Ahmed Hasanin

BACKGROUND: Fluid challenge test is a widely used method for the detection of fluid responsiveness in acute circulatory failure. However, detection of the patient's response to the fluid challenge requires monitoring of cardiac output which is not feasible in many settings. We investigated whether the changes in the pulse oximetry-derived peripheral perfusion index (PPI), as a non-invasive surrogate of cardiac output, can detect fluid responsiveness using the fluid challenge test or not.

METHODS: We prospectively enrolled 58 patients with septic shock on norepinephrine infusion. Fluid challenge test, using 200 mL crystalloid solution, was performed in all study subjects. All patients received an additional 300 mL crystalloid infusion to confirm fluid responsiveness. Velocity time integral (VTI) (using transthoracic echocardiography), and PPI were measured at the baseline, after 200 mL fluid challenge, and after completion of 500 mL crystalloids. Fluid responsiveness was defined by 10% increase in the VTI after completion of the 500 mL. The predictive ability of ∆PPI [Calculated as (PPI after 200 mL - baseline PPI)/baseline PPI] to detect fluid responders was obtained using the receiver operating characteristic curve.

RESULTS: Forty-two patients (74%) were fluid responders; in whom, the mean arterial pressure, the central venous pressure, the VTI, and the PPI increased after fluid administration compared to the baseline values. ∆PPI showed moderate ability to detect fluid responders [area under receiver operating characteristic curve (95% confidence interval) 0.82 (0.70-0.91), sensitivity 76%, specificity 80%, positive predictive value 92%, negative predictive value 54%, cutoff value ≥ 5%]. There was a significant correlation between ∆PPI and ∆VTI induced by the fluid challenge.

CONCLUSION: ∆PPI showed moderate ability to detect fluid responsiveness in patients with septic shock on norepinephrine infusion. Increased PPI after 200 mL crystalloid challenge can detect fluid responsiveness with a positive predictive value of 92%; however, failure of the PPI to increase does not exclude fluid responsiveness.

CLINICAL TRIAL IDENTIFIER: NCT03805321. Date of registration: 15 January 2019. Clinical trial registration URL: https://clinicaltrials.gov/ct2/show/NCT03805321?term=ahmed+hasanin&rank=9 .

In this study, we evaluated the accuracy of oscillometric noninvasive blood pressure (NIBP) measured at the ankle in detecting low arm NIBP during cesarean delivery under spinal anesthesia. In this prospective observational study, a cohort of full-term mothers undergoing elective cesarean delivery under spinal anesthesia was examined. Simultaneous NIBP measurements were obtained from the arm and the ankle. The primary outcome was the accuracy of the ankle NIBP in detecting arm systolic blood pressure (SBP) < 90 mmHg. Other outcomes included the accuracy of ankle NIBP in detecting SBP < 80% of the baseline value. The area under the receiver operating characteristic curve (AUC) was calculated to evaluate the accuracy of ankle NIBP in detecting low arm NIBP. The Bland-Altman analysis was conducted to evaluate the agreement between values. We analyzed 1729 pairs of readings obtained from 97 mothers. Ankle SBP showed good accuracy in detecting SBP < 90 mmHg, with an AUC (95% confidence interval [CI]) of 0.90 (0.89-0.91) and a negative predictive value (NPV) of 99 (98-99%) at a cutoff value of ≤ 103 mmHg. Furthermore, ankle SBP showed good accuracy in detecting SBP < 80% of the baseline value, with an AUC (95% CI) of 0.84 (0.82-0.89) and an NPV of 95 (93-96%) at a cutoff value of ≤ 76% of the ankle baseline SBP. The mean bias between the two sites of measurement was - 5.4 ± 15.5, - 2.0 ± 11, and 0.5 ± 12.1 mmHg for SBP, diastolic blood pressure, and mean arterial pressure, respectively. In conclusion, ankle NIBP measurement is not interchangeable with arm NIBP measurement. However, ankle NIBP measurement showed good accuracy for ruling out low arm NIBP during a cesarean delivery.Clinical trial rejistration: NCT04199156.

