Diaphragmatic dysfunction is a major factor in the etiology of postoperative pulmonary complications after upper abdominal surgery. M-mode ultrasonography is now an accepted qualitative method of assessing diaphragmatic motion in normal and pathological conditions. In this study, we evaluated whether diaphragmatic inspiratory amplitude (DIA) as measured by M-mode sonography can be a predictor of pulmonary dysfunction. A prospective, single-center, single-unit, observational study was performed in 35 ASA physical status I and II nonsmoking patients undergoing open liver lobectomy. Diaphragmatic movements were assessed by M-mode sonography after a pulmonary function test preoperatively and on postoperative days (PODs) 1, 2, and 7. We measured the DIA (cm) during quiet, deep, and sniff breathing. After liver lobectomy, DIA during deep breathing and vital capacity (VC) showed significant reductions of 60% from their preoperative values on PODs 1 and 2 (P < 0.001). By POD 7, the variables recovered significantly, by 30% from the values on PODs 1 and 2 (P < 0.001). During deep breathing, DIA showed a significant correlation with VC (r = 0.839, P < 0.0001). The best cutoff values of DIA for detecting 30% and 50% decreases of VC from preoperative values, calculated by receiver operating characteristic analysis, were 3.61 and 2.41 cm, with sensitivity of 94% and 81% and specificity of 76% and 91%, respectively (P = 0.0001). Two patients showed postoperative diaphragmatic paralysis but did not complain of respiratory distress symptoms or need supplemental oxygen after being transferred to the general ward. DIA using M-mode sonography showed a linear correlation with VC measured by spirometry throughout the postoperative period. We conclude that using the M-mode sonographic technique at the bedside can be a practical way to investigate postoperative diaphragmatic dysfunction, and may also be an effective bedside screening method for diaphragmatic paralysis.

Yoo YC, et al. Yonsei Med J. 2012 Nov;53(6):1197-1202. http://dx.doi.org/10.3349/ymj.2012.53.6.1197

The ability to identify the correct vertebral level through examination is an important skill for clinicians who are performing nerve blocks without fluoroscopy. The conventional palpation method, which identifies the most prominent cervical spinous process as the seventh cervical (C7) spinous process is unreliable in many cases. We compared the accuracy of 2 different palpation methods used for identifying C7. Ninety-six patients scheduled for cervical spine procedures under fluoroscopy guidance were randomized into either the control group or the flexion-extension group. The control group was examined with the conventional method, and the flexion-extension group was examined through assisted flexion and extension of the patient's cervical spine and identifying the lowest freely moving spinous process as C6 and the following stationary cervical spinous process as C7. A single anesthesiologist attempted to identify the C7 spinous process by using either the conventional method or the flexion-extension method and marked the presumed C7 spinous process with a radiopaque indicator. The actual vertebral level was then confirmed by fluoroscopy. The accuracy of the 2 different palpation techniques was compared, and the influence of patients' age, gender, and body mass index (BMI) was also examined. The C7 spinous process was correctly identified in 77.1% of patients in the flexion-extension group, compared with 37.5% in the control group (P<0.001). The C6 spinous process was identified as the most prominent cervical spinous process instead of C7 in 47.9% of patients in the control group, showing that errors are more common in the cephalad direction with the conventional method. The accuracy of the flexion-extension method was significantly higher than the conventional method regardless of the patient's age, gender, and BMI. Particularly, this difference in accuracy was seen not only in patients with a BMI <25 kg/m(2), but also in those with a BMI ≥25 kg/m(2) (BMI <25 kg/m(2), P=0.006 vs BMI ≥25 kg/m(2), P=0.008). The flexion-extension method is more accurate than the conventional method when identifying cervical vertebral level.

This study aimed to determine whether continuous deep neuromuscular blockade (NMB) improves the surgical conditions and facilitates robotic-assisted laparoscopic radical prostatectomy (RALRP) under low intra-abdominal pressure (IAP) to attenuate the increase in intraocular pressure (IOP) during CO₂ pneumoperitoneum in the steep Trendelenburg (ST) position. Sixty-seven patients undergoing RALRP were randomly assigned to a moderate NMB group (Group M), including patients who received atracurium infusion until the end of the ST position, maintaining a train of four count of 1–2; and the deep NMB group (Group D), including patients who received rocuronium infusion, maintaining a post-tetanic count of 1–2. IOP was measured in all patients at nine separate time points. All RALRPs were performed by one surgeon, who rated the overall and worst surgical conditions at the end of the ST position. The highest IOP value was observed at T4 (60 min after the ST position) in both Group M (23.3 ± 2.7 mmHg) and Group D (19.8 ± 2.1 mmHg). RALRP was accomplished at an IAP of 8 mmHg in 88% Group D patients and 25% Group M patients. The overall surgical condition grade was 4.0 (3.0–5.0) in Group D and 3.0 (2.0–5.0) in Group M (P < 0.001). The current study demonstrated that continuous deep NMB may improve surgical conditions and facilitate RALRP at a low IAP, resulting in significant attenuation of the increase on IOP. Moreover, low-pressure pneumoperitoneum, facilitated by deep NMB still provided acceptable surgical conditions. ClinicalTrials.gov NCT02109133