unit (ICU) adversely affects both critically ill patients and medical staff. Recently, several attempts have been made to reduce ICU noise levels, but reliable and effective solutions remain elusive. This study aimed to provide evidence on noise distributions in the ICU to protect patient health. For one week, we measured noise levels in isolated rooms, open units, and nursing stations in medical, surgical, and pediatric ICUs, respectively. We additionally analyzed the noise generated by medical equipment that is frequently used in ICUs. The median (interquartile range) noise exposure level (dBA) of all ICU units was 54.4 dB (51.1–57.5) over 24 h. The highest noise exposure was noted in the surgical ICU’s daytime open unit at 57.6 dB (55.0–61.1). Various ICU medical devices continuously generated low-frequency noise. Mechanical noise levels ranged from a minimum of 41 dB to a maximum of 91 dB. It was also confirmed that patient-monitoring devices generated loud, high-frequency noise at 85 dB. ICU noise levels were much higher than expected. Noise reduction that focuses on behavior modification of medical staff has limited potential; instead, structural improvements should be considered to reduce the transmission of noise.

Predicting fluid responsiveness in patients under mechanical ventilation with low tidal volume (VT) is challenging. This study evaluated the ability of carotid corrected flow time (FTc) assessed by ultrasound for predicting the fluid responsiveness during low VT ventilation. Patients under postoperative mechanical ventilation and clinically diagnosed with hypovolemia were enrolled. Carotid FTc and pulse pressure variation (PPV) were measured at VT of 6 and 10 mL/kg predicted body weight (PBW). FTc was calculated using both Bazett’s (FTcB) and Wodey’s (FTcW) formulas. Fluid responsiveness was defined as a ≥15% increase in the stroke volume index assessed by FloTrac/Vigileo monitor after administration of 8 mL/kg of balanced crystalloid. Among 36 patients, 16 (44.4%) were fluid responders. The areas under the receiver operating characteristic curves (AUROCs) for the FTcB at VT of 6 and 10 mL/kg PBW were 0.897 (95% confidence interval [95% CI]: 0.750–0.973) and 0.895 (95% CI: 0.748–0.972), respectively. The AUROCs for the FTcW at VT of 6 and 10 mL/kg PBW were 0.875 (95% CI: 0.722–0.961) and 0.891 (95% CI: 0.744–0.970), respectively. However, PPV at VT of 6 mL/kg PBW (AUROC: 0.714, 95% CI: 0.539–0.852) showed significantly lower accuracy than that of PPV at VT of 10 mL/kg PBW (AUROC: 0.867, 95% CI: 0.712–0.957; p = 0.034). Carotid FTc can predict fluid responsiveness better than PPV during low VT ventilation. However, further studies using automated continuous monitoring system are needed before its clinical use.

Background and Objectives A triangle formed by the sacral hiatus and posterior superior iliac spines (PSISs) has been known as equiangular and has been proposed as a way to help identify the sacral hiatus for a caudal block. In children, however, no feasibility study of this triangle has been performed. We compared the expected sacral hiatus obtained from the equiangular triangle method and the real sacral hiatus confirmed by ultrasound. Methods Eighty children (aged 0.5–72 months) were placed in the left lateral decubitus position in full hip flexion. The vertex of an equiangular triangle formed inferior to PSISs was considered as the expected sacral hiatus by classic bony landmarks. The real sacral hiatus was identified by ultrasound. The angle formed by the 2 lines connecting each PSIS and the real sacral hiatus (angle &θ) was also measured. The distances between the midpoint of PSISs and expected sacral hiatus (distance E) and real sacral hiatus (distance R) were measured and compared. Results The angle &θ was greater than 60 degrees in all children (79.3 [9.3] degrees) and negatively correlated with age younger than 1 year. Distance R (3.5 [1.1] cm) was significantly shorter than distance E (4.9 [1.2] cm) (P< 0.001). The distance R positively correlated with age, weight, height, and the distance between the PSISs. Conclusions In children, using the equiangular triangle to identify the sacral hiatus may be inappropriate because the actual triangle formed by the sacral hiatus and PSISs is not equiangular.

Although the use of volatile sedatives in the intensive care unit (ICU) is increasing in Europe, it remains infrequent in Asia. Therefore, there are no clinical guidelines available. This study investigates the proper initial concentration of sevoflurane, a volatile sedative that induces a Richmond agitation-sedation scale (RASS) score of –2 to –3, in patients who underwent head and neck surgery with tracheostomy. We also compared the amount of postoperative opioid consumption between volatile and intravenous (IV) sedation. We planned a prospective study to determine the proper initial sevoflurane concentration and a retrospective analysis to compare postoperative opioid consumption between volatile sedation and propofol sedation. Patients scheduled for head and neck surgery with tracheostomy and subsequent postoperative sedation in the ICU were enrolled. In this prospective study, the effective dose 50 (ED50) of initial end-tidal sevoflurane concentration was 0.36% (95% confidence interval [CI], 0.20 to 0.60%), while the ED 95 was 0.69% (95% CI, 0.60 to 0.75%) based on isotonic regression methods. In this retrospective study, remifentanil consumption during postoperative sedation was significantly lower in the sevoflurane group (2.52±1.00 µg/kg/hr, P=0.001) than it was in the IV propofol group (3.66±1.30 µg/kg/hr). We determined the proper initial end-tidal concentration setting of sevoflurane for patients with tracheostomy who underwent head and neck surgery. Postoperative sedation with sevoflurane appears to be a valid and safe alternative to IV sedation with propofol.

Emergence agitation is common after septorhinoplasty, and postoperative pain is the main risk factor for this condition. Infraorbital and infratrochlear nerve block have been reported to facilitate pain management in patients after nasal procedures. The effect of peripheral nerve block on the incidence of emergence agitation has not been evaluated. Sixty-six patients that were scheduled for septorhinoplasty were assigned to receive bilateral infraorbital and infratrochlear nerve block with either 8 mL of 0.5% ropivacaine (Block group) or isotonic saline (Sham Block group). The incidence of emergence agitation was evaluated using the Riker sedation-agitation scale. Analgesic consumption, hemodynamic parameters, postoperative pain scores, adverse events, and patient satisfaction with analgesia were evaluated. The incidence of emergence agitation was lower in the Block group than in the Sham Block group (6 (20.0%) versus 20 (62.5%), p = 0.002). The mean intraoperative remifentanil consumption was lower in the Block group than in the Sham Block group (0.074 ± 0.014 μg/kg/min. versus 0.093 ± 0.019 μg/kg/min., respectively, p < 0.0001), as was the proportion of patients that needed postoperative tramadol administration and median postoperative pain score at 0–2 h after surgery (9 (30.0%) versus 21 (65.6%), p = 0.011; 3.0 (2.0–4.0) versus 4.0 (3.0–4.0), p < 0.0001, respectively). Hemodynamic parameters and the incidence of adverse events were similar between the two groups. The median patient satisfaction score with respect to analgesia was higher in the Block group than in the Sham Block group (3.5 (3.0–4.0) versus 3.0 (3.0–4.0), respectively, p = 0.034). The preoperative bilateral infraorbital and infratrochlear nerve block decreased the incidence of emergence agitation after septorhinoplasty.

Kim WH, et al. Psychiatry Investig. 2009 Jun;6(2):112-114. http://dx.doi.org/10.4306/pi.2009.6.2.112