PURPOSE: To evaluate the accuracy of noninvasive blood pressure (NIBP) measurement at the dependent- and nondependent arms in the lateral position, using invasive blood pressure (IBP) as reference.

METHODS: This prospective observational study included 42 adult patients undergoing surgery in the lateral position. Paired readings of IBP and NIBP were obtained at either arm. The accuracy of both arms in detecting mean arterial pressure (MAP) <70 mmHg was evaluated using the area under the receiver operating characteristic curve (AUC). The agreement between the IBP and NIBP was evaluated using the Bland-Altman and error grid analyses.

RESULTS: We analyzed 350 and 347 paired readings at the dependent- and nondependent arms. The AUC for detecting hypotension was comparable in both arms. The negative and positive predictive values (95% confidence interval) were 100% (99-100%) and 24% (14-34%), respectively for the dependent arm at cutoff value MAP ≤86 mmHg; and were 99% (96-100%) and 21% (13-30%), respectively for the nondependent arm at cutoff value MAP ≤75 mmHg. The mean bias for MAP was -6.0 ± 9.1 and 6.3 ± 10.1 mmHg; and for systolic blood pressure was 0.3 ± 11.6 and 13.2 ± 12.6 mmHg, in the dependent- and nondependent arm, respectively. Error grid analysis showed that the proportions of paired MAP readings in risk zone A were 71 and 82% in the dependent- and the nondependent arms, respectively.

CONCLUSION: In the lateral position, the NIBP readings at both arms are not interchangeable with the corresponding IBP readings. However, NIBP measurement at both arms can be used to accurately rule out hypotension.

BACKGROUND: This study aimed to evaluate the accuracy of pulse oximetry-derived oxygen saturation (SpO) on room air, determined at hospital admission, as a predictor for the need for mechanical ventilatory support in patients with Coronavirus Disease-2019 (COVID-19).

METHODS: In this retrospective observational study, demographic and clinical details of the patients were obtained during ICU admission. SpO and respiratory rate (RR) on room air were determined within the first 6 h of hospital admission. As all measurements were obtained on room air, we calculated the simplified respiratory rate‑oxygenation (ROX) index by dividing the SpO by the RR. Based on the use of any assistance of mechanical ventilator (invasive or noninvasive), patients were divided into mechanical ventilation (MV) group and oxygen therapy group. The accuracy of the SpO, CT score, and ROX index to predict the need to MV were determined using the Area under receiver operating curve (AUC).

RESULTS: We included 72 critically ill patients who tested COVID-19-positive. SpO on the room air could predict any MV requirement (AUC [95% confidence interval]: 0.9 [0.8-0.96], sensitivity: 70%, specificity 100%, cut-off value ≤78%, P < 0.001). Within the MV group, the use of noninvasive ventilation (NIV) was successful in 37 (74%) patients, whereas 13 patients (26%) required endotracheal intubation. The cut-off ROX value for predicting early NIV failure was ≤1.4, with a sensitivity of 85%, a specificity of 86%, and an AUC of 0.86 (95% confidence interval of 0.73-0.94, P < 0.0001).

CONCLUSIONS: A baseline SpO ≤78% is an excellent predictor of MV requirement with a positive predictive value of 100%. Moreover, the ROX index measured within the first 6 h of hospital admission is a good indicator of early NIV failure.

BACKGROUND: Patients with septic shock commonly require endotracheal intubation under general anaesthesia in the operating theatre, the emergency department, and the intensive care unit. Hypotension is a serious complication after induction of general anaesthesia, especially in patients with circulatory failure. No randomised controlled trials had previously investigated protocols for induction of anaesthesia in septic shock patients. The aim of the current work is to compare two protocols, lidocaine-ketamine combination versus ketamine full-dose for rapid-sequence endotracheal intubation in patients with septic shock.

