Hisakazu Kohata

Effect of High Flow Nasal Cannula on Thoraco-abdominal Synchrony in Adult Critically Ill Patients

BACKGROUND: High-flow nasal cannula (HFNC) creates positive oropharyngeal airway pressure and improves oxygenation. It remains unclear, however, whether HFNC improves thoraco-abdominal synchrony in patients with mild to moderate respiratory failure. Using respiratory inductive plethysmography, we investigated the effects of HFNC on thoraco-abdominal synchrony. METHODS: We studied 40 adult subjects requiring oxygen therapy in the ICU. Low-flow oxygen (up to 8 L/min) was administered via oronasal mask for 30 min, followed by HFNC at 30–50 L/min. Respiratory inductive plethysmography transducer bands were circumferentially placed: one around the rib cage, and one around the abdomen. We measured the movement of the rib-cage and abdomen, and used the sum signal to represent tidal volume (VT) during mask breathing, and at 30 min during HFNC. We calculated the ratio of maximum compartmental amplitude (MCA) to VT, and the phase angle. We assessed arterial blood gas and vital signs at each period, and mouth status during HFNC. We used multiple regression analysis to identify factors associated with improvement in thoraco-abdominal synchrony. RESULTS: During HFNC, breathing frequency significantly decreased from 25 breaths/min (IQR 22–27 breaths/min) to 21 breaths/min (IQR 18–24 breaths/min) (P < .001), and MCA/VT (P < .001) and phase angle (P = .047) significantly improved. CONCLUSIONS: HFNC improved thoraco-abdominal synchrony in adult subjects with mild to moderate respiratory failure.

A novel method of post-pyloric feeding tube placement at bedside

PURPOSE Post-pyloric feeding tube placement is often difficult, and special equipment or peristalsis agents are used to aid insertion. Although several reports have described blind techniques for post-pyloric feeding-tube placement, no general consensus about method preference has been achieved. MATERIALS AND METHODS The technique is performed as follows: via the nostril, a stylet-tipped feeding tube is advanced about 70 cm; to confirm tip location to the right of the epigastric area, towards the right hypochondriac region, 5 mL shots of air are injected to enable touch detection of bubbling; finally, the tube is advanced to a length of 100 cm, during which the strength of bubbling seems to diminish under palpation. RESULTS We prospectively enrolled consecutive patients whose oral intake was expected to be difficult for 48 hours in the intensive care unit. Forty-one patients were enrolled and the rate of successful placement at first attempt was 95.1%. Mean duration for successful placement was 15 minutes. CONCLUSIONS With a novel technique, from the bedside, without special tools or drugs, we successfully placed post-pyloric feeding tubes. Essential points when inserting the tube are confirmation of the location of the tube tip by palpation of injected air, and to avoid deflection and looping.

Detecting central-venous oxygen desaturation without a central-venous catheter: Utility of the difference between invasively and noninvasively measured blood pressure ☆ ☆☆ ☆☆☆ ★

OBJECTIVE The objective was to determine whether central-venous oxygen saturation (ScvO2<70%) can be detected from the difference between invasively and noninvasively measured systolic blood pressure (BP) (ie, ΔBP defined as arterial BP minus noninvasive BP). METHODS This is a cross-sectional study at a single medical and surgical intensive care unit in Japan. All hypotensive patients admitted to intensive care unit were eligible. Arterial BP was measured via a radial-artery catheter, and noninvasive BP on the same side was measured via a brachial cuff. ScvO2 was measured by gas analysis of blood sampled from a central-venous chatheter (CVC). We calculate the area under the curve for ΔBP as an indicator of ScvO2<70%. RESULTS Usable data were obtained from the records of 111 patients. The median and interquartile range of ΔBP and ScvO2 were -4mm Hg (-11, 6) and 67% (60.9, 73.9), respectively. The area under the curve of ΔBP as an indicator of ScvO2<70% was 0.81 (95% confidence interval [CI], 0.73-0.89). With a cutoff ΔBP of 0, sensitivity was 65.7% (95% CI, 53.1-76.8), specificity was 97.7% (95% CI, 88.0-99.8), and positive predictive value was 97.8 (95% CI, 88.2-99.9). CONCLUSIONS ΔBP can indicate whether ScvO2 is lower than 70%. When that difference is greater than 0, ScvO2 is very likely to be lower than 70%.

156: WHAT IS ASSOCIATED WITH THE DISCREPANCY BETWEEN NIBP AND IBP?

than in patients with LVEF ≥40% (P <0.05). CFI had a better ability than cardiac output to detect cardiac dysfunction (LVEF <40%) (Area under the curve: 0.85 ± 0.02; P <0.001). A CFI value of <4.2 min-1 had a sensitivity of 82% and specificity of 84% for detecting LVEF <40%. The CFI <4.2 min-1 was associated with delayed cerebral ischemia (DCI) (odds ratio [OR], 2.14; 95% confidence interval [CI], 1.33-2.86; P = 0.004) and poor 3-month functional outcome on modified Rankin Scale of 4-6 (OR, 1.87; 95% CI, 1.06-3.29; P = 0.02). An ELWI >14 mL/kg after day 4 increased the risk of poor functional outcome at 3-month follow-up (OR, 2.10; 95% CI, 1.11-3.97; P = 0.04). Conclusions: Prolonged cardiac dysfunction and pulmonary edema increased the risk of DCI and poor 3-month functional outcome in patients with SAH suffering from TCM. Serial measurements of CFI and ELWI by transpulmonary thermodilution may provide an easy bedside method of detecting early changes of the cardiopulmonary function in directing proper post-SAH treatment.