METHODS: Forty-four adult patients, with septic shock, scheduled for emergency surgical intervention were enrolled in this randomised, double-blinded, controlled study. Patients were randomised to receive either 1 mg/kg ketamine (ketamine group, n = 22) or 0.5 mg/kg ketamine plus 1 mg/kg lidocaine (ketamine-lidocaine group, n = 22) for induction of anaesthesia in addition to 0.05 mg/kg midazolam (in both groups). Our primary outcome was the mean arterial pressure (MAP). Other outcomes included frequency of post-induction hypotension, heart rate, and cardiac output.

RESULTS: Forty-three patients were available for final analysis. The average MAP reading in the first 5 min post-induction was higher in ketamine-lidocaine group than in the ketamine group {82.8 ± 5.6 mmHg and 73 ± 10.2 mmHg, P < 0.001}. Furthermore, the incidence of post-intubation hypotension was lower in the ketamine-lidocaine group than in the ketamine group {1 patient (5%) versus 17 patients (77%), P < 0.001}. The ketamine-lidocaine group showed higher MAP in almost all the readings after induction compared to ketamine group. Other haemodynamic variables including cardiac output and heart rate were comparable between both study groups.

CONCLUSION: Lidocaine-ketamine combination showed less incidence of hypotension compared to ketamine full-dose when used for rapid-sequence endotracheal intubation in patients with septic shock. REGISTRATION URL: https://clinicaltrials.gov/ct2/show/NCT03844984?cond=NCT03844984&amp;rank=1.

BACKGROUND: Super-obesity is a serious disorder which requires bariatric surgery. The association of super-obesity and difficult intubation was not adequately established.

OBJECTIVES: To determine if super-obesity and super-super-obesity are associated with difficult intubation or not.

SETTING: University Hospital.

METHODS: A cohort of obese patients scheduled for bariatric surgery was prospectively recruited. Super-obesity and super-super-obesity were defined as body mass index ≥50 kg/m and 60 kg/m, respectively. Intubation difficulty was assessed by 2 methods: (1) intubation difficulty scale; (2) number of intubation attempts. Risk factors for difficult intubation were recorded. Univariate and multivariate analysis for risk factors for difficult intubation and difficult mask ventilation were performed.

RESULTS: A total of 658 patients were enrolled in the study including 205 (31%) super-obese and 52 (8%) super-super-obese patients. Ninety-nine (15%) patients required more than 1 intubation attempt, while 215 (33%) patients had intubation difficulty scale ≥5. Ninety-four (14.4%) patients had mask ventilation of moderate difficulty, while only 2 (.3%) patients needed 2-person ventilation. The independent risk factors for difficult intubation using the two stated definitions were STOP-Bang and Mallampati score values. The independent risk factors for mask ventilation of moderate difficulty were STOP-Bang score, Mallampati score, and limited neck extension.

CONCLUSION: Within obese patients, neither super-obesity nor super-super-obesity was associated with difficult intubation or difficult mask ventilation. High STOP-Bang and Mallampati score are the independent factors for difficult intubation.

BACKGROUND: Elderly population are at increased risk of spinal anesthesia-induced hypotension increasing their risk for postoperative morbidity and mortality. This study aimed to compare the hemodynamic effects of prophylactic infusion of norepinephrine (NE) versus phenylephrine (PE) in elderly patients undergoing hip fracture surgery under spinal anesthesia.

METHODS: Elderly patients scheduled for hip fracture surgery were randomized to receive either NE infusion (8 µg/min) (NE group, n = 31) or PE infusion (100 µg/min) (PE group, n = 31) after spinal anesthesia. Outcomes included mean heart rate, mean blood pressure, cardiac output, incidence of spinal anesthesia-induced hypotension, incidence of bradycardia, and incidence of hypertension.

RESULTS: Sixty-two patients with a mean age of 71 ± 6 years were included in the final analysis (31 patients in each group). The NE group showed a higher mean heart rate and cardiac output than the PE group. The NE group had a lower incidence of reactive bradycardia (10% vs. 36%, P = 0.031) and hypertension (3% vs. 36%, P = 0.003) than the PE group. No study participant developed hypotension, and the mean blood pressure was comparable between the two groups.

CONCLUSIONS: Both NE and PE infusions effectively prevented spinal anesthesia-induced hypotension in elderly patients undergoing hip fracture surgery. However, NE provided more hemodynamic stability than PE; maintaining the heart rate, higher cardiac output, less reactive bradycardia, and hypertension.

OBJECTIVE: The aim of this work is to compared ketamine-based versus fentanyl-based regimens for endotracheal intubation in patients with septic shock undergoing emergency surgery.

DESIGN: This was a randomised double-blinded controlled trial.

PARTICIPANTS: Patients with septic shock on norepinephrine infusion scheduled for emergency surgery.

SETTING AND INTERVENTIONS: At induction of anaesthesia, patients were allocated into ketamine group (n=23) in which the participants received ketamine 1 mg/kg, and fentanyl group (n=19) in which the participants received fentanyl 2.5 mcg/ kg. Both groups received midazolam (0.05 mg/kg) and succinyl choline (1 mg/kg).

MEASUREMENT: The primary outcome was mean arterial blood pressure. The secondary outcomes included: heart rate, cardiac output, and incidence of postintubation hypotension defined as mean arterial pressure ≤80% of baseline value.

RESULTS: Forty-two patients were available for final analysis. The mean blood pressure was higher in the ketamine group than in the fentanyl group at 1, 2 and 5 minutes after the induction of anaesthesia. Furthermore, the incidence of postinduction hypotension was lower in the ketamine group than in the fentanyl group (11 [47.8%] versus 16 [84.2%], P-value= 0.014). Other hypodynamic parameters, namely the heart rate and cardiac output, were comparable between both groups; and were generally maintained in relation to the baseline reading in each group.

CONCLUSION: The ketamine-based regimen provided better hemodynamic profile compared to fentanyl-based regimen for rapid-sequence intubation in patients with septic shock undergoing emergency surgery.

BACKGROUND: We aimed to evaluate the ability of diaphragmatic excursion at hospital admission to predict outcomes in patients with coronavirus disease-2019 (COVID-19).

METHODS: In this prospective observational study, we included adult patients with severe COVID-19 admitted to a tertiary hospital. Ultrasound examination of the diaphragm was performed within 12 h of admission. Other collected data included peripheral oxygen saturation (SpO), respiratory rate, and computed tomography (CT) score. The outcomes included the ability of diaphragmatic excursion, respiratory rate, SpO, and CT score at admission to predict the need for ventilatory support (need for non-invasive or invasive ventilation) and patient mortality using the area under the receiver operating characteristic curve (AUC) analysis. Univariate and multivariable analyses about the need for ventilatory support and mortality were performed.

RESULTS: Diaphragmatic excursion showed an excellent ability to predict the need for ventilatory support, which was the highest among respiratory rate, SpO, and CT score; the AUCs (95% confidence interval [CI]) was 0.96 (0.85-1.00) for the right diaphragmatic excursion and 0.94 (0.82-0.99) for the left diaphragmatic excursion. The right diaphragmatic excursion also had the highest AUC for predicting mortality in relation to respiratory rate, SpO, and CT score. Multivariable analysis revealed that low diaphragmatic excursion was an independent predictor of mortality with an odds ratio (95% CI) of 0.55 (0.31-0.98).

CONCLUSION: Diaphragmatic excursion on hospital admission can accurately predict the need for ventilatory support and mortality in patients with severe COVID-19. Low diaphragmatic excursion was an independent risk factor for in-hospital mortality.